[Federal Register Volume 64, Number 225 (Tuesday, November 23, 1999)]
[Proposed Rules]
[Pages 65767-66078]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 99-28981]



[[Page 65767]]

_______________________________________________________________________

Part II





Department of Labor





_______________________________________________________________________



Occupational Safety and Health Administration



_______________________________________________________________________



29 CFR Part 1910



Ergonomics Program; Proposed Rule

  Federal Register / Vol. 64, No. 225 / Tuesday, November 23, 1999 / 
                             Proposed Rules

[[Page 65768]]

DEPARTMENT OF LABOR



Occupational Safety and Health Administration



29 CFR Part 1910



[Docket No. S-777]

RIN No. 1218-AB36




Ergonomics Program



AGENCY: Occupational Safety and Health 
Administration (OSHA), Department of Labor.

ACTION: Proposed rule; request for comments; 
scheduling of informal public hearing.

---------------------------------------------


SUMMARY: The Occupational Safety and Health 
Administration is proposing an ergonomics 
program standard to address the significant 
risk of work-related musculoskeletal 
disorders (MSDs) confronting employees in 
various jobs in general industry workplaces. 
General industry employers covered by the 
standard would be required to establish an 
ergonomics program containing some or all of 
the elements typical of successful ergonomics 
programs: management leadership and employee 
participation, job hazard analysis and 
control, hazard information and reporting, 
training, MSD management, and program 
evaluation, depending on the types of jobs in 
their workplace and whether a musculoskeletal 
disorder covered by the standard has 
occurred. The proposed standard would require 
all general industry employers whose 
employees perform manufacturing or manual 
handling jobs to implement a basic ergonomics 
program in those jobs. The basic program 
includes the following elements: management 
leadership and employee participation, and 
hazard information and reporting. If an 
employee in a manufacturing or manual 
handling job experiences an OSHA-recordable 
MSD that is additionally determined by the 
employer to be covered by the proposed 
standard, the employer would be required to 
implement the full ergonomics program for 
that job and all other jobs in the 
establishment involving the same physical 
work activities. The full program includes, 
in addition to the elements in the basic 
program, a hazard analysis of the job; the 
implementation of engineering, work practice, 
or administrative controls to eliminate or 
substantially reduce the hazards identified 
in that job; training the employees in that 
job and their supervisors; and the provision 
of MSD management, including, where 
appropriate, temporary work restrictions and 
access to a health care provider or other 
professional if a covered MSD occurs. General 
industry employers whose employees work in 
jobs other than manual handling or 
manufacturing and experience an MSD that is 
determined by the employer to be covered by 
the standard would also be required by the 
proposed rule to implement an ergonomics 
program for those jobs.
   The proposed standard would affect 
approximately 1.9 million employers and 27.3 
million employees in general industry 
workplaces, and employers in these workplaces 
would be required in the first year after 
promulgation of the standard to control 
approximately 7.7 million jobs with the 
potential to cause or contribute to covered 
MSDs. OSHA estimates that the proposed 
standard would prevent about 3 million work-
related MSDs over the next 10 years, have 
annual benefits of approximately $9.1 
billion, and impose annual compliance costs 
of approximately $900 per covered 
establishment and annual costs of $150 per 
problem job fixed.
   OSHA is scheduling informal public 
hearings to provide interested parties the 
opportunity to orally present information and 
data related to the proposed rule.

DATES: Written comments. Written comments, 
including materials such as studies and 
journal articles, must be postmarked by 
February 1, 2000. If you submit comments by 
facsimile or electronically through OSHA's 
internet site, you must transmit those 
comments by February 1, 2000.
   Notice of intention to appear at the 
informal public hearing. Notices of intention 
to appear at the informal public hearing must 
be postmarked by January 24, 2000. If you 
submit your notice to intention to appear by 
facsimile or electronically through OSHA's 
Internet site, you must transmit the notice 
by January 24, 2000.
   Hearing testimony and documentary 
evidence: If you will be requesting more than 
10 minutes for your presentation, or if you 
will be submitting documentary evidence at 
the hearing, you must submit the full 
testimony and all documentary evidence you 
intend to present at the hearing, postmarked 
by February 1, 2000.
   Informal pubic hearing. The hearing in 
Washington, DC, is scheduled to begin at 9:30 
a.m., February 22, 2000 at the Frances 
Perkins Building, U.S. Department of Labor. 
The hearing in Washington, DC, is scheduled 
to run for 4 weeks. It will be followed by a 
hearing March 21-31, 2000, in Portland OR, 
and April 11-21, 2000, in Chicago, IL. Time 
and location for the regional hearings will 
be announced later in the Federal Register.

ADDRESSES: Written comments: Mail: Submit 
duplicate copies of written comments to: OSHA 
Docket Office, Docket No. S-777, U.S. 
Department of Labor, 200 Constitution Avenue, 
N.W., Room N-2625, Washington, DC 20210, 
telephone (202) 693-2350.

   Facsimile: If your written comments are 10 
pages or less, you may fax them to the Docket 
Office. The OSHA Docket Office fax number is 
(202) 693-1648.
   Electronic: You may also submit comments 
electronically through OSHA's Homepage at 
www.osha.gov. Please note that you may not 
attach materials such as studies or journal 
articles to your electronic comments. If you 
wish to include such materials, you must 
submit them separately in duplicate to the 
OSHA Docket Office at the address listed 
above. When submitting such materials to the 
OSHA Docket Office, you must clearly identify 
your electronic comments by name, date, and 
subject, so that we can attach them to your 
electronic comments.
   Notice of intention to appear: Mail: 
Notices of intention to appear at the 
informal public hearing may be submitted by 
mail in quadruplicate to: Ms. Veneta Chatman, 
OSHA Office of Public Affairs, Docket No. S-
777, U.S. Department of Labor, 200 
Constitution Avenue, N.W., Room N-3647, 
Washington, DC 20210, Telephone: (202) 693-
2119.
   Facsimile: You may fax your notice of 
intention to appear to Ms. Chatmon at (202) 
693-1634.
   Electronic: You may also submit your 
notice of intention to appear electronically 
through OSHA's Homepage at www.osha.gov.
   Hearing testimony and documentary 
evidence: You must submit in quadruplicate 
your hearing testimony and the documentary 
evidence you intend to present at the 
informal public hearing to Ms. Chatmon at the 
address above. You may also submit your 
hearing testimony and documentary evidence on 
disk (3\1/2\ inch) in WP 5.1, 6.0, 6.1, 8.0 
or ASCII,

[[Page 65769]]

provided you also send the original hardcopy 
at the same time.
   Informal public hearing: The informal 
public hearing to be held in Washington DC 
will be located in the Frances Perkins 
Building, U.S. Department of Labor, 200 
Constitution Avenue, N.W., Washington, DC 
20210. The locations of regional hearings in 
Portland, OR, and Chicago, IL, will be 
announced in a later Federal Register notice.

FOR FURTHER INFORMATION CONTACT: OSHA's 
Ergonomics Team at (202) 693-2116, or visit 
the OSHA Homepage at www.osha.gov.

SUPPLEMENTARY INFORMATION:


Table of Contents

   The preamble and proposed standard are 
organized as follows:

I. Introduction
II. Events Leading to the Proposed Standard
III. Pertinent Legal Authority
IV. Summary and Explanation
V. Health Effects
VI. Risk Assessment
VII. Significance of Risk
VIII. Summary of the Preliminary Economic 
    Analysis and Initial Regulatory 
    Flexibility Analysis
IX. Unfunded Mandates
X. Environmental Impacts
XI. Additional Statutory Issues
XII. Federalism
XIII. State Plan States
XIV. Issues
XV. Public Participation
XVI. OMB Review under the Paperwork Reduction 
    Act of 1995
XVII. List of Subjects in 29 CFR Part 1910
XVIII. The Proposed Standard

   References to the rulemaking record are in 
the text of the preamble. References are 
given as ``Ex.'' followed by a number to 
designate the reference in the docket. For 
example, ``Ex. 26-1'' means exhibit 26-1 in 
Docket S-777. A list of the exhibits and 
copies of the exhibit are available in the 
OSHA Docket Office.


I. Introduction


A. Overview

   The preamble to this proposed ergonomics 
program standard discusses the data and 
events leading OSHA to propose the standard, 
the Agency's legal authority for proposing 
this rule, requests for information on a 
number of issues, and a section describing 
the significance of the ergonomic-related 
risks confronting workers in manufacturing, 
manual handling, and other general industry 
jobs. The preamble also contains a summary of 
the Preliminary Economic and Initial 
Regulatory Flexibility Analysis, a summary of 
the responses OSHA has made to the findings 
and recommendations of the Small Business 
Regulatory Fairness Enforcement Act Panel 
convened for this rule, a description of the 
information collections associated with the 
standard, and a detailed explanation of the 
Agency's rationale for proposing each 
provision of the proposed standard.


B. The Need for an Ergonomics Standard

   Work-related musculoskeletal disorders 
(MSDs) currently account for one-third of all 
occupational injuries and illnesses reported 
to the Bureau of Labor Statistics (BLS) by 
employers every year. These disorders thus 
constitute the largest job-related injury and 
illness problem in the United States today. 
In 1997, employers reported a total of 
626,000 lost workday MSDs to the BLS, and 
these disorders accounted for $1 of every $3 
spent for workers' compensation in that year. 
Employers pay more than $15-$20 billion in 
workers' compensation costs for these 
disorders every year, and other expenses 
associated with MSDs may increase this total 
to $45-$54 billion a year. Workers with 
severe MSDs can face permanent disability 
that prevents them from returning to their 
jobs or handling simple, everyday tasks like 
combing their hair, picking up a baby, or 
pushing a shopping cart.
   Thousands of companies have taken action 
to address and prevent these problems. OSHA 
estimates that 50 percent of all employees 
but only 28 percent of all workplaces in 
general industry are already protected by an 
ergonomics program, because their employers 
have voluntarily elected to implement an 
ergonomics program. (The disparity in these 
estimates shows that most large companies, 
who employ the majority of the workforce, 
already have these programs, and that smaller 
employers have not yet implemented them.) 
OSHA believes that the proposed standard is 
needed to bring this protection to the 
remaining employees in general industry 
workplaces who are at significant risk of 
incurring a work-related musculoskeletal 
disorder but are currently without ergonomics 
programs.


C. The Science Supporting the Standard

   A substantial body of scientific evidence 
supports OSHA's effort to provide workers 
with ergonomic protection (see the Health 
Effects, Preliminary Risk Assessment, and 
Significance of Risk sections of this 
preamble, below). This evidence strongly 
supports two basic conclusions: (1) There is 
a positive relationship between work-related 
musculoskeletal disorders and workplace risk 
factors, and (2) ergonomics programs and 
specific ergonomic interventions can reduce 
these injuries.
   For example, the National Research 
Council/National Academy of Sciences found a 
clear relationship between musculoskeletal 
disorders and work and between ergonomic 
interventions and a decrease in such 
disorders. According to the Academy, 
``Research clearly demonstrates that specific 
interventions can reduce the reported rate of 
musculoskeletal disorders for workers who 
perform high-risk tasks'' (Work-Related 
Musculoskeletal Disorders: The Research Base, 
ISBN 0-309-06327-2 (1998)). A scientific 
review of hundreds of peer-reviewed studies 
involving workers with MSDs by the National 
Institute for Occupational Safety and Health 
(NIOSH) also supports this conclusion.
   The evidence, which is comprised of peer-
reviewed epidemiological, biomechanical and 
pathophysiological studies as well as other 
published evidence, includes:
    More than 2,000 articles on work-
related MSDs and workplace risk factors;
    A 1998 study by the National 
Research Council/National Academy of Sciences 
on work-related MSDs;
    A critical review by NIOSH of 
more than 600 epidemiological studies (1997);
    A 1997 General Accounting Office 
report of companies with ergonomics programs; 
and
    Hundreds of published ``success 
stories'' from companies with ergonomics 
programs;
   Taken together, this evidence indicates 
that:
    High levels of exposure to 
ergonomic risk factors on the job lead to an 
increased incidence of work-related MSDs;

[[Page 65770]]

    Reducing these exposures reduces 
the incidence and severity of work-related 
MSDs;
    Work-related MSDs are 
preventable; and
    Ergonomics programs have 
demonstrated effectiveness in reducing risk, 
decreasing exposure and protecting workers 
against work-related MSDs.
   As with any scientific field, research in 
ergonomics is ongoing. The National Academy 
of Sciences is undertaking another review of 
the science in order to expand on its 1998 
study. OSHA will examine this and all 
research results that become available during 
the rulemaking process, to ensure that the 
Agency's ergonomics program standard is based 
on the best available and most current 
evidence. However, more than enough evidence 
already exists to proceed with a proposed 
standard. In the words of the American 
College of Occupational and Environmental 
Medicine, the world's largest occupational 
medical society, ``there is an adequate 
scientific foundation for OSHA to proceed 
with a proposal and, therefore, no reason for 
OSHA to delay the rulemaking process * * *.''


D. Employer Experience Supporting the 
Standard

   Employers with companies of all sizes have 
had great success in using ergonomics 
programs as a cost-effective way to prevent 
or reduce work-related MSDs, keeping workers 
on the job, and boosting productivity and 
workplace morale. A recent General Accounting 
Office (GAO) study of several companies with 
ergonomics programs found that their programs 
reduced work-related MSDs and associated 
costs (GAO/HEHS-97-163). The GAO also found 
that the programs and controls selected by 
employers to address ergonomic hazards in the 
workplace were not necessarily costly or 
complex. As a result, the GAO recommended 
that OSHA use a flexible regulatory approach 
in its ergonomics standard that would enable 
employers to develop their own effective 
programs. The standard being proposed today 
reflects this recommendation and builds on 
the successful programs that thousands of 
proactive employers have found successful in 
dealing with their ergonomic problems.


E. Information OSHA is Providing to Help 
Employers Address Ergonomic Hazards

   Much literature and technical expertise 
already exists and is available to employers, 
both through OSHA and a variety of other 
sources. For example:
    Information is available from 
OSHA's ergonomics Web page, which can be 
accessed from OSHA's World Wide Web site at 
http://www.osha.gov by scrolling down and 
clicking on ``Ergonomics'';
    Many publications, informational 
materials and training courses are available 
from OSHA through Regional Offices, OSHA-
sponsored educational centers, OSHA's state 
consultation programs for small businesses, 
and through the Web page;
    Publications on ergonomics 
programs are available from NIOSH at 1-800-
35-NIOSH. NIOSH is also a ``link'' on the 
OSHA ergonomics Web page;
    OSHA's state consultation 
programs will provide free on-site 
consultation services to employers requesting 
help in implementing their ergonomics 
programs; and
    OSHA is developing a series of 
compliance assistance materials and will make 
them available before a final ergonomics 
standard becomes effective.


II. Events Leading to the Proposed Standard

   In proposing this standard, OSHA has 
relied upon its own substantial experience 
with ergonomics programs, the experience of 
private firms and insurance companies, and 
the results of research studies conducted 
during the last 30 years. Those experiences 
clearly show that: (1) Ergonomics programs 
are an effective way to reduce occupational 
MSDs; (2) ergonomics programs have 
consistently achieved that objective; (3) 
OSHA's proposal is consistent with these 
programs; and (4) the proposal is firmly 
grounded in the OSH Act and OSHA policies and 
experience. The primary lesson to be learned 
is that employers with effective, well-
managed ergonomics programs achieve 
significant reductions in the severity and 
number of work-related MSDs their employees 
experience. These programs also generally 
improve productivity and employee morale and 
reduce employee turnover and absenteeism (see 
Section VIII of this preamble and Chapters IV 
(Benefits) and V (Costs of Compliance) of 
OSHA's Preliminary Economic Analysis (Ex. 28-
1).
   OSHA's long experience with ergonomics is 
apparent from the chronology below. As this 
table shows, the Agency has been actively 
involved in ergonomics for more than 20 
years.

                       OSHA Ergonomics Chronology
------------------------------------------------------------------------
 
------------------------------------------------------------------------
Early 1980s                   OSHA begins discussing ergonomic
                               interventions with labor, trade
                               associations and professional
                               organizations. OSHA issues citations to
                               Hanes Knitwear and Samsonite for
                               ergonomic hazards.
------------------------------------------------------------------------
August 1983                   The OSHA Training Institute offers its
                               first course in ergonomics.
------------------------------------------------------------------------
May 1986                      OSHA begins a pilot program to reduce back
                               injuries through review of injury records
                               during inspections and recommendations
                               for job redesign using NIOSH's Work
                               Practices Guide for Manual Lifting.
------------------------------------------------------------------------
October 1986                  The Agency publishes a Request for
                               Information on approaches to reduce back
                               injuries resulting from manual lifting.
                               (57 FR 34192)
------------------------------------------------------------------------
July 1990                     OSHA/UAW/Ford corporate-wide settlement
                               agreement commits Ford to reduce
                               ergonomic hazards in 96 percent of its
                               plants through a model ergonomics
                               program.
------------------------------------------------------------------------
August 1990                   The Agency publishes ``Ergonomics Program
                               Management Guidelines for Meatpacking
                               Plants.''
------------------------------------------------------------------------

[[Page 65771]]

 
Fall 1990                     OSHA creates the Office of Ergonomics
                               Support and hires more ergonomists.
------------------------------------------------------------------------
November 1990                 OSHA/UAW/GM sign agreement bringing
                               ergonomics programs to 138 GM plants
                               employing more than 300,000 workers.
                               Throughout the early 90s, OSHA signed 13
                               more corporate-wide settlement agreements
                               to bring ergonomics programs to nearly
                               half a million more workers.
------------------------------------------------------------------------
July 1991                     OSHA publishes ``Ergonomics: The Study of
                               Work,'' as part of a nationwide education
                               and outreach program to raise awareness
                               about ways to reduce musculoskeletal
                               disorders.
------------------------------------------------------------------------
July 1991                     More than 30 labor organizations petition
                               Secretary of Labor to issue an Emergency
                               Temporary Standard.
------------------------------------------------------------------------
January 1992                  OSHA begins a special emphasis inspection
                               program on ergonomic hazards in the
                               meatpacking industry.
------------------------------------------------------------------------
April 1992                    Secretary of Labor denies petition.
------------------------------------------------------------------------
August 1992                   OSHA publishes an Advance Notice of
                               Proposed Rulemaking on ergonomics.
------------------------------------------------------------------------
1993                          OSHA conducts a survey of general industry
                               and construction employers to obtain
                               information on the extent of ergonomics
                               programs in industry and other issues.
------------------------------------------------------------------------
March 1995                    OSHA begins a series of meetings with
                               stakeholders to discuss approaches to a
                               draft ergonomics standard.
------------------------------------------------------------------------
January 1997                  OSHA/NIOSH conference on successful
                               ergonomic programs held in Chicago.
------------------------------------------------------------------------
April 1997                    OSHA introduces the ergonomics web page on
                               the Internet.
------------------------------------------------------------------------
February 1998                 OSHA begins a series of national
                               stakeholder meetings about the draft
                               ergonomics standard under development.
------------------------------------------------------------------------
March 1998                    OSHA releases a video entitled ``Ergonomic
                               Programs That Work.''
------------------------------------------------------------------------
February 1999                 OSHA begins small business (Small Business
                               Regulatory Enforcement Fairness Act
                               (SBREFA)) review of its draft ergonomics
                               rule, and makes draft regulatory text
                               available to the public.
------------------------------------------------------------------------
April 1999                    OSHA's Assistant Secretary receives the
                               SBREFA report on the draft ergonomics
                               program proposal, and the Agency begins
                               to address the concerns raised in that
                               report.
------------------------------------------------------------------------
November 1999                 OSHA publishes proposed ergonomics program
                               standard.
------------------------------------------------------------------------

A. Regulatory and Voluntary Guidelines 
Activities

   In 1989, OSHA issued the Safety and Health 
Program Management Guidelines (54 FR 3904, 
Jan. 26, 1989), which are voluntary program 
management guidelines to assist employers in 
developing effective safety and health 
programs. These program management 
guidelines, which are based on the widely 
accepted industrial hygiene principles of 
management commitment and employee 
involvement, worksite hazard analysis, hazard 
prevention and control, and employee 
training, also serve as the foundation for 
effective ergonomics programs. In August 
1990, OSHA issued the Ergonomics Program 
Management Guidelines for Meatpacking Plants 
(Ex. 2-13), which utilized the four program 
components from the safety and health 
management guidelines, supplemented by other 
ergonomics-specific program elements (e.g., 
medical management). The ergonomic guidelines 
were based on the best available scientific 
evidence, the best practices of successful 
companies with these programs, advice from 
the National Institute for Occupational 
Safety and Health (NIOSH), the scientific 
literature, and OSHA's experience with 
enforcement actions. Many commenters in 
various industries have said that they have 
implemented their ergonomics programs 
primarily on the basis of the OSHA ergonomics 
guidelines (Exs. 3-50, 3-61, 3-95, 3-97, 3-
113, 3-121, 3-125), and there has been 
general agreement among stakeholders that 
these program elements should be included in 
any OSHA ergonomics standard (Exs. 3-27, 3-
46, 3-51, 3-61, 3-89, 3-95, 3-113, 3-119, 3-
160, 3-184).
   OSHA has also encouraged other efforts to 
address the prevention of work-related 
musculoskeletal disorders. For example, OSHA 
has actively participated in the work of the 
ANSI Z-365 Committee, which was tasked with 
the development of a consensus standard for 
the control of cumulative trauma disorders.


1. Petition for Emergency Temporary Standard

   On July 31, 1991, the United Food and 
Commercial Workers Union (UCFW), along with 
the AFL-CIO and 29 other labor organizations, 
petitioned OSHA to take immediate action to 
reduce the risk to employees from exposure to 
ergonomic hazards (Ex. 2-16). The petition

[[Page 65772]]

requested that OSHA issue an emergency 
temporary standard (ETS) on ``Ergonomic 
Hazards to Protect Workers from Work-Related 
Musculoskeletal Disorders (Cumulative Trauma 
Disorders)'' under section 6(c) of the Act. 
The petitioners also requested, consistent 
with section 6(c), that OSHA promulgate, 
within 6 months of issuance of the ETS, a 
permanent standard to protect workers from 
cumulative trauma disorders in both general 
industry and construction.
   OSHA concluded that, based on the 
statutory constraints and legal requirements 
governing issuance of an ETS, there was not a 
sufficient basis to support issuance of an 
ETS. Accordingly, on April 17, 1992, OSHA 
decided not to issue an ETS on ergonomic 
hazards (Ex. 2-29). OSHA agreed with the 
petitioners, however, that available 
information, including the Agency's 
experience and information in the ETS 
petition and supporting documents, supported 
the initiation of a rulemaking, under section 
6(b)(5) of the Act, to address ergonomic 
hazards.


2. Advance Notice of Proposed Rulemaking

   At the time OSHA issued the Ergonomic 
Program Management Guidelines for Meatpacking 
Plants, (Ex. 2-13), the Agency also indicated 
its intention to begin the rulemaking process 
by asking the public for information about 
musculoskeletal disorders (MSDs). The Agency 
indicated that this could be accomplished 
through a Request for Information (RFI) or an 
Advance Notice of Proposed Rulemaking (ANPR) 
consistent with the Administration's 
Regulatory Program. Subsequently, OSHA 
formally placed ergonomics rulemaking on the 
regulatory agenda (Ex. 2-17) and decided to 
issue an ANPR on this topic.
   In June 1991, OSHA sent a draft copy of 
the proposed ANPR questions for comment to 
232 parties, including OSHA's advisory 
committees, labor organizations (including 
the petitioners), trade associations, 
occupational groups, and members of the 
ergonomics community (Ex. 2-18). OSHA 
requested comments on what questions should 
be presented in the ANPR. OSHA received 47 
comments from those parties. In addition, 
OSHA met with the Chemical Manufacturers 
Association, Organization Resources 
Counselors, Inc., and the AFL-CIO and several 
of its member organizations. OSHA reviewed 
the comments and submissions received and 
incorporated relevant suggestions and 
comments into the ANPR.
   On August 3, 1992, OSHA published the ANPR 
in the Federal Register (57 FR 34192), 
requesting information for consideration in 
the development of an ergonomics standard. 
OSHA received 290 comments in response to the 
ANPR. Those comments have been carefully 
considered by the Agency in developing the 
proposed ergonomics program standard.


3. Outreach to Stakeholders

   In conjunction with the process of 
developing the proposed ergonomics rule, OSHA 
has established various communication and 
outreach efforts since publication of the 
ANPR. These efforts were initiated in 
response to requests by individuals who would 
be affected by the rule (stakeholders) that 
they be provided with the opportunity to 
present their concerns about an ergonomics 
rule and that they be kept apprised of the 
efforts OSHA was making in developing a 
proposed rule. For example, in March and 
April 1994, OSHA held meetings with industry, 
labor, professional and research 
organizations covering general industry, 
construction, agriculture, healthcare, and 
the office environment. A list of those 
attending the meetings and a record of the 
meetings has been placed in the public record 
of this rulemaking (Ex. 26-1370).
   In March, 1995, OSHA provided a copy of 
the draft proposed ergonomics rule and 
preamble to these same organizations. 
Thereafter, during April 1995, OSHA met again 
with these groups to discuss whether the 
draft proposed rule had accurately responded 
to the concerns raised earlier. A summary of 
the comments has been placed in the public 
record (Ex. 26-1370).
   During 1998, OSHA met with nearly 400 
stakeholders to discuss ideas for a proposed 
standard. The meetings were held in February, 
July and September of 1998. The first series 
of meetings was held in Washington, DC and 
focused on general issues, such as the scope 
of the standard and what elements of an 
ergonomics program should be included in a 
standard. The second series of meetings was 
held in Kansas City and Atlanta and focused 
on what elements and activities should be 
included in an ergonomics program standard. 
The third set of meetings was held in 
Washington, DC and emphasized revisions to 
the elements of the proposal based on 
previous stakeholder input. A summary of 
those meetings has been placed on the OSHA 
web site and in the public docket (Ex. 26-
1370). After OSHA released a working draft of 
the proposed ergonomics standard to members 
of the Small Business Regulatory Enforcement 
Fairness Act Panel for review under that 
Act., the draft was posted on the OSHA web 
site (February 9, 1999).


4. Small Business Regulatory Enforcement 
Fairness Act (SBREFA) Panel

   In accordance with SBREFA and to gain 
insight from employers with small businesses, 
OSHA, the Office of Management and Budget 
(OMB), and the Small Business Administration 
(SBA) created a Panel to review and comment 
on a working draft of the ergonomics program 
standard. As required by SBREFA, the Panel 
sought the advice and recommendations of 
potentially affected Small Entity 
Representatives (SERs). A total of 21 SERs 
from a variety of industries participated in 
the effort. The working draft, supporting 
materials (a brief summary of a preliminary 
economic analysis and risk assessment and 
other materials) were sent to the SERs for 
their review. On March 24-26, 1999, 
representatives from OSHA, SBA, and OMB 
participated in a series of discussions with 
the SERs to answer questions and receive 
comments from the SERs. The SERs also 
provided written comments, which served as 
the basis of the Panel's final report (Ex. 
23). The final SBREFA Panel Report was 
submitted to the Assistant Secretary on April 
30, 1999. The findings and recommendations 
made by the Panel are addressed in the 
proposed rule, preamble, and economic 
analysis (see the discussion in Section VIII, 
Summary of the Preliminary Economic Analysis 
and Initial Regulatory Flexibility Analysis).


B. Other OSHA Efforts in Ergonomics

   In 1996, OSHA developed a strategy to 
address ergonomics through a four-pronged 
program including training, education, and 
outreach activities; study and analysis of 
the work-related hazards that lead to MSDs; 
enforcement; and rulemaking.


1. Training, Education, and Outreach

   a. Training. The OSHA ergonomics web page 
has been an important part of the Agency's 
education and outreach effort. Other OSHA 
efforts in training, education and outreach 
include the following:
    Grants to train workers and 
employees about hazards and hazard abatement;
    Training courses in ergonomics;

[[Page 65773]]

    One day training for nursing home 
operators in each of five targeted states;
    Booklets on ergonomics, 
ergonomics programs, and computer 
workstations; and
    Videotapes on ergonomics programs 
in general industry and specifically in 
nursing homes.
   OSHA has awarded almost $3 million for 25 
grants addressing ergonomics, including 
lifting hazards in healthcare facilities and 
hazards in the red meat and poultry 
industries. These grants have enabled workers 
and employers to identify ergonomic hazards 
and implement workplace changes to abate the 
hazards.
   Some grant program highlights follow.

   The United Food and Commercial 
Workers International Union (UFCW) conducted 
joint labor-management ergonomics training at 
a meatpacking plant that resulted in a major 
effort at the plant to combat cumulative 
trauma disorders. The program was so 
successful that management asked the UFCW to 
conduct the ergonomics training and work with 
management at some of its other facilities.
   The University of California at 
Los Angeles (UCLA) and the Service Employees 
International Union (SEIU) both had grants 
for preventing lifting injuries in nursing 
homes. SEIU developed a training program that 
was used by UCLA to train nursing home 
workers in California. UCLA also worked with 
some national back injury prevention 
programs. At least one of the nursing home 
chains has replicated the program in other 
states.
   Mercy Hospital in Des Moines, 
Iowa, had a grant to prevent lifting injuries 
in hospitals. It trained over 3,000 hospital 
workers in Des Moines and surrounding 
counties. It had a goal of reducing lost work 
days by 15 percent. The goal was surpassed, 
and, six months after the training, none of 
those trained had had a lost workday due to 
back injury.
   Hunter College in New York City is 
training ergonomics trainers for the United 
Paperworkers International Union. The 
trainers then return to their locals and 
conduct ergonomics training for union 
members. As a result of this training, 
changes are being made at some workplaces. 
Examples include purchasing new equipment 
that eliminates or reduces workers' need to 
bend or twist at the workstation, rotating 
workers every two hours with a ten-minute 
break before each rotation, and modifying 
workstations to reduce worker strain.

   b. Education and Outreach. To provide a 
forum to discuss ergonomic programs and to 
augment information in the literature with 
the experience of companies of different 
sizes and from a variety of industries, OSHA 
and NIOSH sponsored the first in a series of 
conferences that brought industry, labor, 
researchers, and consultants together to 
discuss what works in reducing MSDs. The 1997 
OSHA and NIOSH conference was followed by 11 
more regional conferences across the country. 
OSHA and NIOSH held the second national 
conference on ergonomics in March of 1999. 
More than 200 presentations were given at the 
conferences on how companies have 
successfully reduced MSDs. Presentations were 
made by personnel from large and small 
companies in many different industries.
   Other examples of successful ergonomics 
programs have come from OSHA's Voluntary 
Protection Program (VPP). The VPP program was 
established by OSHA to recognize employers 
whose organizations have exemplary workplace 
safety health programs. Several sites that 
have been accepted into VPP have excellent 
ergonomics programs.


2. Ergonomics Best Practices Conferences

   During the period from Sept. 17, 1997 
through Sept. 29, 1999, OSHA and its Regional 
Education Centers co-sponsored 11 Ergonomics 
Best Practices conferences. These Conferences 
were designed to provide good examples of 
practical and inexpensive ergonomics 
interventions implemented by local companies. 
The concept was that if OSHA and its Regional 
partners could initiate the development of a 
network of local employers, contractors, and 
educators to provide practical information to 
solve ergonomics problems, it would be 
assisting employers in providing a workplace 
for employees that would be ``free of 
recognized health and safety hazards.'' To 
date, attendance has exceeded 2,400 
participants, including employers, 
contractors, and employees. Finally, OSHA has 
made numerous outreach presentations to 
labor, trade, industry and professional 
organizations during the development of the 
proposed rule.


3. Studies and Analyses

   Throughout the 1990s and continuing to the 
present, OSHA staff have monitored the 
ergonomics literature, developed analyses, 
and reviewed the work of other Federal and 
non-Federal agencies and organizations 
related to ergonomics issues. In some cases, 
OSHA staff have conducted site visits to 
observe ergonomics programs at first hand. 
Much of the information learned through these 
activities is reflected in the material in 
this preamble.
   The most important reports and studies to 
appear in the last few years are listed 
below. OSHA has reviewed each of these 
documents in detail, and findings from them 
that are relevant to the discussions in this 
preamble are referenced in the text. 
Important recent studies that have supported 
the conclusion that ergonomic interventions 
and programs are a successful way to reduce 
MSDs:
    Elements of Ergonomics Programs, 
NIOSH, 1998 (Ex. 26-2);
    Musculoskeletal Disorders and 
Workplace Factors, NIOSH, 1997 (Ex. 26-1);
    Worker Protection: Private Sector 
Ergonomics Programs Yield Positive Results, 
GAO 1997 (Ex. 26-5); and
    Work-related Musculoskeletal 
Disorders, NRC 1998 (Ex. 26-37).
   Other reports that support the use of 
ergonomic interventions in the context of an 
ergonomics program include:
    ASC Z-365 draft, Control of 
Cumulative Trauma Disorders, June 1997; and
    Applied Ergonomics, case studies, 
Volume 2 (case studies from the OSHA/NIOSH 
conference 1999).
   In addition, in 1994, OSHA conducted eight 
site visits to companies that have 
implemented ergonomic controls. These site 
visits were at the invitation of companies in 
industries including meatpacking, 
manufacturing, and automotive manufacturing. 
In conjunction with three of these site 
visits, OSHA also held ``town meetings'' with 
other industry, labor and professional 
representatives in the geographical area. 
These meetings allowed OSHA to learn about 
other ergonomic programs that have been 
implemented by companies in the same area as 
well as issues regarding an OSHA ergonomics 
rule.


4. Enforcement

   In the absence of a federal OSHA 
ergonomics standard, OSHA has addressed 
ergonomics in the workplace under the 
authority of section 5(a)(1) of the OSHAct. 
This section is referred to as the General 
Duty Clause and requires employers to provide 
work and a work environment free from 
recognized hazards that are causing or are 
likely to cause death or serious physical 
harm.

[[Page 65774]]

   OSHA has successfully issued over 550 
ergonomics citations under the General Duty 
Clause. Only one case has been decided by the 
Occupational Safety and Health Review 
Commission. In the majority of these cases, 
employers have realized that the 
implementation of ergonomics programs is in 
their best interest for the reduction of 
injuries and illnesses. Examples of companies 
cited under the General Duty Clause for 
ergonomics hazards and which then realized a 
substantial reduction in injuries and 
illnesses after implementing ergonomics 
programs include: the Ford Motor Company, 
Empire Kosher, Sysco Foods, and Kennebec 
Nursing Home.
   When serious physical harm cannot be 
documented in the work environment but 
hazards have been identified by OSHA, 
Compliance Officers both discuss the hazards 
with the employer during the closing 
conference of an inspection and write a 
letter to the employer. These letters are 
called ``ergonomic hazard alert letters.'' As 
of June 1, 1999, approximately 260 letters 
had been sent to employers. Ergonomic hazard 
alert letters have been sent to employers in 
approximately 50% of OSHA ergonomic 
inspections.
   Since ergonomic solutions vary from one 
industry to another, OSHA has provided both 
general and industry-specific training to 
compliance officers. There are currently 
three main ergonomic courses offered to OSHA 
compliance staff: Introduction to Ergonomics, 
Ergonomics in Nursing Homes, and Ergonomics 
Compliance (an advanced ergonomics course). 
Over 600 compliance staff have been trained 
in just the past three years. These courses 
cover three weeks of material.
   In addition, OSHA has appointed one Area 
Office Ergonomic Coordinator and a Regional 
Ergonomic Coordinator in every region. These 
coordinators meet monthly to discuss recent 
case developments and the scientific 
literature on ergonomics, share knowledge of 
ergonomic solutions, and ensure that 
enforcement resources are provided to 
compliance staff for enforcement. A PhD 
level, professionally certified ergonomist 
serves as the National Ergonomics Enforcement 
Coordinator in OSHA's Directorate of 
Compliance Programs.


5. Corporate Wide Settlement Agreements

   Among the companies that were cited for 
MSD hazards, 13 companies covering 198 
facilities agreed to enter into corporate-
wide settlement agreements with OSHA. These 
agreements were primarily in the meat 
processing and auto assembly industries, but 
there were also agreements with 
telecommunications, textile, warehousing 
grocery, and paper companies. As part of 
these settlement agreements, the companies 
agreed to develop ergonomics programs based 
on OSHA's Meatpacking Guidelines (Ex. 2-13) 
and to submit information on the progress of 
their program.
   OSHA held a workshop in March 1999, in 
which 10 companies described their experience 
under their settlement agreement and with 
their ergonomics programs. All the companies 
that reported results to OSHA showed a 
substantially lower severity rate for MSDs 
since implementing their programs (Ex. 26-
1420). In addition, most companies reported 
lower workers' compensation costs, as well as 
higher productivity and product quality. A 
report from the March 1999 workshop on 
corporate wide settlement agreements 
summarizing the results from 13 companies 
involved in the agreements has been placed in 
the docket (Ex. 26-1420). Only 5 of the 13 
companies consistently reported the number of 
MSD cases or MSD case rates. All five 
companies that reported data on MSD-related 
lost workdays showed a significant decline in 
the number of lost workdays. None of the 
companies that reported severity statistics 
showed an increase in lost workdays as a 
result of the ergonomics program.


C. Summary

   As this review of OSHA's activities in the 
last 20 years shows, the Agency has 
considerable experience in addressing 
ergonomics issues. OSHA has also used all of 
the tools authorized by the Act--enforcement, 
consultation, training and education, 
compliance assistance, the Voluntary 
Protection Programs, and issuance of 
voluntary guidelines--to encourage employers 
to address musculoskeletal disorders, the 
single largest occupational safety and health 
problem in the United States today. These 
efforts, and the voluntary efforts of 
employers and employees, have led to a recent 
5-year decline in the number of reported lost 
workday ergonomics injuries. However, in 
1997, more than 626,000 such injuries and 
illnesses were still reported. Promulgation 
of an ergonomics program standard will add 
the only tool the Agency has so far not 
deployed against this hazard--a mandatory 
standard--to these other OSHA and employer-
driven initiatives. Over the first 10 years 
of the standard's implementation, OSHA 
predicts that more than 3 million lost 
workday musculoskeletal disorders will be 
prevented in general industry. Ergonomics 
programs can lead directly to improved 
product quality by reducing errors and 
rejection rates. In an OSHA survey of more 
than 3,000 employers, 17 percent of employers 
with ergonomics programs reported that their 
programs had improved product quality. In 
addition, a large number of case studies 
reported in the literature describe quality 
improvements. Thus, in addition to better 
saftey and health for workers, the standard 
will save employers money, improve product 
quality, and reduce employee turnover and 
absenteeism.


III. Pertinent Legal Authority

   The purpose of the Occupational Safety and 
Health Act (``OSH Act''), 29 U.S.C. 651 et 
seq., is ``to assure so far as possible every 
working man and woman in the nation safe and 
healthful working conditions and to preserve 
our human resources.'' 29 U.S.C. 651(b). To 
achieve this goal Congress authorized the 
Secretary of Labor to promulgate and enforce 
occupational safety and health standards. 29 
U.S.C. 655(b) (authorizing promulgation of 
standards pursuant to notice and comment), 
654(b) (requiring employers to comply with 
OSHA standards).
   A safety or health standard is a standard 
``which requires conditions, or the adoption 
or use of one or more practices, means, 
methods, operations, or processes, reasonably 
necessary or appropriate to provide safe or 
healthful employment or places of 
employment.'' 29 U.S.C. 652(8).
   A standard is reasonably necessary or 
appropriate within the meaning of Section 
652(8) if:
    A significant risk of material 
harm exists in the workplace and the proposed 
standard would substantially reduce or 
eliminate that workplace risk;
    It is technologically and 
economically feasible;
    It is cost effective;
    It is consistent with prior 
Agency action or supported by a reasoned 
justification for departing from prior Agency 
action;
    It is supported by substantial 
evidence; and
    If this standard is preceded by a 
national consensus standard, it is better 
able to effectuate the purposes of the OSH 
Act than the standard it supersedes.


[[Page 65775]]


International Union, UAW v. OSHA (LOTO II), 
37 F.3d 665 (D.C. Cir. 1994); 58 FR 16612--
16616 (March 30, 1993).
   OSHA has generally considered an excess 
risk of 1 death per 1000 workers over a 45-
year working lifetime as clearly representing 
a significant risk. Industrial Union Dept. v. 
American Petroleum Institute (Benzene), 448 
U.S. 607, 646 (1980); International Union v. 
Pendergrass (Formaldehyde), 878 F.2d 389, 393 
(D.C. Cir. 1989); Building and Construction 
Trades Dept., AFL-CIO v. Brock (Asbestos), 
838 F.2d 1258, 1264-65 (D.C. Cir. 1988).
   A standard is technologically feasible if 
the protective measures it requires already 
exist, can be brought into existence with 
available technology, or can be created with 
technology that can reasonably be expected to 
be developed. American Textile Mfrs. 
Institute v. OSHA (Cotton Dust), 452 U.S. 
490, 513 (1981), American Iron and Steel 
Institute v. OSHA (Lead II), 939 F.2d 975, 
980 (D.C. Cir. 1991).
   A standard is economically feasible if 
industry can absorb or pass on the costs of 
compliance without threatening the industry's 
long-term profitability or competitive 
structure. See Cotton Dust, 452 U.S. at 530 
n. 55; Lead II, 939 F.2d at 980.
   A standard is cost effective if the 
protective measures it requires are the least 
costly of the available alternatives that 
achieve the same level of protection. Cotton 
Dust, 453 U.S. at 514 n. 32; International 
Union, UAW v. OSHA (LOTO III), 37 F.3d 665, 
668 (D.C. Cir. 1994).
   All standards must be highly protective. 
See 58 FR 16612, 16614-15 (March 30, 1993); 
LOTO III, 37 F.3d at 669. However, health 
standards must also meet the ``feasibility 
mandate'' of section 6(b)(5) of the OSH Act, 
29 U.S.C. 655(b)(5). Section 6(b)(5) requires 
OSHA to select ``the most protective standard 
consistent with feasibility'' that is needed 
to reduce significant risk when regulating 
health hazards. Cotton Dust, 452 U.S. at 509.
   Section 6(b)(5) also directs OSHA to base 
health standards on ``the best available 
evidence,'' including research, 
demonstrations, and experiments. 29 U.S.C. 
655(b)(5). OSHA shall consider ``in addition 
to the attainment of the highest degree of 
health and safety protection * * * the latest 
scientific data * * * feasibility and 
experience gained under this and other health 
and safety laws.'' Id.
   Section 6(b)(7) authorizes OSHA to include 
among a standard's requirements labeling, 
monitoring, medical testing and other 
information gathering and transmittal 
provisions, as appropriate. 29 U.S.C. 
655(b)(7).
   Finally, whenever practical, standards 
shall ``be expressed in terms of objective 
criteria and of the performance desired.'' 
Id.


IV. Summary and Explanation

   Based on the best currently available 
evidence, OSHA has preliminarily concluded 
that the requirements of the proposed 
Ergonomics Program Standard are reasonably 
necessary and appropriate to provide adequate 
protection from hazards that are reasonably 
likely to cause or contribute to work-related 
musculoskeletal disorders.
   In developing this proposed rule, OSHA has 
carefully considered the large body of 
scientific articles and studies, as well as 
other data that OSHA has collected since the 
initiation of the Agency's ergonomic efforts 
more than a decade ago. In particular, OSHA 
has carefully considered the large number of 
pathophysiological, biomechanical and 
epidemiologic studies on MSD hazards, 
including those that were reviewed by NIOSH 
and NRC/NAS in their comprehensive studies in 
1997 and 1998, respectively. Examples of 
other data OSHA has carefully considered in 
developing the proposed rule include case 
studies, papers, and ``best practices'' about 
ergonomics programs and controls that have 
been successfully implemented by a number of 
establishments.
   OSHA also met with more than 400 
stakeholders in several informal meetings 
during the development of the proposed rule, 
and considered the major points raised by the 
stakeholders during these meetings. In 
addition, the proposed rule has undergone the 
Panel review process required by the Small 
Business Regulatory Enforcement Fairness Act 
(SBREFA) 5 U.S.C. Chapter 8. All of the 
information developed to assist the small 
entity representatives (SERs) involved in the 
SBREFA process, the comments of the 
representatives, and the Panel's report and 
recommendations to OSHA have been placed in 
the rulemaking record (Ex. 23). Moreover, in 
conjunction with the SBREFA process, OSHA 
released a draft, on the OSHA web page, of 
the proposed rule and carefully considered 
stakeholder comments on that draft.
   When a final standard is published, OSHA 
will undertake a number of outreach and 
compliance assistance activities. These will 
be particularly beneficial to small 
businesses. Outreach and compliance 
assistance activities OSHA intends to make 
available include:
    Publication of booklets 
summarizing the standard and providing 
specific information about different ways in 
which employers can comply with the standard;
    Development of computer-based 
materials to help small businesses identify 
and respond to MSDs and MSD hazards;
    Development of a Small Entity 
Compliance Guide, as required by SBREFA; and
    Development of a compliance 
directive that answers compliance-related 
questions about the standard.
   In this summary and explanation for the 
proposed rule, OSHA has provided a number of 
examples of practices and controls that the 
Agency believes will work to reduce MSDs and 
exposure to MSD hazards. Although these 
certainly are not the only ways employers 
could comply with the proposed rule, the 
discussion provides information that 
employers can use or adapt for their 
workplaces. OSHA has used a variety of 
methods to help stakeholders understand the 
proposed requirements. For example, the 
summary and explanation includes a number of 
tables, exhibits and figures to show data, 
examples, requirements and ways to comply 
with the requirements. To make the preamble 
easier to use, the discussion of each 
provision of the proposed rule begins with a 
reprint of that provision from the proposed 
rule. In addition, the summary and 
explanation is included at the beginning of 
the preamble so stakeholders understand what 
the proposed rule would require when they 
examine other sections of the preamble, such 
as the information on the costs and impacts 
of the proposed rule.
   OSHA believes that this proposed 
ergonomics program standard fulfills a 
promise President Clinton and Vice-President 
Gore made in the 1995 National Performance 
Reveiw document, ``The New OSHA: Reinventing 
Worker Safety and Health.'' That document 
promised that OSHA would address the issue of 
ergonomics by working with business and labor 
to develop a flexible, plain-language 
ergonomics standard. The standard being 
proposed today reflects OSHA's commitment to 
common-sense rulemaking.

[[Page 65776]]

Does This Standard Apply to Me? 
(Secs. 1910.901-1910.904)

   The discussion of ``Does this standard 
apply to me?'' (i.e., Scope of the proposed 
ergonomics program rule) is divided into 
three parts. Part A explains what employers 
and jobs the proposed standard covers. Part B 
discusses the definitions of the covered jobs 
and the other sections related to the Scope 
of the standard. Part C addresses OSHA's 
authority to limit the scope of the 
ergonomics program standard.


A. Industries, Employers and Jobs This 
Standard Covers


1. How Serious Is the Problem of Work-Related 
MSDs?

   The problem of occupational 
musculoskeletal disorders (MSDs) is serious 
and widespread, and the scope of the proposed 
standard is also broad, so that it will 
capture a substantial portion of these MSDs. 
Lost workday MSDs constitute one-third of all 
job-related injuries and illnesses reported 
to BLS every year.
   a. MSD cases. Since 1993, the first year 
BLS began reporting data on musculoskeletal 
disorders, private industry employers have 
reported more than 620,000 MSDs every year 
that have been serious enough to result in 
days away from work for the employee, 
according to the Bureau of Labor Statistics 
(BLS). (These MSDs are referred to in this 
preamble as ``lost-workday MSDs'' or ``LWD 
MSDs.'') MSDs now account for one-third of 
all reported LWD injuries and illnesses. The 
total number of reported MSDs, lost-time and 
non-lost-time MSDs combined, is much higher. 
The combined total is estimated to be almost 
three times higher than the number of LWD 
MSDs. (BLS data indicate that about two-
thirds of all injuries and illnesses do not 
involve days away from work.)
   b. Annual MSD rates. In addition, BLS data 
shows that annual incidence rates for LWD 
MSDs are high. In 1996, LWD MSD rates were as 
high as 36.58 per 1,000 full-time employees 
(FTE) (SIC 45--Transportation by Air). For a 
number of 2-digit industry sectors, LWD MSD 
rates exceeded 10 per 1,000 FTE. And only 
three industry sectors had an annual rate of 
less than 1 LWD MSD per 1,000 FTE. (A 
detailed discussion of LWD MSD cases and 
rates by industry and occupation are 
presented in the Preliminary Risk Assessment 
Section VI.)
   c. Lifetime MSD rates. The lifetime rates 
for LWD MSDs are substantially higher. The 
estimated probability that a worker will 
experience at least 1 work-related MSD during 
a working lifetime (45 years) ranges from 24 
to 813 per 1,000 FTE, depending on the 
industry sector. In addition, it is possible 
for a worker to experience more than one MSD 
in a working lifetime. There is evidence in 
the record indicating that many employees 
working in establishments without an 
ergonomics program have suffered more than 
one serious MSD (Exs. 26-23, 26-24, 26-25, 
26-26, 26-1263, 26-1370). For example, a 
number of employees have had multiple 
surgeries for carpal tunnel syndrome (CTS). 
The expected number of MSDs that will occur 
during a working lifetime among 1,000 FTE 
workers who begin working in an industry at 
the same time ranges from 24 to 1,646, for 
various general industry sectors (see Section 
VII, Significance of Risk).
   d. MSD costs. Each year MSDs alone account 
for about $15-20 billion in workers' 
compensation costs, which is roughly $1 of 
every $3 spent for workers' compensation. The 
average costs for MSD cases are higher than 
those for other injuries. For example, the 
average per case costs for carpal tunnel 
syndrome cases are $8,070, which is more than 
double the $4,000 average per case costs for 
all other injuries and illnesses (Exs. 26-43, 
26-1286). According to Liberty Mutual 
Insurance Company, low-back pain is the most 
prevalent and costly work-related MSD in the 
nation. Low-back pain MSDs account for 15% of 
all Liberty Mutual workers' compensation 
claims and 23% of the costs of these claims 
(Ex. 26-54).
   e. MSDs widespread. Data and other 
evidence show that the problem of work-
related MSDs is widespread. Stakeholders have 
told OSHA that MSDs and MSD hazards are found 
in every industry in the nation (Ex. 3-59, 3-
183, 3-184, 3-217). And each year employers 
in every industry report substantial numbers 
of LWD MSDs. In 1997, more than 626,000 LWD 
MSDs were reported in private industry, about 
567,000 of which were in general industry. 
(See Section VI, Preliminary Risk Assessment, 
for a more detailed discussion of the number 
and rates of MSDs reported to the Bureau of 
Labor Statistics.)


2. Why and How Is OSHA Limiting the Scope of 
the Proposed Ergonomics Program Standard?

   Although these and other data indicate 
that the problem of MSDs is serious and 
widespread, for several reasons OSHA believes 
it is prudent to proceed with the ergonomics 
rulemaking in phases. Regulating workplace 
exposure to MSD hazards presents special 
problems. In particular, the analysis and 
control of MSD hazards involves complex 
issues, because most often several ergonomic 
risk factors combine to create an MSD hazard, 
and these risk factors occur in many 
different combinations. The multi-factoral 
nature of MSD hazards also makes the 
development of a rule to address these 
hazards more complex, because it requires 
more Agency resources for the rulemaking, for 
additional analyses, and for materials for 
effective outreach and training.
   OSHA applied two general principles in 
determining the scope of the first phase of 
the Ergonomics Program Standard. OSHA decided 
to focus on those areas where: (1) The 
problems are severe, and (2) the solutions 
are well-understood.
   These principles are consistent with 
statutory factors governing OSHA rulemakings, 
including the criteria in section 6(g) of the 
OSH Act that OSHA must consider when setting 
rulemaking priorities. 29 U.S.C. 655(g). They 
are also consistent with the feasibility and 
substantial evidence requirements in the OSH 
Act. 29 U.S.C. 655(b)(5).
   Applying these principles, OSHA made two 
basic decisions on the scope of the first 
phase of the Ergonomics Program Standard. 
OSHA first decided to limit the proposed 
standard to general industry because that is 
where the Agency has the most data and 
evidence on ergonomics solutions. And OSHA 
decided to focus on three areas within 
general industry where the problem is likely 
to be severe.
   a. General industry. The vast majority of 
the large body of evidence and data showing 
that ergonomics programs and control 
interventions are successful in reducing MSDs 
pertains to general industry. (Exs. 26-1, 26-
37). For example, the vast majority of 
studies reviewed in the NIOSH and NRC/NAS 
reports pertain to general industry. Almost 
all of the studies on the effectiveness of 
ergonomics programs and control interventions 
focused on general industry (see Section VI, 
Preliminary Risk Assessment). The vast 
majority of the success stories OSHA has 
gathered on the accomplishments of employers 
with ergonomics programs pertain to general 
industry employers. (See discussion of Job 
Hazard Analysis and Control below in this 
section, and the Preliminary Economic 
Analysis, for control scenarios and success 
stories.)

[[Page 65777]]

   Evidence on ergonomic solutions from 
OSHA's own experience dealing with MSD 
hazards is also primarily derived from 
general industry. For example, all of OSHA's 
ergonomics enforcement experience under the 
General Duty Clause is in general industry. 
This includes more than 550 uncontested cases 
and 13 corporate settlement agreements 
covering 198 facilities.
   Information about ergonomic solutions that 
OSHA has derived from the hundreds of 
ergonomics consultations the Agency pertains 
primarily to general industry. OSHA's 
ergonomics guidance and outreach efforts have 
been directed to general industry because 
most of the data and information are there. 
For example, the ergonomics program 
management guidelines OSHA published in 1990 
focused on the red meat industry (Ex. 26-3). 
OSHA's other major ergonomics initiative 
targeted the nursing homes industry, a 
service industry within the general industry 
sector.
   OSHA recognizes that MSD problems are also 
serious in the construction, maritime and 
agricultural industries. In 1996 alone, 
employers in these industries reported more 
than 60,000 LWD MSD. In the Construction--
Special Trades industry sector (SIC 17), more 
than 35,000 LWD MSDs were reported, and the 
incidence rate was 11.57 per 1,000 FTE. OSHA 
intends to conduct rulemaking for those 
sectors at a later date. However, at this 
time the Agency has less well-developed data 
on ergonomics solutions in the construction, 
maritime and agriculture industries, and 
these industries have unique characteristics 
that warrant separate rulemakings. (Part C 
discusses the characteristics in those 
industries.)
   b. Covered jobs. Within general industry, 
OSHA is applying the proposed rule to the 
following three areas where the problem is 
especially likely to be severe:
    Manufacturing production jobs;
    Manual handling jobs requiring 
forceful exertions; and
    Jobs where ``OSHA recordable'' 
MSDs meeting the screening criteria are 
reported.
   Manufacturing and manual handling jobs. 
Data and other evidence in the record 
indicate that in these jobs MSD hazards are 
especially likely to be present. (In the 
proposed rule MSD hazards are defined as 
``physical work activities and/or physical 
work conditions in which risk factors are 
present, that are reasonably likely to cause 
or contribute to a covered MSD.''). BLS data 
and evidence in the record indicate that 
there is a heavy concentration of reported 
MSDs and MSD hazards in manual handling and 
manufacturing jobs. These jobs account for 
about 60% of all reported MSDs that are 
severe enough to have resulted in days away 
from work, even though manufacturing and 
manual handling jobs employ less than 28% of 
the general industry workforce, according to 
BLS.
   For many occupations involving 
manufacturing or manual handling, MSD rates 
are high. In 1996, LWD MSD rates for 
occupations involving manufacturing and 
manual handling were as high as 30.4 and 42.4 
per 1,000 FTE, respectively. For example, 
among nursing aides, orderlies and 
attendants, the LWD MSD rate was 31.6 per 
1,000, and about 58,400 cases were reported. 
(For the entire health services industry 
sector, which involves a variety of patient 
handling tasks, more than 103,000 LWD MSDs 
were reported, or almost 15% of all private 
industry cases.)
   The fact that manufacturing production and 
manual handling jobs account for the largest 
share of workers' compensation costs is 
another indication that there is likely to be 
a high concentration of MSD hazards in those 
jobs. MSDs of the back are one of the most 
costly workplace injuries and account for a 
very large percentage of permanent 
occupational disability cases and costs. As 
mentioned above, according to Liberty Mutual 
Insurance Company (1988, Ex. 26-54), MSDs of 
the back are the most prevalent and costly 
work-related MSD in the nation.
   Other general industry jobs in which 
covered MSDs occur. In general industry jobs 
other than manufacturing and manual handling, 
exposure to MSD hazards is more variable, 
depending on particular work activities and 
conditions. There are, however, a very large 
number of MSDs reported outside manufacturing 
and manual handling jobs. An employer's 
report of a work-related MSD that is serious 
enough to result in work restrictions, days 
away from work or medical treatment, is a 
logical indicator that MSD hazards are likely 
to be present in a job. OSHA is therefore 
extending coverage to jobs in which covered 
MSDs occur. This scope of coverage will reach 
jobs in which MSD hazards are likely to be 
present while excluding other jobs unless and 
until a covered MSD occurs in them.
   Evidence of the severity of the MSD 
problem outside of manufacturing and manual 
handling includes the following. In 1996, 
about 230,000 LWD MSDs were reported in jobs 
other than manufacturing and manual handling. 
The annual LWD MSD rates that year exceeded 1 
per 1,000 in all but three general industry 
sectors that typically do not involve 
manufacturing or manual handling jobs.
   A significant percentage of carpal tunnel 
syndrome (CTS) cases, the type of MSD 
generally requiring the most extensive 
recovery time, is found in jobs other than 
manufacturing or manual handling. In 1996, 
CTS cases resulted in the highest median 
number of days away from work for any injury 
or illness: 25 days for CTS compared to 5 
days for all injuries and illnesses combined. 
That year, more than 57% of lost-workday CTS 
cases involved more than 20 days away from 
work, and more than 42% of all lost-workday 
CTS cases involved more than 30 days away 
from work. For amputations and fractures, 32% 
and 36% of cases, respectively, involved more 
than 30 days away from work.
   In conclusion, although the proposed rule 
applies to only three categories within 
general industry, it will capture those jobs 
in which 90% of LWD MSDs have been reported 
in recent years in private industry. And 
because there are so many well-recognized 
ergonomic solutions to MSD problems in 
general industry, OSHA believes the proposed 
standard should substantially reduce MSD 
hazards as well as the number and severity of 
work-related MSDs in covered industries. OSHA 
requests comment on the scope of the proposed 
rule, particularly on whether and to what 
extent the scope of the rule should be 
expanded or reduced.


B. Definitions of Manufacturing Jobs, Manual 
Handling Jobs and Jobs With MSDs and 
Explanation of Other Scope Sections

   Part B discusses the Scope sections of the 
proposed rule. The first section explains the 
definitions of the jobs the proposed rule 
covers: manufacturing jobs, manual handling 
jobs, and jobs with covered MSDs. The second 
section discusses the other sections of the 
Scope of the proposed rule (Secs. 1910.901-
1910.904).
   1. Definitions of Covered Jobs
   The proposed rule is job-based, and the 
scope of the proposed rule is defined in 
terms of jobs: manufacturing jobs, manual 
handling jobs, and jobs in which an employee 
has experienced a covered MSD. The proposed 
rule applies

[[Page 65778]]

to employers who have any of these jobs, but 
only to the extent that their workplaces have 
such jobs. Where employers do not have manual 
handling or manufacturing jobs that have 
given rise to a covered MSD, the Ergonomics 
Program Standard would not apply at all.
   a. Why is OSHA using a job-based approach 
for defining the scope of the proposed rule? 
OSHA is proposing a job-based approach for 
defining the scope and application of the 
ergonomics standard because this approach 
focuses on areas where MSD hazards are likely 
to be present, is relatively easy to apply, 
and appears to be more cost-effective than 
other approaches. OSHA believes employers 
should be able to determine whether the 
standard applies to them without having to do 
a job hazard analysis for all jobs in their 
workplace. In addition, the three job 
categories addressed by the scope should 
include most jobs in which MSD hazards are 
present.
   Easy to apply. The three job categories 
OSHA is proposing to cover should help 
employers quickly focus on the areas where 
they need to be looking for ergonomic 
problems. Employers should know whether they 
have manufacturing production jobs or jobs 
where employees are regularly handling heavy 
loads. In addition, it should not be 
difficult for employers to determine whether 
they have OSHA recordable MSDs, since most of 
them are already familiar with recording 
work-related illnesses and injuries in order 
to comply with the OSHA recordkeeping rule, 
29 CFR Part 1904. Even employers who do not 
keep OSHA 200 logs should not have difficulty 
identifying whether any of their employees 
has been injured to the extent that they 
require medical treatment, restricted work, 
transfer to an alternative duty job, or time 
away from work to recuperate.
   ``Proxy'' for MSD hazards. These three job 
categories are appropriate because each is an 
accurate and reasonable proxy for an 
increased risk of exposure to ergonomic 
hazards that are reasonably likely to cause 
or contribute to serious physical harm, that 
is, to a covered MSD. For example, 
manufacturing production jobs frequently 
involve repetition of the same task 
throughout the workday, without much 
variation. A large body of evidence, which is 
discussed in greater detail in the Health 
Effects section (Section V), shows that 
employees who have frequent and/or prolonged 
exposure to highly repetitive motions 
(particularly when they are carried out in 
combination with high force and/or awkward 
postures) have a much higher risk of 
developing an MSD as compared to employees 
with lower levels of exposure (See e.g., 
NIOSH, 1997, Ex. 26-1; Bernard, 1993, Ex. 26-
439; Higgs et al. 1992, Ex. 26-1232; Burt et 
al. 1990, Ex. 26-698; deKrom et al. 1990, Ex. 
26-41; Silverstein et al. 1987, Ex. 26-34; 
Armstrong et al. 1987, Ex. 26-48). The high 
incidence rates in manufacturing production 
occupations confirm this. OSHA is not saying 
that all manufacturing jobs present MSD 
hazards. OSHA is saying that manufacturing 
jobs present an increased risk of such 
hazards, and it is therefore logical to cover 
them in the proposed standard.
   The same is true for manual handling jobs. 
Manual handling jobs typically involve 
regular lifting of heavy loads. A large body 
of evidence shows that doing forceful 
exertions repeatedly or for a prolonged 
period of time significantly increases the 
risk of developing an MSD of the back (See 
e.g., NIOSH, 1997, Ex. 26-1; Holmstrom et 
al., 1992, Ex. 26-36; Punnett et al., 1991, 
Ex. 26-36; Liles et al., 1984, Ex. 26-33). 
Occupations and industries where these 
hazards are present have very high LWD MSD 
rates and a large number of cases. As 
mentioned above, in 1996, nurses aides, 
orderlies and health care attendants, who 
spend much of their time doing patient 
lifting tasks, had an annual LWD MSD rate of 
31.6 per 1,000 FTE, and the health services 
industry alone accounted for almost 15% of 
all LWD MSD cases. Finally, the report of an 
MSD that is serious enough to warrant 
recording on the OSHA 200 log is a logical 
indicator that MSD hazards may be present, 
especially since assessing the work-
relatedness of the MSD for the purposes of 
this standard involves a determination by the 
employer about whether the MSD has a 
connection to the activities and conditions 
of the job.
   More practical and less-burdensome. 
Although not a perfect indicator of the 
presence of MSD hazards, reliance on the 
these job categories to determine the scope 
of the proposed standard is more practical 
than other approaches. Using this approach, 
employers do not have to do a job hazard 
analysis of their facility or use a checklist 
to screen all of their jobs, and do not have 
to measure the total weights lifted by an 
employee or the number of repetitions made, 
to determine whether the standard applies to 
them. Thus, the job-based approach does not 
require employers to spend much time and 
resources reviewing the standard to determine 
whether they are covered or reviewing jobs 
where no hazard exists. OSHA believes that 
determining in the first instance whether the 
standard applies should require nothing more 
of employers than a common sense 
determination as to whether they have 
manufacturing productions jobs, forceful 
manual handling jobs, or jobs with OSHA 
recordable MSDs. OSHA anticipates that 
employers should be able to make this 
determination based on existing knowledge 
rather than on formal job analysis.
   OSHA agrees with stakeholder and SBREFA 
Panel comments to the effect that the scope 
should be easy to understand. Accordingly, to 
help employers understand the scope of the 
rulemaking, the definitions of manufacturing 
and manual handling jobs include examples of 
jobs that would typically be included in and 
excluded from the definition (see 
Sec. 1910.945).
   b. What about other methods for defining 
scope? OSHA believes the job-based approach 
is superior to other ways of defining 
coverage, because, on balance, it is the most 
accurate of the cost-effective approaches to 
reducing MSD hazards. OSHA presents 
alternative approaches below and requests 
comment on this issue.
   Preliminary job hazard analysis. OSHA 
considered requiring all general industry 
employers to do an initial job hazard 
analysis for all jobs in the workplace to 
identify those jobs where MSD hazards are 
present. That approach is similar to the 
approach OSHA uses in other health standards. 
In those standards, employers make an initial 
assessment about the presence of hazardous 
substances in the workplace (i.e., ``Do I 
have operations that involve formaldehyde in 
my workplace?''). Requiring a preliminary job 
hazard analysis to screen for ergonomic 
hazards is analogous to this initial 
assessment for toxic substances. Although 
conducting a preliminary analysis is the most 
thorough and accurate way to initially 
determine whether MSD hazards are present, it 
is more resource-intensive for employers. To 
the extent that doing an initial job hazard 
analysis would require employers to expend 
considerable resources and efforts where no 
MSD hazards are present, it would not be 
cost-effective. In contrast, the practical 
design of the proposed job-based approach 
allows employers to make common sense 
determinations about whether the proposed 
rule applies, rather than requiring that the 
determination be based on a formal job hazard 
analysis. At the same time, since evidence in 
the record shows that MSD hazards are likely 
to be present in these jobs and that these 
three categories account for such a large 
proportion of all

[[Page 65779]]

reported MSDs, using the three job categories 
is a reasonably accurate approach.
   Specification. OSHA also could have used a 
specification approach in the proposed rule, 
defining coverage by specific measurements 
such as weight limits, number of repetitions, 
or number of hours performing a certain job 
or task demand. A number of studies have 
identified exposure-response relationships in 
particular circumstances (Holmstrom et al. 
1992, Ex. 26-36 ; Punnett et al. 1991, Ex. 
26-39; de Krom et al. 1990, Ex. 26-41; Liles 
et. al. 1984, Ex. 26-33), and a number of 
models exist for equating safe levels of 
exposure (e.g., NIOSH Lifting Index, Ex. 26-
572; Snook ``Push-Pull'' tables, Ex. 26-
1008).
   Specification approaches, however, are 
more likely to be overinclusive or 
underinclusive. See International Union, UAW 
v. OSHA (LOTO II), 37 F.3d 665 (D.C. Cir. 
1994). For example, if the proposed rule were 
to cover any task that required lifting a 
certain weight (e.g., more than 40 pounds), 
the proposed rule might not cover a number of 
very hazardous lifting tasks in which MSDs 
are reasonably likely to occur. This is 
because the weight limit might not adequately 
consider the impact of other factors on the 
force required to complete a lift. To 
illustrate, a task requiring an employee to 
lift 40 pounds may be safe if twisting, 
bending or reaching is not involved, but it 
could be unsafe if long horizontal reaches or 
bending is required.
   On the other hand, a proposed rule that 
defined coverage in terms of a weight limit 
that takes other ergonomic risk factors into 
account could be overinclusive because the 
recommended lift weight could vary greatly 
with each lifting task. For example, a 
lifting task that does not involve any risk 
factors other than force would be treated the 
same as a lift involving many risk factors. 
However, to expand a specification approach 
to make it more precise (i.e., so that it was 
not underinclusive or overinclusive) would 
necessarily make the approach more complex. 
It would require employers to determine what 
risk factors are present in order to 
determine their impact on the weight limit, 
and thus would essentially require a basic 
job hazard analysis simply to make a decision 
about whether they are subject to the rule.
   Checklist. OSHA could also have used a 
checklist approach for defining coverage 
under the proposed ergonomics standard. A 
simple checklist has advantages: it can be 
administered by a person with limited 
training and is simple and fast to 
administer. However, some checklists are not 
designed to capture complex situations and 
thus might be underinclusive. For example, a 
simple checklist that omits questions that 
are important to a particular job might 
erroneously exclude a hazardous job or treat 
it as no more hazardous than another job. On 
the other hand, making a checklist more 
thorough and accurate would make it harder to 
use and more costly and complex.
   Industry. Finally, OSHA could have defined 
the coverage of the standard purely by 
industry (i.e., industries with the highest 
MSD rates), as some stakeholders have 
recommended. For several reasons, however, 
OSHA believes that this approach would not be 
as accurate as the proposed approach in 
focusing the standard on areas where the 
problem is severe. Regardless of the industry 
in which employees work, they face a 
significant risk of material harm when they 
are exposed to physical work activities and 
conditions that are reasonably likely to 
cause or contribute to a covered MSD. For 
example, in an industry where manual handling 
is rarely performed or is restricted to a 
small group of employees, the overall 
incidence rate for the industry is likely to 
be low. But even if the overall industry 
incidence rate is low, those employees who do 
perform manual handling and are exposed to 
MSD hazards are at significant risk of 
material health impairment. Conversely, an 
industry-based approach would result in low-
hazard jobs in a covered industry being 
included, while employees performing 
identical jobs in other industries would be 
excluded. Defining coverage by industry, 
therefore, would make the standard both 
underinclusive and overinclusive.
   In addition, using industry incidence 
rates is not necessarily an accurate measure 
of the prevalence of MSD hazards. For 
example, even where large numbers of MSDs are 
reported in an industry, the rate may still 
be low because the industry employs so many 
workers, some of whom are not exposed to the 
same degree to MSD hazards. In part, this is 
due to the fact that available industry 
classifications were established for purposes 
other than occupational safety and health 
analysis. Therefore, the courts recognized 
that such classifications ``appear 
essentially irrelevant'' to the task of 
regulating hazards. LOTO II, 37 F.3rd at 670.
   In the remainder of this discussion, OSHA 
will describe the specific provisions of the 
proposed standard that deal with Scope.
   c. Manufacturing jobs. Section 1910.901  
Does this standard apply to me?

  This standard applies to employers in 
general industry whose employees work in 
manufacturing jobs or manual handling jobs, 
or report musculoskeletal disorders 
(``MSDs'') that meet the criteria of this 
standard. This standard applies to the 
following jobs:
  (a) Manufacturing jobs. Manufacturing jobs 
are production jobs in which employees 
perform the physical work activities of 
producing a product and in which these 
activities make up a significant amount of 
their worktime;

   There are many kinds of jobs in 
manufacturing firms (e.g., production, 
professional and technical, maintenance, 
repair, sales, etc.), some of which do not 
have exposure to MSD hazards. The proposed 
rule focuses on manufacturing jobs involving 
the physical work activities of production 
because these jobs present an increased risk 
of MSD hazards.
   Production jobs. The manufacturing jobs 
the proposed rule covers are production jobs 
in manufacturing, those that directly involve 
production work tasks; they are the hands on 
jobs of processing, assembling, or 
fabricating finished or semi-finished 
products (durable and non-durable). 
Production work involves the range of tasks 
from handling raw materials or components 
through packaging the final product to leave 
the production facility. Manufacturing 
production jobs are frequently referred to as 
assembly line, production line, paced work, 
piecework, or factory jobs.
   Evidence in the record indicates that MSDs 
reported in manufacturing are heavily 
concentrated in production jobs. All of the 
manufacturing occupations, as defined by the 
BLS, with high LWD MSD rates are production 
jobs. In 1996, for instance, the 
manufacturing jobs with the highest LWD MSD 
rates were the following production 
occupations:

 
 Machine feeders     34.6 per 1,000 FTE
 and offbearers
 Punching and        30.4 per 1,000 FTE
 stamping machine operators
 Sawing machine      18.9 per 1,000 FTE
 operators
 Furnace, kiln,      18.0 per 1,000 FTE
 oven operators (except
 food)
 Grinding,           17.9 per 1,000 FTE
 abrading, polishing
 machine operators
 Assemblers          16.2 per 1,000 FTE
 


[[Page 65780]]

   The rate for each of these manufacturing 
production occupations substantially exceeded 
and in some cases was 5 times as high as the 
rate for all manufacturing injuries and 
illnesses combined (10.3 per 1,000 FTE). 
These rates were also more than 4 times 
higher than the LWD rate for all injuries and 
illnesses combined (2.5 per 1,000 FTE).
   MSDs reported in manufacturing are heavily 
concentrated in production jobs because these 
are the jobs that are likely to involve 
significant exposure to the combinations of 
ergonomic risk factors that are associated 
with significantly elevated risks of harm. 
Studies show that production work tasks, 
which frequently involve highly repetitive 
tasks and are often combined with high force 
and awkward postures, are the jobs in 
manufacturing that are most closely 
associated with significantly-elevated risks 
of harm (See e.g., NIOSH, 1997, Ex. 26-1; 
Bernard et al. 1993, Ex. 26-439; Higgs et al. 
1992, Ex. 26-1232; Silverstein et al. 1987, 
Ex. 26-34; Armstrong et al. 1987, Ex. 26-48).
   Duration. The manufacturing production 
jobs that the proposed standard covers are 
those in which employees perform production 
tasks for a ``significant amount'' of their 
worktime. In general, significant amount 
means that performing production tasks is a 
key or characteristic element of the 
employee's job. It will probably be obvious 
that employees are performing production 
tasks for a significant amount of their 
worktime. The purpose of the significant 
amount of the worktime aspect of the 
definition of manufacturing jobs is to 
reinforce that the definition is intended to 
include jobs in which production work is 
characteristic of the job, while excluding 
jobs in which an employer might, on rare 
occasions, perform production tasks. This is 
illustrated by the examples of jobs that are 
and are not typically included in the 
definition (see discussion of Sec. 1910.945).
   Evidence in the record, including that 
discussed in the Health Effects section 
(Section V), indicates that MSD hazards may 
be present where production work is performed 
for a significant amount of time. Job tasks 
that require the use of the same muscles or 
motions for long periods of time increase the 
likelihood of both localized and general 
fatigue. In general, the longer the period of 
continuous exertion, the longer the recovery 
or rest time required (NIOSH , 1997, Ex. 26-
1). Studies show that one of the biggest 
contributors to the occurrence of MSDs in 
manufacturing production jobs is lack of 
adequate recovery time (Exs. 26-1, 26-1275). 
Inadequate recovery time may be the result of 
the length of time work tasks are performed 
(deKrom et al. 1990, Ex. 26-102), or the 
frequency with which job cycles are 
performed.
   For example, the risk of developing carpal 
tunnel syndrome (CTS) increases steadily with 
increases in daily exposure to flexed or 
extended wrist postures (deKrom et al. 1990. 
Ex. 26-102). The odds ratio for wrist 
disorders for a group of employees exposed to 
flexed wrist postures between 8-19 hours a 
week (i.e., an average of 1 to <4 hours per 
day) was 3, while that for employees exposed 
to these postures for between 20-40 hours a 
week (i.e., an average of 4 to 10 hours per 
day) was 9 (deKrom et al. 1990, Ex. 26-102).
   Other studies reach the same general 
conclusions. Researchers who reviewed the 
literature found that exposure to a 
combination of repetitive motions and either 
high forces, awkward postures or vibrating 
tools, or to various combinations of risk 
factors, for more than 4 hours a day puts 
workers at high risk of developing MSDs (Exs. 
26-1163, 26-1352). (The relationship between 
duration of exposure to repetitive tasks and 
the occurrence of MSDs is discussed in 
greater detail in the Section V, Health 
Effects, of this preamble.) Although adverse 
effects have been reported following 
extremely high levels of exposure for very 
short durations (Hagberg, 1981, Ex. 26-955), 
studies show that exposure to workplace risk 
factors for less than 2 hours normally 
permits sufficient recovery time for the 
muscles, nerves and tendons in most workers 
to prevent chronic adverse health effects 
(Punnett et al., 1991, Ex. 26-39; Punnet, 
1998, Ex. 26-38)).
   To clarify further the definition of 
manufacturing job, the proposed rule includes 
a list of examples of jobs that typically are 
included in and excluded from the proposed 
definition. This list is intended to be a 
practical guide about the kinds of jobs that 
OSHA intends to include as manufacturing 
production jobs. Table IV-1 includes this 
list:

[[Page 65781]]



                                                   Table IV-1
----------------------------------------------------------------------------------------------------------------
                                                                      EXAMPLES OF JOBS THAT TYPICALLY ARE NOT
      EXAMPLES OF JOBS THAT TYPICALLY ARE MANUFACTURING JOBS                     MANUFACTURING JOBS
----------------------------------------------------------------------------------------------------------------
 Assembly line jobs producing:                              Administrative jobs
   Products (durable and non-durable)                       Clerical jobs
   Subassemblies                                            Supervisory/managerial jobs that do
   Components and parts                                     not involve production work
 Paced assembly jobs (assembling and disassembling)         Warehouse jobs in manufacturing
 Piecework assembly jobs (assembling and disassembling)     facilities
 and other time critical assembly jobs                              Technical and professional jobs
 Product inspection jobs (e.g., testers, weighers)          Analysts and programmers
 Meat, poultry, and fish cutting and packing                Sales and marketing
 Machine operation                                          Procurement/purchasing jobs
 Machine loading/unloading                                  Customer service jobs
 Apparel manufacturing jobs                                 Mail room jobs
 Food preparation assembly line jobs                        Security guards
 Commercial baking jobs                                     Cafeteria jobs
 Cabinetmaking                                              Grounds keeping jobs (e.g.,
 Tire building                                              gardeners)
                                                                    Jobs in power plant in manufacturing
                                                                    facility
                                                                    Janitorial
                                                                    Maintenance
                                                                    Logging jobs
                                                                    Production of food products (e.g.,
                                                                    bakery, candy and other confectionary
                                                                    products) primarily for direct sale on the
                                                                    premises to household customers
----------------------------------------------------------------------------------------------------------------

   d. Manual handling jobs.

  (b) Manual handling jobs. Manual handling 
jobs are jobs in which employees perform 
forceful lifting/lowering, pushing/pulling, 
or carrying. Manual handling jobs include 
only those jobs in which forceful manual 
handling is a core element of the employee's 
job;

  Note: Although each manufacturing and 
manual handling job must be considered on the 
basis of its actual physical work activities 
and conditions, the definitions section of 
this standard (Sec. 1910.945) includes a list 
of jobs that are typically included in and 
excluded from these definitions.

   The second group of jobs OSHA is proposing 
to cover are manual handling jobs. Manual 
handling is the forceful movement (i.e., 
lifting, lowering, pushing, pulling, 
carrying) of materials, equipment, objects, 
people or animals. The movement may be done 
by hand, as in lifting an object or pushing 
hand carts or pallets. The movement can also 
be done with the help of automated equipment 
or aids, such as forklift trucks, storage and 
retrieval systems, conveyors, and mechanical 
lift devices; such assisted handling would be 
considered manual handling as long as the 
movement still required forceful exertions by 
the employee.
   The vast majority of MSDs reported in 
manual handling jobs are back disorders 
(i.e., overexertions). For example, the jobs 
with the highest rate of time-loss injuries 
due to overexertion are those in nursing and 
personal care facilities, where employees are 
required to do frequent patient handling and 
lifting. Manual handling tasks are also 
associated with back pain in 25-70% of all 
worker's compensation claims (Snook and 
Ciriello, 1991, Ex. 26-1008; Cust et al., 
1972, Ex. 26-1194). There is also strong and 
consistent evidence that MSDs of the lower 
back are associated with work-related lifting 
and forceful exertions (see Section V below).
   Most employees handle and move objects 
occasionally at the workplace. A number of 
stakeholders have expressed concern that the 
ergonomics standard would apply to any 
lifting, lowering, pushing, pulling or 
carrying tasks (collectively referred to as 
lifting) that employees do. That is not 
OSHA's intention, and the proposed definition 
of manual handling jobs clarifies that. Table 
IV-2 contains the examples of jobs from the 
definition that typically would be included 
in and excluded from the proposed rule:
   Forceful lifting. Manual handling jobs are 
defined to include only those jobs that 
require forceful manual handling tasks. Force 
is the mechanical effort required to carry 
out a specific movement (NIOSH Elements of 
Ergonomics Programs, 1997, Ex. 26-2). 
Forceful exertions place higher loads on the 
muscles, tendons, ligaments, and joints 
(NIOSH 1997, Ex. 26-1; see also section V, 
Health Effects, of this preamble. Increasing 
the force required to lift a load also means 
increasing body demands (i.e., greater muscle 
exertion is necessary to sustain the 
increased effort), and imposing greater 
compressive forces on the spine (Marras et 
al. 1995). As force increases, muscles 
fatigue more quickly. Prolonged or recurrent 
exertions of this type can also lead to MSDs 
where there is not adequate time for rest or 
recovery (NIOSH 1997, Ex. 26-1).
   Studies indicate employees who perform 
forceful manual handling tasks face a 
significant risk of developing an MSD (See 
Health Effects, Chapter V). The majority of 
epidemiologic studies (13 of 18 studies) in 
the 1997 NIOSH review show that odds ratios 
are higher--in the range of 5.2 to 11--for 
employees who have high exposure to force and 
lifting. (These results are consistent with 
biomechanical and other laboratory evidence 
regarding the effects of lifting and dynamic 
motion on back tissues.) NIOSH also found 
that the high odds ratios for employees with 
high exposure were ``unlikely to be caused by 
confounding or other effects of lifestyle 
covariates'' (NIOSH 1997, Ex. 26-1).

[[Page 65782]]



                                                   Table IV-2
----------------------------------------------------------------------------------------------------------------
                                                                   EXAMPLES OF JOBS/TASKS THAT TYPICALLY ARE NOT
     EXAMPLES OF JOBS THAT TYPICALLY ARE MANUAL HANDLING JOBS                   MANUAL HANDLING JOBS
----------------------------------------------------------------------------------------------------------------
 Patient handling jobs (e.g., nurses aides, orderlies,      Administrative jobs
 nurse assistants)                                                  Clerical jobs
 Package sorting, handling and delivering                   Supervisory/managerial jobs that do
 Hand packing and packaging                                 not involve manual handling tasks or work
 Baggage handling (e.g., porters, airline baggage           Technical and professional jobs
 handlers, airline check-in)                                        Jobs involving unexpected manual
 Warehouse manual picking and placing                       handling
 Beverage delivering and handling                           Lifting object or person in
 Stock handling and bagging                                 emergency situation (e.g., lifting or
 Grocery store bagging                                      carrying injured co-worker)
 Grocery store stocking                                     Jobs involving manual handling that
 Garbage collecting                                         is so infrequent it does not occur on any
                                                                    predictable basis (e.g., filling in on a job
                                                                    due to unexpected circumstances, replacing
                                                                    empty water bottle, lifting of box of copier
                                                                    paper)
                                                                    Jobs involving manual handling that
                                                                    is done only on an infrequent ``as needed''
                                                                    basis (e.g., assisting with delivery of
                                                                    large or heavy package, filling in once for
                                                                    an absent employee)
                                                                    Jobs involving minor manual handling
                                                                    that is incidental to the job (e.g.,
                                                                    carrying briefcase to meeting, carrying
                                                                    baggage on work travel)
----------------------------------------------------------------------------------------------------------------

   Core element. Manual handling jobs are 
jobs in which manual handling tasks are a 
core element of the employee's job. A core 
element of a job refers to the tasks or 
physical work activities that are a key 
function of a job. Manual handling tasks may 
be a core element because they are a basic or 
essential function of a job. They may be a 
core element because they are frequently 
repeated or performed for a period of time. 
The following are examples of jobs in which 
manual handling would typically be considered 
a core element:
    Jobs where the basic purpose is 
to lift loads. These types of jobs include 
furniture moving, package and product 
delivery, and airline baggage handling;
    Jobs where lifting or pushing/
pulling is an essential function of the job. 
Patient lifting, for example, is an essential 
element of nurse aide or health aide jobs and 
pushing is an essential element for 
orderlies;
    Jobs where manual handling is a 
regular element of the job cycle. These types 
of jobs typically include bringing supplies 
to a production workstation, loading machines 
for processing, and moving partially 
assembled products to the next workstation or 
onto or off a conveyor;
    Jobs where forceful exertions 
comprise a significant amount of the 
employee's work time. These jobs typically 
include warehousing, stocking and garbage 
collection;
    Jobs where employees end up doing 
manual handling on a routine or regular basis 
even if manual handing is not included in 
their job description. These jobs typically 
include unloading supplies or products that 
are delivered on a regular basis.
   Including the concept of core element in 
the definition of covered manual handling 
jobs serves several purposes. First, it helps 
to ensure that employer attention is focused 
on those manual handling jobs for which data 
indicate that MSD hazards are most likely to 
be present: manual handling jobs with high 
MSD rates and numbers of cases. Studies 
indicate that manual handling jobs in which 
employees do forceful exertions repeatedly or 
for an appreciable period of time are 
associated with elevated risks of harm. For 
example, studies show a positive association 
between duration of exposure to workplace 
risk factors during manual handling and back 
pain (Wild 1995, Exs. 26-1104, 26-1105, 26-
1106; Liles et al. 1984, Ex. 26-33). Studies 
also show that odds ratios for back MSDs 
increase significantly as daily duration of 
exposure to forceful manual handling 
increases (Holmstrom et al. 1992, Ex. 26-36; 
Punnett et al. 1991, Ex. 26-39; Liles et al. 
1984, Ex. 26-33). Other studies indicate that 
the rate and duration of continuous lifting 
significantly reduces the worker's lifting 
capacity, making the worker more susceptible 
to MSDs associated with lifting (Snook and 
Ciriello, 1991, Ex. 26-1008).
   Second, OSHA used core element rather than 
a duration component because, while duration 
and frequency play a role in determining 
whether the manual handling job imposes a 
risk of harm, studies show that employees can 
be at risk of developing an MSD at relatively 
short durations of lifting if the tasks 
involve extreme force (Hagberg 1981, Ex. 26-
955) (see Section V of the preamble).
   Finally, core element is a reasonable, 
shorthand way to inform employers that OSHA 
does not intend to cover manual handling that 
is so isolated or so incidental to the job 
that it is not reasonably likely to lead to 
an MSD. These types of jobs are not 
associated with high numbers or rates of 
MSDs.
   OSHA requests information and comments 
about whether the Ergonomics Program Standard 
should include manual handling jobs. If so, 
how should manual handling jobs be defined? 
Should the definition use a flexible approach 
or be based on quantitative methods such as 
the NIOSH Lifting Equation?
   c. Jobs with MSDs.

  (c) Jobs with a musculoskeletal disorder. 
Jobs with an MSD are those jobs in which an 
employee reports an MSD that meets all of 
these criteria:
  (1) The MSD is reported after [the 
effective date];
  (2) The MSD is an OSHA recordable MSD, or 
one that would be recordable if you were 
required to keep OSHA injury and illness 
records; and
  (3) The MSD also meets the screening 
criteria in Sec. 1910.902.


[[Page 65783]]


  Note to Sec. 1910.901(c): In this standard, 
the term covered MSD refers to a 
musculoskeletal disorder that meets the 
requirements of this section.

   The final group of jobs this standard 
proposes to cover are those in which an 
employee reports a musculoskeletal disorder 
(MSD).
   What is an MSD? Musculoskeletal disorders 
are injuries or disorders of the:

    Muscles
    Tendons
    Joints
    Spinal discs
    Nerves
    Ligaments
    Cartilage

   MSDs develop as a result of repeated 
exposure to ergonomic risk factors. The 
proposed rule covers the following ergonomics 
risk factors:

    Force (including dynamic motions)
    Repetition
    Awkward or static postures
    Contact stress
    Vibration
    Cold temperatures

MSDs covered by the proposed standard do not 
include injuries to muscles, nerves, tendons, 
ligaments, or other musculoskeletal tissues 
that are caused by accidents such as slips, 
trips, falls, being struck by objects, or 
other similar accidents.
   Table IV-3 contains examples of MSDs that 
may develop as a result of exposure to the 
ergonomic risk factors the proposed rule 
covers:

                               Table IV-3
------------------------------------------------------------------------
  EXAMPLES OF MUSCULOSKELETAL DISORDERS THE ERGONOMICS PROGRAM STANDARD
            WOULD COVER IF CONDITIONS OF THE STANDARD ARE MET
-------------------------------------------------------------------------
 Carpal tunnel syndrome
 Epicondylitis
 Herniated spinal discs
 Tarsal tunnel syndrome
 Raynaud's phenomenon
 Sciatica
 Ganglion cyst
 Tendinitis
 Rotator cuff tendinitis
 DeQuervain's disease
 Carpet layers knee
 Trigger finger
 Low back pain
------------------------------------------------------------------------

   The presence of MSD signs and/or symptoms 
is usually the first indication that an 
employee may be developing an MSD. The 
proposed rule defines both terms.
   MSD signs are objective physical findings 
that an employee may be developing an MSD.
   MSD symptoms, on the other hand, are 
physical indications that an employee may be 
developing an MSD. Symptoms can vary in 
severity, depending on the amount of exposure 
to MSD hazards. Often symptoms appear 
gradually, for example, as muscle fatigue or 
pain at work that disappears during rest. 
Usually symptoms become more severe as 
exposure continues. For example, tingling in 
the fingers that formerly occurred only when 
the employee was doing a repetitive task 
subsequently continues even when the employee 
is off work or at rest. If the employee 
continues to be exposed, symptoms may 
increase to the point that they interfere 
with performing the job. For example, as 
exposure continues the employee's grip 
strength (e.g., ability to hold or grip an 
object or exert pressure with the hand) may 
decrease to the point where the employee has 
difficulty holding tools or gripping objects. 
Finally, pain may become so severe that the 
employee is unable to perform physical work 
activities). Table IV-4 includes examples of 
MSD signs and symptoms that OSHA is proposing 
to cover in this standard:

                               Table IV-4
------------------------------------------------------------------------
                   EXAMPLES OF MSD SIGNS AND SYMPTOMS
-------------------------------------------------------------------------
               MSD SIGNS                           MSD SYMPTOMS
------------------------------------------------------------------------
 Deformity                        Numbness
 Decreased grip strength          Tingling
 Decreased range of motion        Pain
 Loss of function                 Burning
                                          Stiffness
                                          Cramping
------------------------------------------------------------------------

   What MSDs does this standard cover? The 
proposed rule does not cover all MSDs, and 
thus a report of an MSD would not 
automatically require the employer to set up 
an ergonomics program or to provide MSD 
management. The proposed rule only covers 
those MSDs that meet all of the following 
requirements:

    They are ``OSHA recordable'' 
MSDs, and
    They are reported after the 
effective date of the standard, and
    They meet the screening criteria 
in Sec. 1910.902 (i.e., physical work 
activities and/or conditions are reasonably 
likely to cause the type of MSD reported and 
are a core element of the job and/or make up 
a significant amount of the employee's 
worktime).

   OSHA recordable MSDs are those that meet 
the recording criteria of the OSHA 
recordkeeping rule, 29 CFR Part 1904. These 
MSDs must be recorded on the OSHA injury and 
illness logs, or are MSDs that would have to 
be recorded if the employer were obligated to 
keep such logs.
   The OSHA recordkeeping rule does not 
require that every MSD be recorded.
   The OSHA Meatpacking Guidelines explain 
what MSDs employers must record under the 
recordkeeping rule. A recordable MSD is a 
work-related MSD that results in one or more 
of the following:

 A diagnosis of an MSD by a HCP; or
 At least one positive physical 
    finding, or
 An MSD symptom plus:
       Medical treatment,
       Restricted duty,
       One or more lost work days, or
       Transfer/rotation to another 
job.

   Positive physical finding. A positive 
physical finding is a report of any of the 
MSD signs listed above that is observable

[[Page 65784]]

by the employer and/or HCP. It is also a 
positive result on a medical test (i.e., 
Finkelstein's, Phalen's or Tinel's test) 
conducted by an HCP. Because a positive 
physical finding is able to be observed by 
others, unlike a symptom, OSHA considers 
positive physical findings to be a recordable 
MSD, even if the employee has not missed 
work, been placed on work restrictions, or 
received medical treatment for the problem.
   MSD symptom plus other action. Under 
OSHA's recordkeeping rule, MSD symptoms are 
recordable if they have resulted in medical 
treatment beyond first aid, restricted duty, 
one or more days away from work or transfer/
rotation to another job. For example, where 
an employer responds to an employee report of 
symptoms (e.g., numbness in the fingers or 
pain in the wrist) by putting the employee in 
a light duty job or by directing the employee 
to stay at home to rest the injured area, the 
event must be recorded.
   When an employee requires medical 
treatment to obtain relief from and resolve 
MSD signs or symptoms, the condition is a 
recordable MSD. Conservative medical 
treatment of MSDs, for example, may include 
prescription anti-inflammatories, splints or 
braces to immobilize movement of the injured 
area while at rest or sleeping, and/or 
physical therapy.
   There are several reasons why OSHA is 
proposing to use an OSHA recordable MSD as an 
initial trigger, rather than other incident 
triggers (e.g., MSD rates, any report of MSD 
signs or symptoms, accepted workers' 
compensation claims) to determine coverage. 
First, using an OSHA recordable should not be 
difficult or burdensome for most employers 
because they are familiar with this 
definition from their OSHA injury and illness 
logs. This is why many stakeholders said they 
supported using an OSHA recordable MSD in the 
ergonomics rule. Using the same definition 
for both rules (the recordkeeping and 
ergonomics rules) would reduce employer 
burdens in complying with the ergonomics rule 
because employers would not have to develop 
or learn a new recordkeeping system. In 
addition, it would reduce paperwork burdens 
because the OSHA logs would satisfy both the 
ergonomics rule and also the OSHA 
recordkeeping requirement.
   Second, a number of stakeholders support 
using an OSHA recordable MSD because they 
believe it is a reasonable, objective 
definition. For example, a number of 
stakeholders oppose using any report of MSD 
symptoms because they are concerned that such 
reports may be subjective, and, unless the 
symptoms are persistent, may not really mean 
that an injury is present. These stakeholders 
also said that an OSHA recordable is more 
objective than other measures, such as the 
results of discomfort surveys.
   Third, limiting coverage to jobs with a 
high incidence rate would have limited value. 
The typical job has between 1 to 10 
employees, i.e., between 1 and 10 employees 
in a given establishment perform the same 
job. Even if one of these employees has an 
MSD, the annual rate would be an unacceptably 
high incidence rate of 10%. For all except 
rare situations in which there are more than 
100 employees with the same job, defining the 
trigger in terms of a rate is not 
fundamentally different from a one-incident 
trigger (see the discussion in Chapter VII of 
the Preliminary Economic Analysis, Ex. 28-1).
   Defining coverage in terms of a job with a 
workers' compensation award would result in 
unequal treatment of employees and employers 
covered by the ergonomics standard. State 
workers' compensation laws vary significantly 
and the same MSD may not be compensable in 
all States. For example, some States 
compensate an injured employee only if MSD 
hazards are the predominant cause of the MSD 
or if there is clear and convincing evidence 
that the MSD hazard caused the MSD. In 
Virginia, a number of MSDs are not 
compensable (e.g., rotator cuff syndrome). 
Moreover, defining an MSD in terms of 
workers' compensation claims puts employers 
who willingly acknowledge the work-
relatedness of an MSD at a disadvantage 
compared to those employers who discourage 
claims and challenge compensation awards.
   Finally, using an OSHA recordable MSD as 
the initial trigger would make the ergonomics 
rule more protective than using a number of 
the other MSD measures. Using an OSHA 
recordable MSD would require employers to 
respond to every MSD that is sufficiently 
important to warrant recording. In contrast, 
using multiple MSDs or incidence rates would 
mean that the ergonomics rule would not 
require some employers to provide protection 
or MSD management for the first employee who 
reports an MSD, even if the MSD is clearly 
work related or has resulted in severe 
permanent damage. (See OSHA's Initial 
Regulatory Flexibility Analysis in Chapter 
VII of the Preliminary Economic Analysis, Ex. 
28-1, for an analysis of the potential 
impacts of alternative triggers.)
   OSHA requests information and comment on 
its proposal to base coverage on the 
occurrence of an OSHA recordable MSD and an 
employer determination that the recordable 
also meets the screening criteria, as well as 
on alternative definitions of the term MSD 
that would be as protective as the proposed 
definition.
   Reported after effective date. OSHA is 
also proposing to limit the MSDs that the 
standard would cover to those that are 
reported after the standard becomes 
effective, which is 60 days after the final 
Ergonomics Program Standard is published in 
the Federal Register. Coverage of the 
standard would not be triggered for MSDs that 
occurred before that date.
   f. Screening criteria. The last 
requirement is that MSDs meet the criteria in 
Sec. 1910.902. If the criteria are not met, 
the employer has no further obligation under 
the proposed rule.
   Section 1910.902  Does this standard allow 
me to rule out some MSDs?

  Yes. The standard only covers those OSHA 
recordable MSDs that also meet these 
screening criteria:
  (a) The physical work activities and 
conditions in the job are reasonably likely 
to cause or contribute to the type of MSD 
reported; and
  (b) These activities and conditions are a 
core element of the job and/or make up a 
significant amount of the employee's 
worktime.

   The screening criteria limit coverage of 
the proposed standard to jobs where exposure 
to MSD hazards is reasonably likely to cause 
or contribute to the type of MSD reported, 
and the job activities are a core element of 
the job and/or make up a significant amount 
of the employee's worktime. Because MSD 
hazards are physical work activities or 
conditions that are reasonably likely to 
cause MSDs, normally the occurrence of a 
recordable MSD is a good indicator that an 
MSD hazard is present. However, there are 
occasions in which MSDs result from 
idiosyncratic or unusual work circumstances. 
While work-related, such an MSD may not 
evince underlying hazards of the type an 
ergonomics program is designed to address. 
For example, if an employee who routinely 
does heavy lifting incurs work-

[[Page 65785]]

related low back pain, that is precisely the 
type of MSD the work activities of the job 
are reasonably likely to have contributed to 
and would be the type of MSD hazard the 
ergonomics program is designed to control. If 
the same employee reports carpal tunnel 
syndrome, however, the situation is 
different. Of course, the condition may not 
be work-related. Even if it is, however, it 
is likely to be related to physical work 
circumstances or reactions that would not 
normally be taken into account in designing 
ergonomic controls. Because the occurrence of 
a recordable MSD is not a good proxy for an 
underlying hazard in this circumstance, the 
MSD would not be a covered MSD for purposes 
of this standard. For the reasons described 
in the explanation of manufacturing and 
manual handling jobs above, covered MSDs are 
limited to those that have a good nexus with 
the physical work activities and conditions 
of the job; that is, the physical work 
activities and conditions that are reasonably 
likely to result in the occurrence of an MSD 
are (1) a core element of the job, and/or (2) 
make up a significant amount of the 
employee's worktime.


2. Other Sections on Scope

   Section 1910.903  Does this standard apply 
to the entire workplace or to other 
workplaces in the company?

  No. This standard is job-based. It only 
applies to jobs specified in Sec. 1910.901 
not to your entire workplace or to other 
workplaces in your company.

   Section 1910.903 specifies that the 
ergonomics rule would apply only to those 
jobs OSHA explicitly identified as covered 
jobs and ensures that the presence of a 
covered job does not bring the rest of the 
workplace under the ergonomics standard. This 
means that employers would not have to 
develop an ergonomics program that covers all 
jobs and employees in the workplace merely 
because one job in the workplace is covered 
by the ergonomics standard. Other jobs in the 
workplace would only be included under the 
standard if they meet the definition of a 
covered job or if they involve the same 
physical work activities and conditions as 
the job in which the employee experienced the 
covered MSD.
   Some stakeholders recommended that if an 
ergonomics program is required in a 
workplace, it should cover the entire 
workplace. They said that a whole-workplace 
approach would be easier because it would 
eliminate the need to determine whether 
certain jobs are covered by the ergonomics 
rule or involve the same physical work 
activities and MSD hazards as the covered job 
(Ex. 26-1370). Some said that a facility-wide 
program achieves greater employee buy in and 
support for the ergonomics program. It would 
also create employee goodwill because all 
employees would be part of the program and 
would be provided protection, as opposed to a 
situation in which employees working side-by-
side would not necessarily both be covered by 
the ergonomics program. Finally, stakeholders 
said they found that developing a facility-
wide program was as a more efficient use of 
resources, because it eliminated duplication 
of efforts such as training. For these 
reasons, they said, many employers have taken 
this approach in their own workplaces.
   OSHA agrees with stakeholders that there 
are advantages to facility-wide ergonomic 
programs and OSHA encourages employers to 
consider a facility-wide approach. However, 
OSHA is not proposing to require a workplace-
wide approach because the risk factors are 
not present in every job to the extent that 
an MSD is reasonably likely to occur. The 
job-based coverage of the proposed rule 
ensures that employers focus first on the 
jobs where intervention is needed the most; 
that is, jobs in which the employees' 
exposure to the risk factors is significant 
enough that MSDs are occurring or reasonably 
likely to occur if exposure continues 
unabated. In any event, if other jobs in the 
workplace are or become problem jobs, those 
employees would also be included in the 
program required by the standard and would 
thus be provided protection from MSD hazards. 
Job-based coverage assures that employers are 
not required to expend resources on jobs in 
which there is little likelihood that MSD 
hazards are present.
   The remaining half of section 1910.903 
informs employers that their program for 
addressing problem jobs does not have to be 
applied corporate-wide. That is, the 
existence of a problem job in one workplace 
does not mean that employers have to set up 
an ergonomics program in every facility owned 
by the company in which that job is 
performed. OSHA is proposing to limit 
employer obligations to the facility in which 
the problem job is identified. At the same 
time, OSHA recognizes that a number of 
employers have developed corporate-wide 
ergonomics programs. OSHA notes that while 
the general program and protocols of such 
corporate programs are applied to all 
workplaces, job hazard analyses and 
determinations about whether and what actions 
are needed in specific jobs are usually made 
at the workplace level.
   OSHA notes that, although the ergonomics 
rule would not apply corporate-wide, the 
employer will need to take action in other 
company-owned facilities if they have any of 
the problem jobs this standard covers (e.g., 
if a covered MSD occurs there).
   Section 1910.904  Are there areas this 
standard does not cover?

  Yes. This standard does not apply to 
agriculture, construction or maritime 
operations.

   OSHA is proposing to exclude firms engaged 
in agriculture, construction and maritime 
operations from the scope of the first phase 
of this ergonomics rulemaking. OSHA 
acknowledges that LWD MSD rates are also high 
in firms engaged in agriculture, construction 
and maritime operations. However, the unique 
problems (e.g., jobs of very short duration, 
no fixed workstations) and the more limited 
information available on effective ergonomic 
controls in these workplaces have convinced 
OSHA that it must, for resource and priority-
setting reasons, limit this first phase to 
general industry. OSHA has preliminarily 
decided to address the MSD hazards in firms 
engaged in these operations in a separate 
rulemaking. (OSHA's reasoning is discussed in 
detail in Part C below.)
   OSHA intends to develop a separate 
ergonomics rule that can be tailored to the 
conditions that are unique to firms in these 
industries. In addition, OSHA believes that 
the experience it gains from the first phase 
will provide valuable assistance in 
developing an effective ergonomics rule for 
agriculture, construction and maritime.
   OSHA requests comments and information 
about whether firms engaged in agriculture, 
construction and maritime operations should 
be included in this ergonomics standard at 
this time. In particular, OSHA requests 
comments and information about whether, for 
example, manual handling operations in 
agriculture, construction and maritime should 
be included in this first phase of the 
ergonomics rulemaking.

[[Page 65786]]

C. Authority and Reasons for Limiting 
Coverage of the Proposed Ergonomics Standard.

   This section discusses OSHA's authority 
under the OSH Act to promulgate the 
ergonomics standard sequentially, and its 
reasons for limiting the proposed ergonomics 
standard at this time to the three types of 
jobs discussed above. This discussion focuses 
on the following questions:
    What authority and reasons 
support promulgating the Ergonomics Program 
Standard sequentially, and limiting the first 
phase to manufacturing jobs, manual handling 
jobs, and other jobs where an OSHA recordable 
MSD is reported?
    What authority and reasons 
support exclusion of the agriculture, 
construction and maritime industries from the 
proposed ergonomics standard?


1. Section 6(g)--OSHA Authority to Limit the 
Scope of Rulemakings

   The OSH Act authorizes OSHA to use a 
phased approach to rulemaking, including 
focusing first on areas where the problem is 
severe and solutions are well-known. Section 
6(g) of the OSH Act, 29 U.S.C. 655, permits 
OSHA to set priorities in establishing 
standards, including limiting the scope of 
particular standards and promulgating 
standards in phases. Section 6(g) provides:

  In determining the priority for 
establishing standards under this section, 
the Secretary shall give due regard to the 
urgency of the need for mandatory safety and 
health standards for particular industries, 
trades, crafts, occupations, businesses, 
workplaces or work environments. The 
Secretary shall also give due regard to the 
recommendations of the Secretary of Health, 
Education, and Welfare regarding the need for 
mandatory standards in determining the 
priority for establishing such standards.

   In proposing the addition of section 6(g) 
to the OSH Act, Senator Jacob Javits 
explained that its purpose was ``to relieve 
the Secretary of the necessity of waiting to 
promulgate whatever standards he wishes 
across the board [by] allowing him to yield 
to more urgent demands before he tries to 
meet others. *  *  *'' Legislative History, 
505.
   The courts have broadly interpreted 
section 6(g) as ``clearly permit[ting] the 
Secretary to set priorities for the use of 
the agency's resources.'' United Steelworkers 
of America v. Auchter (Hazard Communication), 
763 F.2d 728, 738 (3rd Cir. 1985); Forging 
Industry Association v. OSHA (Noise), 773 
F.2d 1436, 1455 (4th Cir. 1985); United 
States Steelworkers v. Marshall (Lead), 647 
F.2d 1189, 1309-1310 (D.C. Cir. 1980), cert. 
denied, 453 U.S. 913 (1981); National 
Congress of Hispanic American Citizens v. 
Usery (Hispanic II), 626 F.2d 882 (D.C. Cir. 
1979); National Congress of Hispanic American 
Citizens v. Usery (Hispanic I), 554 F.2d 
1196, 1199 (D.C. Cir. 1977). Section 6(g) 
authorizes OSHA to ``alter priorities and 
defer action due to legitimate statutory 
considerations,'' Hispanic II, 626 F.2d at 
888 n. 30. In the PELs rulemaking, for 
example, the court upheld OSHA's decision to 
exclude exposure monitoring and medical 
surveillance provisions from the rule as 
being ``purely a matter of regulatory 
priority.'' AFL-CIO v. OSHA (PELs), 965 F.2d 
962, 985 (11th Cir. 1992).
   Section 6(g) also permits OSHA ``to 
promulgate standards sequentially.'' Hazard 
Communication, 763 F.2d at 738. See, PELs, 
965 F.2d at 985 . For example, the courts 
have upheld OSHA's decisions to issue 
standards for general industry first and 
thereafter to develop separate rules for 
those other industries that may have unique 
problems requiring special consideration 
(e.g., mobile jobs of very short duration in 
the construction industry). Lead, 647 F.2d at 
1309-10. (See Confined Spaces standard, 29 
CFR 1910.146.) Section 6(g) also authorizes 
OSHA to ``act in its legislative capacity `to 
focus on only one aspect of a larger 
problem.' '' Lead, 647 F.2d at 1310 (citing 
Chief Justice Burger concurring in Benzene, 
448 U.S. at 663 (1980)) (emphasis added). In 
the PELs rulemaking, OSHA limited the 
standard solely to revising exposure limits 
and excluded ancillary provisions designed to 
provide further protection even though most 
other health standards included such 
provisions. See, PELs, 965 F.2d at 985.
   Although OSHA's discretionary authority 
under section 6(g) is quite broad, it is not 
absolute:

  The scope of an agency's discretion is 
bounded by law; an agency cannot justify a 
decision by reference to its discretionary 
authority, if the decision lies beyond the 
scope of agency's discretion. (citations 
omitted) A statute may define as off-limits 
to an agency a particular basis for a 
decision, just as it may foreclose a 
particular result altogether. Farmworkers 
Justice Fund, Inc. v. Brock (Field 
Sanitation), 811 F.2d 613, 620 (D.C. Cir.), 
vacated as moot, 811 F.2d 890 (1987).
   The Supreme Court has made clear that an 
agency's decision will be set aside if it 
relied on factors which the Congress did not 
intend it to consider. Motor Vehicle 
Manufacturers Assn. v State Farm Mutual 
Automobile Insurance Co., 463 U.S. 29, 43 
(1983). In section 6(g), Congress established 
factors OSHA must consider in setting its 
priorities: OSHA must give ``due regard to 
the urgency of the need'' for a standard in, 
among others, particular industries, 
occupations, workplaces, or work 
environments.1 The court in Hazard 
Communication said that this language 
suggests a statutory standard by which to 
measure the exercise of OSHA's discretion. 
Hazard Communication, 763 F.2d at 738. 
Authorizing rulemaking priority for the most 
severe hazards also comports with the 
criteria of section 6(c), which authorizes 
OSHA to pursue expedited rulemaking (i.e., 
emergency temporary standard) but only where 
employees are exposed to ``grave dangers.'' 
Hispanic II, 626 F.2d at 889 n.36.
---------------------------------------------------------------------------
  \1\ See also, Hispanic I, 554 F.2d at 1199 
(``The Act has built in flexibilities that 
the Secretary may use, such as *  *  * the 
priorities between the various occupations 
that require standards. *  *  *'').
---------------------------------------------------------------------------
   The Third Circuit has held that there is 
another limit on OSHA's 6(g) authority 
depending on where OSHA is in the rulemaking 
process. Hazard Communication, 763 F.2d at 
738. The court said that, in situations where 
OSHA is setting priorities for future 
rulemaking, the agency has great latitude 
under section 6(g) to address greater hazards 
first. Id. However, the court held that where 
OSHA has decided to promulgate a standard to 
address an issue it is not enough for the 
agency to declare that it has selected 
certain industries or jobs for coverage 
because they present greater hazards. Id. 
Where significant risk exists in other 
industries and a standard is feasible there 
as well, OSHA may exclude those industries 
only if covering them would ``seriously 
impede the rulemaking process.'' Id.
   The standard in question, Hazard 
Communication (29 CFR 1910.1200), only 
required employers to provide employees with 
information and training about hazardous 
chemicals in the workplace, based on analyses 
generally conducted by the chemical 
manufacturer or importer. The standard did 
not require employers to analyze jobs, 
implement controls, or provide medical 
management. The court apparently believed 
that there was no substantial question about 
the feasibility of the rule, and therefore no 
question about whether the rule could be 
expanded without impeding the rulemaking 
process. It is not clear the court would have 
reached the same result or announced the same 
principle if the standard

[[Page 65787]]

in question had posed more complex scientific 
and feasibility issues. In any event, OSHA's 
decision to limit the proposed standard is 
consistent with the Hazard Communication 
decision because, as discussed below, 
expansion of the rule at this time to include 
construction, maritime and agriculture would 
seriously impede the rulemaking process.


2. Focus on Jobs Where Problems Are Severe 
and Solutions Are Well-Understood

   OSHA has developed a general principle, 
based on the underlying legislative intent 
and the case law interpreting section 6(g), 
that it proposes to follow in determining 
what jobs should be covered in the first 
phase of this rulemaking. As mentioned above, 
that principle is: Focus on areas where 
problems are severe and solutions are well-
understood. OSHA's decision, based on this 
guiding principle, to cover manufacturing, 
manual handling and general industry jobs 
where there are MSDs is consistent with the 
language and legislative intent of section 
6(g).


3. Reasons for Excluding Agriculture, 
Construction and Maritime Industries From the 
Proposed Standard

   Some stakeholders recommended that the 
proposed rule be expanded to include all 
industries. They said that the number and 
rates of MSDs in the construction industry 
are very high. They added that incidence 
rates for some construction industries are 
higher than for some manufacturing industries 
that are to be covered in the first phase. 
However, for the reasons set forth below, 
OSHA is not proposing that the first phase of 
the Ergonomics Program Standard cover these 
other industries.
   a. Unique problems. OSHA acknowledges that 
employees in the agriculture, construction 
and maritime industries face significant risk 
of harm due to exposure to MSD hazards. In 
1996, for example, almost 65,000 employees in 
these industries reported MSDs that were 
serious enough to result in days away from 
work, according to OSHA's analysis of BLS 
data (Ex. 1413). This means that 10% of all 
reported lost-workday MSDs occurred in just 
three industry sectors. Nonetheless, 
consistent with its discretion under section 
6(g), OSHA proposes to exclude these 
industries from this proposal and to give 
them special consideration in subsequent 
rulemaking. Lead, 647 F.2d at 1310.
   First, work conditions and factors present 
in agricultural, construction and maritime 
activities often are quite different from 
those of general industry. To illustrate, 
much of construction work involves or is 
affected by an interaction among several 
factors. These factors include the following 
aspects or conditions of work:
    Consisting primarily of jobs of 
short duration;
    Under a variety of adverse 
environmental and workplace conditions (e.g., 
cold, heat, confined spaces, heights);
    At non-fixed workstations or non-
fixed work sites;
    On multi-employer work sites;
    Involving the use of ``day 
laborers'' and other short-term ``temporary 
workers,'';
    Involving situations in which 
employees provide their own tools and 
equipment; and
    Involving employees who may be 
trained by unions or other outside certifying 
organizations.
   While some of these factors may be present 
at times in other industries, they are 
continuously present in construction. OSHA 
may need to develop an ergonomics standard 
that takes this range of special conditions 
into account. For example, OSHA may also need 
to revise job hazard analysis and hazard 
control provisions in the current proposal so 
they are effective for industries where jobs 
are of such short duration that they may be 
completed before analysis and control can be 
implemented. These and other unique work 
conditions also are present in agricultural 
and maritime activities. For example, in 
longshoring, quite often workers are obtained 
from union hiring halls where they have been 
trained and certified in the use of certain 
machinery.
   In addition, as compared to the very large 
body of evidence that exists for general 
industry, OSHA's experience with and 
information about ergonomic solutions in the 
agriculture, construction and maritime 
industries are relatively limited. OSHA 
believes that the information it does have 
will support the promulgation of an 
ergonomics standard in these industries in 
the second phase of this rulemaking. However, 
the Agency needs more time to gather and 
analyze this evidence to develop an effective 
ergonomics standard for agriculture, 
construction and maritime. For example, OSHA 
must gather and examine information on the 
types of ergonomic controls that would work 
in an industry with a high number of non-
fixed workstations.
   Because of the unique problems in these 
industries, it could take considerably more 
time to gather the needed information. And 
after waiting until an equivalent body of 
evidence is gathered and analyzed for these 
industries, the evidence might still show 
that separate ergonomics rules are warranted 
for construction, agriculture and maritime in 
any event.
   b. Substantially impede the rulemaking. 
Implicit in setting rulemaking priorities 
based on the urgency of the need for action 
is whether a standard can be issued in a time 
frame that is responsive to the urgent need. 
Another reason OSHA is proposing to limit the 
ergonomics rule to general industry is that 
OSHA believes that expanding the rule to 
cover agriculture, construction and maritime 
would seriously delay addressing the urgent 
need for protection in the covered jobs. This 
is because information and experience on 
ergonomics in these industries is more 
limited than is the case in general industry. 
Expanding the scope could place substantial 
additional burdens on an already complex 
rulemaking. For example, if OSHA must first 
gather and analyze evidence for every 
industry before it may propose an ergonomics 
standard, 90% of the employees who already 
have been injured and for whom a standard can 
be promulgated now may be forced to wait for 
their urgently needed protection until OSHA 
is also able to provide it to the remaining 
employees exposed to MSD hazards. Also, 
expanding the scope of this proposed standard 
could strain OSHA's limited resources to the 
detriment not only of the ergonomics 
rulemaking but to other OSHA priorities as 
well, including other priorities for the 
construction, maritime and agricultural 
industries.
   On the other hand, focusing on areas where 
a large body of evidence of effective 
ergonomics programs and control interventions 
exists should help OSHA to respond quickly to 
urgent situations where worker protection is 
needed now. Limiting the scope of the 
proposed rule at this time is thus fully 
consistent with OSHA's obligations under 
section 6(g).
   By contrast, in agriculture, construction 
and maritime, the information on ergonomics 
programs and interventions is more limited. 
Only now is NIOSH conducting a study on 
ergonomic problems and interventions in the 
shipyard

[[Page 65788]]

industry, and the results of that study are 
not expected for more than a year.


How Does This Standard Apply to Me? 
(Secs. 1910.905-1910.910)

   OSHA's proposed ergonomics program 
standard has several unique features. First, 
it is a job-based standard. As the preamble 
sections for 1910.901 through 1910.904 of the 
proposed standard make clear, the standard 
applies to general industry employers whose 
employees: (1) Work in manual handling jobs; 
(2) work in manufacturing jobs; and (3) work 
in other general industry jobs and experience 
a musculoskeletal disorder (MSD) that is 
covered by this standard. Second, employers 
within the scope of the standard are required 
only to implement the ergonomics program 
required by the standard for those jobs 
specifically listed above; they are not 
required to have a program for all of the 
jobs in their workplace. Third, the 
requirements of the standard apply 
differently to different general industry 
employers, because the standard is also risk 
based. That is, for employers whose employees 
perform manual handling or manufacturing 
jobs--jobs which together account for a 
disproportionate share (60%) of all reported 
work-related MSDs--employers are required to 
implement only those elements of the proposed 
standard that will prepare them to deal with 
a covered MSD should one occur. Thus, 
employers whose employees work in these high-
risk jobs must put several of the required 
program elements in place even before their 
employees experience a covered MSD, because 
the likelihood that they will do so is great. 
If an employee in a manual handling or 
manufacturing job subsequently experiences a 
covered MSD, the employer would then be 
required to implement the remaining elements 
of the ergonomics program required by the 
standard, including job hazard analysis and 
control, MSD management, training, and 
program evaluation.
   For general industry employers without 
manual handling or manufacturing jobs in 
their workplace, however, the proposed 
standard would not require action until an 
employee actually experiences such an MSD. In 
other words, for general industry employers 
with other types of jobs, the event that 
``triggers'' coverage by the standard is the 
occurrence of an MSD that the employer 
determines to be covered. As explained above 
in the summary and explanation for sections 
1910.901 through 1910.904, such an MSD could 
occur in any general industry job, e.g., 
grocery store cashier, newspaper reporter, 
secretary, cafeteria worker, restaurant 
server, computer programmer, mail sorter, 
janitor, etc. Relying on the occurrence of a 
covered MSD to trigger the standard's 
coverage for non-manual handling, non-
manufacturing jobs is consistent with the 
risk-based design of the standard: The 
occurrence of an MSD that is determined by 
the employer to be, first, an OSHA-recordable 
MSD, second, an MSD that has occurred in a 
job in which the physical work activities are 
reasonably likely to cause or contribute to 
the type of MSDs reported, and third, an MSD 
that has occurred in a job where the physical 
work activities and conditions are a core 
element of the job and/or make up a 
significant amount of the employee's 
worktime. The scope provisions of the 
standard (sections 1910.901 through 1910.904) 
also indicate that employers whose employees 
engage in construction, agricultural, or 
maritime operations are not covered by the 
scope of the rule.
   Sections 1910.905 through 1910.910 of the 
proposed standard, titled ``How does this 
standard apply to me?,'' determine how 
various elements of the proposal would apply 
to these three different groups of general 
industry employers, depending on the jobs 
their employees perform and/or whether their 
employees experience a musculoskeletal 
disorder that is covered by the standard. 
These sections of the proposal thus contain 
the internal ``action levels'' or 
``triggers'' that OSHA has built into the 
standard to tailor its requirements to the 
extent of the ergonomics problem present in a 
given workplace.
   Specifically, these sections of the 
proposal contain the following requirements:
    Section 1910.905 describes the 
elements of a complete ergonomics program;
    Section 1910.906 establishes the 
requirements of the program that apply to all 
general industry employers that have manual 
handling or manufacturing production jobs in 
their workplaces;
    Section 1910.907 sets forth the 
requirements of the rule applying to general 
industry employers whose employees experience 
a covered MSD in jobs other than manual 
handling or manufacturing;
    Section 1910.908 establishes the 
criteria general industry employers wishing 
to avail themselves of the proposed 
standard's ``grandfather'' clause must meet 
in order to qualify for grandfather status;
    Section 1910.909 provides general 
industry employers with a Quick Fix option, 
which would allow them to avoid setting up an 
ergonomics program for any problem job that 
they can fix completely within a short period 
of time, provided that they also meet the 
other requirements delineated in this 
section; and
    Section 1910.910 specifies the 
requirements applying to employers whose 
Quick Fix controls have not eliminated MSD 
hazards in the problem jobs they tried to 
address through the Quick Fix option.
   The following paragraphs explain OSHA's 
rationale for each of these sections of the 
proposed rule.
   Section 1910.905  What are the elements of 
a complete ergonomics program?

  In this standard, a full ergonomics program 
consists of these six program elements:
   Management Leadership and Employee 
Participation;
   Hazard Information and Reporting;
   Job Hazard Analysis and Control;
   Training;
   MSD Management; and
   Program Evaluation.

   OSHA is proposing in this standard that 
employers implement an ergonomics program 
that contains well-recognized program 
elements. OSHA is not alone in believing that 
all of these core elements are essential to 
the effective functioning of ergonomics 
programs. Many private sector companies, OSHA 
stakeholders, insurers, employee and employer 
associations, safety and health 
professionals, and other Federal agencies 
(e.g., NIOSH, GAO) have endorsed these 
elements as key to ergonomic program 
effectiveness. Evidence of the widespread 
acceptance of these program elements and 
their effectiveness is reflected in the 
following documents, regulatory actions, and 
sources of expert opinion: 1
---------------------------------------------------------------------------
  \1\ There is no provision for WRP in the 
OSHA safety and health program guidelines, 
state safety and health programs, nor the 
ASSE program; of these, the OSHA guidelines 
and ASSE program are voluntary.

---------------------------------------------------------------------------

[[Page 65789]]

    They track OSHA's 1989 voluntary 
Safety and Health Program Management 
Guidelines (54 FR 3904), which were well 
received and widely adopted by employers and 
other stakeholders;
    State safety and health program 
regulations, most of which address ergonomic 
issues. Of the 32 states that encourage or 
mandate workplace safety and health programs, 
21 have provisions corresponding to the core 
elements in this proposal;
    OSHA's Ergonomics Program 
Management Guidelines for Meatpacking Plants 
(Ex. 2-13 ), which includes all of these core 
elements. Facilities that have developed 
programs based on the meatpacking guidelines 
have experienced dramatic reductions in the 
severity and number of MSDs (Ex. 26-1420);
    Consensus among occupational 
safety and health professionals that these 
are the elements needed in an effective 
safety and health program. (see, e.g., the 
American Society of Safety Engineers Safety 
and Health Program Manual). The core elements 
in this proposal are also similar to the 
components in the approach used by the 
Accredited Standards Committee in developing 
the draft consensus standard, ``Control of 
Cumulative Trauma Disorders'' for the 
American National Standards Institute (Z-
365);
    A study by the General Accounting 
Office of ergonomics programs, which found 
that effective programs include the same set 
of core elements as OSHA has proposed; and
    The 1997 NIOSH document titled 
``Element of Ergonomics Programs,'' which 
outlines the ``approach most commonly 
recommended for identifying and correcting 
ergonomic problems.'' Thus, OSHA finds that 
these elements are the ones needed for an 
effective ergonomics program and represent 
the tried and true mainstream approach to 
ergonomic programs.
   The core elements in this proposal will 
allow employers to manage all aspects of the 
process of protecting workers from MSDs and 
are a way of organizing that process into 
parts that can be meaningfully understood and 
implemented. All of the elements are 
important, although many safety and health 
professionals believe that management 
leadership and employee participation are the 
keystone of an effective ergonomics program 
(OSHA/NIOSH conference 1997). OSHA believes 
that all of the elements are necessary to 
achieve the overall goal of managing MSDs and 
ensuring that MSD hazards are systematically 
and routinely prevented, eliminated, or 
controlled.
   Many OSHA stakeholders and respondents to 
the ergonomics ANPR published in 1992 (57 FR 
34192) have endorsed the program approach. 
For example, the M & M Protection Center (Ex. 
3-51) stated: ``Generic components described 
in the ANPR and in the Meat Packing 
Guidelines are feasible and necessary 
elements of an ergonomic hazards control 
strategy. These form a practical foundation 
from which to build a more industry-specific 
program.''
   Another commenter, Arvin Industries, Inc. 
(Ex. 3-46) emphasized the value of the 
program approach to companies engaged in 
different businesses:

  The use of the * * * [program] approach has 
been shown to provide effective solutions and 
a significant reduction in ergonomics hazards 
in jobs in many different industries.

   Employees, represented by the AFL-CIO (Ex. 
3-184), urged OSHA to include all of the 
program elements in the Meatpacking 
Guidelines in any future ergonomics standard:

  The AFL-CIO strongly supports the inclusion 
of the listed elements in OSHA's proposed 
ergonomics standard.

   OSHA has been responsive to these 
commenters by including the six core elements 
listed above in the ergonomics program 
required by the proposed standard for jobs 
where the hazards present are such as to pose 
a reasonable likelihood of lending to a 
covered MSD, or have already caused or 
contributed to such an MSD.
   The summary and explanation sections of 
the preamble for each program element 
describe OSHA's reasoning for including each 
element in the proposed program.
   Section 1910.906  How does this standard 
apply to manufacturing and manual handling 
jobs?
  You must:
  a. Implement the first two elements of the 
ergonomics program (Management Leadership and 
Employee Participation, and Hazard 
Information and Reporting) even if no MSD has 
occurred in those jobs.
  b. Implement the other program elements 
when either of the following occurs in those 
jobs (unless you eliminate MSD hazards using 
the Quick Fix option in section 1910.909):
  1. A covered MSD is reported; or
  2. Persistent MSD symptoms are reported 
plus:
  i. You have knowledge that an MSD hazard 
exists in the job;
  ii. Physical work activities and conditions 
in the job are reasonably likely to cause or 
contribute to the type of MSD symptoms 
reported; and
  iii. These activities and conditions are a 
core element of the job and/or make up a 
significant amount of the employer's 
worktime.
  Note To Sec. 1910.906: ``Covered MSD'' 
refers to MSDs that meet the criteria in 
Sec. 1910.901(c). As it applies to 
manufacturing and manual handling jobs, 
``covered MSDs'' also refers to persistent 
symptoms that meet the criteria of this 
section.

   This section of the rule sets out the 
requirements applying to general industry 
employers whose employees perform the high-
risk jobs of manual handling or product 
manufacturing. As discussed in the Risk 
Assessment and Benefits chapter of the 
preamble and Preliminary Economic Analysis, 
respectively, these two jobs account for 60% 
of all reported general industry MSDs but 
employ only 28% of all general industry 
employees. Section 1910.901(a) defines 
manufacturing jobs as production jobs in 
which employees perform the physical work 
activities of producing a product and in 
which these activities make up a significant 
amount of their worktime, and section 
1910.902(b) defines manual handling jobs as 
those in which employees perform forceful 
lifting/lowering, pushing/pulling, or 
carrying and in which such forceful manual 
handling is a core element of the employee's 
job.
   Examples of jobs that are typically 
manufacturing jobs include assembly line 
jobs, product inspection jobs, and jobs 
involving machine operation, meat packing, 
and tire building, among others. Examples of 
manual handling jobs are those involving 
patient handling, baggage handling, grocery 
store stocking, garbage collecting, and 
janitorial work, among others. Examples of 
other jobs that would typically be considered 
manual handling or manufacturing jobs, and 
examples of those that would not be so 
classified, can be found in proposed section 
1910.945, Definitions.
   Paragraphs (a) and (b) of section 1910.906 
mandate that employers whose operations 
involve manual handling or manufacturing 
jobs, as defined by the proposed standard, 
implement the first two elements of the 
ergonomics program required by the standard 
in these jobs. These elements are:

[[Page 65790]]

(1) Management leadership and employee 
participation, and (2) hazard information and 
reporting. Each general industry employer 
whose operations involve either or both of 
these types of jobs would be required to 
implement these two program elements in these 
jobs within one year of the standard's 
effective date (see proposed section 
1910.942). Compliance with these two elements 
is required even if no employee in these jobs 
has experienced a covered MSD. As discussed 
above, OSHA is requiring that these basic 
elements of an ergonomics program be in place 
in these jobs because of the high-risk nature 
of the physical work activities associated 
with these jobs. Having these elements in 
place ensures that employers and employees 
are informed and aware of MSD hazards and the 
signs and symptoms of MSDs and have 
established the management structure and 
employee participation mechanisms necessary 
to respond quickly if the need arises.
   This section of the proposal also requires 
employers with manual handling or 
manufacturing jobs to comply with the other 
elements of an ergonomics program, including 
MSD management, job hazard analysis and 
control, training, and program evaluation, if 
an employee in a manual handling or 
manufacturing job experiences an MSD that the 
employer determines, in accordance with 
proposed sections 1910.901 (c) and 1910.902, 
to be covered by the proposed standard. As 
explained in the summary and explanation for 
those sections, a covered MSD, as defined by 
this standard, is one that occurs after the 
effective date of the standard, is an OSHA-
recordable MSD (as defined by OSHA's 
recordkeeping rule, 29 CFR part 1904), and is 
determined by the employer to have occurred 
in a job in which the physical work 
activities and conditions are reasonably 
likely to have caused or contributed to the 
type of MSD reported, or to have aggravated a 
pre-existing MSD. For manufacturing or manual 
handling jobs, it is important to note that 
covered MSDs also include: (1) Reports by 
employees of persistent symptoms of MSDs 
(persistent is defined as lasting for 7 
consecutive days), (2) where the employer has 
knowledge that such jobs pose MSD hazards to 
employees, (3) where the job is one in which 
the physical work activities and conditions 
of the job are reasonably likely to cause or 
contribute to the type of MSD reported, and 
(4) where the activities and conditions are a 
core element of the job and/or make up a 
significant amount of the employee's 
worktime. By ``have knowledge,'' OSHA means 
that the employer has been provided with 
information that MSD hazards exist in that 
job by personnel from an insurance company, 
or by a consultant, a health care 
professional, or a person working for the 
employer who has the requisite training to 
identify and analyze MSD hazards. Inclusion 
of this action trigger in the proposed 
standard is consistent with OSHA's risk-based 
approach, because the occurrence of 
persistent symptoms, such as constant pain, 
tingling, or numbness, coupled with 
information from a knowledgeable source that 
the employee's job is one that poses an 
ergonomic hazard, is strong evidence that the 
job is one that is reasonably likely to cause 
or contribute to a covered MSD. OSHA believes 
that employers generally accept and rely on 
information from these sources because they 
are perceived of as unbiased, knowledgeable, 
and aware of conditions in the employer's 
specific workplace.
   Section 1910.906 of the proposal would 
allow employers whose work involves 
manufacturing or manual handling operations 
to limit their ergonomics program for those 
jobs to two elements, management commitment/
employee participation, and hazard 
information and reporting, until a problem 
job (i.e., one held by an employee who has 
experienced a covered MSD, or a job in the 
workplace that has the same physical 
activities and conditions as the job held by 
such an employee) has been identified. If no 
covered MSD occurs in the manufacturing or 
manual handling job, the employer is not 
required to implement the other elements of 
the program.
   By requiring employers whose employees 
work in manual handling or manufacturing jobs 
to implement the first two elements of an 
ergonomics program even before a covered MSD 
occurs among the employees in that job, OSHA 
is requiring these employers to establish a 
basic surveillance system for MSDs. This 
basic system consists, under the management 
leadership element, of assigning 
responsibilities for the ergonomics program 
to managers, supervisors, and employees so 
that these individuals know what their role 
in the program is, providing these 
individuals with the information, resources, 
information and training they need to carry 
out these responsibilities effectively, and 
communicating with employers on a regular 
basis about the program and their concerns 
about ergonomics issues. In addition, the 
employer must, as part of management 
leadership, make sure that its existing 
policies and procedures do not discourage 
employee reporting of MSDs or participation 
in the program. By following these 
requirements, employers will have established 
the management process necessary to a 
functioning ergonomics program: management at 
the workplace will have a basic system in 
place to ensure that employee concerns about 
MSDs are being expressed and responded to, 
program responsibilities are understood, 
resources have been made available to the 
program, and no barriers stand in the way of 
early and full employee reporting.
   The employee participation component of 
this first program element is the other side 
of the basic surveillance system the standard 
requires employers with these two kinds of 
high-risk jobs to implement. To comply with 
the employee participation provisions of the 
standard, employers must set up a way for 
employees and their designated 
representatives to report MSD signs and 
symptoms to the employer, receive prompt 
responses to these reports, have access to a 
copy of the ergonomics standard (either 
through posting or by providing hand copies 
to employees) and to information about the 
employer's ergonomics program, and ways to 
participate in the development, 
implementation, and evaluation of the 
ergonomics program.
   By implementing these provisions, the 
second half of the first program element will 
be put in place: employees will know how to 
report MSDs and their signs and symptoms, 
they will expect to receive responses to 
those reports from management, they will 
understand their employers' ergonomics 
program, and they will know how they can 
participate effectively in making the program 
a success.
   Section 1910.906 also requires, at 
paragraph (b), that employers with these jobs 
comply with all of the other elements of an 
ergonomics program--job hazard analysis and 
control, MSD management, training, and 
program evaluation--if a covered MSD occurs 
in a manual handling or manufacturing job. 
(As discussed above, for these jobs, 
persistent MSD symptoms are considered 
covered MSDs if they also meet the criteria 
specified in paragraph (b)(2) of this 
section.) There is one exception to 
compliance with paragraph (b) of this 
section: employers who choose the proposed 
rule's Quick Fix option (described below) do 
not have to implement the other program 
elements.
   Section 1910.907  How does this standard 
apply to other jobs in general industry?


[[Page 65791]]


  In other jobs in general industry, you must 
comply with all of the program elements in 
the standard when a covered MSD is reported 
(unless you eliminate the MSD hazards using 
the Quick Fix option).

   As discussed earlier in this section of 
the preamble, employers with other jobs 
(i.e., jobs that do not involve either 
manufacturing or manual handling) are not 
required by the proposed rule to take any 
action until and unless a covered MSD occurs 
in such a job. Thus, for most employers in 
general industry in a given year, no action 
is required by the standard. However, if a 
covered MSD occurs in one of these ``other'' 
jobs, it becomes a ``problem job,'' as 
defined in the standard, and the full 
ergonomics program must be implemented for 
that job and all jobs in the workplace that 
involve the same physical work activities.
   OSHA has included section 1910.907 in the 
proposed standard to provide employees who 
have experienced a covered MSD in these other 
jobs with the same program protections 
afforded to manual handling and manufacturing 
employees who have suffered a covered MSD.
   Section 1910.908  How does this standard 
apply if I already have an ergonomics 
program?

  If you already have an ergonomics program 
for the jobs this standard covers, you may 
continue that program, even if it differs 
from the one this standard requires, provided 
you show that:
  a. Your program satisfies the basic 
obligation section of each program element in 
this standard, and you are in compliance with 
the recordkeeping requirements of this 
standard (Secs. 1910.939 and 1910.940);
  b. You have implemented and evaluated your 
program and controls before [the effective 
date]; and
  c. The evaluation indicates that the 
elements are functioning properly and that 
you are in compliance with the control 
requirements in Sec. 1910.921.

   This section of the proposed standard is a 
limited grandfather clause that is designed 
to permit employers who have already 
implemented and evaluated an ergonomics 
program in those jobs covered by the standard 
to continue their program, if: it has been 
shown to eliminate or materially reduce MSD 
hazards according to Sec. 1910.921, it has 
the core elements of the program OSHA is 
requiring, and it meets the basic obligation 
of each of the core elements in the proposed 
rule.
   By requiring that grandfathered programs 
meet the conditions set out in paragraphs (a) 
through (c) of section 1910.908, OSHA is 
affirming the importance of each of the core 
elements, as well as recordkeeping, to the 
proper functioning of an effective ergonomics 
program. OSHA is also emphasizing the 
importance the Agency places on the basic 
obligation sections of the proposed standard 
(sections 1910.911, 1910.914, 1910.917, 
1910.923, 1910.929, and 1910.936). These 
sections establish the basic requirements 
employers must follow to implement each core 
element but do so in less detail than the 
implementing requirements that follow the 
basic obligation section for each core 
element. OSHA believes that the requirements 
identified in the basic obligations sections 
of the proposal are the minimum requirements 
needed to effectively implement the core 
element to which they pertain. In other 
words, although OSHA is proposing to grant 
grandfather status to effective ergonomics 
programs, it believes that the requirements 
set forth in each basic obligation section 
must be present in an ergonomics program for 
that element to be effective. Thus, employers 
whose existing programs meet the conditions 
of the limited grandfather clause in section 
1910.908 are free not to implement the more 
detailed provisions that follow the basic 
obligation section, provided that they comply 
fully with the basic obligation section's 
provisions.
   OSHA has several reasons for including the 
standard's core elements in any ergonomics 
program that is grandfathered in under the 
standard. OSHA's reasoning is discussed 
below.
   First, except for WRP, the core elements 
(management leadership and employee 
participation, hazard identification and 
assessment, hazard prevention and control, 
MSD management, training, and evaluation) are 
included in the safety and health programs 
recommended or used by many different 
organizations (the ergonomics standard uses 
slightly different terminology for some of 
these elements):
    OSHA's VPP, SHARP, and 
consultation programs;
    The safety and health programs 
mandated by 18 states;
    The safety and health programs 
recommended by insurance companies for their 
insureds (many of which give premium 
discounts for companies that implement these 
programs or impose surcharges on those that 
do not);
    The safety and health programs 
recommended by the National Federation of 
Independent Business, the Synthetic Organic 
Chemical Manufacturers Association, the 
Chemical Manufacturers Association, the 
American Society of Safety Engineers, and 
many others;
    The strong recommendations of 
OSHA's Advisory Committees (NACOSH, ACCSH, 
and MACOSH), which consider these program 
elements essential to effective worker 
protection programs.
   Second, OSHA believes, and most 
stakeholders agree, that enforcement of the 
standard will be more consistent and more 
equitable, as well as less time-consuming, 
for employers and compliance officers alike, 
if the test of an employer's program is 
whether the program contains the core 
elements, rather than whether it is 
effective. The term effectiveness is subject 
to many different interpretations. 
Effectiveness can be measured in many 
different ways (e.g., decreases in the number 
of MSDs, decreases in the severity of MSDs, 
increases in product quality, decreases in 
insurance premiums, decreases in the number 
of claims, decreases in turnover, decreases 
in absenteeism, increases in productivity, 
increases in the number of MSDs reported 
early, etc.), several of which have built-in 
incentives to discourage reporting of MSDs 
(as discussed in the Significance of Risk 
(Section VII) section of the preamble, 
underreporting of MSDs is already extensive. 
In addition, there are no data that would 
allow OSHA to evaluate or to choose among 
these various effectiveness measures. OSHA 
solicits comments on measures of program 
effectiveness that are not susceptible to 
underreporting and that can be used reliably 
and simply by establishments of all sizes. 
For example, are there measures of 
effectiveness that OSHA could use as a 
measure of effectiveness when determining 
whether to allow a program to be 
grandfathered in?
   In addition, evaluating programs using the 
core elements test is administratively 
simpler, both for OSHA personnel and 
employers. The Agency is in the process of 
validating a measurement tool for compliance 
officers and employers to use in assessing 
the effectiveness of ergonomics programs. 
This tool, which is based on the consultation 
program's Form 33, has been tested for face 
validity and is being tested for construct 
validity at the present time; OSHA intends to 
disseminate it to employers, so that both 
OSHA personnel and employers will be 
operating from the same ``sheet of music.'' 
OSHA believes that use of a tool based on the 
core

[[Page 65792]]

elements rather than on unproven measures of 
effectiveness will thus benefit OSHA, 
workers, and their employers.
   OSHA is including WRP, or equivalent 
protections against wage loss, as a 
requirement for all programs because, without 
it, OSHA believes that there will be 
increased pressure on employees not to report 
once an enforceable standard is in place. 
There is strong evidence that such 
underreporting is currently taking place (see 
the table summarizing the many articles on 
this topic in Section VII of the preamble), 
as well as evidence that protecting workers 
from wage loss increases reporting (the 
Krueger studies). OSHA's purpose in proposing 
a WRP provision in this standard is to ensure 
employee participation and free and full 
reporting of MSDs and MSD hazards. The 
ergonomics standard depends, more heavily 
than any OSHA health standard promulgated to 
date, on employee reporting for its 
effectiveness. Absent such reporting, the 
standard will not achieve its worker 
protection goals. The success of the 
standard, like that of the many effective 
ergonomics programs our stakeholders have 
told us about, depends on it.
   The proposed grandfather clause is also 
limited in its applicability to programs that 
are in place and have been evaluated and 
found to be working properly by the effective 
date of the standard. OSHA believes that this 
provision is appropriate because it will 
encourage employers to be proactive and 
establish programs to protect their employees 
before the effective date. It will require 
these programs to have been evaluated before 
they qualify for grandfather status, which 
will avoid a last minute rush to implement 
programs before the effective date and ensure 
that those programs allowed under the 
grandfather clause are mature, fully 
functioning programs. It will also avoid the 
administrative and compliance problems that 
would arise if OSHA permitted employers to 
establish ergonomics programs that differ 
from the one in the standard even after the 
effective date.
   OSHA seeks comment on all aspects of the 
grandfather clause provisions, particularly 
on the protectiveness and appropriateness of 
including such a provision in a final 
standard.
   Section 1910.909  May I do a Quick Fix 
instead of setting up a full ergonomics 
program?

  Yes. A Quick Fix is a way to fix a problem 
job quickly and completely. If you eliminate 
MSD hazards using a Quick Fix, you do not 
have to set up the full ergonomics program 
this standard requires. You must do the 
following when you Quick Fix a problem job:
  (a) Promptly make available the MSD 
management this standard requires;
  (b) Consult with employee(s) in the problem 
job about the physical work activities or 
conditions of the job they associate with the 
difficulties, observe the employee(s) 
performing the job to identify whether any 
risk factors are present, and ask employee(s) 
for recommendations for eliminating the MSD 
hazard;
  (c) Put in Quick Fix controls within 90 
days after the covered MSD is identified, and 
check the job within the next 30 days to 
determine whether the controls have 
eliminated the hazard;
  (d) Keep a record of the Quick Fix 
controls; and
  (e) Provide the hazard information this 
standard requires to employee(s) in the 
problem job within the 90-day period.

  Note to Sec. 1910.909: If you show that the 
MSD hazards only pose a risk to the employee 
with the covered MSD, you may limit the Quick 
Fix to that individual employee's job.

   OSHA is permitting employers who meet all 
the requirements of this section to refrain 
from setting up the full ergonomics program 
otherwise required. For example, employers 
can avoid the training and program 
requirements of the standard if they can 
eliminate the MSD hazard in the problem job 
(including other jobs meeting the ``same 
job'' definition in the standard) quickly.
   The Quick Fix option is designed for those 
problem jobs where the hazard can be readily 
identified, the solution is obvious, and the 
solution can be implemented within 90 days 
after the covered MSD is identified. OSHA has 
heard repeatedly from stakeholders and others 
that a large number of jobs will fall into 
this category. The proposed Quick Fix process 
differs from the job hazard analysis and 
control process described in sections 
1910.917 through 1910.922, which is 
appropriate for MSD hazards and jobs 
requiring iterative changes or extensive 
analysis to resolve.
   The proposed rule requires that employees 
in problem jobs receive MSD management, 
including work restriction protection, for 
their injuries without regard to whether the 
job is controlled using the Quick Fix option 
or the full job hazard analysis and control 
approach. In addition, employee(s) in problem 
jobs that are fixed through the Quick Fix 
process must be involved in the Quick Fix 
process, just as they are involved in the 
full job hazard analysis and control process. 
In other words, employers choosing the Quick 
Fix option must demonstrate management 
leadership and implement employee 
participation for the problem job, but would 
not have to continue these elements after the 
job is fixed (unless they are employers with 
manual handling or manufacturing jobs).
   The Quick Fix controls must be implemented 
within 90 days to qualify for this option. 
OSHA believes that this period is sufficient 
for employers to identify appropriate 
engineering controls, to eliminate the MSD 
hazards entirely, and to order and implement 
those controls. Again, this time period is 
consistent with the principal concept behind 
Quick Fix: that the problem job be fixed 
quickly, simply and completely. Examples of 
Quick Fixes include purchasing an adjustable 
VDT workstation, placing a box under the work 
surface of an employee who must bend down to 
see the work, and tilting the work surface 
toward the employee to prevent long reaches.
   As stated in paragraph (b) of this 
section, if the employer can demonstrate that 
the MSD hazard that caused or contributed to 
the MSD only poses a risk to the particular 
employee with the MSD, the employer may limit 
the Quick Fix to that individual employee's 
job. In other words, in this limited case, 
the employer would not be required to fix the 
jobs of others in the problem job, because 
the hazard is one unique to the employee 
rather than the job. For example, a very tall 
employee might only need to have the work 
surface raised, and a very small employee 
might only need to have the work surface 
repositioned closer to his or her body.
   Paragraph (c) of section 1910.109 requires 
employers using the Quick Fix option to 
evaluate the controls within 30 days to be 
sure that they have eliminated the hazard. 
One of the best ways to determine whether the 
Quick Fix has worked is to ask the injured 
employee. Employers typically can tell almost 
immediately that the MSD hazard has been 
eliminated; however, it may take a week or 
two for the symptoms to resolve.
   NIOSH recommends that employers wait a 
minimum of two weeks before evaluating 
control effectiveness, because employees need 
time to acclimate to the changes. NIOSH

[[Page 65793]]

also recommends, and the proposed standard 
would require, that employers not wait longer 
than 30 days to evaluate controls, to enable 
changes to be made if they are not working.
   Paragraph (d) of section 1910.909 requires 
employers who avail themselves of this option 
to keep records of the Quick Fix controls 
they implement. This means that employers 
must document the controls they have 
implemented, when they are implemented, and 
the results of the 30-day evaluation. These 
records are essential to document the 
employer's choice of this option and to 
support the employer's decision not to 
implement the other components of the 
ergonomics program.
   Section 1910.910  What must I do if the 
Quick Fix does not work?

  You must set up the complete ergonomics 
program if either of these occurs:
  (a) The Quick Fix controls do not eliminate 
the MSD hazards within the Quick Fix deadline 
(within 120 days after the covered MSD is 
identified); or
  (b) Another covered MSD is reported in that 
job within 36 months.
  Exception: If a second covered MSD occurs 
in that job resulting from different physical 
work activities and conditions, you may use 
the Quick Fix a second time.

   This section requires employers who have 
chosen the Quick Fix option but have not been 
successful in eliminating the MSD hazards in 
the job to implement the full ergonomics 
program. The employer must implement the full 
ergonomics program for a job either where the 
Quick Fix fails to eliminate MSD hazards 
within 120 days, or if another covered MSD 
occurs in that job within 36 months after 
implementing the Quick Fix.
   This paragraph of the proposed standard 
contains an exception: where an employer has 
implemented a Quick Fix in a job and another 
covered MSD occurs in that job, the employer 
may may use the Quick Fix approach a second 
time if the second covered MSD is one caused 
or contributed to by work activities that are 
different from those that caused or 
contributed to the first covered MSD in that 
job. The exception to section 1910.910 would 
apply when, for example, a particular job 
requires the employee to perform a 
manufacturing assembly or data entry job for 
a significant amount of their worktime and 
also to perform forceful lifting as a core 
element of the job. In such a situation, an 
employee in that job could experience a case 
of carpal tunnel syndrome, and the employer 
could use a Quick Fix to control the MSD 
hazard. If any employee in the same job 
subsequently (e.g., 2 years later) develops a 
lower back injury, the exception to section 
1910.910 would permit the employer to use a 
Quick Fix to address the manual handling 
hazard. However, the proposed standard would 
only permit the Quick Fix option to be used 
twice in the same job because, if covered 
MSDs continue to occur in the same job, job 
hazard analysis and control, as well as the 
other provisions of the full program, must be 
implemented.
   Evidence of the failure of the Quick Fix 
approach could take two forms: the evaluation 
performed within 30 days of the 
implementation of the Quick Fix reveals that 
the control has not eliminated the hazard 
(e.g., the employee reports that his/her 
signs or symptoms have worsened) or an 
employee in that job suffers a covered MSD to 
which the exception does not apply. Where the 
Quick Fix option has failed, the employer 
would be required to move into the full 
program, i.e., job hazard analysis and 
control, training, and program evaluation.


Management Leadership and Employee 
Participation (Secs. 1910.911-1910.913)

   Sections 1910.911-913 of the proposed 
standard describe and explain the proposed 
requirements for the management leadership 
and employee participation element of the 
Ergonomics Program standard. These two 
program components are critical to the 
successful implementation of an ergonomics 
program in any workplace. The importance of 
management leadership is well-recognized 
(Exs. 26-17; 26-10; 26-27; 26-22; 26-18; 26-
13; 26-14). Likewise, the importance of 
employee participation in ergonomics program 
success is also well-documented (Exs. 26-30; 
26-17; 26-4; 26-21; 26-19; 26-10; 26-15; 26-
16; 26-20; 26-27; 26-22; 26-11; 26-12; 26-18; 
26-13; 26-14).
   Management leadership and employee 
participation are complementary (Exs. 2-12; 
2-13). Management leadership and commitment 
provides the motivating force and the 
resources for organizing and controlling 
activities within an organization (Ex. 2-12). 
In effective ergonomics programs, management 
regards the protection of employee health and 
safety as a fundamental value of the 
organization, and incorporates objectives for 
the success of this program into its broader 
company goals (Ex. 2-12). Employee 
participation provides the means through 
which workers develop and express their own 
commitment to safe and healthful work, as 
well as sharing in the overall success of the 
company (Ex. 2-12).
   OSHA has decided to include a management 
leadership component in its proposed 
Ergonomics Program standard because the 
importance of management leadership has been 
emphasized throughout the literature on 
ergonomics programs (Exs. 2-13; 26-2; 26-5; 
26-9; 26-17; 26-10; 26-27; 26-22; 26-18; 26-
13; 26-14). For example, OSHA's Ergonomics 
Program Management Guidelines for Meatpacking 
Plants (``Meatpacking Guidelines'') states 
that an ``effective ergonomics program 
includes a commitment by the employer to 
provide the visible involvement of top 
management, so that all employees, from 
management to line workers, fully understand 
that management has a serious commitment to 
the program'' (Ex. 2-13, p. 2). NIOSH also 
emphasizes management commitment in its 
primer, Elements of Ergonomics Programs (Ex. 
26-2). According to NIOSH, the ``occupational 
safety and health literature stresses 
management commitment as a key and perhaps 
controlling factor in determining whether any 
worksite hazard control effort will be 
successful'' (Ex. 26-2, p. 6). Adams (Ex. 26-
9, p. 182) states simply that ``to launch an 
ergonomics process, management support is 
key.'' In its report titled, ``Worker 
Protection: Private Sector Ergonomics 
Programs Yield Positive Results,'' the 
Government Accounting Office (GAO) also found 
management commitment to be a key component 
for program success (Ex. 26-5). The GAO found 
that ``management commitment demonstrates the 
employer's belief that ergonomic efforts are 
essential to a safe and healthy work 
environment for all employees' (Ex. 26-5, 
letter:3.1).
   In response to questions raised in OSHA's 
Advance Notice of Proposed Rulemaking (ANPR) 
(Ex. 1), a number of comments were received 
that addressed the issue of management 
commitment for a successful ergonomics 
program (Exs. 3-136; 3-173; 3-124; 3-27). For 
example, the American Automobile 
Manufacturers Association stated that an 
ergonomics program should incorporate 
``employer commitment in writing to health 
and safety,'' and that management commitment 
is an ``essential part of any

[[Page 65794]]

successful program'' (Ex. 3-173, p. 2). Ms. 
Anne Tramposh, Vice President of Advantage 
Health Systems, Inc., also wrote of the 
importance of management commitment (Ex. 3-
124, p. 5). She stated:

  At the risk of over-generalizing this 
issue, we have found that companies lacking 
management commitment will not truly 
implement the comprehensive multi-
disciplinary program approach that is needed 
to address the ``Ergonomic Disorders'' 
problem. These companies tend to look for 
band-aids, not solutions.
  On the other hand, companies with strong 
top management commitment, that literally 
cringe at [the] thought that they may be 
injuring their employees, will seek the root 
causes of the problem. They will dedicate 
financial and personnel resources to the 
program. They will not quit when the ``going 
gets tough'' and more employees are reporting 
injuries (at the beginning of a program).
  Any standard or regulation for this problem 
must ensure top management commitment. The 
Ergonomic Disorder problem will not go away 
without it.

Another statement of support for management 
commitment was provided by Mr. Stephen 
Rohrer, Section Head, EG&G Energy 
Measurements, Inc. (Ex. 3-27). In explaining 
the ergonomics program at his company, Mr. 
Rohrer stated, ``[O]ne of the key components 
of the program was obtaining upper management 
support for ergonomics. This was accomplished 
by a policy statement placing ergonomics at 
the same level of importance as the company's 
production processes' (Ex. 3-27, p. 2).
   OSHA believes that employee participation 
is as important for program success as 
management leadership. OSHA's Meatpacking 
Guidelines (Ex. 2-13) recommend employee 
involvement as essential to the 
identification of existing and potential 
hazards and the development and 
implementation of effective hazard abatement. 
NIOSH found that promoting employee 
participation to improve workplace conditions 
has several benefits, including: enhanced 
worker motivation and job satisfaction; added 
problem-solving capabilities; greater 
acceptance of change; and greater knowledge 
of the work and organization (Exs. 26-2; 26-
4). Employee participation also helps to 
secure employee buy-in to the ergonomics 
program.
   Section 8 of the OSH Act also recognizes 
the value of employee involvement in 
workplace safety and health. For example, 
this section of the Act spells out specific 
requirements for employee involvement in the 
observation of employee monitoring to 
identify employee exposure to workplace 
hazards, obtaining and reviewing records, 
receiving information, and reporting hazards.
   Active employee participation is 
especially important in the proposed 
Ergonomics Program standard because this 
standard, more than most OSHA standards, 
depends for its effectiveness on the 
voluntary reporting of MSD signs and symptoms 
by employees. To ensure that employees 
voluntarily participate when the signs and 
symptoms of MSDs first arise, OSHA believes 
they must be active participants in program 
development, implementation, and evaluation, 
and must be sure that they will not be 
discriminated against for such participation 
(see the discussion of proposed section 
1910.911 below). Also, when it came to the 
issue of employee participation, many of 
OSHA's stakeholders said that this element is 
essential to program success (Exs. 26-23; 26-
24).
   Additionally, OSHA received many comments 
in response to its ANPR that support the idea 
of employee participation in ergonomics 
programs (Exs. 3-27; 3-66; 3-94; 3-96; 3-98; 
3-124; 3-136; 3-155; 3-173). For example, Mr. 
James Torgerson, Director-Corporate Safety, 
Sara Lee Corporation, stated (Ex. 3-66, p. 
4):

  Further, it is our belief that employee 
involvement in the development and 
implementation of a company's ergonomic 
program is desirable for both the company and 
for the employees. We believe that employers 
should be encouraged to consider where 
employee involvement can best be utilized in 
their individual program. For example, 
employees can be used as a resource to assist 
in identifying and resolving ergonomic 
problems. Mandatory joint labor/management 
committees, however, should not be part of 
the standard.

   Dr. Tom Leamon, Vice President, Liberty 
Mutual Insurance Company, also commented on 
the need for an employee participation 
requirement (Ex. 3-96). He stated, ``[t]he 
effectiveness of regulations would be 
enhanced by a provision for worker 
participation, in particular the 
identification of potential problems and 
solutions and providing this information to 
the management decision process within the 
unit'' (Ex. 3-96, p. 2).
   Additionally, Mr. Steve Trawick, Director, 
Health and Safety, United Paperworkers 
International Union and Mr. Daniel Kass, 
Director of the Hunter College Center for 
Occupational and Environmental Health, 
clearly stated their support of employee 
participation in ergonomics programs. In 
response to the ANPR, they wrote ``[e]mployee 
involvement is crucial to the success of the 
ergonomic program. Workers know jobs in the 
plant better than anyone and can offer 
invaluable input in the analysis and decision 
making process'' (Ex. 3-136, p. 4).
   However, OSHA is aware that there is 
opposition to the inclusion of the management 
commitment and employee participation 
provisions in the proposed Ergonomics Program 
standard. For example, several stakeholders 
have expressed concern about the 
implementation and enforceability of the 
management leadership requirements, asserting 
that they amount to micro-management of their 
business. Clearly, OSHA does not intend this 
proposed program element to be a form of 
micro-management. Precisely to avoid this 
unwanted outcome, the requirements for 
management leadership and employee 
participation have been proposed in 
performance oriented language. Thus, 
employers covered by this standard may manage 
their leadership of the ergonomics program in 
whatever ways work best for their workplaces, 
as long as the basic requirements are 
satisfied.
   Additional opposition to this proposed 
provision was expressed in a stakeholder 
meeting held in Washington, DC, when one 
participant stated that legislation of 
employer commitment and employee 
participation is problematic because it is 
not clear what these provisions require (Ex. 
26-23). Other stakeholders have stated that, 
in their opinion, employee participation is 
not needed in successful programs (Ex. 26-
23). Still others have argued that employee 
participation, as proposed by OSHA, is in 
violation of the National Labor Relations Act 
(NLRA) (Ex. 26-23).
   Regarding conflicts with the NLRA, 
testimony presented by Henry L. Solano, 
Solicitor of Labor, Department of Labor, 
before the Subcommittee on Workforce 
Protections Committee on Education and the 
Workforce in the House of Representatives on 
May 13, 1999 (Ex. 26-29), clearly states that 
``the interplay of the OSH Act and the 
National Labor Relations Act (NLRA) does not 
present an obstacle to progress in this area 
[of employee participation in promoting a 
safe and healthful workplace].'' Mr. Solano 
identified many ways in which employers can 
involve their employees in safety and health 
matters without raising any concern that

[[Page 65795]]

they may be violating Section 8(a)(2) of the 
NLRA. OSHA is proposing to require employee 
participation but not to specify the form 
that participation is to take. There are 
several lawful forms of employee 
participation that have been upheld or 
described with approval by the National Labor 
Relations Board (NLRB) in the course of 
deciding cases under Section 8(a)(2).
   According to Mr. Solano (Ex. 26-29, pp. 
11-12), brainstorming groups are one such 
example. A group of employees that 
brainstorms about MSD hazards, for example, 
presents management with a list of ideas or 
suggestions. Management independently 
considers the ideas and suggestions and may 
or may not act on them. An information-
gathering committee that gathers and presents 
information to the employer, who may or may 
not take action based on the information, is 
also a lawful form of employee participation 
(Ex. 26-29, p. 12). Granting rights to 
individual employees, such as rights to 
report problems and make recommendations is 
consistent with Section 8(a)(2). 
Additionally, employers have the option to 
assign safety-related duties to employees as 
part of their job description (Ex. 26-29, pp. 
12-13, 14). Other forms of employee 
participation that have been approved by the 
NLRB include safety conferences and all-
employee committees in which all employees 
participate (Ex. 26-29, pp. 13-14). Although 
in his testimony Mr. Solano was specifically 
addressing safety and health programs in 
general, his discussion of lawful forms of 
employee participation applies equally to 
ergonomics programs. Another mechanism is a 
joint labor-management committee established 
in compliance with the NLRA by bargaining 
between the employer and the union 
representing the employees. Thus, employers 
complying with the proposed standard's 
employee participation provisions have many 
lawful ways of doing so.
   OSHA notes that the proposed management 
leadership provisions of the rule have been 
written in performance language to allow 
individual employers to implement them as 
appropriate to conditions in their workplace. 
This approach avoids the over specification 
that some stakeholders were concerned about. 
On the second point, the importance of 
employee involvement to program 
effectiveness, the discussion below makes 
clear that OSHA, and many stakeholders, 
safety and health professionals, and 
ergonomists agree that this element is the 
key to program success. OSHA has also been 
careful to structure the proposed rule's 
employee participation requirements so that 
they are entirely consonant with the case law 
based on the NLRA. The proposed rule does 
not, for example, mandate any particular 
method--such as employee committees--for 
ensuring employee participation. This leaves 
employers free to involve employees in the 
program in ways that do not violate the NLRA 
but will further meaningful employee 
participation.
   Section 1910.911  What is my basic 
obligation?

  You must demonstrate management leadership 
of your ergonomics program. Employees (and 
their designated representatives) must have 
ways to report ``MSD signs'' and ``MSD 
symptoms;'' get responses to reports; and be 
involved in developing, implementing and 
evaluating each element of your program. You 
must not have policies or practices that 
discourage employees from participating in 
the program or from reporting MSD signs or 
symptoms.

   Section 1910.911 of the proposed 
Ergonomics Program standard provides 
employers with an answer to the question 
``What is my basic obligation?'' First, 
employers would be required to demonstrate 
management leadership of their ergonomics 
program. Management leadership is 
demonstrated through personal concern for 
employee health and safety, as evidenced by 
the priority placed on the ergonomics 
program. OSHA believes that, to be effective, 
the demonstration of management leadership 
must be active rather than passive. 
Leadership that is limited to a ``paper 
program,'' such as having written policies 
and procedures neatly packaged in a three-
ring binder that sits on a shelf, would not 
be viewed by OSHA as meeting the intention of 
this provision. On the other hand, management 
leadership that is known throughout the 
organization via active engagement in the 
ergonomics process, with appropriate follow-
through on commitments, would meet OSHA's 
intention. Employers who comply with the 
requirements of Section 1910.911 would 
certainly be fulfilling the leadership 
portion of the standard. Employers may 
further demonstrate leadership, if they so 
choose, by participating in plant 
walkarounds, holding meetings with employees 
on ergonomic issues, and monitoring reports 
on program effectiveness.
   Second, proposed section 1910.911 would 
also obligate employers to create ways for 
employees, and their designated 
representatives, to report MSD signs and 
symptoms, get responses to reports, and be 
involved in the program. OSHA has vigorously 
advocated employee participation in workplace 
safety and health issues for many years and 
is pleased by the growing recognition of the 
importance of employee participation by 
private-sector companies, trade associations, 
safety and health professionals, and 
employees themselves. OSHA supports employee 
participation because employees have the most 
direct interest in their safety and health on 
the job, they have an in-depth knowledge of 
the operations and tasks they conduct at the 
worksite, they often have excellent ideas on 
how to solve health and safety problems, and 
their interest in the program is vital to its 
success. If employees do not report their 
injuries and illnesses or recognized job-
related hazards, any workplace program 
intended to promote safety and health will 
fail.
   Congress also recognized the importance of 
employee participation in safety and health 
activities when it enacted the Occupational 
Safety and Health Act in 1970. In section 2 
of the Act, titled ``Congressional Findings 
and Purpose,'' Congress declared that its 
goal of assuring safe and healthful 
workplaces was to be achieved by joint 
employer-employee efforts to reduce hazards 
and implement effective programs for 
providing safe and healthful working 
conditions. Additionally, Congress 
acknowledged that employers and employees 
have separate roles and rights connected with 
the achievement of safe and healthful working 
conditions. Thus, the Act offers employees 
opportunities to become involved in setting 
standards, variance processes, enforcement, 
and training. To assist employees in 
exercising these rights, Congress gave 
employees access to a wide variety of 
information. Employees were also given rights 
to file complaints and to participate 
actively in OSHA inspections, hazard 
abatement verification, citation contests, 
and the observation of the monitoring of 
toxic substances.
   The value of employee participation in 
ergonomics programs has been recognized by 
other federal agencies. The GAO concluded in 
1997 that effective ergonomics programs must 
include both management commitment and 
employee involvement as two of the core 
elements necessary to ensure that ergonomics 
hazards are identified and controlled to 
protect workers (Ex. 26-5). According to the 
GAO (Ex. 26-5), some of the ways in which 
employee participation can be demonstrated 
include:

[[Page 65796]]

    Creating committees or teams to 
receive information on ergonomic problem 
areas, analyze the problems, and make 
recommendations for corrective action;
    Establishing a procedure to 
encourage prompt and accurate reporting of 
signs and symptoms of MSDs by employees so 
that these symptoms can be evaluated and, if 
warranted, treated;
    Undertaking campaigns to solicit 
employee reports of potential problems and 
suggestions for improving job operations or 
conditions; and
    Administering periodic surveys to 
obtain employee reactions to workplace 
conditions so that employees may point out or 
confirm problems.
   NIOSH also recognizes the benefits of 
employee involvement in the publication 
Elements of Ergonomics Programs (Ex. 26-2). 
According to NIOSH (Ex. 26-2, p. 8) these 
benefits include:
    Enhanced worker motivation and 
job satisfaction;
    Added problem-solving 
capabilities;
    Greater acceptance of change; and
    Greater knowledge of the work and 
organization.

Further, NIOSH recommends that employees be 
encouraged to provide input on defining job 
hazards, controlling job hazards, and how 
best to implement controls (Ex. 26-2). Forms 
of employee involvement described by NIOSH 
(Ex. 26-2, pp. 8-9) include:
    Joint labor-management safety and 
health committees;
    Department or area work groups; 
and
    Direct individual employee input.

However, NIOSH clearly states that ``[n]o 
single form or level of worker involvement 
fits all situations or meets all needs. Much 
depends on the nature of the problems to be 
addressed, the skills and abilities of those 
involved, and the company's prevailing 
practices for participative approaches in 
resolving workplace issues'' (Ex. 26-2, p. 
9).
   Employee involvement, along with 
management commitment, is also one of the 
major elements included in OSHA's Safety and 
Health Program Management Guidelines, 
published in January 1989 (54 FR 3904-3916). 
Issued with strong public support, the 
guidelines state, ``[e]mployee involvement 
provides the means through which workers 
develop and/or express their own commitment 
to safety and health protection, for 
themselves and for their fellow workers'' (54 
FR 3909). At that time, OSHA stated that ``* 
* * employee involvement in decisions 
affecting their safety and health results in 
better management decisions and more 
effective protection'' (54 FR 3907). OSHA 
continues to believe that employee 
participation plays a crucial role in 
protecting the safety and health of employees 
and must be an integral part of any 
ergonomics program.
   A recommendation for employee involvement 
was included in OSHA's ``Meatpacking 
Guidelines'' as the complement to management 
commitment (Ex. 2-13, pp. 2-3). The 
Guidelines recommended:

  An effective program includes a commitment 
by the employer to provide for and encourage 
employee involvement in the ergonomics 
program and in decisions that affect worker 
safety and health, including the following:
  1. An employee complaint or suggestion 
procedure that allows workers to bring their 
concerns to management and provide feedback 
without fear of reprisal.
  2. A procedure that encourages prompt and 
accurate reporting of signs and symptoms of 
[MSDs] by employees so that they can be 
evaluated and, if warranted, treated.
  3. Safety and health committees that 
receive information on ergonomic problem 
areas, analyze them, and make recommendations 
for corrective action.
  4. Ergonomic teams or monitors with the 
required skills to identify and analyze jobs 
for ergonomic stress and recommend solutions.

   Third, section 1910.911 of the proposed 
standard informs employers that policies or 
practices that discourage employees from 
reporting MSD signs or symptoms or from 
participating in the program would not be 
allowed. Such actions on the part of the 
employer would undermine the intention of 
Sec. 1910.911. As discussed above, OSHA 
believes that meaningful employee 
participation in the ergonomics program is 
essential both to identify existing and 
potential MSD hazards, and to develop and 
implement an effective solution to abate 
these hazards.
   In the ANPR, OSHA requested comments 
related to early reporting of MSD signs or 
symptoms (question D2), the developing and 
implementing of ergonomics programs including 
involvement on the ergonomics team (question 
A6), and the benefits of an ergonomics 
program (question A7). In response to this 
request, OSHA received information that 
supports the proposed requirements in Section 
1910.911. For example, Mr. Rohrer of EG&G 
Energy Measurements, Inc. commented (Ex. 3-
27, p. 3):

  The main benefits of this [ergonomics] 
program are educating employees and 
empowering employees to recognized ergonomic 
problems in their work environment while 
helping to provide solutions to those 
problems. The program invites employees to 
make known work problems without fear of 
retribution from management, even in a period 
of size restructuring. One of the program 
philosophies is quite simple--a problem can't 
be solved unless it's identified.

   Additionally, Mr. John Clark, 
International Representative, International 
Union, UAW provided this comment (Ex. 3-155, 
p. 3):

  The structured participation of workers is 
needed for several reasons. Complaints of 
symptoms will not be freely given if workers 
fear reprisal by management. Workers know 
their job best and must be brought into the 
process of redesign. The close relationship 
of this activity to work standards and 
productivity issues requires prior 
understandings and continuing oversight. The 
program must maintain an emphasis on the 
prevention of pain and suffering, not a cost 
benefit calculation, and that requires worker 
involvement.

   Section 1910.912  What must I do to 
provide management leadership?

  You must:
  (a) Assign and communicate responsibilities 
for setting up and managing the ergonomics 
program so managers, supervisors and 
employees know what you expect of them and 
how you will hold them accountable for 
meeting those responsibilities;
  (b) Provide those persons with the 
authority, ``resources,'' information and 
training necessary to meet their 
responsibilities;
  (c) Examine your existing policies and 
practices to ensure they encourage and do not 
discourage reporting and participation in the 
ergonomics program; and (d) Communicate 
``periodically'' with employees about the 
program and their concerns about MSDs.
   Proposed section 1910.912 provides 
employers with answers to the following 
question: ``What must I do to provide 
management leadership?'' This section 
explains four management leadership 
responsibilities that employers

[[Page 65797]]

would have under the proposed ergonomics 
standard. First, as stated in paragraph (a), 
employers must assign and communicate 
responsibilities for setting up and managing 
the ergonomics program so that managers, 
supervisors and employees know what is 
expected of them and how they will be held 
accountable for meeting those 
responsibilities. Although proposed paragraph 
(a) would require that ergonomics program 
responsibilities be assigned, it does not 
specify who should be assigned to carry out 
what responsibility. OSHA believes that the 
employer is in the best position to decide 
who should have responsibility for the 
various parts of the process of implementing 
an ergonomics program, and the proposal gives 
the employer great leeway in making these 
decisions.
   The proposed rule also does not describe 
how safety and health responsibility is to be 
allocated. In larger workplaces, where 
responsibilities are described in writing, 
the allocation might be accomplished through 
official statements, such as job descriptions 
or individual annual objectives. In very 
small worksites, oral instruction would 
suffice as long as everyone knows who has 
been assigned what responsibilities. In fact, 
in all cases, the key factor is that those to 
whom responsibility has been assigned 
understand that responsibility and take it 
seriously.
   Individuals with responsibility for the 
ergonomics program must understand how they 
will be held accountable for meeting these 
responsibilities. OSHA has not specified how 
employers should accomplish this proposed 
requirement. Again, OSHA believes that 
employers are in the best position to decide 
how accountability should be determined and 
evaluated. Some employers may chose to 
incorporate accountability measures into 
performance appraisals. For example, one 
study reports that supervisor performance 
evaluations had been modified to include an 
assessment of whether or not ergonomic 
problems had been addressed (Ex. 26-28).
   Second, as stated in proposed paragraph 
(b), employers must provide individuals 
assigned responsibilities in the ergonomics 
program with the authority, resources, 
information and training necessary to meet 
their responsibilities. Providing adequate 
authority, resources, information and 
training necessary to carry out program 
responsibilities demonstrates management 
leadership. If, for example, an employee is 
assigned responsibility for evaluating a 
potential MSD hazard, that employee would 
need access to relevant information about the 
job creating the potential hazard, adequate 
knowledge to competently evaluate the job, 
sufficient time to evaluate the job, and the 
authority to recommend changes to the job if 
it is found to present MSD hazards.
   Authority, as used in this provision of 
the proposed standard, means the delegated 
ability to take action. Such delegated 
authority is essential if decisions are to be 
made in a timely manner and progress is to be 
made in accomplishing ergonomic program 
goals. Individuals assigned a particular 
responsibility under the ergonomics program 
must have the authority they need to 
discharge those responsibilities.
   Resources, as defined in this proposed 
standard (see Sec. 1910.945, which contains 
definitions of key terms), are the provisions 
necessary to develop, implement and maintain 
an effective ergonomics program. Resources 
include money (such as the funds needed to 
purchase equipment to perform job hazard 
analysis, develop training materials, and 
implement controls), personnel and the work 
time to conduct program responsibilities, 
such as job hazard analysis or training. The 
resources needed to meet program 
responsibilities under this standard will 
vary with circumstances.
   The proposed standard would also require 
employers to provide individuals with 
assigned responsibility for the ergonomics 
program with the information and training 
they need to meet their responsibilities. For 
individuals involved in ergonomics program 
implementation and management, employers 
would be required to provide information and 
training so that these individuals understand 
and know, at a minimum:
    The ergonomics program and their 
role in it.
    How to identify and analyze MSD 
hazards.
    How to identify, evaluate, and 
implement measures to control MSD hazards.
    How to evaluate the effectiveness 
of ergonomics programs.

Sections 1910.923-928 of the proposed rule 
provides additional information about 
proposed requirements for ergonomics program 
training.
   Proposed paragraph (b) is written to allow 
broad discretion for employers to decide just 
what authority, resources, information, and 
training are needed for the specific 
responsibilities assigned. The employer is, 
however, required by this paragraph to 
provide the authority, resources, information 
and training necessary to discharge the 
responsibility the employer has assigned.
   Problems in fulfilling program 
responsibilities are often caused by lack of 
the necessary authority or resources to 
accomplish those responsibilities. For 
example, an employee may be assigned the 
responsibility for evaluating MSD hazards and 
getting those hazards corrected. However, if 
the same hazards are found on repeat 
inspections, it may be that the employee 
lacked the authority to require correction or 
that no training or inadequate training in 
the evaluation of MSD hazards has been 
provided. In both of these examples, the 
employer has not provided the authority, 
resources, information and training necessary 
for the employee to meet his or her assigned 
responsibilities.
   Third, as stated in proposed paragraph 
(c), employers would be required to examine 
their existing policies and practices to 
ensure that they encourage the reporting of 
MSD signs and symptoms and do not discourage 
reporting and participation in the ergonomics 
program. The intent of this proposed 
provision is to inform employers that they 
are prohibited by the proposed rule from 
taking actions that might undermine or 
otherwise interfere with the reporting of MSD 
signs and symptoms or ergonomics program 
participation by their employees.
   OSHA has included this provision in the 
proposed standard because the Agency believes 
that such protection is needed to encourage 
early reporting of the symptoms and signs of 
MSDs and meaningful employee participation in 
the ergonomics program. OSHA believes that 
employees in all workplaces should be 
encouraged by their employers to report 
injuries, illnesses, and hazards of all 
kinds--not just those related to ergonomic 
issues--because only full and frank reporting 
allows employers to identify hazards and do 
something about them. In workplaces where 
employees are discouraged, either implicitly 
or explicitly, from participating fully in 
all aspects of safety and health in the 
workplace, deaths, injuries, and illnesses 
will continue to occur, employers will 
continue to pay high workers' compensation 
premiums, worker morale will suffer, and 
product quality will be below par. 
Encouraging employee

[[Page 65798]]

participation, and particularly the reporting 
of MSD signs and symptoms, is especially 
important under the proposed ergonomics rule 
because the success of the program depends on 
such reporting. That is, the standard is 
structured so that employee reports of MSD 
signs and symptoms trigger employer actions.
   OSHA is aware that some employers 
discourage reporting unintentionally, and 
that this can happen even in workplaces where 
an ergonomics program has been implemented in 
good faith. For example, employers may be 
discouraging full and early reporting if they 
have:
    A policy that every employee who 
reports MSD signs or symptoms must rest at 
home without pay.
    A policy that requires drug 
testing of every employee who reports an 
injury.
    A supervisory practice of 
withholding overtime work for anyone who 
reports MSD signs or symptoms.
    A policy that prohibits the use 
of sick leave if an employee is off work 
because of a work-related injury.

It should be noted that OSHA does not 
consider that having a drug testing policy 
is, in and of itself, a violation of the 
standard. However, if the drug testing policy 
was applied in a discriminatory way, or had a 
chilling effect on employees' willingness to 
report, the Agency would evaluate the 
situation on a case-by-case basis.
   Because the underreporting of occupational 
illnesses and injuries is a widely recognized 
problem, and is especially serious in the 
case of ergonomic injuries and illnesses (see 
discussion of underreporting in the 
Significance of Risk section (Section VII of 
this preamble), the purpose of this proposed 
provision is to ensure that employees in jobs 
covered by the standard will not be 
discouraged from reporting problems to their 
employers. For example, the use of incentive 
or award programs that focus on achieving low 
numbers or rates of reported MSDs may 
discourage early reporting. Such programs, 
although sometimes intended to improve 
employee safety and health, may inadvertently 
lead to the underreporting of MSD cases and 
thus actually increase unsafe working 
conditions. Programs that offer financial 
rewards, such as individual or group 
performance bonuses, management promotions, 
or safety game awards (``safety bingo''), or 
provide personal recognition of individual 
employees (``safe employee of the month'') to 
employees, groups, or supervisors if they 
achieve a zero or low incidence of reportable 
injuries or illnesses may put considerable 
pressure on workers not to report and thus 
discourage reporting, whether intentionally 
or unintentionally.
   OSHA's objective is that employees feel 
free to report MSD signs and symptoms as 
early as possible, because doing so prevents 
pain and suffering, averts disability, and 
reduces employer costs. To achieve this 
objective, all MSDs must be reported so that 
they can be assessed to determine whether 
they are covered by the standard. Thus, the 
Agency's concern is with the proper reporting 
of MSD injuries and illnesses, not on the 
design of the employer's incentive program. 
If such programs have the effect of 
discouraging reporting or employee 
participation, however, employers would not 
be in compliance with this section of the 
standard. Thus, because these programs have 
the potential to discourage reporting, 
employers should take special care to ensure 
that they do not do so.
   In comments submitted to OSHA in response 
to requests made in the ANPR, Martin Marietta 
Energy Systems, Inc., among others, stated 
that incentive programs may pose possible 
barriers to early reporting (Ex. 3-151). The 
International Union of Electrical, Salaried, 
Machine and Furniture Workers urged OSHA to 
discourage practices that inhibit early 
reporting, and specifically pointed to the 
use of safety contests (Ex. 3-183).
   OSHA is not prohibiting the use of safety 
incentive or award programs, and nothing in 
the proposed rule would do so. However, OSHA 
is encouraging employers who wish to use such 
programs to design them to reward safe work 
practices, such as active participation in 
the ergonomics program, the identification of 
MSD hazards in the workplace, and the 
reporting of the early signs and symptoms of 
MSDs, rather than to reward employees for 
having fewer MSDs or lower rates of MSDs. The 
differences in these two kinds of programs--
those that focus on safe work practices and 
those that stress fewer reported MSDs--is 
that the former, when coupled with 
appropriate supervisory feedback to 
employees, may actually reinforce and 
encourage the kinds of safe practices and 
participation that employers need to enhance 
safety and health, while the latter too often 
encourage employees not to report.
   OSHA would not consider incentive programs 
to be ``illegal'' under this rule except 
where they are applied in a discriminatory 
way or have a chilling effect on employees' 
willingness to report. OSHA's practice is to 
evaluate the recordkeeping system, and the 
accuracy and completeness of reporting, when 
it inspects facilities. If no underreporting 
is apparent, OSHA does not inquire about any 
incentive programs that may be in place at 
the facility. However, if there does appear 
to be underreporting, OSHA evaluates the 
situation further to determine what is 
contributing to the underreporting. OSHA 
would not cite the employer under this 
standard for having an incentive program 
unless it was discouraging reporting or 
participation in the program (Sec. 1910.912 
(c)). OSHA would cite employers for failure 
to record OSHA recordable injuries and 
illnesses, but such a citation would be for a 
violation of the recordkeeping rule, not the 
ergonomics rule.
   It is OSHA's experience that incentive or 
award programs are not needed to motivate 
employees who are active participants in 
workplace safety and health programs, such as 
the ergonomics program proposed by this 
standard. Employees involved in effective 
workplace programs already receive feedback 
from their co-workers, supervisors, and 
managers on safe work practices, regularly 
provide such feedback to others, and are 
``rewarded'' by being full participants in 
achieving a safe and healthful workplace.
   Likewise, only informed employees can 
truly participate effectively in a workplace 
ergonomics program. Employees who have 
received adequate information and training on 
ergonomic hazards in their workplace can act 
as ``another pair of eyes and ears'' for 
their employers. Informed and trained 
employees can contribute to a workplace 
culture that values safety and health.
   Fourth, proposed paragraph (d) would 
require that employers ``communicate 
`periodically' with employees about the 
program and their concerns about MSDs.'' 
Periodic communication between an employer 
and his or her employees means a regular, 
two-way exchange of information in which 
employees receive information about the 
employer's ergonomics program and its 
progress, and the employer receives 
information about MSDs that is of concern to 
the employees. Although OSHA does not specify 
a time period for these communications, the 
frequency of this exchange of information 
should accurately reflect the needs of a 
given workplace. For example, OSHA would 
expect more frequent communication during the 
start-up

[[Page 65799]]

phase of an ergonomics program, when MSD 
signs or symptoms are reported, and prior to 
the implementation of workplace changes. At a 
minimum, communications must be often and 
timely enough to ensure that employees have 
the information necessary to protect 
themselves from MSDs, and have effective 
input into the operation of the ergonomics 
program.
   Employers will be able to demonstrate this 
communication by periodically checking to see 
whether their employees have accurate 
information about the process for reporting 
MSD signs or symptoms. Employees should be 
able to state the various steps of this 
process, or at a minimum, the first step in 
the reporting process. Additionally, 
employers will be able to inspect the reports 
themselves (if they are in writing) to 
determine whether employees are actually 
reporting MSD signs or symptoms and if they 
are reporting them early.
   Section 1910.913  What ways must employees 
have to participate in the ergonomics 
program?

  Employees (and their designated 
representatives) must have:
  (a) A way to report MSD signs and symptoms;
  (b) Prompt responses to their reports;
  (c) Access to this standard and to 
information about the ergonomics program; and
  (d) Ways to be involved in developing, 
implementing and evaluating each element of 
the ergonomics program.

   Proposed section 1910.913 of the 
ergonomics program standard informs employers 
of OSHA's specific requirements for employee 
participation. It provides an answer to the 
question, ``What ways must employees have to 
participate in the ergonomics program?'' 
Proposed paragraph (a) contains the 
requirement that employees, and their 
designated representatives, if the employees 
are represented by a union or unions, must 
have a way to report MSD signs and symptoms. 
This proposed provision requires employers to 
establish a clear process for reporting MSD 
signs and symptoms and to make that process 
known to his or her employees, so that 
reports are received in a timely and 
systematized manner. For example, employees 
must know whom to make reports to. These 
reporting systems may be either formal or 
informal, depending on the nature and size of 
the affected employee population. The 
intention of this provision is for a means of 
communication to be available and for 
employees to know how to have access to the 
system.
   Prompt answers to employee reports are 
necessary so that employees know that their 
reports have been received and considered. 
Paragraph (b) of section 1910.913 of the 
proposed ergonomics program standard requires 
that employees and their designated 
representative(s), where applicable, receive 
prompt responses to their reports. OSHA 
believes that a timely and good faith 
response is essential to reinforce the 
reporting and information exchange process. 
Quick responses to employee reports are a way 
to demonstrate management leadership of the 
ergonomics program. The requirements in 
proposed paragraphs (a) and (b) of section 
1910.913 are the complements to proposed 
section 1910.916, which requires employers to 
identify at least one person to receive and 
respond promptly to employee reports of MSD 
signs or symptoms, and to take the action 
this standard requires.
   Proposed paragraph (c) of section 1910.913 
states that employees, and their designated 
representative(s), if applicable, must have 
``access to this standard and to information 
about the ergonomics program.'' Such 
information includes: the assignment of 
responsibilities under the program; job 
hazard analysis results; hazard control 
plans; and records of reports related to the 
occurrence of covered MSDs and the 
identification of MSD hazards; ergonomic 
program evaluation results; and lists of 
alternative duty jobs. Additionally, 
employees must be provided with access to a 
copy of this Ergonomics Program standard. 
Employers can comply with this provision by 
posting a copy of the standard on the 
bulletin board. OSHA believes that employees 
must have this information to meaningfully 
participate in the ergonomics program. 
However, employee access to information does 
not include access to confidential or private 
information the employer may have that is of 
a personal nature, such as medical records.
   Assuring employee access to information 
related to their safety and health on the job 
is not unique to this proposed standard. 
Employers are already obligated to provide 
employees with access to their exposure and 
medical records by the requirements set forth 
in OSHA's standard ``Access to Employee 
Exposure and Medical Records'' (29 CFR 
1910.1020). Additionally, OSHA requires 
employers covered by the Process Safety 
Management standard (29 CFR 1910.119) to 
provide employee access to process hazard 
analyses and all other information required 
to be developed under that standard.
   Paragraph (d) of section 1910.913 proposes 
that employees and their designated 
representatives, if applicable, must have 
``ways to be involved in developing, 
implementing and evaluating each element of 
the ergonomics program.'' Element of 
ergonomics program refers to elements that 
are required by this standard, as listed in 
proposed section 1910.905. OSHA believes that 
employees must be involved in these important 
elements of an ergonomics program in order 
for the program to be effective. For example, 
when it comes to job hazard analysis and 
control, no one knows the job better than the 
employee(s) who does the job on a regular 
basis. Employees are also most likely to have 
valuable input regarding the most effective 
and inexpensive solutions to MSD hazards 
related to their jobs.
   For example, employees must have input in 
the development, implementation, and 
evaluation of ergonomic training programs, 
where training is required under this 
standard. Employees themselves are the best 
advisors regarding effective training program 
content and level of understanding for 
sometimes complex training material. 
Obviously, in workplaces where the primary 
language of some of the employees to be 
trained is not English, employees must play a 
critical role in assuring that the training 
material is presented in language that is 
understood by the employees. In many cases, 
that language will be English, because many 
workers will have acquired a good 
understanding of English. The standard 
intends, however, that the training program 
content be understood by all employees who 
are required to receive training.
   Employees must also be involved in 
evaluating the effectiveness of the 
ergonomics program and the control measures 
that are implemented. OSHA believes that the 
employees who perform jobs that have MSD 
hazards are in the best position to know 
whether or not the ergonomics program and 
control measures are effective as implemented 
or if they need to be modified. To 
effectively eliminate MSD hazards, employers 
and employees must form a partnership, with 
each contributing his or her unique expertise 
to achieve the goals of the ergonomics 
program.

[[Page 65800]]

   The nature, form, and extent of how 
employers must provide employees with 
opportunities to participate will vary among 
workplaces. Each workplace and workforce is 
different, and what will be effective will 
vary, depending on such factors as:
    The nature of the MSD hazards;
    The number and type of problem 
jobs in the workplace;
    Past experience with employee 
participation programs;
    The presence or absence of a 
union;
    The general safety and health 
culture of the workplace;
    Relevant state or local laws; and
    The employer's financial 
resources.

OSHA proposes to provide great latitude to 
each employer, in consultation with 
employees, to find the optimal means for 
achieving the participation required by this 
proposed standard in their workplace.


Hazard Information and Reporting 
(Secs. 1910.914-1910.916)

   Proposed sections 1910.914-1910.916 would 
require employers whose employees work in 
manufacturing or manual handling operations, 
or in jobs in which a covered MSD has 
occurred, to provide employees in those jobs 
with basic information about musculoskeletal 
disorders (MSDs), including their signs and 
symptoms and how to recognize them. Some 
signs and symptoms of MSD problems are 
obvious, such as trigger finger, while 
others, such as the early stages of 
tendinitis, may be more subtle. However, 
explaining the nature of the problem, the 
characteristic signs and symptoms, and the 
importance of early reporting is a necessary 
component of any ergonomics program.
   The proposed requirements in these 
sections are designed to ensure that 
employers with high-risk employees, such as 
those in manual handling and manufacturing 
jobs, have a system in place that will 
respond appropriately if a covered MSD is 
reported. In order for employees to report 
the first signs or symptoms of an MSD, they 
must recognize those signs and symptoms and 
understand the urgency of reporting them to 
the employer promptly. To achieve this end, 
the proposed rule requires employers to 
establish a system that includes an MSD 
reporting system. These sections also require 
that employers provide pertinent information 
to employees in problem jobs; this 
information must address the signs and 
symptoms of MSDs and common MSD hazards.
   These sections stress the importance of 
early reporting to ensure that employees with 
MSD signs or symptoms receive help before 
serious damage occurs. Additionally, the 
early reporting of MSDs helps to avoid the 
development of MSD signs or symptoms in other 
employees in the workplace in the same job. 
Receiving reports from employees and 
reviewing available information is an easy 
and straightforward way to identify problem 
jobs. For example, employers who follow up on 
employee reports of MSD signs or symptoms, 
such as undue strain, localized fatigue, 
discomfort, or pain that does not go away 
after overnight rest will be able to take 
preventive action at the earliest stages.
   OSHA's proposed reporting system is a tool 
for secondary prevention of MSDs. Its purpose 
is to identify employees with covered MSDs 
before they would otherwise seek health care 
for their signs or symptoms. Thus, by design, 
the reporting system should be highly 
sensitive, i.e., identify both those 
employees who definitely have a covered MSD 
as well as those who, upon further 
evaluation, are found not to have a covered 
MSD. OSHA believes this approach is 
appropriate because certain requirements of 
this proposed rule are triggered by the 
occurrence of a covered MSD. Reporting all 
signs or symptoms of MSDs will help to ensure 
that covered MSDs are properly identified.
   It is important to note that reporting of 
all signs or symptoms of MSDs through this 
system does not mean that all of these cases 
will turn out, on further investigation, to 
be OSHA recordable cases. Once an employee 
reports signs or symptoms of an MSD, his or 
her case would need to be evaluated for OSHA 
recordability. If the case is determined to 
be an OSHA recordable MSD and in addition 
meets the screening criteria (see 
Sec. 1910.902), it is a covered MSD as 
defined by the proposed standard.
   The information that employers would be 
required to provide to employees under these 
sections is general information about MSDs 
and common MSD hazards. This information, for 
example, would not have to be specific about 
the precise conditions or MSD hazards of a 
particular job. Job-specific training that 
results from a job hazard analysis is only 
required if the requirements in the sections 
that address training (Secs. 1910.9 23-928) 
are triggered by the occurrence of a covered 
MSD. Examples of the ``big picture'' 
information that would be required by section 
1910.915 include: general hazards associated 
with MSDs; what musculoskeletal disorders are 
and the signs and symptoms they cause; the 
importance of early reporting of MSD signs 
and symptoms to full recovery; and 
information about the systems in place to 
handle employee reporting of MSD signs and 
symptoms. The intent of this section is to 
make employees aware of MSDs and common MSD 
hazards.
   In debates over the OSH Act before its 
passage, Senator Williams stressed that the 
hidden nature of harmful physical agents made 
employee awareness of these hazards 
critically important to providing them with 
adequate protection from excessive exposure 
(Legislative History, at 415). MSD hazards 
are an example of harmful physical agents. 
This observation continues to be true today, 
and is particularly apparent in the case of 
MSDs, which are widely underreported, in part 
because neither employers nor employees make 
the link between workplace risk factors and 
the signs and symptoms of MSDs.
   Section 1910.914  What is my basic 
obligation?

  You must set up a way for employees to 
report MSD signs and symptoms and to get 
prompt responses. You must evaluate employee 
reports of MSD signs and symptoms to 
determine whether a covered MSD has occurred. 
You must periodically provide information to 
employees that explains how to identify and 
report MSD signs and symptoms.

   Proposed section 1910.914 informs 
employers of what they are required to do to 
facilitate employee reporting of MSD signs 
and symptoms. There are three proposed 
obligations under this section. First, 
employers would be required to: ``set up a 
way for employees to report MSD signs and 
symptoms and to get prompt responses.'' By 
using the word ``way,'' OSHA has created 
flexibility for employers to use either 
formal or informal approaches to establishing 
a reporting system. Large employers may 
decide that a formal system of reporting that 
includes written documentation is appropriate 
to ensure that nothing falls through the 
cracks. Employers with fewer than 10 
employees, on the other hand, may find that 
oral reporting systems are adequate. Many 
employers may already have reporting systems 
in place that can be adapted to accommodate 
the requirements of the proposed Ergonomics 
Program standard. However, regardless of how 
methods are tailored to meet the needs

[[Page 65801]]

of a specific workplace and workforce, the 
process must be systematic and accessible to 
all employees.
   The MSD signs and symptoms to be reported 
are defined in the section of this standard 
that covers key terms (Sec. 1910.945). Signs 
of MSDs are defined as ``objective physical 
findings that an employee may be developing 
an MSD.'' Examples of signs of MSDs include:
    Decreased range of motion;
    Decreased grip strength;
    Loss of function; and
    Deformity.
Symptoms of MSDs are more subjective physical 
experiences that an employee may report that 
indicate he or she may be developing an MSD. 
Examples of MSD symptoms in the affected body 
part include:
    Numbness;
    Burning;
    Pain;
    Cramping;
    Tingling; and
    Stiffness.

Symptoms can vary in their severity, 
depending on the amount of exposure an 
employee has had. Often symptoms may appear 
gradually and be evidenced as muscle fatigue 
or pain at work that disappears during rest. 
Usually symptoms become more severe as 
exposure continues. For example, at first 
tingling may continue during rest, then 
numbness or pain may make it difficult to 
perform the job, and finally pain may be so 
severe that the employee is unable to perform 
physical work activities.
   There are several reasons why OSHA 
believes the proposed reporting system is 
important for a successful ergonomics 
program. First, an important trigger in this 
proposed standard is the occurrence of an 
MSD. In order for an employer to be made 
aware of MSDs in his or her workplace, 
employees must have a mechanism for reporting 
this information. Second, if an accessible 
reporting system is not made available to 
employees, they will be discouraged from 
reporting MSD signs and symptoms and the 
ergonomics program will fail. A reporting 
system that is well-known to employees is one 
way to ensure employee participation in the 
ergonomics program.
   Section 1910.914 further proposes that 
``you must evaluate employee reports of MSD 
signs and symptoms to determine whether a 
covered MSD has occurred.'' This requirement 
has been written to allow maximum flexibility 
for employers. In order to determine whether 
an employee who has experienced MSD signs or 
symptoms actually has a covered MSD, many 
employers will choose to have employees who 
report MSD signs or symptoms evaluated by an 
ergonomist or health care professional. Other 
employers will use ergonomics committee 
members or other staff with appropriate 
training. Some employers may have a health 
care professional available on-site for 
employee evaluations, and others may use a 
contract provider to whom employees are 
referred. Regardless of who does this 
evaluation, employers would be required to 
take reports of MSD signs or symptoms 
seriously and to provide employees, when 
appropriate, with early assessment and access 
to prompt and effective evaluation at no cost 
to the employees. When the occurrence of a 
covered MSD is confirmed, employers would be 
responsible for providing MSD management of 
that MSD to the affected employee. Proposed 
employer obligations for MSD management are 
found in sections 1910.929-1910.935 and are 
discussed below in connection with those 
sections of the proposed standard.
   As part of their basic obligation, 
employers would also be required to 
``periodically provide information to 
employees that explains how to identify and 
report MSD signs and symptoms.'' The 
information that would be required to be 
communicated to fulfill the basic obligation 
under this section (Sec. 1910.914) differs 
from the information to be provided through 
the training provisions contained in sections 
1910.923-1910.928 of the proposed rule. The 
information to be shared with employees under 
this section is general information related 
to MSDs, MSD hazards, and the ergonomics 
program. Employees need access to this 
information in order to be alert to the onset 
of MSD signs or symptoms and to effectively 
participate in the ergonomics program, as 
well as to protect themselves while at work.
   In order to provide employers with maximum 
flexibility, the time intervals for these 
activities have not been specified in the 
proposed rule. However, in the section on key 
terms in this standard (Sec. 1910.945), OSHA 
states that ``periodically means that a 
process or activity, such as records review 
or training, is performed on a regular basis 
that is appropriate for the conditions in the 
workplace.'' By using the term ``regular 
basis,'' OSHA provides employers with a 
flexible definition that is adaptable to an 
employer's specific situation. OSHA proposes 
that information for employees be provided 
periodically because retention of information 
diminishes over time.
   The section on key terms in this standard, 
Sec. 1910.945, further defines 
``periodically'' to mean ``that the process 
or activity is conducted as often as needed, 
such as when significant changes are made in 
the workplace that may result in increased 
exposure to MSD hazards.'' Examples of 
significant changes in the workplace include 
the introduction of new equipment, new 
processes, or new production demands that may 
increase the likelihood that employees will 
be exposed to MSD hazards.
   Section 1910.915  What information must I 
provide to employees?

  You must provide this information to 
current and new employees:
  (a) Common MSD hazards;
  (b) The signs and symptoms of MSDs, and the 
importance of reporting them early;
  (c) How to report MSD signs and symptoms; 
and
  (d) A summary of the requirements of this 
standard.

   Proposed section 1910.915 informs 
employers of the specific information they 
must provide to current and new employees in 
manufacturing operations, manual handling 
operations and other jobs with covered MSDs. 
The provision of this information to 
employees is necessary to facilitate their 
active participation in the ergonomics 
program. Additionally, since the 
identification of problem jobs is triggered 
by employee reporting of a covered MSD, 
informed employees are critical to assure the 
accuracy of the reporting system, regardless 
of whether the system is written or oral.
   OSHA considers ``current'' employees to be 
those in either manufacturing operations, 
manual handling operations, or other problem 
jobs at the time this standard becomes 
effective. ``New'' employees include newly 
hired employees, as well as those who are new 
to manufacturing and manual handling 
operations or other jobs with covered MSDs, 
but not necessarily new to the company.

[[Page 65802]]

   At a minimum, OSHA would require that 
employers provide their employees with 
information that covers four topics. First, 
proposed paragraph (a) would require that 
employers provide information to current and 
new employees in manufacturing operations, 
manual handling operations, and other jobs 
with covered MSDs so they know about the 
``common MSD hazards.'' By using the word 
``common'' OSHA means general, as opposed to 
job specific, MSD hazards.
   Second, as stated in paragraph (b), 
employees must know ``the signs and symptoms 
of MSDs, and the importance of reporting them 
early.'' A discussion of MSD signs and 
symptoms and the importance of early 
reporting can be found in the summary and 
explanation of section 1910.914.
   The ultimate goal of early reporting of 
signs and symptoms is to identify MSDs while 
they are still reversible in order to prevent 
pain, suffering, and disability due to MSD 
hazards. Such a goal creates a win-win 
environment for both employers and employees. 
Employees are assured that their health and 
safety will be protected, and employers will 
benefit from the decreased occurrence and 
costs of covered MSDs in their workforce.
   Third, proposed paragraph (c) would 
require employers to provide information to 
their employees in manufacturing operations, 
manual handling operations and other jobs 
with covered MSDs so they know how to report 
MSD signs and symptoms. OSHA does not specify 
how this information must be shared. It can 
be communicated either in writing or orally, 
depending on the nature of the work 
environment. However, employers must be sure 
that their affected employees understand how 
to access this reporting system. This 
requirement complements the obligation set 
forth in section 1910.914, which states that 
employers must set up a way for employees to 
report MSD signs and symptoms.
   Fourth, proposed paragraph (d) would 
require employers to provide ``a summary of 
the requirements of this standard'' to their 
employees in manufacturing operations, manual 
handling operations, and other jobs with 
covered MSDs. OSHA believes that employees 
are entitled to information about the 
ergonomic program elements and specific 
requirements contained in this standard. 
Moreover, employees must have this 
information to meaningfully participate in 
the ergonomics program.
   OSHA believes that there are many 
practical ways that employers would be able 
to accomplish these proposed requirements. 
One method that aids the understanding of 
somewhat technical information is to allow 
employees an opportunity to ask questions 
about information presented to them and 
receive answers to their questions. There are 
many ways that question and answer sessions 
can be incorporated into the work schedule. 
Examples include question and answer sessions 
that are: organized classroom style; part of 
regularly scheduled meetings with employees 
and their supervisors; an outgrowth of 
informal talks with employees; and 
incorporated into safety meetings. OSHA 
believes that merely arranging for employees 
to view a videotape on common MSD hazards, 
without an opportunity for discussion or 
questions and answers, is unlikely to ensure 
that the necessary information has been 
effectively communicated.
   Another method critical to employee 
understanding of information related to 
common MSD hazards and the signs and symptoms 
of MSDs is to provide the information in the 
language and at levels the employees 
comprehend. Commercially available 
information related to common MSD hazards and 
MSD signs and symptoms is often available in 
languages other than English and at various 
comprehension levels. When purchasing 
prepared informational materials, employers 
must consider language and comprehension when 
making their selections. For employers with 
predominantly non-English speaking workers, 
an effective alternative to commercially 
prepared informational material may be 
selecting and training a worker who speaks 
both English and the predominant language of 
the workforce to deliver MSD hazard 
information. For employers with workers who 
cannot read, employers would be required to 
provide information orally or through visual 
displays or graphics.
   OSHA recognizes that retention periods for 
information, especially technical 
information, can sometimes be short, and that 
it often takes multiple presentations of 
information before it is effectively 
understood, processed, and applied. 
Therefore, OSHA would expect employers to be 
creative in meeting these proposed 
obligations. Some additional ideas that 
employers may consider include: posting 
information in conspicuous locations as a 
continuous reminder; frequently changing the 
message conveyed in the posted information so 
that it doesn't become stale and invisible; 
using plain language and terms to communicate 
the information; incorporating visually 
appealing pictures or displays; and setting 
up interactive displays of model work 
stations so employees can experiment with 
equipment while they are not engaged in 
production or service provision.
   Section 1910.916  What must I do to set up 
a reporting system?

  You must:
  (a) Identify at least one person to receive 
and respond to employee reports, and to take 
the action this standard requires.
  (b) Promptly respond to employee reports of 
MSD signs or symptoms in accordance with this 
standard.

   Proposed section 1910.916 advises 
employers of what they must ``do to set up a 
reporting system.'' This section contains two 
requirements that employers must meet. First, 
proposed paragraph (a) would require that 
employers ``identify at least one person to 
receive and respond to employee reports, and 
to take the action this standard requires.'' 
These proposed requirements provide 
additional support and encouragement for 
employees to report MSD signs and symptoms. 
If employees are expected to report MSD signs 
and symptoms, there must be at least one 
person assigned the responsibility to receive 
and respond to the reports and act upon them.
   The employer may decide who the person or 
persons to receive such reports should be and 
how many persons are needed. In many places 
of employment, all front-line supervisors 
have the responsibility to receive and 
respond to reports of work-related injuries 
and illness. In other workplaces, a safety 
officer or safety committee has the 
responsibility to receive and respond to such 
reports. In still other companies an 
occupational health nurse may be available to 
receive and respond to reports of MSD signs 
and symptoms.
   Small employers, on the other hand, may 
choose to carry out these responsibilities 
themselves instead of delegating them to 
others. For example, a small employer could 
simply make sure that all employees are 
encouraged to report MSD signs and symptoms 
directly to him or her. In response to those 
reports, that same small employer would then 
also be the designated individual to ensure 
that the appropriate action, as required by 
this standard, is initiated when the employee 
has a covered MSD. In the proposed standard 
the

[[Page 65803]]

choice of designee is left to the employer, 
because OSHA recognizes that various 
employers may elect to implement this 
provision differently.
   Second, proposed paragraph (b) of this 
section would require employers to `` 
promptly respond to employee reports of MSD 
signs or symptoms in accordance with this 
standard.'' The summary and explanation for 
most of this requirement has been previously 
discussed in section 1910.914, which covers 
the employer's basic obligation. Any employee 
reports of MSD signs or symptoms must be 
taken seriously by the employer; if a covered 
MSD has occurred, the employee's job is a 
problem job, and the employer must then 
comply with the job hazard analysis and 
control provisions of sections 1910.917 
through 1910.922. Such reports may also 
indicate that an element(s) of the ergonomics 
program is not properly functioning. Thus, 
employers must critically evaluate employee 
reports of MSD signs or symptoms and 
determine what actions must be taken to 
comply with the requirements of this proposed 
Ergonomics Program standard.


Job Hazard Analysis and Control 
(Secs. 1910.917-1910.922)

   This part of the Summary and Explanation 
discusses the proposed requirements for Job 
Hazard Analysis and Control (Secs. 1910.917-
1910.922). It describes the proposed 
requirements, provides information on the 
process of job hazard analysis and control, 
and presents examples of controls that have 
been used effectively by employers to 
eliminate or materially reduce MSD hazards.
   Job hazard analysis and control is the 
heart of any ergonomics program because it is 
the first step in eliminating or materially 
reducing MSD hazards. Through job hazard 
analysis, employers identify and assess where 
and how employees' physical capabilities have 
been exceeded in a given job. It does this by 
identifying what aspects of the physical work 
activities and conditions of the job and what 
ergonomics risk factors may be causing or 
contributing to the MSD hazards.
   Once MSD hazards have been identified, the 
next step is to eliminate or control them. An 
effective hazard control process involves 
identifying and implementing control measures 
to obtain an adequate balance between worker 
capabilities and work requirements so that 
MSDs are not reasonably likely to occur 
(Karwowski and Salvendy, Ergonomics in 
Manufacturing, 1998, Ex. 26-1419).
   OSHA is proposing a flexible approach to 
the analysis and control of MSD hazards. A 
flexible approach helps to ensure that the 
required job hazard analysis and control 
process is appropriate for a diverse range of 
employers and is applicable to a variety of 
different jobs. For example, OSHA believes 
that both small and large employers will be 
able to use the job hazard analysis and 
control provisions of the standard and will 
be able to comply with them.
   Section 1910.917  What is my basic 
obligation?

  You must analyze the problem job to 
identify the ``ergonomic risk factors'' that 
result in MSD hazards. You must eliminate the 
MSD hazards, reduce them to the extent 
feasible, or materially reduce them using the 
incremental abatement process in this 
standard. If you show that the MSD hazards 
only pose a risk to the employee with the 
covered MSD, you may limit the job hazard 
analysis and control to that individual 
employee's job.

   OSHA is proposing that employers analyze 
jobs in which a covered MSD is reported. (In 
the proposed rule these jobs are called 
``problem jobs.'') If employers determine, 
through the job hazard analysis, that there 
are physical work activities and work 
conditions in the problem job that are 
reasonably likely to be causing or 
contributing to the covered MSD, they would 
be required to implement controls to achieve 
one of these control endpoints: eliminate MSD 
hazards, reduce hazards to the extent 
feasible, or materially reduce the hazard 
(following the incremental abatement process 
in Sec. 1910.922). (The control endpoints in 
this basic obligation section would also 
apply to those ergonomics programs that might 
be grandfathered in under Sec. 1910.908.)


1. Covered MSDs

   OSHA is proposing to limit employers' 
obligation to analyze and control MSD hazard 
requirements to jobs in which covered MSDs 
have been reported after the date the 
Ergonomics Program Standard becomes 
effective. This means that the only employers 
who would have to analyze and control jobs 
are those who have determined that a covered 
MSD has occurred in their workplace.
   Many stakeholders support limiting job 
hazard analysis and control to jobs in which 
there is an identified MSD hazard, such as an 
injury (Exs. 3-56, 3-99, 3-114, 3-133, 3-161, 
26-1370). Other stakeholders suggested that 
an ergonomics rule should require employers 
to analyze and control any job in which 
employees are exposed to MSD hazards (Exs. 3-
141, 3-183, 3-184). OSHA requests comment on 
whether job hazard analysis and control 
should be limited to jobs with covered MSDs 
or expanded to include jobs in which 
employees are exposed to MSD hazards, even if 
no injuries have been reported.


2. Problem Jobs

   OSHA is proposing that employers must do 
hazard analysis and control in problem jobs. 
The requirement that employers analyze jobs 
with covered MSDs is not limited to the 
injured employee's job or workstation. It 
also includes the workstations of others in 
that job in the establishment who are exposed 
to the same physical work activities and 
conditions and thus the same MSD hazards. If 
the job is performed on more than one work 
shift in the establishment, the analysis must 
include employees from the other shifts who 
are to exposed the same physical work 
activities and conditions and thus the same 
MSD hazards. Including in the analysis other 
employees who perform the same physical work 
activities is an important proactive measure 
for preventing other employees from 
developing the type of MSD that has already 
occurred at least once among employees who 
are doing the same type of tasks. (However, 
the employer would not be required to analyze 
the same job performed at other 
establishments of the company.)
   OSHA is proposing that the analysis must 
include all jobs involving the same physical 
work activities and conditions as those where 
a covered MSD has occurred, regardless of 
whether those jobs have the same job title. 
Using job titles/classifications to determine 
which jobs are analyzed is not necessarily 
relevant in terms of safety and health 
concerns. First, jobs involving the same 
physical work activities and conditions may 
have different titles if there are working 
supervisors/managers, a seniority system, or 
different work shifts. For example, 
``Fabricator II'' on the overnight shift may 
be performing the same physical work 
activities as ``Junior Fabricator'' or 
``Apprentice Fabricator'' on the day shift. 
If so, they all may be at increased risk of 
developing an MSD.
   Second, relying on job titles may group 
together employees who have the same title 
but whose jobs are quite different. For 
example, all ``assembler'' jobs on an auto 
assembly line may not involve the same 
physical work activities or conditions. One 
assembler may bolt on a door, another puts on 
the bumper, while the third one installs the

[[Page 65804]]

dashboard. Analyzing these jobs as one group 
may not be helpful because the physical work 
activities may be so different that the 
employees are not exposed to the same risk 
factors and, as a result, the same controls 
will not work.
   Although employees in jobs in the 
workplace must be included in job hazard 
analysis if their jobs involve the same 
physical work activities and conditions, OSHA 
recognizes that jobs may not have the same 
activities and conditions just because 
employees use the same equipment or are 
working on the same product. For example, 
employees do not have to be included if their 
physical work activities differ in terms of 
activities and conditions. For example, VDT 
users may not be considered to be in the same 
job where one user does inputting for more 
than 4 hours a day at a modular VDT 
workstation and the other uses the VDT on the 
desk only to read and send e-mail messages. 
These two employees have significantly 
different levels of exposure to ergonomic 
risk factors. The fact that employees are 
working on the same motorcycle assembly line 
does not necessarily mean they are performing 
the same assembly job. One employee on that 
line may be screwing on the shock absorbers, 
where he is exposed to awkward postures and 
force, while another employee is exposed to 
forceful lifting and lowering while putting 
on the wheels.
   On the other side of the same job issue, 
where employers show that the problem is 
limited to the employee who reported the MSD, 
they may limit job hazard analysis and 
control to addressing the MSD hazards that 
are affecting that individual employee. They 
also may limit the remaining elements of 
their program, such as training, to that 
individual employee.
   Evidence in the record suggests that there 
are likely to be situations in which the 
physical work activities or conditions only 
pose a risk to the reporting employee. For 
example, an employee in a commercial bakery 
may report a back or shoulder MSD related to 
extended reaches involved in sorting rolls. 
However, other employees who have performed 
the job for several years do not have (and 
never have had) difficulties performing the 
physical work activities of the job. In this 
case, an employer might conclude that the 
problem is limited to the injured employee. 
In this situation, the employer could limit 
the response (e.g., analysis, control, 
training) to physical work activities and 
conditions confronting that injured employee.
   Another example might involve 
manufacturing assembly line job where an 
employee is much shorter than other 
employees. The employee reports persistent 
shoulder and elbow pain, which the employer 
observes is caused by having to reach higher 
than the other employees to perform the job 
tasks. This may also be an appropriate case 
for the employer to focus the analysis and 
control efforts on the employee who reported 
the problem.
   Section 1910.918  What must I do to 
analyze a problem job?
  You must:
  (a) Include in the job hazard analysis all 
of the employees in the problem job or those 
who represent the range of physical 
capabilities of employees in the job;
  (b) Ask the employees whether performing 
the job poses physical difficulties, and, if 
so, which physical work activities or 
conditions of the job they associate with the 
difficulties;

* * * * *
   An ergonomics job hazard analysis is the 
employer's process for pinpointing the work-
related causes of MSDs. It involves examining 
the workplace conditions and individual 
elements or tasks of a job to identify and 
assess the ergonomic risk factors that are 
reasonably likely to be causing or 
contributing to the reported MSDs (Ex. 26-2). 
Job hazard analysis can also be a preventive 
measure. That is, it is used to identify jobs 
and job tasks where MSDs and MSD hazards are 
reasonably likely to develop in the future.
   Job hazard analysis is an essential 
element in the effective control of MSD 
hazards. In many situations, the causes of 
MSD hazards are apparent after discussions 
with the employee and observation of the job, 
but in other jobs the causes may not be 
readily apparent. In part, this is because 
most MSD hazards involve exposure to a 
combination of risk factors (i.e., 
multifactoral hazard). For example, it may 
not be clear in a repetitive motion job 
whether exposure to repetition, force or 
awkward postures is the risk factor that is 
causing the problem.
   The job hazard analysis is also important 
to pinpoint where the risk of harm exists and 
to rule out aspects of the job that do not 
put employees at risk. In this sense, a job 
hazard analysis is an efficient way to help 
employers focus their resources on the most 
likely causes of the problem so that the 
control strategy they select has a reasonable 
expectation of eliminating or materially 
reducing the MSD hazards. It also provides 
employers with the information they need to 
target their efforts to those jobs or tasks 
that may pose the most severe problems.
   In this proposed standard, the job hazard 
analysis also serves another purpose. It is a 
systematic method for confirming whether the 
employer's initial determination that the MSD 
is work-related was correct. This is an 
important step for those employers whose 
ergonomics programs include early 
intervention when employees report MSDs. For 
example, a number of employers said that they 
provide MSD management first (i.e., immediate 
restricted work activity whenever an employee 
reports MSD signs or symptoms), and afterward 
look to see whether they need to take action 
to fix the job. For these employers, the job 
hazard analysis includes two parts: first, 
after careful examination the employee is 
determined by the analysis to be exposed to 
ergonomic risk factors to the extent that a 
covered MSD is reasonably likely to occur; 
and second, the employers has determined that 
no job fix is needed. The job hazard analysis 
steps in such a case help employers who have 
an effective reporting and MSD management 
system and who have relied on a preliminary 
determination to trigger medical intervention 
not to go further than is necessary to 
address the hazard.
   The proposed rule does not require that 
employers use a particular method for 
identifying and analyzing MSD hazards. 
Employers are free to select the method or 
process that best fits the conditions of 
their workplaces, and there are many 
different approaches currently in use (see, 
for example, Exs. 26-2, 26-5). Some employers 
use simple and fairly informal procedures to 
analyze their problem jobs. This is 
especially true for employers who have only 
limited or isolated problems. For example, 
the United States General Accounting Office 
reported that the job hazard analysis process 
for the ergonomics programs they reviewed 
often focused only on the particular job 
element that was thought to be the problem 
(Ex. 26-5). For other employers, the process 
may be very detailed or more formalized. For 
example, their process may include job-task 
breakdown, videotaping or photographing the 
job, job or hazard checklists, employee 
questionnaires, use of measuring tools, or 
biomechanical calculations (Ex. 26-2). For 
example, checklists, together with other 
screening methods such as walk-through 
observational surveys, and worker and

[[Page 65805]]

supervisory interviews, employee symptom or 
discomfort surveys, are recognized ergonomic 
evaluation methods (Exs. 26-2, 26-3, ANSI Z-
365 Draft, 1997, Ex. 26-1264). A few of these 
methods are described in this section. 
Information on other methods of job hazard 
analysis are included in the public docket of 
this rulemaking. (Exs. 26-2, 26-5). According 
to this information and stakeholder comments, 
the job hazard analysis methods employers use 
have the following steps or activities in 
common. OSHA has designed the proposed job 
hazard analysis requirements around these 
steps:

   Obtaining information about the 
specific tasks or actions the job involves;
   Obtaining information about the 
job and problems in it from employees who 
perform the job;
   Observing the job;
   Identifying specific job factors; 
and
   Evaluating those factors (e.g., 
duration, frequency and magnitude) to 
determine whether they are causing or 
contributing to the problem (Ex. 26-2, 26-5, 
26-1370).

   The proposed rule requires that the hazard 
analysis and control of problem jobs be 
conducted by person(s) who have received 
training in the process of analyzing and 
controlling MSD hazards (See Sec. 1910.925).


1. Paragraph (a)

   Paragraph (a) of proposed Sec. 1910.918 
would require that, if the employer does not 
show that the MSD hazards only pose a risk to 
the employee who has the covered MSD, the 
employer must do a job hazard analysis for 
other employees in the problem job as well as 
for the injured employee. Doing a job hazard 
analysis for all employees in a problem job 
ensures that employers have available the 
most complete information about the causes of 
the problem when they are identifying and 
assessing ways to control MSD hazards. Having 
this information also helps to ensure that 
the controls employers select will eliminate 
or materially reduce MSD hazards for all 
employees in the job.
   At the same time, OSHA is aware that 
conducting a job hazard analysis that covers 
all employees in a problem job may be 
burdensome for some employers. For example, 
some employers may have large numbers of 
employees who perform the same job at one 
workplace (e.g., telephone operators, 
customer service representatives, catalog 
sales representatives, data processors, 
nurses aides, package handlers, sorting and 
delivery persons). Conducting a job hazard 
analysis for each one of these employees 
could be time and resource intensive. In 
addition, if the controls are likely to be 
the same for all of the employees in a 
particular job, continuing to conduct job 
hazard analyses after a certain point may 
have diminishing returns.
   Doing job hazard analysis for all 
employees also may be difficult in jobs that 
do not have fixed workstations (e.g., 
beverage delivery, package delivery, 
furniture moving, appliance delivery, home 
repair, visiting nurse, home health aide). 
Some of these jobs may have constantly 
changing work conditions, all of which it may 
not be possible to analyze.
   Therefore, OSHA is proposing in paragraph 
(a) that employers not be required to conduct 
a job hazard analysis for each employee in a 
problem job. Under the Ergonomics Program 
Standard, employers would be allowed to limit 
the number of employees' jobs that they 
analyze, provided that the jobs they do 
analyze represent the range of physical 
capabilities of all of the employees who 
currently are in the job. The intention of 
this provision is to reduce the job hazard 
analysis burdens on employers, who would 
otherwise have to do many individual hazard 
analyses, while at the same time ensuring 
that the process accurately identifies and 
does not underestimate the exposure of 
employees to the MSD hazards in the problem 
job.
   To ensure that the job hazard analysis is 
an accurate estimate of exposure, employers 
would be required to do a job hazard analysis 
for a sufficient number of employees in the 
job (from all work shifts) for the analysis 
to be representative of all of the employees 
in the problem job in terms of their physical 
work activities. To illustrate, to get an 
accurate estimate of exposure to MSD hazards 
of all employees in an assembly line job, an 
employer may have to include the following 
employees in the hazard analysis group:

   Shortest employees in the job 
because they are likely to have to make the 
longest reaches or to have a working surface 
that is too high,
   Tallest employees because they may 
have to maintain the most excessive awkward 
postures (e.g., leaning over the assembly 
line, reaching down with the arms) while 
performing tasks,
   Employees with the smallest hands 
because they may have to exert considerably 
more force to grip and operate hand and power 
tools,
   Employees who work in the coldest 
areas of the workplace because they may have 
to exert more force to perform repetitive 
motions, and
   Employees who wear bifocals 
because they may be exposed to awkward 
postures (e.g., bending neck back to see).


2. Paragraph (b)--``Ask employees''

   Paragraph (b) of this section would 
require employers to consult with employees 
as part of the job hazard analysis process. 
Talking or consulting with employees in a 
problem job helps to ensure that the employer 
has the complete picture about the problems 
in a job, especially if the job hazard 
analysis includes only a limited number of 
employees. Where the job hazard analysis is 
limited, consulting with all employees during 
the hazard analysis and control process is an 
effective way to gain employee acceptance and 
minimize resistance to change when 
implementing controls and job modifications 
become necessary. Nonetheless, for the 
reasons discussed in paragraph (a) of this 
section, OSHA is not proposing to require 
that employers consult with every employee 
during the job hazard analysis process, 
provided that employers consult with at least 
those employees whose jobs are being 
analyzed.
   Many employers have told OSHA that talking 
with employees is a quick and easy way to 
find out what kind of problems are in the job 
(Ex. 26-1370). They said that talking with 
employees is often the best way to identify 
the causes of the problem and to identify the 
most cost-effective solutions to it (Ex. 26-
1370).
   Many stakeholders have said that employee 
input at the job hazard analysis stage is 
essential (Ex. 26-1370). A comment from 
Johnson & Johnson sums up this opinion:

  Hazards cannot be addressed efficiently 
without an accurate evaluation of the 
situation. The line employee is one of the 
best sources of this information * * * [they 
are] local process experts (Ex. 3-232).

   Discussions with employers who have set up 
ergonomics programs, pursuant to corporate 
settlement agreements with OSHA, also confirm 
the necessity of employee input in the

[[Page 65806]]

job hazard analysis (Ex. 26-1420). A number 
of these employers said that employees need 
to be involved in the analysis and control 
process because ``no one knows the job better 
than the person who does it'' (Ex. 26-1420). 
Other stakeholders echo this belief, saying 
that employees have the best understanding of 
what it takes to perform each task in a job, 
and thus, what parts of the job are the 
hardest to perform or pose the biggest 
difficulties:

  ``Job analysis should include input from 
the workers themselves. The employees can 
best tell what conditions cause them pain, 
discomfort, and injuries. They often have 
easy and practical suggestions on how such 
problems can be alleviated.'' American 
Federation of State, County and Municipal 
Employees (Ex. 3-164).

   Involving employees, in addition to 
helping to ensure that the job hazard 
analysis is correct, can make the job hazard 
analysis and control process more efficient. 
Employees can help employers pinpoint the 
causes of problems more quickly and, 
according to a number of stakeholders, 
employees often come up with some of the best 
practical, no-cost or cost-effective, 
solutions (Ex. 26-1370). The American Health 
Care Association agrees:

  Employers and employees alike who work in 
the industry are in the best possible 
position to identify risk factors in their 
workplace and to develop prevention methods 
that concentrate on the significant problems 
unique to their particular industry's 
environment (Ex. 3-112).

   There are many different ways in which 
employers can comply with the requirement to 
ask employees about the problem job, and OSHA 
does not intend to require employers to use a 
certain method. Employers are free to use any 
method to get information from employees 
about the problems in the job. Employers may 
do something as simple as informally talking 
with employees while observing the job being 
performed. Consulting with employees in the 
problem job can be made part of a regular 
staff or production meeting or ``toolbox 
chat.'' Employers may ask employees through 
surveys/questionnaires and more formal 
employee interviews. Many employers have 
developed very effective tools for gathering 
important job information from employees who 
do the job.

  AMP Inc., a manufacturer of electronic 
components, with 300 employees, uses a one-
page ``Ergonomic Evaluation Form'' that asks 
employees to answer simple ``yes/no'' 
questions about the employee's ease and 
comfort when performing certain job tasks. 
After the company's ergonomics team 
(comprised of line employees) reviews the 
form, a member of the team interviews the 
employee. (Ex. 26-5).

   Paragraph (b) would require that employers 
ask employees whether performing the job 
poses physical difficulties. This language 
should not be interpreted as requiring 
employers to conduct symptom or discomfort 
surveys. Rather, the intention of this 
provision is for employers to ask employees 
to help identify the physical work 
activities, job conditions and ergonomic risk 
factors that may be making the job difficult 
to perform.
   Section 1910.918  What must I do to 
analyze a problem job?

  You must:

 * * * * *
  (c) Observe the employees performing the 
job to identify which of the following 
physical work activities, workplace 
conditions and ergonomic risk factors are 
present:

------------------------------------------------------------------------
  PHYSICAL WORK ACTIVITIES
       AND CONDITIONS         ERGONOMIC RISK FACTORS THAT MAY BE PRESENT
------------------------------------------------------------------------
(1) Exerting considerable    (i) Force
 physical effort to          (ii) Awkward postures
 complete a motion           (iii) Contact stress
------------------------------------------------------------------------
(2) Doing same motion over   (i) Repetition
 and over again              (ii) Force
                             (iii) Awkward postures
                             (iv) Cold temperatures
------------------------------------------------------------------------
(3) Performing motions       (i) Repetition
 constantly without short    (ii) Force
 pauses or breaks in         (iii) Awkward postures
 between                     (iv) Static postures
                             (v) Contact stress
                             (vi) Vibration
------------------------------------------------------------------------
(4) Performing tasks that    (i) Awkward postures
 involve long reaches        (ii) Static postures
                             (iii) Force
------------------------------------------------------------------------
(5) Working surfaces are     (i) Awkward postures
 too high or too low         (ii) Static postures
                             (iii) Force
                             (iv) Contact stress
------------------------------------------------------------------------
(6) Maintaining same         (i) Awkward posture
 position or posture while   (ii) Static postures
 performing tasks            (iii) Force
                             (iv) Cold temperatures
------------------------------------------------------------------------
(7) Sitting for a long time  (i) Awkward posture
                             (ii) Static postures
                             (iii) Contact stress
------------------------------------------------------------------------
(8) Using hand and power     (i) Force
 tools                       (ii) Awkward postures
                             (iii) Static postures
                             (iv) Contact stress
                             (v) Vibration
                             (vi) Cold temperatures
------------------------------------------------------------------------
(9) Vibrating working        (i) Vibration
 surfaces, machinery or      (ii) Force
 vehicles                    (iii) Cold temperatures
------------------------------------------------------------------------
(10) Workstation edges or    (i) Contact stress
 objects press hard into
 muscles or tendons
------------------------------------------------------------------------
(11) Using hand as a hammer  (i) Contact stress
                             (ii) Force
------------------------------------------------------------------------
(12) Using hands or body as  (i) Force
 a clamp to hold object      (ii) Static postures
 while performing tasks      (iii) Awkward postures
                             (iv) Contact stress
------------------------------------------------------------------------
(13) Gloves are bulky, too   (i) Force
 large or too small          (ii) Contact stress
------------------------------------------------------------------------

[[Page 65807]]

 
                             MANUAL HANDLING
           (Lifting/lowering, pushing/pulling, and carrying)
------------------------------------------------------------------------
(14) Objects or people       (i) Force
 moved are heavy             (ii) Repetition
                             (iii) Awkward postures
                             (iv) Static postures
                             (v) Contact stress
------------------------------------------------------------------------
(15) Horizontal reach is     (i) Force
 long (Distance of hands     (ii) Repetition
 from body to grasp object   (iii) Awkward postures
 to be handled)              (iv) Static postures
                             (v) Contact stress
------------------------------------------------------------------------
(16) Vertical reach is       (i) Force
 below knees or above the    (ii) Repetition
 shoulders (Distance of      (iii) Awkward postures
 hands above the ground      (iv) Static postures
 when object is grasped or   (v) Contact stress
 released)
------------------------------------------------------------------------
(17) Objects or people are   (i) Force
 moved significant distance  (ii) Repetition
                             (iii) Awkward postures
                             (iv) Static postures
                             (v) Contact stress
------------------------------------------------------------------------
(18) Bending or twisting     (i) Force
 during manual handling      (ii) Repetition
                             (iii) Awkward postures
                             (iv) Static postures
------------------------------------------------------------------------
(19) Object is slippery or   (i) Force
 has no handles              (ii) Repetition
                             (iii) Awkward postures
                             (iv) Static postures
------------------------------------------------------------------------
(20) Floor surfaces are      (i) Force
 uneven, slippery or sloped  (ii) Repetition
                             (iii) Awkward postures
                             (iv) Static postures
------------------------------------------------------------------------

* * * * *


1. Paragraph (c)

   Paragraph (c) of proposed Sec. 1910.918 
requires employers to do the following:

   Observe the employee performing 
the job,
   Identify whether any of the 
physical work activities or conditions listed 
in the section are present, and
   Identify whether any of the 
relevant ergonomic risk factors listed in the 
section are involved in the particular work 
activity or condition.

   a. ``Observe'' employees performing the 
job. The proposed rule requires employers to 
watch employees perform the physical work 
activities of the job and look at the 
conditions under which the job is performed. 
Job observation allows the employer to see 
how the employee does the job and provides 
information about the workstation layout, 
tools, equipment and general environmental 
conditions in the workplace.
   There are several ways employers may 
comply with the observation requirement of 
the proposed standard. Employers may simply 
watch employees perform the job tasks. Often, 
all it takes to identify the problem and how 
to solve it is to watch the employee do the 
job. For example, watching a data processor 
reaching to use the mouse because the 
keyboard tray is not long enough to 
accommodate it may be all it takes to 
identify the likely cause of the employee's 
shoulder pain.
   Videotaping the job is a common practice 
for ``observing'' jobs. A number of 
employers, especially in situations where the 
work activities are complex or the causes of 
the problem may not be easily identifiable, 
say that they videotape or photograph the 
job. These employers find it helpful to be 
able to refer to a record of the job while 
evaluating the ergonomic risk factors or 
identifying and assessing possible control 
measures (Ex. 26-1370).
   ``Job task analysis'' is another job 
hazard analysis process that is widely used. 
This process involves breaking the job down 
into its various discrete elements or actions 
and then identifying and evaluating or 
measuring the extent to which the risk 
factors that are present in the physical work 
activities and conditions are reasonably 
likely to be contributing to the MSD hazard 
(Exs. 26-2, 26-1247). To do a job task 
breakdown, a number of employers look at the 
job as a series of individual, distinct tasks 
or steps (Exs. 26-2, 26-5, 26-1247, 26-1370). 
Focusing on each task allows for easier 
identification of the physical activities 
required to complete the job. While observing 
the job employers record a description of 
each task for use in later risk factor 
analysis as well as other information that is 
helpful in completing the analysis:

   Tools or equipment used to perform 
task,
   Materials used in task,
   Amount of time spent doing each 
task,
   Workstation dimensions and layout,
   Weight of items handled,
   Environmental conditions (cold, 
glare, blowing air),
   Vibration and its source,
   Personal protective equipment worn 
(Ex. 26-2).

   Many employers use hazard identification 
and analysis checklists to help focus the job 
observation process. OSHA agrees that well 
designed checklists, when used in the context 
for which they are intended, do provide a 
range of employers, especially small business 
owners, with effective alternatives to hiring 
a consultant. There are many ways in which 
checklists may be useful: identifying 
physical work activities and conditions, 
identifying ergonomic risk factors, 
evaluating jobs, prioritizing jobs for 
further analysis, and providing a systematic 
review of risk factors.
   b. Identify physical work activities, 
workplace conditions and ergonomic risk 
factors. Paragraph (c) would require that, as 
part of the job observation, employers 
identify the physical work activities, 
workplace conditions, and ergonomic risk 
factors present in the problem job that may 
be causing or contributing to the MSD hazard. 
Identifying the presence of physical work 
activities and conditions is the starting 
point for pinpointing the hazards the job may 
involve. Once the applicable activities and 
conditions are identified, employers would 
have to determine whether any of the 
ergonomic risk factors that OSHA has listed 
as being potentially relevant to those 
activities and conditions are present.
   c. Ergonomic risk factors. Ergonomic risk 
factors are the aspects of a job or task that 
impose a biomechanical stress on the worker. 
Ergonomic risk factors are the synergistic

[[Page 65808]]

elements of MSD hazards. In the Health 
Effects section of this preamble (section V), 
OSHA discusses the large body of evidence 
supporting the finding that exposure to 
ergonomic risk factors in the workplace can 
cause or contribute to the risk of developing 
an MSD. This evidence, which includes 
thousands of epidemiologic studies, 
laboratory studies, and extensive reviews of 
the existing scientific evidence by NIOSH and 
the National Academy of Science, shows that 
the following ergonomic risk factors are most 
likely to cause or contribute to an MSD:

    Force
    Repetition
    Awkward postures
    Static postures
    Vibration
    Contact stress
    Cold temperatures

   These risk factors are described briefly 
below (a more detailed discussion of 
ergonomic risk factors is included in the 
Health Effects section):
   Force. Force refers to the amount of 
physical effort that is required to 
accomplish a task or motion. Tasks or motions 
that require application of higher force 
place higher mechanical loads on muscles, 
tendons, ligaments, and joints (Ex. 26-2). 
Tasks involving high forces may cause muscles 
to fatigue more quickly. High forces also may 
lead to irritation, inflammation, strains and 
tears of muscles, tendons and other tissues.
   The force required to complete a movement 
increases when other risk factors are also 
involved. For example, more physical effort 
may be needed to perform tasks when the speed 
or acceleration of motions increases, when 
vibration is present, or when the task also 
requires awkward postures.
   Force can be internal, such as when 
tension develops within the muscles, 
ligaments and tendons during movement. Force 
can also be external, as when a force is 
applied to the body, either voluntarily or 
involuntarily. Forceful exertion is most 
often associated with the movement of heavy 
loads, such as lifting heavy objects on and 
off a conveyor, delivering heavy packages, 
pushing a heavy cart, or moving a pallet. 
Hand tools that involve pinch grips require 
more forceful exertions than those that allow 
other grips, such as power grips.
   Repetition. Repetition refers to 
performing a task or series of motions over 
and over again with little variation. When 
motions are repeated frequently (e.g., every 
few seconds) for prolonged periods (e.g., 
several hours, a work shift), fatigue and 
strain of the muscle and tendons can occur 
because there may be inadequate time for 
recovery. Repetition often involves the use 
of only a few muscles and body parts, which 
can become extremely fatigued while the rest 
of the body is little used.
   Awkward postures. Awkward postures refer 
to positions of the body (e.g., limbs, 
joints, back) that deviate significantly from 
the neutral position 1 while job 
tasks are being performed. For example, when 
a person's arm is hanging straight down 
(i.e., perpendicular to the ground) with the 
elbow close to the body, the shoulder is said 
to be in a neutral position. However, when 
employees are performing overhead work (e.g., 
installing or repairing equipment, grasping 
objects from a high shelf) their shoulders 
are far from the neutral position. Other 
examples include wrists bent while typing, 
bending over to grasp or lift an object, 
twisting the back and torso while moving 
heavy objects, and squatting. Awkward 
postures often are significant contributors 
to MSDs because they increase the work and 
the muscle force that is required.
---------------------------------------------------------------------------
  \1\ Neutral posture is the position of a 
body joint has requires the least amount of 
muscle activity to maintain. For example, the 
wrist is neutral in a handshake position, the 
shoulder is neutral when the elbow is near 
the waist, the back is neutral when standing 
up straight.
---------------------------------------------------------------------------
   Static postures. Static postures (or 
``static loading'') refer to physical 
exertion in which the same posture or 
position is held throughout the exertion. 
These types of exertions put increased loads 
or forces on the muscles and tendons, which 
contributes to fatigue. This occurs because 
not moving impedes the flow of blood that is 
needed to bring nutrients to the muscles and 
to carry away the waste products of muscle 
metabolism. Examples of static postures 
include gripping tools that cannot be put 
down, holding the arms out or up to perform 
tasks, or standing in one place for prolonged 
periods.
   Vibration. Vibration is the oscillatory 
motion of a physical body. Localized 
vibration, such as vibration of the hand and 
arm, occurs when a specific part of the body 
comes into contact with vibrating objects 
such as powered hand tools (e.g., chain saw, 
electric drill, chipping hammer) or equipment 
(e.g., wood planer, punch press, packaging 
machine). Whole-body vibration occurs when 
standing or sitting in vibrating environments 
(e.g., driving a truck over bumpy roads) or 
when using heavy vibrating equipment that 
requires whole-body involvement (e.g., 
jackhammers).
   Contact stress. Contact stress results 
from occasional, repeated or continuous 
contact between sensitive body tissue and a 
hard or sharp object. Contact stress commonly 
affects the soft tissue on the fingers, 
palms, forearms, thighs, shins and feet. This 
contact may create pressure over a small area 
of the body (e.g., wrist, forearm) that can 
inhibit blood flow, tendon and muscle 
movement and nerve function. Examples of 
contact stress include resting wrists on the 
sharp edge of a desk or workstation while 
performing tasks, pressing of tool handles 
into the palms, especially when they cannot 
be put down, tasks that require hand 
hammering, and sitting without adequate space 
for the knees.
   Cold temperatures. Cold temperatures refer 
to exposure to excessive cold while 
performing work tasks. Cold temperatures can 
reduce the dexterity and sensitivity of the 
hand. Cold temperatures, for example, cause 
the worker to apply more grip force to hold 
hand tools and objects. Also, prolonged 
contact with cold surfaces (e.g., handling 
cold meat) can impair dexterity and induce 
numbness. Cold is a problem when it is 
present with other risk factors and is 
especially problematic when it is present 
with vibration exposure.
   Of these risk factors, evidence in the 
Health Effects chapter shows that force 
(i.e., forceful exertions), repetition, and 
awkward postures, especially when occurring 
at high levels or in combination, are most 
often associated with the occurrence of MSDs. 
Exposure to one ergonomic risk factor may be 
enough to cause or contribute to a covered 
MSD. For example, a job task may require 
exertion of so much physical force that, even 
though the task does not involve additional 
risk factors such as awkward postures or 
repetition, an MSD is likely to occur. For 
example, using the hand or knee as a hammer 
(e.g., operating a punch press or using the 
knee to stretch carpet during installation) 
alone may expose the employee to such a 
degree of physical stress that the employee 
has a significant risk of being harmed.

[[Page 65809]]

   However, most often ergonomic risk factors 
act in combination to create a hazard. The 
evidence in the Health Effects section shows 
that jobs that have multiple risk factors 
have a greater likelihood of causing an MSD, 
depending on the duration, frequency and/or 
magnitude of exposure to each. Thus, it is 
important that ergonomic risk factors be 
considered in light of their combined effect 
in causing or contributing to an MSD. This 
can only be achieved if the job hazard 
analysis and control process includes 
identification of all the ergonomic risk 
factors that may be present in a job. If they 
are not identified, employers will not have 
all the information that is needed to 
determine the cause of the covered MSD or 
understand what risk factors need to be 
reduced to eliminate or materially reduce the 
MSD hazards.
   Although certain of the risk factors 
described above are easy to identify and it 
is not difficult to understand why they may 
be likely to create hazardous exposures, 
others are not as apparent or observable. 
Employers who already have ergonomics 
programs and persons who manage ergonomics 
programs should not have difficulty 
identifying risk factors in the workplace. 
Because these persons have training and 
experience, ergonomic risk factors are likely 
to be familiar concepts for them. Through the 
process of developing and implementing their 
ergonomics programs these persons have gained 
a good working knowledge of the ergonomic 
risk factors that are most likely to be 
present in their workplaces.
   For those employers who are just beginning 
their programs and have little or no training 
and experience dealing with ergonomic risk 
factors, OSHA has tried to make the process 
of identifying them as workable as possible. 
Therefore, in the proposed rule OSHA has 
taken the ergonomic risk factors and the 
combination of risk factors most associated 
with the occurrence of MSDs and tried to 
present them in ways that those with more 
limited knowledge about ergonomics can 
readily identify. In this way, the ergonomic 
risk factors the proposed rule covers are 
presented in terms of specific and physically 
observable work activities and conditions. If 
any of these activities or conditions are 
present, the table in Sec. 1910.918(c) tells 
employers which risk factors are likely to be 
relevant.
   OSHA is proposing that employers use this 
list of physical work activities or 
conditions as a starting point for hazard 
evaluation, for several reasons. First, the 
list of activities and conditions is easy for 
employers to understand because they will be 
able to translate them to their own 
workplaces more readily than would be the 
case for ergonomic to risk factors. For 
example, ``hand used as a hammer'' is more 
easily understood than the term ``contact 
stress,'' and ``long reaches'' graphically 
explains an ``awkward posture'' that may be a 
problem.
   Second, the list helps employers quickly 
focus on the aspects of a job that are most 
likely to be associated with covered MSDs. At 
the same time, the list also identifies the 
risk factors that are most likely to be 
associated with the activities and/or 
conditions, which should help employers 
further focus their analysis. In this way the 
list serves as a bridge to the combinations 
of risk factors that studies have shown to be 
associated with an increased risk of 
developing work-related MSDs.
   Third, having employers start the MSD 
identification and evaluation process with 
this list ensures that the analysis will be 
comprehensive. This is because the list 
includes the major components of work that 
have been associated with MSDs.
   c. Physical work activities and 
conditions. The physical work activities and 
conditions OSHA has included in the proposed 
rule cover the basic physical aspects of jobs 
and workstations. These aspects include:

   Physical demands of work;
   Workplace and workstation 
conditions and layout;
   Characteristics of object(s) that 
are handled or used; and
   Environmental conditions.

   The following table shows the physical 
work activities and workplace conditions that 
are associated with those physical aspects:

------------------------------------------------------------------------
  PHYSICAL ASPECTS OF        EXAMPLES OF PHYSICAL WORK ACTIVITIES AND
 JOBS AND WORKSTATIONS    CONDITIONS ASSOCIATED WITH THE PHYSICAL ASPECT
------------------------------------------------------------------------
Physical demands of       Exerting considerable physical effort
 work                     to complete a motion
                          Doing the same motion over and over
                          again
                          Performing motions constantly without
                          short pauses or breaks in between
                          Maintaining same position or posture
                          while performing tasks
                          Sitting for a long time
                          Using hand as a hammer
                          Using hands or body as a clamp to hold
                          object while performing tasks
                          Objects or people are moved
                          significant distances
------------------------------------------------------------------------
Layout and condition of   Performing tasks that involve long
 the workplace or         reaches
 workstation              Working surfaces too high or too low
                          Vibrating working surfaces, machinery
                          or vehicles
                          Workstation edges or objects press
                          hard into muscles or tendons
                          Horizontal reach is long
                          Vertical reach is below knees or above
                          the shoulders
                          Floor surfaces are uneven, slippery or
                          sloped
------------------------------------------------------------------------
Characteristics of the    Using hand and power tools
 object(s) handled        Gloves bulky, too large or too small
                          Objects or people moved are heavy
                          Object is slippery or has no handles
------------------------------------------------------------------------

[[Page 65810]]

 
Environmental             Cold temperatures
 Conditions
------------------------------------------------------------------------

   Employers who examine the job in which a 
covered MSD occurred to identify the physical 
work activities and workplace conditions in 
paragraph (c) and then evaluate the risk 
factors that OSHA has identified as 
potentially relevant, will be considered to 
be in compliance with the hazard analysis 
requirements of the proposed rule.
   Exerting considerable force to complete a 
motion (i.e., forceful exertions). It is not 
difficult to understand why jobs that require 
employees to apply a lot of physical effort 
may involve significant exposure to ergonomic 
risk factors and pose an increased risk of 
injury. For example, it is easy to see how 
much biomechanical stress employees are under 
when you see them grimace while trying to 
loosen lug nuts on an old tire, shift body 
weight and stance to wrench open stuck 
valves, or stiffen the body in order to lift 
a heavy or bulky object from the floor of a 
truck. Simply put, forceful exertions like 
these take more out of a person than tasks 
that do not require much physical effort. An 
easy way to confirm whether a task involves 
forceful exertions is to ask workers who are 
doing the task, or to try to do it yourself.
   Performing forceful exertions requires an 
application of considerable contraction 
forces by the muscles, which causes them to 
fatigue rapidly. The more force that must be 
applied in the exertion, the more quickly the 
muscles will fatigue or become strained. 
Excessive or prolonged exposure to forceful 
exertions also leads to overuse of muscles 
and may result in muscle strain, soreness and 
damage. Performing forceful exertions can 
also irritate tendons, joints and discs, 
which leads to inflammation, fluid build up, 
and constriction of blood vessels and nerves 
in the area. Increased compression of nerves 
from the pressure imposed by inflamed tendons 
or muscle contractions may cause disorders of 
the nervous system (e.g., carpal tunnel 
syndrome and other nerve entrapment 
disorders).
   Injuries related to forceful exertions can 
occur in any tissue or joint. As mentioned 
above, back injuries from overexertion are a 
leading cause of workplace injuries and 
workers' compensation cases. A number of 
studies also show that repeated forceful 
exertions of the hands and arms are 
associated with work-related MSDs (e.g., 
using tools, pinching or pushing with the 
fingers).
   Lifting and carrying heavy objects are 
usually the tasks that come to mind as 
examples of forceful lifting tasks, but high 
forces are also involved in other types of 
jobs. These include jobs that require 
employees to apply pinch forces with their 
fingers (e.g., picking up or placing small 
items on an assembly line with the fingers), 
static forces (e.g., applying a lot of 
physical effort to put the last turn on a 
screw, pulling hard on a 30-inch wrench to 
loosen a bolt), and dynamic forces (e.g., 
tossing objects into containers). (Forceful 
lifting/lowering, pushing/pulling and 
carrying are discussed under ``Manual 
Handling'' activities and conditions below.)
   Force. Performing forceful exertions may 
place excessive mechanical loads on the 
tissues (e.g., muscles, tendons, other 
tissues) that are used to exert or transfer 
force from the skeletal system to the work. 
Heavy loading of tissues causes the body to 
fatigue more quickly, and increases the 
amount of time tissues need to recover from 
the effects of such exertions. Tasks 
involving prolonged forceful exertions or 
excessive force alone can result in harm, 
including muscle strain or tears. However, 
where other risk factors are present, 
especially frequent repetition of exertions, 
awkward postures, or static postures they add 
to the force required to accomplish the 
exertion. In such cases, even tasks involving 
moderate levels of force may lead to injury 
and tissue damage because there may not be 
adequate recovery time. Forceful exertions 
can also cause or contribute to nerve 
disorders. Application of high levels of 
muscle and tendon tension and the contraction 
necessary to perform forceful exertions may 
increase pressure on entrapped/confined 
nerves and other tissues. For example, many 
employees who perform cutting and trimming 
tasks on poultry production lines have 
developed carpal tunnel syndrome (e.g., a 
nerve entrapment disorder) from repeated 
forceful exertions of the hands and wrists to 
cut through the skin, meat, or bone. The 
continuous application of muscle-tendon 
movements in the hand and wrist inflames the 
tendons and puts pressure on the median nerve 
running through the carpal tunnel in the 
wrist to the hand. In addition, if the 
tendons and other soft tissue in the wrist or 
hand do not have adequate recovery time from 
the forceful exertions, they can become 
inflamed enough to put pressure on the median 
nerve.

Examples:
  Pulling meat off a bone on a meat cutting 
    assembly line,
  Pulling hard to tighten bolts or screws in 
    assembly line work,
  Squeezing hard on a pair of pliers, or
  Pulling hard on a long wrench to tighten or 
    loosen a bolt

   Awkward postures. Working in awkward 
postures increases the amount of force needed 
to accomplish an exertion. Awkward postures 
create conditions where the transfer of power 
from the muscles to the skeletal system is 
inefficient. To demonstrate this, hold a dry 
marker in your hand with your wrist straight 
and then let someone try to pull it out of 
your hand. Now hold the marker with your 
wrist bent toward the inside of your forearm 
as far as you can and hold the marker while 
someone tries to pull it out of your hand. To 
overcome muscle inefficiency, employees must 
apply more force both to initiate and 
complete the motion or exertion. In general, 
the more extreme the postures (i.e., the 
greater the postures deviate from neutral 
positions), the more inefficiently the 
muscles operate and, in turn, the more force 
is needed to complete the task. Thus, awkward 
postures make forceful exertions even more 
forceful, from the standpoint of the muscle, 
and increase the amount of recovery time that 
is needed.

Examples:
   Throwing 20-pound bundles of 
    printed material to overhead conveyors.
   Bolting or screwing a new part 
    into an auto that is on a lift.

   Contact stress. Mechanical friction (i.e., 
pressure of a hard object on soft tissues and 
tendons) causes contact stress, which is 
increased when tasks require forceful 
exertion. The addition of force adds to the 
friction created by the repeated or 
continuous contact between the soft tissues 
and a hard object. It also adds to the 
irritation of tissues and/or to the pressures 
on parts of the body, which can further 
inhibit blood flow and nerve conduction.

[[Page 65811]]

Examples:
   Using the hand as a hammer is an 
    example of force plus contact stress.
   Operating a carpet kicker with the 
    knees

   Doing the same motions over and over again 
(i.e., repetitive motions). Many jobs that 
involve repetition of the same job again and 
again are apparent even upon cursory 
observation: assembly line jobs where motions 
are repeated every few seconds, data 
processing jobs, directory assistant 
operators, court reporting, letter and 
package sorting. Repetitive motion jobs 
include performance of identical motions 
again and again, but also include repeating 
multiple tasks where the motions of each task 
are very similar and involve the same muscles 
and tissues.
   Evidence in the Health Effects section 
shows a strong association between the 
occurrence of MSDs and jobs involving 
exposure to repetitive motions. The joints 
are most susceptible to repetitive motion 
injuries, especially the wrists, fingers, 
shoulders, and elbows. Repetitive work that 
is done with the foot (e.g., operating foot 
activated controls) or knees (e.g., climbing 
ladders or using a carpet kicker) may also 
result in an MSD.
   Repetition. Motions that are repeated 
again and again with little variation may 
cause fatigue and overuse of the muscles, 
tendons, and joints that are involved in the 
exertion (Ex. 26-2). Overuse leads to muscle 
strain, inflammation of joints and tendons, 
and increased pressure on nerves. As exposure 
continues or intensifies (e.g., pace 
increases) tears in muscle fibers occur. The 
more frequently repetitive motions are 
performed (i.e., fast pace), the longer they 
are performed (i.e., long sessions without a 
break or more than 8 hours a day), and/or the 
more risk factors that are involved, the 
greater the risk of injury due to overuse and 
lack of adequate recovery time.
   Exposure to repetition alone can cause 
MSDs. This is especially true where the same 
motions or tasks are performed for an 
extended period and/or where the task cycle 
is short (e.g., the task cycle lasts only a 
few seconds). The risk of injury is 
significantly increased when other risk 
factors are also present.

Examples:
   Packing bags of potato chips into 
    shipping boxes.
   Intensive keying of information 
    into computer.

   Force. The effects of repetitive motions 
on the body are increased when high forces 
are involved. Repetition of forceful 
exertions requires employees to exert more 
muscle tension and contraction, which leads 
to muscle fatigue. When repetitive motions 
involve high forces, even more recovery time 
is required for muscles than repetitive 
motions that do not contain high forces.
   Prolonged repetition of forceful exertions 
also may result in inflammation in tendons 
and joints. In addition, the added muscle 
tension from forceful repetitive motions also 
puts more pressure on surrounding nerves and 
other confined tissues. This may cause damage 
to entrapped nerves and tissues.

Examples:
   Filleting fish in a processing 
    plant, or
   Constantly using screwdriver to 
    drive screws into wood.

   Awkward postures. Performing repetitive 
motions in awkward postures (e.g., bent 
wrists, extended arms) adds significantly to 
the muscular effort required to perform each 
motion. The added force hastens the onset of 
fatigue and increases the likelihood of 
injury from overuse.
   In some cases, awkward postures may be so 
extreme that they can turn a low risk 
repetitive motion job into a high risk job. 
For example, an assembly job involving 
tightening bolts may not pose any problem 
where objects being assembled are at mid-
torso level. However, the same job at the 
same pace may be hazardous if tightening the 
bolts involves overhead work.

Examples:
   Sorting parts or letters into bins 
    of different heights and locations (e.g., 
    behind the employee), or
   Working with bent wrists to 
    assemble small circuit breakers.

   Cold temperatures. Cold temperature adds 
to the amount of force necessary to perform 
repetitive motions and increases the 
perception of stiffness of the joints and 
tissues in the body. Exposure to cold 
temperatures triggers the body to redirect 
blood flow from the extremities (hands, feet, 
and ears) in order to conserve body heat. 
When the blood supply to the hands is 
diminished, the manual dexterity and tactile 
sensitivity of the fingers are reduced. 
Employees compensate by applying more force 
to the muscles in the hands and fingers in 
order to complete the motions.
   Exposure to cold temperatures also reduces 
the ability of tissues to recover from 
repetitive exertions. The reduction in blood 
flow reduces the delivery of oxygen and 
energy to tissues, and the removal of heat 
and waste products. This reduction in blood 
flow can also lead to pain and injury.

Example:
   Trimming chicken or turkey breasts 
    in a processing plant, or
   Working in an operating room of a 
    hospital.

   Performing motions constantly without 
short pauses or breaks in between (i.e., 
inadequate recovery time). Jobs that do not 
provide short pauses or breaks between 
motions or task cycles are often a problem 
because there may not be adequate time for 
muscles to recover from the effects of the 
exertion before the motion must be repeated. 
If there are no pauses between motions or the 
pauses are too short, the muscles cannot 
recover to the rested condition. Thus, the 
effects of the forces on the muscles 
accumulates and the muscles become fatigued 
and strained. The lack of adequate recovery 
time often occurs in jobs involving highly 
repetitive tasks. This happens when task 
cycle lengths are very short, which also 
means that the job involves a high number of 
cycle repetitions per minute. For example, 
some research shows that tendons and muscles 
in the wrists may not be able to recover 
where repeated task cycles are less than 5 
seconds in length, that is, they are repeated 
more than 12 times per minute (Ex. 26-2).
   Jobs involving constant muscle activity 
(static contractions) also may not provide 
adequate recovery time. These types of jobs 
may involve continuously holding hand tools 
(e.g., knife, paint brush, staple gun), which 
means that employees have constant exposure 
to static postures and low contraction 
forces.
   The longer motions or job tasks are 
performed, the less likely that there will be 
adequate recovery time. The accumulation of 
exposure leads to muscle fatigue or overuse. 
In addition, where the intensity of exposure 
is greater, for example, in repetitive motion 
jobs that involve exposure to additional risk 
factors (e.g., force, awkward postures, or 
static postures), the increased forces 
required for the exertion also increase the 
amount of recovery time that is needed. Any 
part of the musculoskeletal system involved 
in moving the body is subject to injury where 
there is inadequate recovery time, and the 
recovery times needed vary by body part. For 
example, although employees may

[[Page 65812]]

not be at high risk for forearm injury if 
task cycles are 25 seconds long or not 
repeated more than 3 times per minute, they 
may be at high risk of shoulder injury under 
this regimen.
   Repetition. As task cycles in repetitive 
motion jobs get shorter (and the number of 
repetitions per minute increases) employees 
are at greater risk of injury. Where task 
cycles are short, the same muscles are in 
constant use and the muscles get no rest from 
the force required to perform the task cycle. 
In addition, where task cycles are short, 
there is little variation in the physical 
demands of the tasks, which would allow some 
muscles to rest while others are in use. 
Thus, muscle fatigue continues to accumulate 
and may lead to muscle-tendon strain.
   The following table shows the frequency of 
repetition and length of tasks cycles that 
are associated with increased risk of injury 
in repetitive motion jobs:

--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                    VERY HIGH RISK IF
                BODY AREA                       FREQUENCY REPETITION PER MINUTE                     LEVEL OF RISK                  MODIFIED  BY EITHER:
--------------------------------------------------------------------------------------------------------------------------------------------------------
Shoulder                                   More than 2.5                              High                                       High external force,
                                                                                                                                  speed, high static
                                                                                                                                  load, extreme posture,
--------------------------------------------------------------------------------------------------------------------------------
Upper arm/elbow                            More than 10                               High                                       Lack of training, high
                                                                                                                                  output demands, lack
                                                                                                                                  of control,
--------------------------------------------------------------------------------------------------------------------------------
Forearm/wrist                              More than 10                               High                                       Long duration of
                                                                                                                                  repetitive work
--------------------------------------------------------------------------------------------------------------------------------
Finger                                     More than 200                              High
--------------------------------------------------------------------------------------------------------------------------------------------------------

(Kilbom, 1994)

Examples:
   Deboning operation in a poultry 
    plant where the cycle time is short and 
    the birds are conveyed at a fast rate,
   Inserting coils to build an inner-
    spring mattress at a rate of one per 
    second, or
   Letter sorting.

   Force. Motions involving high forces, like 
highly repetitive motions, put a lot of 
mechanical stress on the body because muscles 
must apply considerably more contraction 
forces to accomplish the task. Thus, these 
tasks require significantly more muscle 
recovery time as compared to tasks that do 
not involve high force. If recovery time is 
not adequate, these employees are at greater 
risk of injury due to fatigue and 
overexertion.

Examples:
   The chuck boner job in a beef 
    processing plant, or
   Shaking crab meat from Alaskan 
    king crab legs.
   Awkward postures, static postures, contact 
stress, vibration. The presence of any or all 
of these risk factors in a job, particularly 
jobs involving repetitive motion or forceful 
exertion, increases the force already 
required to perform job tasks and, therefore, 
increases the amount of time muscles need to 
recover from the exertions the task requires. 
If the recovery time is not adequate, the 
presence of these risk factors hastens the 
onset of fatigue and the effects associated 
with overuse of muscles, joints and tendons.

Examples:
   Attaching doors on the bathroom 
    vanity assembly line, or
   Capping and cupping cookies on an 
    assembly line.

   Performing tasks that involve long 
reaches. Many job tasks involve long reaches: 
working overhead, putting items on a high 
shelf, reaching across a conveyor to put in a 
part or grasp an object, or bending over to 
reach a part in the bottom of a big supply 
box. These tasks expose employees to extreme 
awkward postures. Where long reaches are 
momentary and/or infrequent and the forces 
are low, these tasks are not a problem 
because there is likely to be adequate time 
for the body to recover between reaches. 
However, when long reaches are done 
frequently, force is involved and/or a long 
reach lasts more than a few seconds, the risk 
of harm increases.
   Long reaches usually have the greatest 
impact on the shoulders and lower back. The 
shoulder is unique in its wide range of 
motion when compared with other joints in the 
body. The bony restraints are minimal, but 
soft tissue constrains the motion. Thus, 
injuries usually occur when the soft tissue 
is used to maintain an awkward posture and/or 
forceful exertion.
   The back is flexed forward or extended 
back to extend reaches beyond the limit of 
the arm length. In addition, workers in 
repetitive jobs will often bend their back so 
that they can reduce the awkward shoulder 
posture. Bending the back forward adds the 
weight of the upper body to the force exerted 
by the back muscles and supported by the 
spine. Bending to the side, backwards or 
twisting puts the spine and back muscles in 
awkward postures.
   Awkward postures. When employees are 
performing tasks that involve long reaches 
they are exposed to extreme awkward postures; 
that is, the positions of their shoulders, 
elbows and/or back deviate significantly from 
more neutral positions. Repeatedly performing 
tasks in such positions poses increased 
stress on the joints and/or spinal discs. As 
mentioned before, muscles do not work as 
efficiently in awkward postures, and the 
muscles must exert more physical effort to 
accomplish the task. This increased force 
contributes to muscle-tendon fatigue and 
strain. For example, the shoulder may deviate 
at least 90 deg. from its neutral position 
when reaching across a conveyor to grasp an 
object. If the employee continues doing such 
reaches, the stress on the muscles and 
tendons in the shoulder can cause irritation 
and inflammation of the tendons and shoulder 
joint. This, in turn, may place increased 
pressure on nerves and blood vessels, 
reducing the supply of blood to the affected 
muscles and tendons.

Examples:
   Reaching above the head to 
    activate a press or other machine,
   Reaching frequently for small 
    parts in a bin that is at or close to the 
    limit of the arm's reach,
   Reaching down and behind the back 
    to pick up parts to feed to a press or 
    place on a conveyor,
   Reaching across a conveyor to pick 
    up items.

[[Page 65813]]

   Reaching to pick up items on the 
    other side of the scanner on a grocery 
    checkout conveyor.

   Static postures. The effects on the body 
from doing tasks that require long reaches 
are exacerbated where the reaches must be 
maintained for more than a very few seconds. 
Holding extreme postures places very high 
static loads on the body, resulting in rapid 
fatigue. Not only do the static postures add 
to the muscular effort required to do the 
task, but the lack of motion impedes the 
blood flow that is necessary for tissue 
recovery.
   The constricted blood flow reduces the 
supply of nutrients to the muscles and the 
removal of acids and other waste products 
away from the tissues. Reduced blood flow 
also slows down delivery of oxygen to the 
muscles.
   The longer or more frequently static 
loading occurs, the greater the risk of 
injury due to overuse of muscles, joints and 
other tissues.

Examples:
   Doing extensive repair work when 
    the automobile is overhead on a vehicle 
    lift.
   Holding out the arm to use a mouse 
    that is on a surface more than 15 inches 
    from the body because the keyboard tray 
    is not big enough to hold the mouse.

   Force. Because of exposure to extreme 
postures, tasks that involve long reaches 
require considerably more force to accomplish 
than tasks that can be performed close to the 
body. For example, it requires much more 
physical effort to hold and operate a 10-
pound rivet gun 2 feet in front or above the 
body than close to the body. First, the 
employee must apply more muscle force to 
simply hold a 10-pound gun when the arms are 
extended and the back is bent. The longer the 
gun must be held in that position, the more 
effort the muscles must exert. Second, the 
employee must apply more force in order to 
operate the gun in such an extreme position. 
Thus, long reaches can turn a low or moderate 
force task into a high force task that places 
employees at greater risk of harm. The 
addition of static postures to the extreme 
awkward postures further increases the force 
necessary to perform the task. Muscle-tendon 
fatigue and strain may occur very rapidly 
where these tasks are performed frequently 
because of lack of time to recover from such 
forceful exertions.
   Long reaches can also increase the dynamic 
forces of the exertion. For example, long 
reaches to get a bag of flour from a shopping 
cart and bring it to the scanner can result 
in high acceleration forces of the back and 
wrist.
   Finally, employees may be exposed to 
forceful exertions, even if long reaches do 
not involve lifting heavy objects. When 
employees bend over to perform long reaches, 
the muscles in the back must exert a lot of 
force to lift and lower the weight of the 
upper body. This causes the back muscles to 
fatigue more rapidly and puts pressure on the 
discs in the lower back. Where employees have 
to maintain long reaches for more than a few 
seconds, a large amount of static force is 
applied by the back muscles to the discs.
Examples:
   Throwing items into an overhead 
    container,
   Reaching over the bagging area to 
    place bags of groceries into shopping 
    carts.

   Working surfaces are too high or too low. 
Working surfaces that are too high or too low 
are another way in which employees are 
exposed to awkward postures. Where employees 
must work on such surfaces for a long period, 
the risk of tissue damage and other MSD 
problems increases.
   Working surfaces can be too high or too 
low for many employees because most working 
surfaces are not adjustable. For example, 30 
inches is a typical height for desks, tables 
and other working surfaces operated from a 
sitting position, and 36 to 40 inches is a 
typical height range for working surfaces 
operated from a standing position. Although 
employees of average height may be able to 
work comfortably at these working surfaces, 
the typical heights may not work for shorter 
or taller employees. An assembly-line 
employee who is 6'5'' may have to bend over 
significantly to assemble the parts on a 
conveyor that is 36 inches high, while a 5-
foot employee working on a 42-inch conveyor 
may have to work with her elbows away from 
the body.
   The height of working surfaces can also be 
too high or too low when employees must use 
work surfaces or workstations that were not 
designed for the tasks being performed. For 
example, typical desks (i.e., 30 inches high) 
are not designed for computer use. Even 
persons of average height may have to raise 
their elbows and shoulders to use the 
keyboard on their desks. This is especially 
true where desk chairs cannot be raised high 
enough to correct the problem. Even when the 
employee can be raised to a good height, the 
feet are often left dangling above the floor.
   Awkward postures. Awkward posture is the 
primary ergonomic risk factor to which 
employees are exposed when the height of 
working surfaces is not correct. Working at 
surfaces that are too high can affect several 
parts of the body. Employees may have to lift 
and/or bend their shoulders, elbows and arms 
(including hands and wrists) into 
uncomfortable positions to perform the job 
tasks on higher surfaces. For example, 
employees may have to raise their shoulders 
or move their elbows out from the side of 
their body to do a task on a high working 
surface. Also, they may have to bend their 
heads and necks to see the work they are 
doing.
   Working surfaces that are too high usually 
affect the shoulders. The muscles must apply 
considerably more contraction force to raise 
and hold the shoulders and elbows out to the 
side, particularly if that position also must 
be maintained for more than a couple of 
seconds. The shoulder muscles fatigue quickly 
in this position.
   On the other hand, when surfaces are too 
low, employees may have to bend their backs 
and necks to perform their tasks while 
hunched over the working surface. They may 
also have to reach down with their arms and 
shoulders to do the tasks. Where working 
surfaces are very low, employees may have to 
kneel or squat, which places very high forces 
on the knees to maintain the position and the 
weight of the body. Working surfaces that are 
too low usually affect the lower back and 
occasionally the neck.
   As mentioned above, since muscles operate 
less efficiently in awkward positions, more 
force must be expended to do the task. Where 
employees work on high or low surfaces only 
occasionally (e.g., once a week, only a short 
time each day), it does not pose a problem. 
However, where employees' primary working 
surface is too high or low, there is greater 
risk of injury due to exposure to awkward 
postures.

Examples:
   Threading extruded fiber onto a 
    spool that is 15 inches above the floor, 
    or
   Activating palm switches that are 
    60 inches above the floor.

   Static postures. When awkward working 
positions must be maintained (i.e., without 
support), it also increases the static

[[Page 65814]]

loading of muscles and tendons. This causes 
the body to fatigue even more quickly.

Examples:
   Working on a vertical drafting 
    table, or
   Sitting at grinding bench where 
    the grinding wheel is 24 inches above the 
    floor.

   Contact stress. There are two ways in 
which contact stress can occur when working 
surfaces are too high or low. The incorrect 
height can create contact points that would 
not exist if the surface was at the correct 
height. In addition, contact stress can occur 
when employees, whose arms and shoulders are 
fatigued from prolonged awkward and static 
postures, end up resting their forearms, 
wrists or hands on hard or sharp edges in 
order to rest their arms and shoulders.

Examples:
   Working at a computer placed on a 
    folding table, or
   Holding an injection molded part 
    at eye level by resting the elbows on the 
    work surface.

   Maintaining same work positions or posture 
for a long period. The chief complaint people 
usually make when they have worked for a long 
time in the same position is that they feel 
``stiff, sore and tired.'' These are some of 
the effects that result when tasks involve 
static postures (e.g., driving for several 
hours without a break).
   Static postures increase the amount of 
force required to do a task because, in 
addition to the force required to perform the 
task, contraction forces must be applied to 
hold the body in position throughout the work 
shift. Maintaining the same position or 
posture includes a variety of things. It 
includes holding the arms and shoulders in a 
non-neutral posture without moving.
   The effects of maintaining the same work 
positions can occur in almost any joint of 
the body and vary depending on body location. 
For example, the effect on the knees and back 
from squatting or kneeling for 2 hours is 
likely to be greater than the effect on the 
neck and shoulders from looking up at a 
monitor for the same period.
   Static postures. Tasks requiring employees 
to maintain the same position for an extended 
period increase the static loads/forces on 
muscles and other tissues. The longer 
postures must be maintained, the greater the 
loading of muscles and other tissues. This 
increased force contributes to fatigue and 
muscle-tendon strain.
   Exposure to contact stress may be a by-
product of prolonged static loading. When 
muscles become fatigued, employees look for 
ways to rest the affected areas. Sometimes 
employees may rest their arms or wrists on 
the hard surface and edges of the 
workstation. For example, computer operators 
may relieve static loading on their forearms 
and wrists by resting their wrists on the 
edge of the computer table. However, the 
blood flow and movement of their wrists may 
continue to be reduced because of the contact 
stress.
Examples:
   Watching a computer monitor that 
    is above eye level, or
   Holding a mouse that is located in 
    front of the keyboard.

   Awkward postures. The effects of static 
loading on the body are made worse where it 
is an awkward posture that must be 
maintained. Awkward postures add to the 
strain that muscles and tendons are already 
feeling because of static postures.
   In addition, the fatigue that results from 
static loads may cause employees to assume 
awkward positions in order to rest fatigued 
areas. For example, employees assembling 
microchips and computer circuits may rest 
their elbows on the work surface in order to 
relieve static loading on arms, wrists and 
hands. However, leaning on the elbows to 
continue working may result in static loading 
of the back, shoulders, neck and contact 
stress on the cubital tunnel.

Examples:
   Cradling a phone on the shoulder, 
    or
   Holding the arms on the top half 
    of a steering wheel.

   Cold temperatures. Exposure to cold 
temperatures exacerbates the effects of 
static postures because it too reduces blood 
flow to muscles and other tissues. This may 
interfere with the ability of muscles and 
other tissues to recover from the effects of 
static loading. Exposure to cold temperatures 
also causes reduction in manual dexterity and 
feeling.

Examples:
   A butcher working in the plant's 
    cooler for several hours, or
   Standing to direct traffic on a 
    busy road in the winter.

   Sitting for a long time. Sitting for long 
periods without the opportunity to stand up 
and move around is another way in which 
employees are exposed to static loading of 
tissues, primarily in the lumbar area of the 
back. It can also affect the upper back, neck 
and legs. The problem is exacerbated where 
awkward postures are also present.
   Static postures. Employees may be exposed 
to static postures when they must sit for a 
prolonged period on chairs, stools or benches 
that do not provide adequate lumbar support, 
that is, either the back rest of the seat 
does not provide good lumbar support or there 
is no back rest at all. When there is no 
lumbar support and the back is bent forward, 
the muscles of the back are trying to force 
the lumbar region out of it natural curve 
(i.e., proper alignment of the vertebrae), 
which places pressure on the discs and 
reduces blood supply to the spinal tissue. 
The constant exertion of the contraction 
forces leads to muscle fatigue.
   When the back muscles become sore, people 
tend to slouch. In this posture more force is 
being placed on the back and the discs. As 
the static loading continues, pressure 
continues to be applied to the membranes of 
the discs and they may become stressed. 
Stressed discs, in turn, may put pressure on 
blood vessels and may pinch a nerve (e.g., 
sciatic nerve), which results in pain.
   Even where the chair has a back rest with 
lumbar support to help maintain the back in a 
neutral position, employees still may 
continue to be exposed to static loading 
because they cannot take advantage of the 
back rest. This may occur when the seat pan 
is too big or the seat is too high for the 
employee. Many employees respond by sitting 
forward, instead of against the back rest, so 
that their feet can be on the ground, thus 
pressing the spine out of the natural curve 
and placing pressure on the discs.
   Awkward postures. Employees are also 
exposed to awkward back postures when they 
are working in a seated position and the back 
is not in a neutral position. The awkward 
postures may be caused by the physical work 
activities employees perform while sitting, 
the level of fatigue, the characteristics of 
the seat, and/or the height of the working 
surface (and objects on the working surface).
   The back is in an awkward position if the 
employee is leaning forward, slouching or 
slumping in their seats to work. Employees 
may lean forward because they are fatigued, 
because they must reach or lift an object, 
because the work surface is too low or not 
tilted, or because they

[[Page 65815]]

must move closer to see what they are working 
on. The awkward postures add to the static 
forces being applied to the discs and the 
muscles in the back. In addition, employees 
may be exposed to awkward neck postures when 
they look to see the work.

Examples:
   Working at a computer workstation 
    where the operator must lean forward to 
    see the screen,
   Working in a chair on an uneven 
    floor.

   Contact stress. Although contact stress 
that occurs from prolonged sitting is not 
directly related to the occurrence of MSDs, 
contact stress can increase discomfort and 
awkward postures. For example, where the seat 
pan is not padded at the edge, is too big or 
too high, it can create contact stress on the 
back of the thighs, which may result in 
constriction of blood flow to the legs. If 
employees sit forward to relieve this stress, 
the back is not supported and the employee 
may have a hard time maintaining the back in 
a neutral position.

Examples:
   Working in a chair where the seat 
    pan is too long, or
   Working in chair with arm rests 
    that are too close to the body.

   Using hand and power tools. ``Using hand 
and power tools'' to perform physical work 
activities does not in itself mean that 
employees are exposed to ergonomic risk 
factors that put them at risk of injury. 
Rather, it is a shorthand way of alerting 
employers that there are aspects of tool 
design and use that need to be checked out to 
see whether ergonomic risk factors may be 
present. These include:

   Weight and size of tool,
   Tool handles and/or grips,
   Tool activation (repetitively, one 
finger),
   Tool kickback, vibration and 
maintenance.

   Force. There are many ways in which 
operating hand and power tools can expose 
employees to high forces. First, when hand or 
power tools are heavy (e.g., more than 10 
pounds), employees may be exposed to high 
levels of force just to hold and control the 
tool. This is over and above the muscle force 
that must be applied to operate the tool and 
may cause the muscles to fatigue quickly.
   Second, power tools that do not have good 
weight distribution can increase the force 
needed to operate the tools. This occurs when 
employees cannot hold tools at the ``center 
of gravity,'' and the tool rotates or spins 
around when it is in use. Employees must 
exert considerable muscle force and maintain 
the contraction forces to prevent such 
rotation.
   Third, when tool handles or grips are too 
small or too big, employees must exert 
greater force to operate the tools because 
such handles/grips reduce grip capacity. 
Where handles are too narrow, employees may 
have to exert high muscle contraction forces 
to hold and operate the tool. For example, 
operating certain dental tools may require 
the exertion of considerable force and result 
in high pressure on the fingers and hand 
because they have very small handles (i.e., 
narrower than a pen or pencil). And if the 
handles are too wide, there is less ability 
to generate the force (i.e., muscle 
contraction) necessary to operate the tools, 
and employees are more likely to be exposed 
to awkward postures when they must bend or 
flex their wrists to maintain a grip on the 
tool handle.
   Fourth, the way in which tools are 
activated can add considerably to the amount 
of force needed to operate the tool. Tools 
that have squeeze triggers may require 
employees to apply a lot of muscle 
contraction in the hands and fingers. Some 
triggers are so small that there is only room 
for them to be activated with one finger, 
that is, all the force to squeeze the trigger 
must be generated by one finger, which places 
excessive forces on the muscles and tendons 
of the finger. Because the fingers may not 
have enough strength to operate the squeeze 
trigger, the muscles may fatigue quickly. In 
addition, tendons may become so inflamed that 
fluid builds up in the area and it may be 
difficult to continue bending the fingers to 
squeeze the trigger. This is especially true 
for the use of manual hand tools, where 
exertion of a lot of force may be necessary 
to overcome the trigger's activation 
resistance.
   Finally, application of high forces may be 
necessary to stop kickbacks and to resist the 
weight and power of some tools. For example, 
a logger or arborist may have to apply a lot 
force when cutting felled trees in order to 
prevent the kickback that could occur if the 
saw hits a very hard spot (e.g., a knot in 
the tree). Employees using powered floor-
buffers have to apply a lot of physical 
exertion to keep the buffers on a flat and 
centered plane and to keep them from spinning 
out.

Examples:
   Using powered driver to run and 
    tighten nuts on bolts and opposing force 
    when the driver reaches the end of the 
    tightening process, or
   Constantly pressing the trigger to 
    activate a drill with the index finger.

   Awkward postures. There are several 
reasons why employees may be exposed to 
awkward postures when they are using hand and 
power tools. Awkward postures may be the 
result of bad tool design or workstation 
layout. Others may be poorly designed for the 
task so that the posture (awkward posture) 
requires more force and leads to overexertion 
of the fingers, hand, wrist, elbow, or 
shoulder (such as the use of a 90 deg. 
screwdriver when an in-line screwdriver is 
more appropriate). A pistol grip electric 
drill may be fine on a vertical surface but 
on a horizontal surface the operator must 
turn the drill 90 deg. to use it. Any force 
that must be maintained on the tool requires 
much more contraction of the muscles, which 
leads, in turn, to more rapid fatigue.

Examples:
   Reaching over a barrier to operate 
    a rivet gun, or
   Squatting to tighten 20 bolts on a 
    pipe flange.

   Static postures. In many jobs the work 
situation requires that the worker constantly 
hold the tool and does not allow the worker 
to put the tool down. As a result, the grasp 
muscles and other support muscles are 
constantly active or statically loaded. Tools 
that require the worker to maintain some 
level of exertion to achieve a steady flow or 
activity such as a glue gun or a frosting bag 
require the muscles to be constantly in 
tension/contraction and applying some level 
of force. When workers have to hold a tool 
without putting it down, they must maintain 
the muscles in contraction. Mouse users who 
grip a mouse constantly because their work 
requires so much click and drag also 
experience these low but constant forces. 
Over time, fatigue of muscles and 
inflammation of tendons occurs.

Examples:
   Constantly holding knife used to 
    trim chicken breasts in poultry plant,
   Holding a wire wrap gun.


[[Page 65816]]


   Contact stress. Poor tool design is often 
the cause of contact stress in the use of 
operating tools. For example, gripping 
handles that are small may press the handle 
or handle edge into the skin, resulting in 
contact stress. Knurls (indentations in 
handles) may result in contact stress if they 
push into the fingers because they do not fit 
the operator's hand.

Examples:
   Using a screwdriver with edges on 
    the handle to tighten bolts on an 
    assembly line,
   Using a small wire clippers 
    (handles press into the palm) to remove 
    component lead after wave solder.
   Vibration. Although using powered hand 
tools (e.g., electric, hydraulic, pneumatic) 
may help to reduce risk factors such as force 
and repetition, they can expose employees to 
vibration. Vibrating hand tools transmit 
vibrations to the operator and, depending on 
the level of the vibration and duration, may 
contribute to the occurrence of Raynaud's 
phenomenon (i.e. vibration-induced white-
finger MSDs) (Ex. 26-2). Vibration inhibits 
the blood supply to the hand and fingers, 
which leads to numbness and tingling in the 
fingers. These vibration-induced MSDs show a 
progression of symptoms beginning with 
occasional or intermittent numbness or loss 
of color (i.e., blanching) in the tips of a 
few fingers. Continued exposure leads to more 
persistent attacks, affecting greater parts 
of most fingers and reducing feeling (i.e., 
tactile discrimination) and manual dexterity 
(Ex. 26-2) (see the Health Effects section 
for a more-detailed discussion of specific 
MSDs).
   The level of vibration can be the result 
of bad design, poor maintenance, and age of 
the powered hand tool. For example, even new 
powered hand tools can expose employees to 
excessive vibration if it they do not include 
any devices to dampen the vibration or in 
other ways shield the operator from it. Using 
vibrating hand tools can also contribute to 
muscle-tendon stress and fatigue. Operators 
may have to use increased grip force to 
steady such hand tools.

Examples:
   Cutting trees with chain saw, or
   Using grinding tools to form 
    dentures.
   Cold temperatures. The effects of any or 
all of the risk factors discussed can be 
exacerbated if the employee is exposed to 
cold while operating the tool. The cold 
temperatures can be due to the workplace 
environment (e.g., deboning meat when 
temperatures must be maintained below certain 
levels, using a chain saw in the winter) or 
due to air blowing from the power tool across 
the operator's hand. When cold air blows 
across the hands, the fingers get cold and 
they are less dextrous. The reduction in 
dexterity occurs because blood flow is 
reduced in the cold fingers, blood flow 
becomes constricted, and the tissue becomes 
stiff.

Examples:
   Using a knife to process catfish 
    fillets,
   Using a socket wrench to change 
    out equipment on the roof in the winter.

   Vibrating working surfaces, machinery or 
vehicles. Most jobs that involve contact with 
vibrating surfaces, machines and vehicles are 
easy to see, hear or feel. Since many 
products and processes are disturbed by 
vibration, employers often isolate and dampen 
vibration to levels below the threshold of 
effect on workers. However, there are some 
processes for which vibrating surfaces are 
unavoidable. An employee who comes into 
contact with such a surface may absorb enough 
vibration energy to create a health concern. 
Exposure to vibration energy usually results 
in one of two types of exposure--whole body 
vibration and hand/arm vibration. The 
exposures can result in an increase in 
forceful exertions, fatigue, numbness, 
tingling, and a loss of dexterity. These 
results are exacerbated by the presence of a 
cold environment.
   Work conditions that involve sitting, 
standing or lying on a vibrating surface 
produce whole-body vibration. Excessive 
levels of whole-body vibration or exposure to 
it for prolonged periods can make it 
difficult to perform job tasks due to 
numbness and tingling and a loss of 
dexterity. Vibration energy can disrupt blood 
flow and affect the nervous system. Body 
parts that absorb the vibration (like the 
back and knees) are particularly vulnerable. 
Workers who stand on vibrating surfaces 
absorb most of the vibration energy in their 
legs, particularly the knees. Whole body 
vibration forces on the spinal discs can 
cause microfractures in the disc structure, 
which may lead to herniated or ruptured 
discs. Vibration can also disrupt the blood 
supply to the tissue around the spine, 
resulting in fatigue and inflammation. When 
the feet or buttocks are in contact with a 
vibrating surface, injury is usually to the 
spine.

Examples:
   Working near a 100-ton press,
   Working near a vibratory bowl, or
   Operating a fork truck over rough 
    dock plates or gravel.

   When the hands are in contact with a 
vibrating surface, the energy is primarily 
absorbed in the hands and arms and may lead 
to hand-arm vibration illnesses. The most 
common sources of hand-arm vibration syndrome 
are vibrating hand tools (e.g., chainsaws, 
rivet guns, back pack leaf blowers). Some 
more subtle sources are holding pressurized 
hoses with nozzles, using a striking device 
such as a hammer, resting the hand on a 
vibrating machine, and holding a handle such 
as a steering wheel attached to a larger 
piece of equipment. In addition to the damage 
that is caused by the vibration energy, the 
muscles can become fatigued and strained due 
to the additional forces needed to compensate 
for the lack of tactile feedback and 
dexterity caused by the vibration. These 
losses are a result of the disruption of the 
peripheral sensory nerves caused by 
vibration. When the hands are in contact with 
a vibrating surface, injury is usually to the 
hands and arms.

Examples:
   Leaning against a grinding machine 
    while it is operating,
   Holding a wheel while operating a 
    sewing machine, or
   Manually aligning sections of a 
    newspaper using a vibrating table.

   Cold temperatures. Vibration reduces blood 
flow to the affected tissues. Vibration has a 
synergistic effect on the loss of blood flow 
in the presence of cold temperatures. The 
effect is present in the extremities because 
the body reacts to cold temperatures by 
shunting blood away from the extremities to 
preserve body heat.

Examples:
   Driving a fork truck over rough 
    surfaces in a frozen food warehouse, or
   Using vibrating etching tools in a 
    clean room

   Workstation edges or objects press hard 
into tissues or joints. In some workplaces 
there are sharp edges or corners that press 
into the workers' skin during the course of 
their job. Workers who, because of the job 
and workstation design, must rest their arms 
or lean against a table with a

[[Page 65817]]

hard, squared edge, exemplify this situation. 
Contact stress generally causes 
musculoskeletal disorders when the 
compression occurs against tendons that are 
being used or against nerves or blood vessels 
in vulnerable locations. Contact stress can 
restrict the movement of the tendon (more 
resistance), which requires more force and 
leads to inflammation of the tendon and 
surrounding tissues. Contact stress that 
pushes sharply into deeper tissues may reduce 
blood flow and result in early muscle 
fatigue. Tissue that is compressed for 
prolonged periods of time may be damaged. 
Nerves that are exposed to contact stress in 
multiple locations are especially vulnerable. 
The problem becomes worse with extended or 
repeated exposure.

Examples:
   Extensive use of shears or 
    scissors,
   Using a tool with a small, thin 
    handle that digs into the palm,
   Using tools with grooved handles 
    that press against the side of fingers,
   Leaning against a metal work bench 
    with a square edge,
   Using a keyboard on a standard 
    table or desk with unrounded edges, or
   Sitting in a bench or chair that 
    does not have a padded seat.

   Using hand as a hammer (i.e., contact 
stress). When the hand is used to strike 
something, extreme contact stress may be 
created. This is sometimes done to avoid 
damage to the product, but the result of 
using the hand as a hammer is damage to the 
worker. Striking a hard object with the base 
of the palm to align, seat, release or move a 
part is the type of job where the hand is 
most likely to be used as a hammer. Even 
occasional hammering with the hand can cause 
problems, but repeated activity of this sort 
will result in serious damage to the tissues 
of the hand.
   When the palm is used to deliver a blow to 
an object, the force from the blow passes 
into the soft tissues and then deeper into 
the tendons, nerves and muscles. The force 
from the hit can cause acute trauma to the 
palm, but over time the palm becomes 
calloused and acute trauma is no longer 
protective of the deep tissue, and 
consequently the tendons and muscles can be 
subjected to frequent disruption of blood 
supply, irritation, and trauma due to the 
reaction force from the hit. The more force 
that is required to hammer the part, the more 
residual force that will pass into the 
tendons, nerves and muscles. The forces from 
the hit may cause bruising of muscles and add 
to swelling and inflammation of tendons.

Examples:
   Pounding on a two part mold to get 
    it to seat or come together properly,
   Hitting a palm button to activate 
    a machine,
   Striking two parts to separate 
    them, or
   Striking the handle of a vice to 
    loosen it.

   Using hands or body as a clamp to hold 
objects while performing tasks. Sometimes 
this is referred to as having the worker act 
as a ``human clamp'' or ``human vise.'' In 
these situations the worker usually holds the 
object being worked on with one hand (often 
in an awkward, forceful posture) while force 
is applied by the other hand. The hand being 
used as a clamp has to hold the object while 
resisting the forces being applied by the 
other hand. Using the hand as a clamp leads 
to muscle fatigue and inflammation of the 
muscles and tendons.
   The strain on the muscles and tendons in 
the clamping hand is especially high when the 
task involves static postures or contact 
stress. Although the hand and arms are most 
often used as a clamp, some larger jobs 
require the feet, legs, hips or torso 
(lateral bending of the back) to support a 
part while work is performed.

Examples:
   Holding the head of a cow on a 
    slippery surface while attempting to 
    remove meat,
   Holding a small part while 
    assembling it,
   Drilling a hole in a part that the 
    worker has to hold, or
   Using the hips or thighs to hold a 
    part in place while working on the part.

   Force. Higher force requirements on the 
clamping hand results in more strain on the 
muscles and tendons. Sometimes the clamping 
hand is used in an inefficient pinch grip. 
When high forces are required throughout the 
shift day after day, the muscles and tendons 
may not have time to recover, leading to 
muscle fatigue and inflammation of the 
tendons. Higher clamp forces are required 
when the part is heavy or the forces applied 
to the part are high.

Examples:
   Holding an extrusion nozzle while 
    checking each hole (50 holes) to ensure 
    it is the appropriate size,
   Holding a jar in one hand while 
    attempting to remove the lid with the 
    other hand.

   Static postures. Often when the body is 
used to position and hold an object, the 
clamping part of the body maintains the same 
posture (static posture). Static loading 
reduces blood flow because the muscles are 
not moving (i.e., contracting and relaxing). 
The constant muscle tension can lead to 
swelling and pressure on nearby nerves. 
Static loading and high forces can lead to 
tears in the muscle tissue. Static loading of 
the tendons can also lead to inflammation and 
swelling to the point where motion is 
restricted and the swelling may put pressure 
on (i.e., pinch) the nerves.

Examples:
   Holding a pipe overhead while 
    preparing a fitting, or
   Holding an uncooperative animal on 
    the exam table.
   Awkward postures. More force is required 
when clamping the object requires maintaining 
an awkward posture, because the muscles do 
not operate efficiently in an awkward 
posture. Since the muscles must work harder, 
fatigue sets in sooner, leading to fatigue 
and inflammation. An awkward posture also 
puts additional strain on the tendons, which 
can cause inflammation, swelling, restricted 
movement and pressure on nearby nerves.

Examples:
   Using the hands to wring out a 
    mop,
   Bending sideways using the 
    shoulder to hold a door panel in place 
    while fastening the hinges, or
   Holding a part in place overhead 
    while inserting fasteners.

   Contact stress. If the object being held 
has a sharp edge or knurls (that force the 
fingers into slots), then the object may dig 
into the skin and can restrict the motion of 
the tendons and bruise or reduce blood flow 
to the muscles.

Examples:
   Holding a pane of glass while 
    attaching hardware,
   Using the knee to position a pump 
    while making the electrical connection, 
    or
   Holding onto a nut while turning 
    the bolt.

   Gloves are too large, too small or too 
bulky. For many jobs it is necessary or 
appropriate for workers to wear gloves while 
doing their jobs. Gloves can make grasping an 
object more difficult by changing the 
friction, decreasing dexterity, and 
interfering with sensory feedback. This often 
leads to

[[Page 65818]]

using more muscle force than would be 
required without gloves. Additionally, gloves 
can fold, wrinkle, and bunch so that pressure 
points are created that result in contact 
stress. Gloves that fit or are less bulky may 
help to relieve these problems. An even 
better solution is to eliminate the need to 
wear gloves.
   Examples of glove use that may rise to the 
level of a hazard are providing inappropriate 
gloves for the work, or failing to consider 
the worker's needs when gloves are purchased, 
providing thick gloves for a task that 
requires dexterity beyond that allowed by the 
gloves, or providing vibration dampening 
gloves and expecting levels of dexterity or 
force exertion that are beyond the level 
possible with the gloves.
   Force. Large, bulky, or loose gloves can 
interfere with tactile feedback so much that 
the worker must apply considerably more force 
than would be required to do the same task 
with more appropriate gloves or no gloves. 
Some gloves, such as those used for cut and 
puncture protection, are heavy and may cause 
additional fatigue.

Examples:
   Working on a hot pack used in 
    extruding plastic with heat resistant 
    gloves, or
   Holding a chicken leg while 
    wearing cut resistant gloves.
   Contact stress. Many bulky gloves bunch 
and cause pressure to small areas of the 
hands. Gloves that are supposed to provide 
protection from vibration and those with 
thick leather on the palm side are examples 
of gloves that may cause pressure points. 
When gloves are too small, they may impede 
the movement of the fingers and may reduce 
the blood supply.

Examples:
   Wearing latex gloves that are too 
    tight, or
   Selecting cases in a frozen foods 
    warehouse while wearing knit gloves under 
    thermal gloves.

   Manual handling (lifting/lowering, 
pushing/pulling and carrying). Forceful 
manual handling activities are a leading 
cause of workplace injury and illness. Lower 
back MSDs from lifting account for a large 
percentage of all workers' compensation 
cases. Studies discussed in the Health 
Effects section indicate that employees 
performing manual handling tasks have a 
significantly higher risk of back injury 
where they are exposed to force, repetition 
and/or awkward postures in the job.
   The physical work activities and 
conditions included on the manual handling 
list in the proposal are ones that are likely 
to be a significant problem because they are 
ones in which the major ergonomic risk 
factors associated with manual handling tasks 
are present: force and awkward postures/
static postures. This discussion about 
physical work activities and conditions in 
manual handling tasks is organized by task 
(e.g., lifting, pulling). Manual handling 
tasks are discussed only where the physical 
work activities and conditions and ergonomic 
risk factors are likely to be a significant 
problem.
   Objects or people are heavy (lifting, 
lowering, pushing, pulling, carrying). 
Workers lift, lower and move items every day. 
The heavier the weight that has to be lifted, 
lowered and/or moved, the more force the 
worker will have to exert. The heavier the 
weight, the closer the contraction required 
of the muscles will be to their maximum 
capability. When muscles contract at or near 
their maximum, they fatigue more rapidly and 
the likelihood of damage to the muscle and 
other tissues involved in the activity 
increases. In most situations involving 
lifting, lowering and moving heavy objects or 
people, the predominant risk factor is force. 
Manual handling of heavy objects exposes 
employees to high forces and will usually 
have the greatest impact on the back. Another 
aspect of weight that should be considered is 
a sudden shift in weight. Workers are more 
often able to accomplish a manual handling 
task without injury when they are prepared. 
When a patient's legs suddenly buckle while 
they are being transferred or a load within a 
package or container shifts, the worker may 
not be physically or mentally prepared for 
the weight.
   Lifting and Lowering. In lifting and 
lowering, force is the risk factor that most 
often needs to be addressed. Although there 
may be a perception that lifting is more 
problematic than lowering, they both require 
the worker to exert the forces commensurate 
with the weight of the object. The actual 
forces exerted by the worker are determined 
by the weight of the object. It is obvious 
that lifting containers weighing 25 pounds is 
considerably easier than those weighing 50 
pounds and that more people are capable of 
lifting the smaller amount. Posture can play 
a major role in the force required when 
moving an object. If that object can be held 
or lifted closer to the body, the muscle 
forces required in the back are less. Bulky 
containers present more of a problem when 
being lifted than do those with the same 
characteristics, including weight, that are 
compact. Finally, the frequency with which an 
object is lifted or lowered and the times it 
must be supported may be important in 
determining the risk presented by the job.
Examples:
   Lifting a resident, who has little 
    ability to assist, from the toilet to a 
    wheelchair,
   Lifting a 150 pound package from a 
    loading dock into a van.
   Pushing and Pulling. When pushing and 
pulling objects, the weight of the object or 
conveyance, including its contents, affects 
the force required of the worker. Often 
workers have to slide objects on a table or 
flat surface. In these cases the weight and 
the friction characteristics of the object 
and the surface are the prime determinants of 
the force required. Secondarily, the posture 
or reach may affect the degree of risk 
presented by the job. Where conveyances such 
as carts are used, the force required is 
generally determined by the characteristics 
and weight of the cart and contents. For very 
heavy carts, stopping and controlling the 
cart can sometimes be as difficult and 
important as pushing or pulling it to the 
desired location.

Examples:
   Pushing a 300 pound pump away from 
    the paper machine, or
   Pushing a heavy cart up a sloped 
    ramp.

   Carrying. For carrying the weight, 
distance and object characteristics affect 
the forces required. Often the forces are 
exerted statically for some period of time 
when carrying. Additionally, the worker's 
body is in motion and the stability and 
biomechanics of the activity may be much 
worse than in a simple lifting or lowering 
situation. Examples might be carrying heavy 
parts from one work area to another, carrying 
containers from production to a pallet or 
storage area, or carrying packages when 
delivering them to a customer.
Examples:
   Carrying several 50-pound bags of 
    feedstock material to the basement, or
   Carrying a resident of a nursing 
    home to the bath tub.
   Horizontal reach is long (Distance of 
hands from body to grasp object to be 
handled). Workers who are lifting/lowering, 
pushing/pulling or carrying are greatly 
affected by the distance that the hands are 
from the body during the

[[Page 65819]]

activity. The forces required to manually 
move an object by the muscles in the back and 
shoulder are increased significantly as the 
load is moved away from the body. The 
resulting compression on bone and cushioning 
tissues is also significantly increased. The 
impact on the musculoskeletal system 
increases dramatically as the object or 
weight (center of gravity for bulky objects) 
is farther from the body. When moving objects 
or people, the distance away from the 
worker's body affects the forces for a lift 
or carry. Two characteristics of a lift 
requiring a long horizontal reach make it 
harder on the worker. The first is that the 
worker's own body weight must be supported 
and lifted in addition to the weight of the 
object. The second is that the torque 
required puts the muscles at a greater 
mechanical disadvantage when the objects 
being lifted are at a greater distance from 
the body joint involved. Because of the 
mechanical disadvantage, the predominant risk 
factor in these situations is force, which is 
increased because of the risk factor of 
awkward posture (long reach) present. The 
awkward posture involved in long reaches 
requires higher muscle forces to lift or move 
the same weight as would be necessary if the 
reach were shorter. The problem becomes worse 
when either greater weight or greater 
distance is required. Lifting, lowering and/
or carrying items when a long horizontal 
reach is required will usually have the 
greatest impact on the shoulders, arms and 
back.
   Lifting and Lowering. For lifting and 
lowering where the horizontal reach is long, 
force is the factor that needs to be 
addressed. This is usually accomplished by 
reducing the reaches or the weight. Examples 
would include reaching for a product on the 
far side of a conveyor, reaching to a parts 
supply bin that is on the far edge of the 
work surface, lifting a large box with a 
center of gravity at some distance from the 
body, lifting or lowering something on the 
far side of a barrier, placing packages on 
the far side of a pallet, or assisting a 
patient in sitting.
   Pushing and Pulling. For pushing and 
pulling tasks, there may be reaches that are 
long; however, these are not usually a 
problem unless there is simultaneous lifting 
or unless the pushing and pulling direction 
is side to side rather than in and out. 
Moving objects from side to side is much less 
efficient than toward and away from the body.

Examples:
   Pushing a heavy box on a non-
    powered conveyor

   Carrying. There are times when workers 
carry an object that cannot be rested against 
the body, so the arms are in a position that 
is similar to that of a long reach. This also 
happens when carrying a large box or 
container. When this happens the force risk 
factor is probably the most important, 
followed by the awkward and static posture 
risk factors.

Examples:
   Carrying a hot pack used in 
    extruding plastic to the repair cart, or
   Carrying a carboy of nitric acid.

   Vertical reach is below knees or above the 
shoulders (Distance of hands above the ground 
when the object is grasped or released). 
Workers who are lifting/lowering, pushing/
pulling or carrying must exert more effort if 
the vertical position of the hands (when the 
object is started in motion) is above or 
below 30'' (Snook 1978, Ex. 2-26; Ayoub et 
al. 1978, Ex. 26-1416; Snook and Ciriello 
1991, Ex. 26-1008). The forces required by 
the muscles in the back and shoulder are 
increased significantly as the hands near the 
floor or move above the shoulders. The NIOSH 
lift equation reduces the recommended lift by 
22.5% if the lift occurs at or above shoulder 
level.
   In addition to the force, the resulting 
compression on bone and cushioning tissues 
increases the likelihood of an injury. 
Ideally the hands are at (or slightly below) 
waist level when manual handling begins. 
Manual handling tasks that require the hands 
to be lower than the knees or higher than 
mid-torso put the worker at a biomechanical 
disadvantage, which requires the muscles to 
exert more force than if the starting point 
is near waist height. Low starting points 
require bending or squatting, which adds 
stress to the back and knees, respectively, 
due to the awkward posture. When the lifted 
object is below the worker's knees, he or she 
must bend forward, thus stretching the 
muscles in the back into an awkward and less 
efficient lifting posture. In addition, from 
a stooped posture the worker must lift the 
weight of the torso up as the object is 
lifted.
   When an object is lifted above mid-torso 
heights, the thrust of the lifting force 
shifts from the larger/stronger muscles of 
the back to the smaller muscles of the 
shoulder. As the load is raised higher, the 
muscles of the shoulder become the primary 
movers. When material is lifted overhead, 
control of the lift becomes important. If the 
weight of the load were to suddenly shift 
while being lifted overhead, the resulting 
awkward posture, combined with the weight and 
distance of the load from the lower spine, 
could tear tendons, ligaments and muscles.
   Lifting and Lowering. In lifting and 
lowering from or to low or high positions, 
awkward posture is a risk factor that often 
needs to be addressed. The awkward posture 
makes the muscles less efficient, and results 
in higher muscle forces than would be 
required if the lifting or lowering took 
place with the load within 10 inches of the 
waist.

Examples:
   Picking up a 35 pound spool of 
    yarn from a peg above shoulder height,
   Picking a 40 pound item from a 
    60'' high shelf in a grocery warehouse, 
    or
   Lifting a 50 pound motor off a 
    pallet

   Pushing and Pulling. When pushing or 
pulling objects, the height of hands affects 
the amount of force needed. When the hands 
are slightly above waist height, the worker 
gets the most from the muscles. As the hands 
are moved lower or higher, the worker's 
posture becomes more awkward and requires 
more force from the muscles.

Examples:
   Pushing a cart with the hands 
    above mid chest height, or
   Pulling a wooden pallet across the 
    floor.

   Carrying. Carrying an object combines the 
static loading of the muscles with the 
loading caused by the awkward vertical 
position of the load. The combination of 
static and awkward postures greatly increases 
the fatigue on the muscles. Maintaining a 
stooped posture to carry a load places strain 
on the muscles of the back and shoulder as 
well as the spinal discs. Not only is the 
back supporting the weight of the object, but 
also the weight of the upper body. Carrying 
loads above shoulder height cannot be 
maintained for prolonged periods of time 
because the shoulder muscles will fatigue. 
The exception is when the weight of the load 
is rested on the skeletal system and the arms 
merely balance the weight (e.g., carrying 
objects on the head, carrying trays of food 
on the shoulder).

Examples:
   Carrying large, bulky boxes of 
    machine parts where the worker is unable 
    to carry the box with a horizontal hold, 
    or

[[Page 65820]]

   Carrying a large piece of 
    furniture down steps.

   Objects or people are moved significant 
distance (i.e., pushing, pulling, carrying). 
In producing products or even services it is 
often necessary to move objects or people. 
This may be done by a worker pushing, pulling 
or carrying the item. Almost invariably this 
involves forceful exertions. The method of 
movement, the force required, and the 
distance to be moved are the important 
aspects of the job that will determine the 
presence of MSD hazards. The higher the force 
required and the longer the distance to be 
moved, the more likely it is that the job 
will present a problem. Force is the 
predominant risk factor when objects are 
moved, and it can be mitigated by using carts 
or other conveyances. This type of job is 
most likely to have adverse effects on the 
back, shoulders and arms.
   Lifting and Lowering. Lifting and lowering 
is usually involved in a job of this type 
when the object is to be carried. For the 
lifting and lowering part of the job, the 
discussion of ``objects or people moved are 
heavy,'' above, should be consulted. The 
carry part of the task involves force and 
static postures. The weight of the object and 
the distance affect the force required and 
the time spent in static and forceful 
postures, respectively. Carrying puts the 
body in a dynamic activity where the 
stability is less than when the body is 
stationary. Examples of movement distances 
that might rise to the level of a hazard are 
moving a patient from the bed to the bath, 
lifting a tire from the floor to above the 
head, or carrying a heavy part from a pallet 
to a workstation.
   Pushing and Pulling. When pushing or 
pulling an object for a significant distance, 
the forces required and the distance moved 
are the important aspects of the job. If a 
cart or conveyance is used, the force to push 
or pull it is almost always the risk factor 
of concern. Sometimes large or heavy objects 
are moved by sliding them across the floor. 
This usually involves high forces and is 
better done in other ways such as using a 
cart or powered mover.

Examples:
   Pushing a cart of restaurant 
    supplies from the delivery truck to the 
    restaurant, or
   Pushing a patient on a gurney to 
    physical therapy.

   Carrying. Once again, the weight of the 
object and the distance it must be carried 
are the important factors. The effect of 
these on the worker can be reduced by 
providing some form of conveyance.

Examples:
   Carrying trash cans to the garbage 
    truck, or
   Carrying water bottles to the 
    cooler.

   Bending or twisting during manual 
handling. Bending or twisting while manual 
handling creates an awkward posture and 
changes the way forces are distributed in the 
spine. When the spine is in its natural 
position, forces are directed along the bony 
structure and distributed into the tissue as 
the spine curves. However, bending and 
twisting redirects the forces, placing more 
compressive and shear forces on the discs. 
Psychophysical studies have reported that 
there is a decrease in the maximum acceptable 
weight of lift (MAWL) in the range of 8% to 
22% where twisting of the torso is involved 
(Garg and Badger 1986, Ex. 26-121; Mital and 
Fard 1986, Ex. 26-182; Garg and Banaag 1988, 
Ex. 26-951). Experiments by Adams et al. 
(1980, Ex. 26-701) indicate that combined 
bending and twisting of the spine reduces the 
tissue tolerance of the intervertebral discs, 
predisposing them to rupture.
   When an object to be lifted is below the 
worker's knees, he or she must bend forward, 
thus stretching the muscles in the back into 
an awkward and less efficient lifting 
posture. In addition, from a stooped posture 
the worker must lift the weight of the torso 
up as the object is lifted. Lifting from a 
stooped posture also creates a situation 
where the worker can accelerate the torso as 
they lift.
   Marras and Granata (1995, Ex. 26-1383, and 
1997b, Ex. 26-169) found that increased 
velocity and acceleration in trunk lateral 
bending and twisting result in measurable 
increases in both compressive and shear 
forces experienced by the intervertebral 
discs.
   Lifting and Lowering. In lifting and 
lowering, awkward posture is the risk factor 
that most often needs to be addressed. The 
awkward posture makes the muscles less 
efficient and results in higher forces than 
would be required if the lift or lower were 
10 inches from the waist.

Examples:
   Moving 30 pound motors from a 
    workstation to a conveyor perpendicular 
    (90 deg.) to the workstation,
   Moving a patient from the bed to a 
    wheelchair, or
   Loading luggage into the cargo 
    hold of an airplane.

   Object is bulky, slippery or has no 
handles (lifting, lowering, carrying). Lack 
of good hand holds or good coupling between 
the hand and the object can result in higher 
grasp forces, higher other hand/arm forces, 
higher back forces, or the adoption of 
awkward postures to secure a stable 
relationship with the load. The predominant 
risk factors involved are force and awkward 
postures, which usually affect the back, 
hands, wrists and fingers.
   Lifting and Lowering. When lifting and 
lowering an item in which the coupling is 
poor, the worker has to adapt. Sometimes this 
involves having the hands or center of 
gravity of the load at considerable distance 
from the body, which increases the forces 
required of the back in awkward postures. 
Sometimes the hands have to bend around the 
box corners, resulting in considerable force 
being exerted in an awkward posture. Bulky 
loads cause the worker to bend the back more. 
Open boxes with poor coupling may be picked 
up with pinch grips on the tops of the box 
sides, which results in high forces and an 
ineffective grip.

Examples:
   Lifting a 40 pound fuel pump out 
    of a tank of mineral oil,
   Lifting wet watermelons out of a 
    box (which requires the worker to use 
    excessive grip force), or
   Lifting a patient with little 
    ability to assist out of bed.

   Pushing and Pulling. Hand forces will tend 
to be higher when pushing or pulling bulky 
items or those that have poor coupling.
Examples:
   Pushing a large box of potatoes in 
    a produce warehouse.

   Carrying. The problems of carrying an 
object with poor coupling or that is bulky 
are very similar to those involved in lifting 
and lowering. These problems are exacerbated 
by the static loading required when carrying 
any distance.

Examples:
   Carrying a keg of beer,
   Carrying machined parts to a 
    degreaser, or
   Carrying a side of beef.

   Floor surfaces are uneven, slippery, or 
sloped. Surfaces that are not level require 
the worker to compensate by placing the body 
in an awkward posture. When the spine is in 
its natural position, forces are directed 
along the bony

[[Page 65821]]

structure and distributed into the tissue as 
the spine curves. However, awkward postures 
both redirect the forces, placing more 
compressive and shear forces on the discs and 
placing the muscle in a less efficient 
position. In addition, to move an object 
manually, the forces exerted by the feet need 
to be resisted by the forces that push back 
from the floor. When the floor is slippery or 
sloped, the worker must expend more energy 
resisting the natural tendency for the feet 
to slip. If the load should shift while the 
worker is on an uneven, slippery or sloped 
surface, an injury becomes more likely. Poor 
floor conditions can affect the footing and 
the ease of movement of carts. Force is the 
risk factor that is usually exacerbated by 
poor floor surfaces and the back is the usual 
location of MSDs that are brought on by 
problems of floor surfaces. Lack of good 
footing will result in added stress on the 
postural muscles and other tissues.
   Lifting and Lowering. In lifting and 
lowering, awkward posture is the risk factor 
that most often needs to be addressed. The 
awkward posture makes the muscles less 
efficient and results in higher forces. The 
higher forces lead to fatigue and 
inflammation.

Examples:
   Shoveling grain, or
   Lifting bags of laundry from a wet 
    floor.

   Pushing and Pulling. Pushing or pulling on 
an uneven, slippery, or sloped surface can 
result in a sudden increase in the force 
needed to move or stop an object. The 
increase in force alone can tear muscles or 
strain tendons enough to cause an injury. 
When the increase in force occurs when the 
body is in an awkward posture due to the 
surface, then a muscle or tendon strain is 
more likely, due to the inefficient position 
of the muscles.

Examples:
   Pushing a laundry hamper across a 
    wet floor,
   Pushing a file cabinet on a 
    carpeted floor,
   Pushing a wheelchair through 
    gravel, or
   Pushing a cart on a cracked 
    concrete floor.

   Carrying. Carrying an object while walking 
on uneven, slippery or sloped surfaces causes 
the body to continually shift to accommodate 
the changing working surface.

Example:
   Carrying boxes of metal scraps 
    down steps, or
   Carrying boxes of paper up a ramp 
    into the computer room.

   Section 1910.918  What must I do to 
analyze a problem job?

  You must:

* * * * *
  (b) Evaluate the ergonomic risk factors in 
the job to determine the MSD hazards 
associated with the covered MSD. As 
necessary, evaluate the duration, frequency 
and magnitude of employee exposure to the 
risk factors.


4. Paragraph (d)--``Evaluate''

   Paragraph (d) of this section would 
require employers to evaluate the identified 
ergonomic risk factors to determine whether 
the employee exposure to them is such that a 
covered MSD would be reasonably likely to 
occur. To make this determination, employers 
need to look at the duration, frequency and 
magnitude (i.e., modifying factors) of the 
employee's exposure to the ergonomic risk 
factors.
   OSHA is proposing this evaluation 
provision because, although many jobs have 
ergonomic risk factors, these risk factors do 
not always rise to the level that poses a 
significant risk of injury. This may be 
because the exposure does not last long 
enough, is not repeated frequently enough, or 
is not intensive enough to pose a risk. For 
example, an employee bending to pick up a 
paper clip off the floor is exposed to 
awkward postures; however, this activity is 
not likely to result in a covered MSD because 
it is done infrequently. Also, an employee 
who picks up a box of copier paper is 
certainly exposed to high forces, but a 
covered MSD is not likely to occur where the 
employee does this only, for example, once a 
week. On the other hand, a job that requires 
bending from a neutral posture for most of 
the day would be likely to cause a covered 
MSD. The following is a brief description of 
the modifying factors:
   a. Duration. Duration refers to the length 
of time an employee is continually exposed to 
risk factors. The duration of job tasks can 
have a substantial effect on the likelihood 
of both localized and general fatigue. In 
general, the longer the period of continuous 
work (i.e., the longer the tasks require 
sustained muscle contraction), the longer the 
recovery or rest time required (Ex. 26-2). 
Duration can be mitigated by changing the 
sequence of activities or recovery time and 
pattern of exposure. Breaks or short pauses 
in the work routine help to reduce the 
effects of the duration of exposure.
   b. Frequency. The response of the muscles 
and tendons to work is dependent on the 
number of times the tissue is required to 
respond and the recovery time between 
activity. The frequency can be viewed at the 
micro level, such as grasps per minute or 
lifts per hour. However, often a macro view 
will be sufficient, such as time in a job per 
shift, or days per week in a job.
   2c. Magnitude. Magnitude (or intensity) is 
a measure of the strength of the risk factor, 
for example: how much force, how deviated the 
posture, how great the velocity or 
acceleration of motion, how much pressure due 
to compression. Magnitude can be measured 
either in absolute terms or relative to an 
individual's capabilities. There are studies 
on how much force should be required under 
some circumstances, but as an initial 
estimate, employees can be asked to classify 
the force requirements of the job on a scale 
(e.g., low, moderate or high). Often this is 
all that is needed to focus the analysis on 
the part of the job that needs to be changed.
   There are many qualitative and 
quantitative ways to determine the magnitude 
of exposure. Often all it takes is the 
employer asking employees to describe the 
most difficult part of the job, and the 
answer will indicate the magnitude of the 
risk factor. A common practice for assessing 
forceful exertion is to ask the employee to 
rate the force required to do the task. When 
magnitude is assessed qualitatively, the 
employer is making a relative rating, that 
is, the perceived magnitude of the risk 
factor relative to the capabilities of the 
worker. Relative ratings are very useful in 
understanding whether the job fits the 
employees currently doing the job.
   There are a number of ways to 
quantitatively measure magnitude of exposure. 
For example, the NIOSH Lifting Equation is 
widely used to determine recommended weight 
limits for safe lifting and carrying (Ex. 26-
521). The Snook Push-Pull Tables are used by 
many stakeholders to evaluate and design 
pushing, pulling and carrying tasks (Ex. 26-
1008). For work-related upper extremity MSDs, 
the RULA survey method is often used to 
investigate and evaluate jobs (McAtamney, 
Lynn, Corlet, E. Nigel, 24(2) Applied 
Ergonomics 91-99, 1993, Ex. 26-1421).
   The following is an example of an 
evaluation (qualitative and quantitative) of 
the duration, frequency and magnitude

[[Page 65822]]

of exposure to ergonomic risk factors in a 
computer-work job:

----------------------------------------------------------------------------------------------------------------
   OBSERVATION        RISK FACTORS        FREQUENCY           DURATION          MAGNITUDE            CAUSE
----------------------------------------------------------------------------------------------------------------
Same posture       Repetition,        Constant           6 hours per day    Head movement is   Monitor and sheet
 maintained as      awkward postures                                         about 45 degrees   of paper are
 the head bends                                                              down from          low.
 down to look at                                                             straight up
 the paper and
 screen
----------------------------------------------------------------------------------------------------------------
High work          Awkward postures,  Constant           6 hours per day    Upper arm is       Keyboard at mid-
 surfaces causes    static postures                                          about half way     chest height.
 the elbows to be                                                            between resting
 above mid torso                                                             at the side and
                                                                             straight out
                                                                             from the
                                                                             shoulder
----------------------------------------------------------------------------------------------------------------
Same posture       Awkward postures,  Constant while     Typing time is     Hands do not move  Keyboard use.
 maintained with    static postures    typing             about 6 hours      from the
 the fingers on                                           per day            keyboard
 the keyboard
----------------------------------------------------------------------------------------------------------------
Repetition of the  Repetition         900/min            Typing time is     Moderate level of  Keying.
 same motion by                                           about 6 hours      typing
 the fingers                                              per day
----------------------------------------------------------------------------------------------------------------
Workstation        Contact stress     Constant while     Typing time is     Worker has red     Edge of the desk
 objects press                         typing             about 6 hours      lines on the       pressing into
 hard against the                                         per day            wrist              the wrist.
 body
----------------------------------------------------------------------------------------------------------------
Long reaches for   Awkward postures,  Constant while     Uses the mouse     The arm is fully   The mouse is
 the mouse          static postures    using the mouse    less than one      extended           about 1.5 feet
                                                          hour per day                          from the worker.
----------------------------------------------------------------------------------------------------------------
Prolonged sitting  Static posture     Constant           About 6 hours per  .................  Constant keying,
                                                          day                                   sitting too
                                                                                                long.
----------------------------------------------------------------------------------------------------------------
Workstation chair  Contact stress     Constant           About 6 hours per  .................  Chair seat pan
 presses hard                                             day                                   too high, and
 into the back of                                                                               the feet dangle
 the thigh                                                                                      above the floor
                                                                                                or rest on the
                                                                                                base of the
                                                                                                chair.
----------------------------------------------------------------------------------------------------------------

   As mentioned above, ergonomic risk factors 
are synergistic elements of MSD hazards. 
Simply put, the total effect of these risk 
factors is greater than the sum of their 
parts. As such, employers need to be 
especially watchful for situations where risk 
factors occur simultaneously. Levels of risk 
factors that may pose little risk when found 
alone are much more likely to cause MSDs when 
they occur with other risk factors.
   Controls that reduce a risk factor focus 
on reductions in the risk modifiers 
(frequency, duration or magnitude). By 
limiting exposure to the modifiers, the risk 
of an injury is reduced. Thus in any job the 
combination of the task, environment and the 
worker create a continuum of opportunity to 
reduce the risk by reducing the modifying 
factors. The closer the control approach 
comes to eliminating the frequency, duration 
or magnitude, the more likely it is that the 
MSD hazard has been controlled. Conversely, 
if the control does little to change the 
frequency, duration or magnitude, it is 
unlikely that the MSD hazard has been 
controlled.
   Section 1910.919  What hazard control 
steps must I follow?

  You must:
  (a) Ask employees in the problem job for 
recommendations about eliminating or 
materially reducing the MSD hazards;
  (b) Identify, assess and implement feasible 
controls (interim and/or permanent) to 
eliminate or materially reduce the MSD 
hazards. This includes prioritizing the 
control of hazards, where necessary;
  (c) Track your progress in eliminating or 
materially reducing the MSD hazards. This 
includes consulting with employees in problem 
jobs about whether the implemented controls 
have eliminated or materially reduced the 
hazards; and
  (d) Identify and evaluate MSD hazards when 
you change, design or purchase equipment or 
processes in problem jobs.

  Section Sec. 1910.919 of the proposed rule 
outlines the basic process employers must use 
in controlling MSD hazards. These provisions 
are well-recognized as the basic problem-
solving steps of hazard control (Ex. 26-2).

[[Page 65823]]

1. Paragraph (a) --``Ask employees for 
recommendations''

   Proposed paragraph (a) requires that 
employers ask employees for recommendations 
on controls. Many stakeholders have said that 
employees who are doing a job are usually the 
best resource for finding both the problems 
or difficulties in that job and for 
identifying appropriate solutions that will 
control the hazards (Exs. 3-112, 3-164, 3-
112, 26-5). In addition, employee input and 
participation in the problem solving process 
can minimize the resistance to change when 
job changes become necessary. Many 
stakeholders have testified to the value of 
employee participation in ergonomics:

  Employers and employees alike who work in 
the industry are in the best possible 
position to identify risk factors in their 
workplace and to develop prevention methods 
that concentrate on the significant problems 
unique to their particular industry's 
environment. America Health Care Association 
(Ex. 3-112).
  Job analysis should include input from the 
workers themselves. The employees can best 
tell what conditions have caused them pain, 
discomfort, and injuries. They often have 
easy and practical suggestions on how such 
problems can be alleviated. American 
Federation of State, County and Municipal 
Employees, AFL-CIO (Ex. 3-164).


2. Paragraph (b)--``Identify, assess and 
implement controls''

   OSHA is proposing a requirement that 
employers identify, assess and implement 
feasible controls (interim and permanent) to 
eliminate or materially reduce the MSD 
hazards identified. Controls are considered 
feasible if they are presently in use for the 
application in question, can be adapted for 
such use from technologies that are being 
used in other applications, can be developed 
by improving existing technologies, or is on 
the horizon of technological development. For 
many MSD hazards, the identification and 
assessment of controls will be brief because 
the MSD hazards are obvious or not complex 
and can easily be implemented. Many MSD 
hazards can be addressed with off-the-shelf 
controls. Often controls can be identified 
during the job hazard analysis and even be 
put in as they are identified, such as these 
examples:

   Eliminating awkward postures 
(leaning over workstation) by putting blocks 
under a work bench to raise the work surface 
height.
   Eliminating awkward postures of 
the neck and reducing stress on the back by 
putting a telephone book under a VDT monitor.
   Reducing awkward postures of the 
neck by removing light bulbs that were 
causing glare on the VDT monitor screen.
   Reducing force by cleaning thread 
from the wheels of a cart that had been hard 
to push.

   Where controls are not obvious or off-the-
shelf, the identification and assessment of 
controls may require more effort.


Identify controls

   There are many different methods employers 
can use and places employers can go to 
identify controls. Many employers rely on 
their internal resources to identify possible 
controls. These in-house experts may include:

  4 Employees who perform the job and 
their supervisors,
   Engineering personnel,
   Workplace safety and health 
personnel or committee,
   Maintenance personnel,
   On-site health care professionals,
   Procurement staff, and
   Human resource personnel.

   A number of stakeholders said they bring 
their in-house experts together for 
brainstorming sessions to identify as many 
solutions as possible for the problem job 
(Ex. 26-1370). Some of those stakeholders 
have told OSHA that brainstorming is often a 
good technique for addressing complex 
problems (Ex. 26-1370). Looking at the 
original design and equipment specifications 
is another in-house method for identifying 
solutions. Reviewing the original design 
specifications or even operation manuals can 
help determine whether the job, equipment, 
tools or raw materials have changed 
substantially. If changes are identified, a 
return to the original condition via 
equipment maintenance and repair may be 
enough to correct the problem.
   Another common method of identifying 
controls is to look at similar operations. 
Stakeholders have said that they review 
similar operations at sister worksites to 
identify changes that have worked there over 
time.
   Possible controls can also be identified 
from sources outside the workplace, such as:

   Equipment Catalogs. Review of 
equipment catalogues, especially those 
dealing with the types of problems present. 
For example, if the problem deals with 
handling drummed materials, there are 
equipment catalogues that offer a number of 
pieces of equipment that aid with the 
handling of drums.
   Vendors. Talk to vendors who work 
within a particular industry. They may be 
able to share ideas from other operations. It 
may be useful to develop a partnership with a 
vendor and work collaboratively to resolve 
the problem.
   Trade Associations or Labor 
Unions. Discuss the problem with a trade 
association or a labor union. They may serve 
as a focal point for efforts to initiate 
changes within the industry.
   Conferences and Trade Shows.
   Insurance companies. Insurance 
companies can provide information about what 
other clients with similar operations are 
doing to solve problems.
   OSHA Consultation Services. OSHA 
provides free on-site assistance in 
identifying, analyzing and controlling 
problems. The first priority of OSHA's 
consultation services is small businesses in 
high hazard industries.
   Specialists. Specialists in 
materials handling, layout, work methods, 
occupational safety and health, or ergonomics 
may be able to provide solutions based on 
their experience. Many large organizations 
have such specialists on staff or at 
corporate headquarters.
   Through in-house experts and other sources 
of expertise, employers need to generate 
solutions that eliminate or materially reduce 
ergonomic risk factors. To assist employers 
in identifying solutions, the following table 
provides a list of solutions and control 
measures that have been identified and used 
to eliminate or materially reduce ergonomic 
risk factors in the physical work activities 
and conditions identified in 
Sec. 1910.918(c):

[[Page 65824]]



----------------------------------------------------------------------------------------------------------------
   PHYSICAL WORK ACTIVITIES AND     ERGONOMIC RISK FACTORS THAT MAY BE
            CONDITIONS                            PRESENT                         EXAMPLES OF CONTROLS
----------------------------------------------------------------------------------------------------------------
(1) Exerting considerable physical  (i) Force                           Use powered tools
 effort to complete a motion                                            Change pinch to power grip
                                                                        Use longer handle
                                                                        Use powered lift assist
                                                                        Use lift tables
                                   -----------------------------------------------------------------------------
                                    (ii) Awkward postures               Provide better mechanical advantage such
                                                                         as a longer handle
                                                                        Move the items closer to the worker
                                                                        Design task for smooth movements
                                   -----------------------------------------------------------------------------
                                    (iii) Contact stress                Attach a handle
                                                                        Wrap or coat the handle with cushioning
                                                                         and non slip material
                                                                        Wear gloves that improve the grip
----------------------------------------------------------------------------------------------------------------
(2) Doing same motion over and      (i) Repetition                      Use power tools
 over again                         (ii) Force                          Use job enlargement
                                                                        Use job rotation
                                                                        Reallocate tasks
                                   -----------------------------------------------------------------------------
                                    (iii) Awkward postures              Provide wrist rest
                                                                        Allow short breaks
                                   -----------------------------------------------------------------------------
                                    (iv) Cold temperatures              Take break in a warm area
                                                                        Provide heat where the hands are located
----------------------------------------------------------------------------------------------------------------
(3) Performing motions constantly   (i) Repetition                      Use job enlargement
 without short pauses or breaks in  (ii) Force                          Allow breaks as needed
 between                            (iii) Awkward postures
                                    (iv) Static postures
                                    (v) Contact stress
                                    (vi) Vibration
----------------------------------------------------------------------------------------------------------------
(4) Performing tasks that involve   (i) Awkward postures                Redesign the workplace layout
 long reaches                                                           Reposition object
                                                                        Provide better access to machinery
                                                                        Rotate pallet or work surface
                                                                        Keep work in front of the worker
                                                                        Use a tool to extend the reach
                                   -----------------------------------------------------------------------------
                                    (ii) Static postures                Provide adjustability
                                                                        Allow short breaks
                                                                        Use job enlargement
                                                                        Allow tools and items to be set aside
                                                                         periodically
                                   -----------------------------------------------------------------------------
                                    (iii) Force                         Use lift tables or pallet jacks
----------------------------------------------------------------------------------------------------------------
(5) Working surfaces are too high   (i) Awkward postures                Provide adjustability
 or too low                                                             Raise/lower the worker
                                                                        Use a tool to extend the reach
                                   -----------------------------------------------------------------------------
                                    (ii) Static postures                Use job enlargement
                                    (iii) Force                         Reorient work
                                                                        Allow short breaks
                                                                        Use lift tables
                                   -----------------------------------------------------------------------------
                                    (iv) Contact stress                 Ensure round edges
                                                                        Pad surfaces
----------------------------------------------------------------------------------------------------------------
(6) Maintaining same position or    (i) Awkward postures                Use job enlargement
 posture while performing tasks                                         Reposition object
                                   -----------------------------------------------------------------------------

[[Page 65825]]

 
                                    (ii) Static postures                Reduce weight of object
                                                                        Use job rotation
                                                                        Use job enlargement
                                                                        Allow short breaks
                                                                        Use sit/stand workstation
                                                                        Use anti-fatigue mats
                                                                        Provide foot rest
                                                                        Provide cushioned insoles
                                   -----------------------------------------------------------------------------
                                    (iii) Force                         Use balanced powered hand tools
                                                                        Provide lift assist
                                   -----------------------------------------------------------------------------
                                    (iv) Cold temperatures              Wear thermal clothing
                                                                        Take break in a warm area
                                                                        Provide localized heating
----------------------------------------------------------------------------------------------------------------
(7) Sitting for a long time         (i) Awkward postures                Stand occasionally
                                    (ii) Static postures                Provide lumbar support
                                    (iii) Contact stress                Allow short breaks
                                                                        Provide chairs with padding on the seat
                                                                        Make seat height adjustment
----------------------------------------------------------------------------------------------------------------
(8) Using hand and power tools      (i) Force                           Support weight of the tool mechanically
                                    (ii) Awkward postures               Ensure tool has good balance
                                    (iii) Static postures               Use appropriate size handles
                                    (iv) Contact stress                 Avoid sharp edges and finger slots on
                                                                         the handle
                                   -----------------------------------------------------------------------------
                                    (v) Vibration                       Use low vibration tools
                                    (vi) Cold temperatures              Isolate source of vibration from the
                                                                         worker
                                                                        Maintain tools
                                                                        Reduce vibration
                                                                        Insulate hands
                                                                        Eliminate of reduce draft or blow back
                                                                         on the hands
----------------------------------------------------------------------------------------------------------------
(9) Vibrating working surfaces,     (i) Vibration                       Isolate source of vibration
 machinery or vehicles              (ii) Force                          Use job rotation
                                    (iii) Cold temperatures             Use adsorbing material to reduce the
                                                                         magnitude of the vibration
                                                                        Provide insulation from the cold
                                                                        Allow breaks in a warm area
----------------------------------------------------------------------------------------------------------------
(10) Workstation edges or objects   (i) Contact stress                  Provide round edges
 press hard into muscles or                                             Enlarge handles
 tendons                                                                Pad surfaces and handles
----------------------------------------------------------------------------------------------------------------
(11) Using the hand as a hammer     (i) Contact stress                  Review design specifications
                                    (ii) Force                          Use soft mallet
                                                                        Provide frequent maintenance
----------------------------------------------------------------------------------------------------------------
(12) Using hands or body as a       (i) Force                           Use a fixture, clamp or jig
 clamp to hold object while         (ii) Static posture                 Use job rotation
 performing tasks                   (iii) Awkward posture               Provide round edges
                                    (iv) Contact stress                 Pad surfaces
----------------------------------------------------------------------------------------------------------------
(13) Gloves are bulky, too large    (i) Force                           Provide several sizes and weights of
 or too small                       (ii) Contact stress                  gloves
----------------------------------------------------------------------------------------------------------------
 
[[Page 65826]]

 
                        MANUAL HANDLING (Lifting/lowering, pushing/pulling, and carrying)
----------------------------------------------------------------------------------------------------------------
(14) Objects or people moved are    (i) Force                           Lighten load
 heavy                              (ii) Repetition                     Use lift assist
                                    (iii) Awkward postures              Use lift table
                                    (iv) Static posture                 Place package in larger containers that
                                    (v) Contact stress                   have to be mechanically handled
                                                                        Use two people lift team
                                                                        Rely on gravity to move the object
                                                                        Reduce friction
----------------------------------------------------------------------------------------------------------------
(15) Horizontal reach is long       (i) Force                           Redesign the workplace layout
                                    (ii) Repetition                     Reposition object closer to the employee
                                    (iii) Awkward postures              Provide pallet, table that can be
                                    (iv) Static posture                  rotated
                                    (v) Contact stress                  Provide space so that the employee can
                                                                         walk around to the object
                                                                        Reduce the size of the object
                                                                        Slide the object closer before lifting
                                                                        Eliminate unnecessary barriers
----------------------------------------------------------------------------------------------------------------
(16) Vertical reach is below knees  (i) Force                           Do not place objects to be lifted on the
 or above the shoulders             (ii) Repetition                      floor
                                    (iii) Awkward postures              Use adjustable height tables
                                    (iv) Static posture                 Put employee on a platform
                                    (v) Contact stress                  Store heavy objects stored at waist
                                                                         height
                                                                        Put handles on the object
                                                                        Change the work place layout
----------------------------------------------------------------------------------------------------------------
(17) Objects or people are moved    (i) Force                           Modify the process to eliminate or
 significant distances              (ii) Repetition                      reduce moves over a significant
                                    (iii) Awkward posture                distance
                                    (iv) Static postures                Convey the object (e.g., conveyor, ball
                                    (v) Contact stress                   casters, air)
                                                                        Use fork lifts, hand dollies, carts, or
                                                                         chairs (for people)
                                                                        Use appropriate wheels on carts (and
                                                                         maintain the wheels)
                                                                        Provide handles for pushing, pulling or
                                                                         carrying
----------------------------------------------------------------------------------------------------------------
(18) Bending or twisting during     (i) Force                           Raise work to the appropriate height
 manual handling                    (ii) Repetition                     Lower the employee
                                    (ii) Awkward postures               Arrange workstation so that work is done
                                    (iv) Static postures                 in front of the worker
                                                                        Use conveyors, chutes, slides, or
                                                                         turntables to change direction of the
                                                                         object
----------------------------------------------------------------------------------------------------------------
(19) Object is slippery or has no   (i) Force                           Provide good handles
 handles                            (ii) Repetition                     Provide belt with handholds to assist in
                                    (iii) Awkward posture                moving patients
                                    (iv) Static posture                 Provide gloves that assist in holding
                                                                         slippery objects
----------------------------------------------------------------------------------------------------------------
(20) Floor surfaces are uneven,     (i) Force                           Redesign the handling job to avoid
 slippery or sloped                 (ii) Repetition                      movement over poor surfaces
                                    (iii) Awkward postures              Use surface with treatments or anti-skid
                                    (iv) Static posture                  strips
                                                                        Provide footwear that improves friction
----------------------------------------------------------------------------------------------------------------

   Assess controls. The assessment of 
controls is an effort by employers, with 
input from employees, to select controls that 
are reasonably anticipated to eliminate or 
materially reduce the MSD hazards. The 
employer may find that there are several 
controls that would be reasonably likely to 
reduce the hazard. Multiple control 
alternatives are often available, especially 
when several risk factors contribute to the 
MSD hazard. The employer needs to assess 
which of the possible controls should be 
tried. Clearly, a control that significantly 
reduces several risk factors is preferred 
over a control that only reduces one of the 
risk factors.
   Selection of the risk factor(s) to control 
and/or control measures to try can be based 
on numerous criteria. An example of one 
method involves ranking all of the ergonomic 
risk factors and/or possible controls 
according to how well they meet these four 
criteria:

   Effectiveness--Greatest reduction 
in exposure to the MSD hazards.
   Acceptability--Employees most 
likely to accept and use this control.
   Timeliness--Takes least amount of 
time to implement, train and achieve material 
reduction in exposure to MSD hazards.

[[Page 65827]]

   Cost--Elimination or material 
reduction of exposure to MSD hazards at the 
lowest cost.

   Where there are several jobs that need to 
be controlled, the employer may need to 
consider prioritizing the implementation of 
controls as part of the assessment process. 
Although many employers tend to select the 
most severe problems to control first, the 
criteria above are another way to prioritize 
the control of jobs.
   Implement Controls. Because of the 
multifactoral nature of MSD hazards, it is 
not always clear whether the selected 
controls will achieve the intended reduction 
in exposure to the hazards. As a result, the 
control of MSD hazards often requires testing 
selected controls and modifying them 
appropriately before implementing them 
throughout the job. Testing controls verifies 
that the proposed solution actually works and 
what additional changes or enhancements are 
needed.
   There are a number of ways in which 
employers may test out controls. Many 
employers modify a single workstation first 
to ensure that all necessary revisions have 
been identified and completed. Only then are 
the modifications applied to other 
workstations. Some employers with 
manufacturing operations test out new work 
methods on training lines or training 
workstations, which typically have slower 
line speeds. In addition, employers may have 
employees test out several different models 
of new tools, furniture, and equipment to 
identify the best fit for each employee.
   Stakeholders have told OSHA that sometimes 
it can take a long time to develop, purchase 
and/or install effective permanent controls 
(Ex. 26-1370). To ensure that employers have 
adequate time to identify, assess and test 
out possible control measures, OSHA is 
proposing that employers have up to 3 years 
to implement permanent controls (or 1 year 
after the compliance start-up times have 
passed). However, so that employees do not go 
unprotected for that period of time, OSHA is 
proposing to require that employers implement 
interim controls more quickly. Often simple 
engineering or administrative controls may be 
implemented quickly, while a better solution 
is being designed. A number of stakeholders 
have said that they used administrative 
controls to reduce exposures during the 
interim time it took them to design and 
implement new engineering controls (Ex. 26-
1370).


3. Paragraph (c)--``Track progress''

   Paragraph (c) would require employers to 
track their progress (i.e., evaluate their 
progress and success) in eliminating or 
materially reducing the MSD hazards. OSHA 
believes this provision is important for 
several reasons. First, evaluating the 
effectiveness of controls is the sine qua non 
of an incremental abatement process. Unless 
they follow up on their control efforts, 
employers will not know whether the hazards 
have been adequately controlled or whether 
the abatement process needs to continue. 
Simply put, if the job is not controlled, the 
problem-solving is not complete.
   Second, tracking progress is also 
essential in those cases where employers need 
to prioritize the control of hazards. It 
tells employers whether they are on schedule 
with their abatement plans. Third, tracking 
the progress of control efforts is a good way 
of determining whether the elements of the 
program are functioning properly. For 
example, evaluating controls, especially work 
practice controls, is one way to determine 
whether the ergonomics training has been 
effective.
   Many employers evaluate controls within 30 
to 60 days after implementation. This gives 
employees enough time to get accustomed to 
the controls and to see whether the controls 
have introduced other problems into the job 
(Ex. 26-2).
   Once again, there are many ways that 
employers may track their progress in 
addressing MSD hazards, and OSHA does not 
intend to require employers to use one 
particular method. NIOSH says that the 
evaluation should use the same tool that was 
used to analyze the problem, or another 
method that allows employers to compare the 
before-and-after results (Ex. 26-2). One of 
the easiest approaches is to follow up with 
employees in the problem job and ask them 
whether the controls have reduced the 
physical difficulties of performing the job, 
whether the job is more comfortable, or 
whether the tools and equipment seem to fit 
them better. Many employers take baseline 
measurements before the ergonomics program is 
implemented so they have a way of quantifying 
their success. Some of the measures they use 
include:

   Reductions in severity rates, 
especially at the very start of the program,
   Reduction in incidence rates,
   Reduction in total lost-workdays 
and lost-workdays per case,
   Reduction in job turnover or 
absenteeism,
   Reduction in workers' compensation 
costs/medical costs,
   Increases in productivity or 
quality,
   Reduction in reject rates,
   Number of jobs analyzed and 
controlled,
   Number of problems solved.

   OSHA is not proposing to require that 
employers use one of these methods listed to 
assess the effectiveness of controls. 
Employers are free to choose their own 
criteria. The proposed rule would require, 
however, that whatever measure employers do 
select, their evaluation of controls must 
include consulting employees in the problem 
job.


4. Paragraph (d)--Proactive ergonomics

   Paragraph (d) would require employers to 
identify and evaluate MSD hazards when they 
make process and equipment changes. Sometimes 
this concept is referred to as ``proactive 
ergonomics'' or ``safety through design.'' 
The concept encompasses facilities, hardware, 
equipment, tooling, materials, layout and 
configuration, energy controls, environmental 
concerns and products. Designing or 
purchasing to eliminate or materially reduce 
MSD hazards in the design process helps to 
avoid costly retrofitting. It also results in 
easier and less costly implementation of 
occupational safety and health needs (Ex. 26-
2, Ex. 26-1418).
   OSHA is proposing this requirement, in 
part, because many stakeholders have said 
that the best and most cost-effective way to 
control MSD hazards is to prevent them from 
being introduced into the workplace in the 
first place (Ex. 26-1370):

  Ergonomic principles are most effectively 
applied to workstations and new designs on a 
preventive basis, before injuries or 
illnesses occur. Good design with ergonomics 
provides the greatest economic benefit for 
industry. American Industrial Hygiene 
Association (Ex. 3-197).

   Design strategies should emphasize fitting 
job demands to the capabilities and 
limitations of employees. To achieve this, 
decision-makers must have appropriate 
information

[[Page 65828]]

and knowledge about ergonomic risk factors 
and ways to control them. They need to know 
about the problems in jobs and the causes. 
Designers of in-house equipment, machine and 
processes also need to have an understanding 
of ergonomic risk factors and how to control 
them. For example, they may need 
anthropometric data to be able to design to 
the range of capabilities and limitations of 
employees.
   It is also important that persons involved 
in procurement have basic knowledge about the 
causes of problems and ergonomic solutions. 
For example, they need to know that 
adjustable chairs can reduce awkward postures 
and that narrow tool handles can considerably 
increase the amount of force required to 
perform a task. In addition, to prevent the 
introduction of new hazards into the 
workplace, procurement personnel need 
information about equipment needs.
   Several employers in the meat processing 
industry have told OSHA that they were able 
to communicate their common concerns to 
equipment suppliers and that, as a result, 
several suppliers are now providing tools and 
equipment that reduce the likelihood of an 
MSD. OSHA encourages employers to contact 
individuals and other companies any time 
information about the cause of a workplace 
musculoskeletal disorder could be used to 
prevent similar incidents. Owens and Garg 
(Ex. 26-1415) found that manufacturers are 
often receptive and responsive to 
recommendations for design changes made by 
users of their products in the design phase.
   Section 1910.920  What kinds of controls 
must I use?

  (a) In this standard, you may use any 
combination of engineering, administrative 
and/or work practice controls to eliminate or 
materially reduce MSD hazards. Engineering 
controls, where feasible, are the preferred 
method for eliminating or materially reducing 
MSD hazards. However, administrative and work 
practice controls also may be important in 
addressing MSD hazards.
  (b) Personal protective equipment (PPE) may 
be used to supplement engineering, work 
practice and administrative controls, but may 
only be used alone where other controls are 
not feasible. Where PPE is used, you must 
provide it at no cost to employees.

  Note to Sec. 1910.920: Back belts/braces 
and wrist braces/splints are not considered 
PPE for purposes of this standard.

   Section 1910.920 permits the employer to 
use any combination of engineering, 
administrative, or work practice controls to 
address the MSD hazards identified in problem 
jobs. OSHA is proposing to allow employers 
this flexibility in choice of controls 
because OSHA's experience and reports from 
stakeholders both indicate that all of these 
control approaches have contributed to 
reductions in the number and severity of 
workplace MSDs. In addition, the broad range 
of jobs to which the standard will apply, and 
the great variation in workplace conditions 
covered, make compliance flexibility 
essential.
   Paragraph (a) of Sec. 1910.920 does, 
however, state that engineering controls are 
the preferred method of eliminating or 
substantially reducing MSD hazards in cases 
where these controls are feasible. The 
proposal defines engineering controls as 
controls that physically change the job in a 
way that eliminates or materially reduces the 
MSD hazard or hazards present. Examples of 
engineering controls that are used to address 
ergonomic hazards are workstation 
modifications, changes to the tools or 
equipment used to do the job, facility 
redesigns, altering production processes, 
and/or changing or modifying the materials 
used.
   Engineering controls range from very 
simple to complex: from putting blocks under 
a desk to raise the work surface for a 
taller-than-average worker to providing a 
lumbar support pillow or rolled-up towel to a 
video display unit (VDU) operator to 
redesigning an entire facility to enhance 
productivity, reduce product defects, and 
reduce workplace MSDs.
   When choosing an engineering control to 
address a particular ergonomic problem, 
employers often have many choices, depending 
on how much they wish to spend, how permanent 
a solution they seek, how extensive a 
production process change they need, and 
employee acceptance and preference. For 
example, as MacLeod (Ex. 26-1425) points out, 
an employer whose VDU operators are 
experiencing neck and shoulder problems has 
many options available, including the 
following:

   Raising the height of the monitor 
by putting it on phone books, building a 
monitor stand, buying an adjustable monitor 
stand, buying an adjustable wall-mounted 
monitor stand, or buying an adjustable desk-
mounted monitor stand;
   Putting the desk on blocks; or
   Providing an adjustable-height 
desk or workstation.

   The ergonomics proposal reflects the 
preference of ergonomists and safety and 
health professionals for engineering 
controls, which is based on the ability of 
engineering controls to eliminate the MSD 
hazards posed by the job. The standard 
ergonomics textbooks and guidance documents 
emphasize the superiority of engineering 
controls over other classes of controls, 
i.e., administrative controls, work 
practices, or personal protective equipment 
(PPE) (see, for example, Ex. 26-1487, Ex. 26-
1428, Ex. 26-1424, Ex. 26-2; Ex. 26-1426, Ex. 
26-1425, Ex. 26-1408; and Ex. 26-3). 
According to NIOSH's recent publication, 
``Elements of Ergonomics Programs'':

  A three tier hierarchy of controls is 
widely accepted as an intervention strategy 
for controlling workplace hazards, including 
ergonomic hazards. (Ex. 26-2)

   A recent ergonomics text states, 
``Ergonomic hazards can be effectively 
eliminated by introducing engineering 
controls and applying ergonomic principles 
when developing workstations, tools, or jobs 
* * * only engineering controls eliminate the 
workplace hazards. Other strategies [work 
practices, administrative controls] only 
minimize the risk of injury'' (Ex. 26-1408).
   Ergonomists endorse the hierarchy of 
controls, which accords first place to 
engineering controls, because they believe 
that control technologies should be selected 
based on their reliability and efficacy in 
eliminating or reducing the workplace hazard 
(risk factors) giving rise to the MSD. 
Engineering controls are preferred because 
these controls and their effectiveness are:
    Reliable;
    Consistent;
    Effective;
    Measurable;
    Not dependent on human behavior 
(that of managers, supervisors, or workers) 
for their effectiveness;
    Do not introduce new hazards into 
the process.
   In contrast to administrative and work 
practice controls or personal protective 
equipment, which occupy the second and third 
tiers of the hierarchy, respectively, 
engineering controls fix the problem once and 
for all. However, because

[[Page 65829]]

there is such variability in the workplace 
conditions covered by the proposed standard, 
OSHA is permitting employers to use any 
combination of engineering, work practice, or 
administrative controls as methods of control 
for MSD hazards.
   Work practice controls involve changes in 
the way an employee does the job. They are 
defined by the standard as changes in the way 
an employee performs the physical work 
activities of a job that reduce exposure to 
MSD hazards. Work practice controls involve 
procedures and methods for performing work 
safely. Examples of work practices that 
reduce the potential for exposure to 
ergonomic risk factors are training workers 
to use a new or modified tool properly, 
training workers to vary the tasks they 
perform throughout the day to minimize muscle 
fatigue, and training workers to work in 
positions that reduce risk factors as much as 
possible (e.g., to hold a tool with their 
wrists straight, to avoid awkward postures, 
etc.). In the context of ergonomic programs, 
work practice controls are essential, both 
because they reduce ergonomic stressors in 
their own right and because they are critical 
if engineering controls are to work 
effectively. For example, workers need to be 
trained to use a power grip rather than a 
trigger grip if a new tool is to be 
successful, and they need to be trained to 
adjust an ergonomically designed chair 
properly if it is to substantially reduce the 
risk of neck disorders, shoulder tendinitis, 
or another type of MSD. Work practices, like 
learning to vary job activities during the 
day (e.g., moving from filing to sorting mail 
to using the computer and back again) can 
often reduce the magnitude and duration of 
exposure to the risk factor sufficiently to 
make MSDs unlikely. To be effective, the 
culture at the workplace and supervisory 
support and reinforcement are necessary to 
ensure that safe work practices are routinely 
observed.
   Administrative controls are management-
controlled work practices and policies 
designed to reduce exposures to MSD hazards 
by changing the way work is assigned or 
scheduled. Administrative controls reduce the 
frequency, magnitude, and/or duration of 
exposure and thus reduce the cumulative dose 
to any one worker. Examples of administrative 
controls that are used in the ergonomics 
context are employee rotation, job 
enlargement, and employer-authorized changes 
in the pace of work.
   Administrative controls have been 
effective in addressing MSD hazards in some 
cases. For example, one case study cited in 
the Benefits chapter (Chapter IV of the 
Preliminary Economic Analysis) describes a 
lift team approach that has been quite 
effective in reducing work-related back 
injuries among nursing personnel in a long-
term care facility for the elderly (Ex. 26-
1091). However, many ergonomists note that 
these controls should be used with caution. 
For example, a recent book (Ex. 26-1408) 
states ``* * * the biggest disadvantage with 
administrative controls is that they treat 
the symptoms and not the cause of 
biomechanical stress.''
   Another well-known ergonomics book, 
MacLeod's ``The Ergonomic Edge,'' cautions:

  * * * job rotation is only beneficial if 
the tasks involve different muscle-tendon 
groups or if the workers are rotated to a 
rest cycle * * * Poorly structured job 
rotation programs, may, in fact, increase the 
risk of CTDs. If employees are not properly 
trained or accustomed to the tasks they are 
to do, they can increase their exposure to 
risk factors * * * Furthermore, job rotation 
alone does not change the risk factors 
present in a facility. It only distributes 
the risk factors more evenly across a larger 
group of people. Thus, the risk for some 
individuals can be reduced, while the risk 
for others is increased. * * * When employees 
rotate between two jobs the risk of exposure 
can be thought of as being ``averaged.'' Job 
rotation may drop the average to within a 
safe level, or raise the whole group in 
excess of safe limits * * * Finally, although 
job rotation may have beneficial effects, 
engineering changes should remain the goal of 
the ergonomics program.'' [Ex. 26-1425]

   The proposed standard permits employers to 
use personal protective equipment (PPE) to 
supplement engineering, work practice, and 
administrative controls. However, personal 
protective equipment may not be used alone, 
i.e., as the sole means of employee 
protection unless no other controls are 
feasible. Any PPE that is provided must be 
made available to employees at no cost.
   PPE is equipment that is worn by the 
employee and provides an effective barrier 
between the employee and the MSD hazards in 
the job. Examples are palm pads and knee pads 
to reduce contact stress, vibration-
attenuation gloves, and gloves worn to 
protect against cold temperatures.
   The hierarchy of controls, which is widely 
endorsed by ergonomists, occupational safety 
and health specialists, and health care 
professionals, accords last place to PPE 
because:

   Its efficacy in practice depends 
on human behavior (the manager's, 
supervisor's and worker's),
   Studies have shown that the 
effectiveness of PPE is highly variable and 
inconsistent from one worker to the next,
   The protection provided cannot be 
measured reliably,
   PPE must be maintained and 
replaced frequently to maintain its 
effectiveness,
   It is burdensome for employees to 
wear, because it decreases mobility and is 
often uncomfortable,
   It may pose hazards of its own 
(e.g., the use of vibration-reduction gloves 
may also force workers to increase their grip 
strength).

   One author (Ex. 26-1408) notes that: ``* * 
* in most cases, the use of PPE focuses 
attention upon worker responses and not the 
causes of ergonomic hazards * * * PPE does 
not eliminate ergonomic hazards * * * [and] 
must be considered as the last line of 
defense against ergonomic hazard exposure.'' 
Thus, although the proposed standard permits 
PPE to be used as a supplemental control, it 
cannot be relied on as a permanent solution 
to the presence of MSD hazards unless other 
feasible controls are not available.
   A note to proposed section 1910.920 
states:
   Back belts/braces and wrist braces/splints 
are not considered PPE.
   The proposal includes this note to alert 
employers to the fact that back belts and 
wrist braces, which are widely used in U.S. 
workplaces, are not considered a control to 
reduce ergonomic hazards under the standard. 
These devices are being marketed as equipment 
that can prevent MSDs, although the evidence 
to support these claims is not available.
   The AIHA ``White Book'' (Ex. 26-1424) 
cautions: ``Back belts have become ubiquitous 
in the American workplaces. Some employers 
now require their use by employees. But there 
is little scientific evaluation available 
regarding their use in primary prevention.'' 
Recently, a NIOSH working group reviewed the 
available scientific literature on the use of 
back belts and published a 1994 report 
evaluating them. NIOSH expressed concern that 
wearing a belt may alter workers' perceptions 
of their capacity to lift heavy workloads 
(i.e., belt wearing may foster an increased 
sense of security, which may not be warranted 
or substantiated (Ex. 15-16). NIOSH does not 
recommend the use of back belts as PPE, and 
neither do a number of professional

[[Page 65830]]

societies (Ex. 15-15, Ex. 15-17, Ex. 15-33). 
NIOSH is currently studying the effect of 
back belt use on employees engaged in manual 
handling jobs in WalMart stores.
   Wrist splints and braces present even more 
serious problems:

  ``Wrist splints or braces used to keep the 
wrist straight during work are not 
recommended, unless prescribed by a physician 
for rehabilitation. * * * using a splint to 
achieve the same end may cause more harm than 
good since the work orientation may require 
workers to bend their wrists. If workers are 
wearing wrist splints, they may have to use 
more force to work against the brace. This is 
not only inefficient, it may actually 
increase the pressure in the carpal tunnel 
area, causing more damage to the hand and 
wrist'' (Ex. 26-1424).

   OSHA thus believe that the proposed Note 
to section 1910.920 will alert employers and 
employees to the lack of evidence 
demonstrating the effectiveness of these 
devices.
   Section 1910.921  How far must I go in 
eliminating or materially reducing MSD 
hazards when a covered MSD occurs?

  The occurrence of a covered MSD in a 
problem job is not itself a violation of this 
standard. You must comply with one of the 
following:
  (a) You implement controls that materially 
reduce the MSD hazards using the incremental 
abatement process in Sec. 1910.922; or

  Note to Sec. 1910.921(a): ``Materially 
reduce MSD hazards'' means to reduce the 
duration, frequency and/or magnitude of 
exposure to one or more ergonomic risk 
factors in a way that is reasonably 
anticipated to significantly reduce the 
likelihood that covered MSDs will occur.

  (b) You implement controls that reduce the 
MSD hazards to the extent feasible. Then, you 
periodically look to see whether additional 
controls are now feasible and, if so, you 
implement them promptly; or
  (c) You implement controls that eliminate 
the MSD hazards in the problem job.

  Note to Sec. 1910.921(c): ``Eliminate MSD 
hazards'' means that you eliminate employee 
exposure to ergonomic risk factors associated 
with the covered MSD, or you reduce employee 
exposure to the risk factors to such degree 
that a covered MSD is no longer reasonably 
likely to occur.

   Section 1910.921 of the proposed rule 
tells employers how far they must go to 
reduce exposure to MSD hazards to be in 
compliance with the Ergonomics Program 
Standard. This section sets forth the control 
endpoint that employers must achieve. 
Proposed Sec. 1910.921 includes three control 
endpoints. Employers are in compliance with 
this section when they have implemented 
controls that satisfy one of the following:

   The controls eliminate MSD 
hazards;
   The controls reduce MSD hazards to 
the extent feasible; or
   The controls materially reduce MSD 
hazards.

   Many case studies demonstrate that 
employers have successfully either eliminated 
the risk factors in problem jobs or 
materially reduced the risk factors to a 
level where an MSD is reasonably unlikely to 
occur. (See Applied Ergonomics Case Studies 
Volume 2, Alexander, D.C., ed., 1999; 
Preliminary Risk Assessment (Chapter V); 
Preliminary Economic Analysis (Section 
VIII).)
   Section 1910.921 of the proposed rule 
would not require employers to eliminate the 
occurrence of all MSDs. OSHA recognizes that, 
in a number of jobs, workplaces, and physical 
work activities it may not be possible to 
eliminate MSDs. OSHA is also aware that 
employers who have an effective ergonomics 
program may still receive reports of MSDs. 
The goal of the proposed rule is to have 
employers put a good working system into 
place so that they can take quick and 
effective action when MSDs do occur. And 
section 1910.921 tells employers how far they 
must go in implementing controls after that 
MSD does occur.


1. Materially Reduce (Paragraph (a))

   Paragraph (a) of the proposed rule 
provides that employers are in compliance if 
they implement controls that materially 
reduce MSD hazards in the job using the 
incremental abatement process in 
Sec. 1910.922. Materially reduce MSD hazards 
should not be interpreted to mean that the 
employer may simply make any change, even one 
for which there is only a nominal expectation 
that the control will reduce the likelihood 
that an MSD will occur. The note to paragraph 
(a) emphasizes that materially reduce 
requires more. Materially reduce means that 
the overall effect anticipated to result from 
implementing controls to reduce risk factor 
exposure is a significant reduction in the 
probability that another MSD will occur in 
that job. For example, if the likely cause of 
an MSD hazard is regular unassisted manual 
lifting of 100-pound rolls of roofing 
material, reducing the weight of the roll to 
90 pounds would not significantly change the 
likelihood that an MSD will occur and would 
not be considered a material reduction.
   To further illustrate, a covered MSD of 
the lower back occurs in a manual handling 
job that requires employees to fill and seal 
a 50-pound bag of lead chromate pigment every 
2 minutes, lift the bag and twist to put it 
on a pallet, and pile the bags as high as 4-
feet off the ground. When the pallet is fully 
loaded, employees push it to the loading area 
at the far end of the facility. Reducing the 
risk factors by moving the loading area next 
to the fill lines cuts out more than 75% of 
the distance pallets had been moved. This 
change does materially reduce exposure to 
pushing and pulling the pallet. However, the 
hazards caused by pushing and pulling the 
pallets are not nearly as likely to cause or 
contribute to the type of MSD reported as the 
force and repetition risk factors in the job, 
and therefore the change has done little to 
address the ergonomic risk factors. Thus, 
there does not appear to be a reasonable 
likelihood that the implemented change will 
achieve a material reduction in the 
likelihood of injury. On the other hand, 
changes such as halving the fill weight of 
the job and/or adding additional employees to 
the fill line would be reasonably anticipated 
to materially reduce the probability of 
injury, because they address the primary risk 
factors in the manual handling job.
   At the same time OSHA recognizes that a 
number of MSD hazards are complex and it may 
not always be clear what control(s) will 
achieve a material reduction in the 
probability that MSDs will occur. OSHA is 
aware that it may be necessary in many 
situations for employers to test a solution 
to know if it will work. As a result, OSHA is 
proposing that employers be considered in 
compliance with the requirement to materially 
reduce MSD hazards if they select and 
implement the controls that a reasonable 
person would anticipate would achieve a 
material reduction in the likelihood of 
injury.
   The fact that an employer hired a 
qualified ergonomics consultant to analyze a 
problem job and then implemented the controls 
that the consultant said should significantly 
reduce MSD hazards is good evidence that the 
employer has taken action reasonably 
anticipated to materially reduce the 
likelihood of injury. Examples of other 
evidence that employers have taken action 
that could reasonably be

[[Page 65831]]

expected to significantly reduce the MSD 
hazards are that the implemented controls 
have been shown to reduce MSD hazards in 
other workplaces in the industry; that the 
controls were identified, evaluated and 
implemented by a trained ergonomics 
committee; or that both the MSD hazard and 
solution were obvious. There are also many 
other ways of demonstrating that the controls 
selected could reasonably be anticipated to 
achieve a material reduction in risk factors.
   Employers may materially reduce MSD 
hazards by reducing the frequency (i.e., how 
often), duration (i.e., how long) and/or 
magnitude (i.e., quantity) of exposure to the 
risk factors. For example, a manufacturing 
employer may be able to achieve a significant 
reduction in MSD hazards in an assembly line 
job by reducing or eliminating awkward 
postures, even without changing the frequency 
with which tasks are performed. The employer 
may also achieve the equivalent level of 
protection by reducing the length of time 
employees must perform repetitive tasks 
without a break, or by adding more workers to 
the assembly line so that task cycles are not 
repeated as often. Employers are free to 
proceed as they wish (e.g., eliminating one 
risk factor, reducing the frequency and 
duration but not the magnitude of exposure, 
or trying a combination of eliminating and 
reducing risk factors) so long as the overall 
effect of their actions is to achieve a 
material reduction in the hazard.
   OSHA is also proposing in paragraph (a) 
that employers use the incremental abatement 
process in Sec. 1910.922 to materially reduce 
MSD hazards. As the term indicates, an 
incremental hazard abatement process relieves 
employers from having to implement, all at 
once, the combination of controls that may 
ultimately prove necessary to control the 
hazard. Instead, this process allows 
employers to implement controls in smaller 
increments, e.g., one at a time, and then to 
observe whether the control(s) have been 
successful in materially reducing the hazard 
before moving on to other controls. If the 
control(s) is successful, as measured by the 
resolution of the injured employee's MSD, 
reports from employees that the job is no 
longer physically stressful, or by the 
absence of additional MSDs, the employer 
would be allowed to stop adding controls and 
to wait and see whether additional controls 
will be needed. The proposed rule provides 
that as long as no MSDs occur (i.e., the 
injured employee's condition improves and no 
other MSDs are reported), employers may 
continue in the wait and see mode. If covered 
MSDs occur, employers would be required to 
identify and try out additional controls.
   OSHA believes that it is appropriate and 
reasonable to allow employers to reduce MSD 
hazards using an incremental process. First, 
as mentioned above, MSD hazards are complex 
and there may be a number of situations where 
employers may not know what will fix the job. 
Because of this, OSHA believes that employers 
should be allowed to try out controls in 
smaller increments so they are more clear 
about what solutions will work before they 
have to move on to put in all the necessary 
controls.
   Second, OSHA believes that the incremental 
abatement process is a cost effective 
approach for materially reducing MSD hazards. 
The proposed rule would not require employers 
to implement more controls than are necessary 
to achieve a substantial reduction in the MSD 
hazards. OSHA believes that an incremental 
test and evaluate approach will help assure 
that employers will not have to spend $1,000 
in controls if $100 will fix the problem. In 
fact, a number of stakeholders who have 
ergonomics programs have said that many 
controls cost less than $100 (Ex. 26-1370) 
(see OSHA Web). Given this, OSHA believes it 
is reasonable to allow employers to test the 
less-costly solutions that other employers 
may have identified to see whether those 
solutions will adequately address the hazards 
in their workplaces.
   Third, OSHA is proposing an incremental 
abatement process because it is the process 
that employers with good ergonomics program 
are using. Many stakeholders have told OSHA 
that their programs use an incremental 
abatement process (Ex. 26-1370). In addition, 
there is strong support for this approach 
among stakeholders representing a broad range 
of industries, employers and employees.
   Fourth, the Occupational Safety and Health 
Review Commission has upheld OSHA's authority 
under a section 5(a)(1) ergonomics 
enforcement action to require employers:

  [T]o engage in an abatement process, the 
goal of which is to determine what action or 
combination of actions will eliminate or 
materially reduce the hazard. Secretary of 
Labor v. Pepperidge Farm, 17 OSHC 1993, 2034 
(April 26, 1997).

   Finally, OSHA believes that an incremental 
abatement process provides the best fit with 
the rapidly changing area of ergonomics 
control technology. New controls and 
ergonomics equipment come onto the market 
almost daily. By allowing employers to 
implement controls incrementally rather than 
requiring them to implement all feasible 
controls immediately, employers will have an 
opportunity and incentive to select the 
newest and best solutions. As a result, many 
more MSD hazards are likely to be identified 
and addressed in the design phase and 
eliminated before they enter the workplace. 
It is a well-accepted principle that the best 
way to address ergonomic hazards is in the 
design phase. For example, one stakeholder 
commented that ``With ergonomics programs you 
are never done. The workplace is constantly 
changing.'' (Hank Lick, Ford Motor Company, 
at February 1998 ergonomics stakeholder 
meeting, Ex. 26-1370)
   The concept of incremental hazard 
abatement may suggest to some that ergonomics 
is a never-ending process or continuous loop. 
However, OSHA is proposing a stopping point. 
In Sec. 1910.944, OSHA is proposing that 
employers be permitted to suspend large parts 
of their ergonomics program, including the 
incremental abatement process, if they have 
materially reduced the MSD hazards and no 
covered MSD has been reported for 3 years. 
Where a 3-year wait and see period has passed 
without the occurrence of any covered MSDs, 
the incremental control(s) the employer 
anticipated would significantly reduce the 
likelihood that covered MSDs would occur will 
have been proven in fact to do so. Therefore, 
there is no need to continue all the elements 
of the ergonomics program at that time.


2. Reduce to the Extent Feasible (Paragraph 
(b))

   Paragraph (b) of the proposed standard 
states that employers have implemented all 
necessary controls, if they have implemented 
all the controls that are feasible. This 
control endpoint is statutorily driven. OSHA 
has no authority to require employers to do 
what is not feasible or ``capable of being 
done.'' American Textile Mfrs. Institute v. 
Donovan (Cotton Dust), 452 U.S. 490, 509, 513 
n. 31, 540 (1981). When employers have 
reached this level, they are not required to 
be involved in the incremental abatement 
process since they have already implemented 
the existing feasible control technology. (As 
discussed above, controls are considered 
feasible if they are presently in use for the 
application in question, can be adapted for 
such use from technologies that are being 
used in other applications, can be developed 
by improving existing technologies, or are on 
the horizon of technological development.)

[[Page 65832]]

   However, OSHA is proposing that these 
employers periodically check to see whether 
new technology has been developed and is 
available if they continue to have MSDs in 
their covered jobs. In addition, these 
employers must periodically review whether 
controls that previously may not have been 
feasible are now capable of being implemented 
in the problem job. OSHA is not proposing to 
impose a time period for the periodic review. 
Rather, as periodically is defined in the 
proposed rule, employers must establish a 
regular time period for checking out whether 
the control situation has changed. The time 
basis for review must be appropriate for the 
conditions in the workplace, such as the 
nature and extent of the MSD hazards. A 
review of conditions may be necessary where 
there are significant changes in the 
workplace that may result in increased 
exposure to MSD hazards.
   When additional feasible controls are 
identified, the proposed rule requires that 
employers must implement them promptly. The 
compliance timetable in Sec. 1910.943 is not 
applicable to paragraph (b). That schedule 
incorporates time for identifying and 
analyzing controls before control 
implementation deadlines come due. In 
paragraph (b), on the other hand, the hazards 
are known and the analysis has been 
completed. Given this, OSHA does not believe 
it is necessary or appropriate to give 
employers a year to implement additional 
controls after they become available.


3. Eliminate MSD Hazards (Paragraph (c))

   Of course, employers are also finished 
implementing controls when they have 
eliminated MSD hazards. This control endpoint 
is also statutorily based. Cotton Dust, 452 
U.S. at 505-06; Industrial Union Dep't, AFL-
CIO v. American Petroleum Inst. et al. 
(Benzene), 448 U.S. 607, 642 (1980) .
   The phrase ``eliminate MSD hazards'' 
incorporates two concepts. First, employers 
are finished when they have eliminated 
exposure to the hazard. For example, use of a 
mechanical lift eliminates forceful 
exertions, and a voice-activated computer 
eliminates highly repetitive motions. Second, 
it means that controls have been implemented 
that have reduced exposure to ergonomic risk 
factors to the extent that employees in the 
job are no longer exposed to a reasonable 
likelihood of developing a covered MSD. MSDs 
are no longer reasonably likely to occur in a 
parts assembly job where the awkward reaches 
behind the back for parts has been eliminated 
and parts are now delivered on a conveyor to 
employees.
   Where employers have eliminated the 
reasonable likelihood of the occurrence of a 
covered MSD, they are in compliance with the 
proposed control endpoint. And even if MSDs 
are reported in the job, employers who have 
eliminated MSD hazards have no obligation to 
take control action because the physical work 
activities and conditions of the job are no 
longer reasonably likely to cause or 
contribute to an MSD. In addition, if no 
covered MSD is reported for a period of at 
least 3 years after the employer has 
eliminated MSD hazards, the employer may stop 
parts of the ergonomics program in accordance 
with Sec. 1910.944.
   Section 1910.922  What is the 
``incremental abatement process'' for 
materially reducing MSD hazards?

  You may materially reduce MSD hazards using 
the following incremental abatement process:
  (a) When a covered MSD occurs, you 
implement one or more controls that 
materially reduce the MSD hazards; and
  (b) If continued exposure to MSD hazards in 
the job prevents the injured employee's 
condition from improving or another covered 
MSD occurs in that job, you implement 
additional feasible controls to materially 
reduce the hazard further; and
  (c) You do not have to put in further 
controls if the injured employee's condition 
improves and no additional covered MSD occurs 
in the job. However, if the employee's 
condition does not improve or another covered 
MSD occurs, you must continue this 
incremental abatement process if other 
feasible controls are available.

   Section 1910.922 of the proposed rule 
explains the steps of the incremental 
abatement process that employers are to use 
if they want to materially reduce hazards 
incrementally. The proposed incremental 
abatement process allows employers to test 
solutions in a problem job, and wait and see 
whether the action does significantly reduce 
the hazards before trying out additional 
controls. In Pepperidge Farm, the Commission 
discussed the meaning of an incremental 
abatement process in upholding OSHA's 
authority under section 5(a)(1) of the OSH 
Act to require that an employer engage in 
this process to control ergonomic hazards:

  Incrementalism implies a premium on 
evaluation of the consequences of initial 
actions which have been undertaken. 
Incrementalism also suggests (but does not 
require) that some steps may await the 
completion of others, and admits that actions 
may not have the desired results. Pepperidge 
Farm, 17 OSHC at 2034 n. 114.

   Many stakeholders as well as professionals 
in the field of workplace safety and health 
refer to the incremental abatement process as 
a continuous improvement process (Ex. 26-
1370). A comment by the Electronic Industries 
Association (Ex. 3-230) best sums up the goal 
of the proposed incremental abatement 
process:

  Ergonomics is a continuous improvement 
process. If an employer can show that they 
have made an organized effort to identify 
ergonomic stressors, to educate their 
affected employees on ergonomic principles, 
to implement solutions, and to have a system 
to identify when a solution is not working 
and needs to be readdressed, they have met 
the intent of the law.


1. Paragraph (a)

   Paragraph (a) provides that employers may 
go about addressing MSD hazards by trying out 
a control(s) to see whether this will take 
care of the problem. But it also specifies 
that whatever control(s) the employer wants 
to start with must be one(s) that a 
reasonable person would anticipate to be 
likely to achieve a material reduction in the 
hazard, or where the efficacy of individual 
control measures is unclear, it has the 
potential to significantly reduce the 
likelihood that covered MSDs would occur in 
the job.
   Under this process, employers have great 
flexibility to choose the control or controls 
that would be reasonably likely to materially 
reduce the hazard. Employers may start where 
they wish in addressing the hazard so long as 
their initial action is reasonably 
anticipated to reduce the hazard. Thus, 
employers may start with the ergonomic risk 
factor they prefer to look into first and 
with the modifying factor (i.e., duration, 
frequency, magnitude) they wish to address 
first.
   For example, in a manual handling job that 
requires the worker to quickly lift heavy 
containers off a low flatbed cart all day and 
then to turn to put them on a conveyor, an 
employer is likely to have several options 
about which risk factor(s) to start with: 
size or weight of load, vertical height of 
the lift, turning/twisting motion, or the 
container design. The employer is also likely 
to have several ways to modify (or reduce) 
any of the risk factors: reduce the 
percentage of the work day spent doing this 
task, reduce how quickly each

[[Page 65833]]

load must be moved, reduce the weight of 
load, reduce the vertical height (e.g., raise 
height of flatbed), reduce the amount of 
twisting, add handles to containers, or 
install mechanical lift or lifting assist 
devices.
   Paragraph (a) provides that if reducing 
the vertical height that the employee must 
lift the container does materially reduce the 
likelihood of injury, the employer is not 
required at the outset, for example, to 
purchase and install mechanical lifts. 
However, if the load weighs more than 100 
pounds, for example, it is not reasonable to 
expect that changing the vertical distance 
alone would significantly reduce the 
likelihood that employees performing these 
physical work activities would develop a back 
injury (unless the vertical travel distance 
was reduced to 0 because the requirement to 
lift was eliminated).


2. Paragraph (b)

   Paragraph (b) specifies that if the 
problem does not resolve or gets worse, 
employers must try additional feasible 
controls to achieve a material reduction in 
the hazard. A problem is not considered 
resolved if the injured employee's condition 
does not improve because the employee 
continues to be exposed to ergonomic risk 
factors that are reasonably likely to cause, 
contribute to, or aggravate an MSD of this 
type. Employers need to install additional 
controls if another employee in the job 
reports a covered MSD. The fact that another 
employee in the job has been injured is a 
good indication that additional controls are 
needed to reduce the hazard.


3. Paragraph (c)

   Paragraph (c) proposes that, if after the 
employer implements the initial control(s) 
designed to materially reduce the hazard, the 
injured employee's condition gets better, 
then the employer would not be required to 
take further control action, provided that no 
one else in the job develops a covered MSD. 
This provision would allow the employer, at 
this point, to wait and see whether the 
initial action has been adequate. As long as 
no one in the problem job reports a covered 
MSD, the employer need not put in any 
additional controls.
   When a covered MSD is reported in that 
job, however, the waiting process is over. 
The occurrence of another covered MSD 
indicates that the initial controls were not 
adequate. This means that employers must try 
other feasible controls to materially reduce 
the MSD hazards in the job. As long as 
covered MSDs continue to occur and feasible 
controls exist, employers must be following 
the steps of the incremental abatement 
process.
   As with the control endpoints discussed in 
Sec. 1910.921, there also are endpoints to 
the incremental abatement process. Obviously, 
employers may stop the incremental abatement 
process when they have eliminated the MSD 
hazards because there is nothing remaining in 
the physical work activities and conditions 
of the job that would be reasonably likely to 
cause or contribute to a covered MSD. 
Likewise, the obligation to continue the 
process would cease if employers have tried 
controls and have reduced the hazard to the 
extent feasible, i.e., they have done 
everything at this time. The only remaining 
hazard analysis and control obligation 
required by the standard in such a situation 
is to periodically check to see whether a new 
control that is capable of materially 
reducing the hazard has become available.


Training (Secs. 1910.923-1910.928)

   Training is a critical component of an 
ergonomics program. Training is needed to 
equip employees in problem jobs, their 
supervisors, and persons involved in 
administering the ergonomics program with the 
knowledge and skills necessary to recognize 
and control MSDs and MSD hazards. Effectively 
addressing workplace MSD hazards requires 
that these individuals possess the ability to 
identify the physical work activities and job 
conditions that may increase a worker's risk 
of developing MSDs, recognize the signs and 
symptoms of these disorders, and participate 
in the development and execution of effective 
strategies to eliminate or materially reduce 
them.
   As has already been discussed, the 
proposed standard requires that information 
regarding common MSD hazards, signs and 
symptoms of MSDs, reporting methods, and the 
requirements of the standard be provided to 
at-risk employees. Providing information 
serves to heighten awareness of employees 
with regard to MSDs that may occur and the 
workplace risk factors that can cause them, 
as well as indicating the means of 
communicating any relevant observations to 
the employer. The provision of information 
alone, however, does not constitute training, 
because it may not ensure the level of 
comprehension that is necessary for employees 
to take an active role in the ergonomics 
program. The requirements of the proposed 
standard for training are also broader in 
scope than the requirements for providing 
information, extending to methods of control 
as well as the recognition of MSD hazards.
   Section 1910.923  What is my basic 
obligation?

  You must provide training to employees so 
they know about MSD hazards and your 
ergonomics program and measures for 
eliminating or materially reducing the 
hazards. You must provide training initially, 
periodically, and at least every 3 years at 
no cost to employees.

   Section 1910.923 proposes to require 
employers to provide training to employees 
about MSD hazards, the ergonomics program, 
and control measures in the workplace. 
Training would be required to be provided 
initially, periodically as needed, and at 
least every three years. Training would be 
required to be provided at no cost to 
employees.
   Initial training is necessary to ensure 
that employees in problem jobs, their 
supervisors, and the individuals who set up 
and manage the ergonomics program are 
provided with the knowledge and skills 
necessary to recognize MSD hazards in their 
workplace and to effectively participate in 
the ergonomics program. Periodic training is 
necessary to address new developments in the 
workplace and to reinforce and retain the 
knowledge acquired in initial training. The 
length and frequency of training would be 
determined by the needs of the workplace. 
Individuals would need to be trained 
sufficiently to understand the subjects 
specified in Sec. 1910.925. An interval of 
three years between training sessions is 
proposed as the minimum necessary to preserve 
the knowledge and understanding acquired in 
initial training. Employee participation in 
the ergonomics program, job hazard analysis, 
and program evaluation all depend on adequate 
employee training.
   The proposed requirement that training be 
provided at no cost to employees means that 
the employer would bear any costs associated 
with training. For example, any training 
materials given to employees would have to be 
provided free of charge. Employees would have 
to be compensated at their regular rate of 
pay for time spent receiving training, and 
could not be required to forfeit regularly 
scheduled lunch or rest periods to attend 
training sessions. In addition, where 
training requires employees to travel, the 
employer would have to pay for the cost of 
travel, including travel time when

[[Page 65834]]

the activities are not scheduled during the 
employee's normal work hours.
   The proposed requirement that training be 
provided at no cost to employees reflects 
OSHA's strong belief and past regulatory 
policy that the costs of complying with 
safety and health requirements be borne by 
the employer. The Agency considers training 
to be essential to the effectiveness of other 
provisions of the proposed standard: work 
practice controls, for example, will not be 
effective if employees are not aware of their 
proper application, and MSD management cannot 
be effective if employees do not know when it 
is appropriate or how to obtain access to it. 
OSHA believes it is reasonable for employers 
to bear the cost of training, because, under 
the Occupational Safety and Health Act of 
1970, employers bear the responsibility for 
providing a safe and healthful workplace. 
Having the costs borne by the employee would 
discourage participation in training 
activities, and would thus limit the 
effectiveness of the rule's training 
requirements.
   Section 1910.924  Who must I train?

  You must train:
  (a) Employees in problem jobs;
  (b) Supervisors of employees in problem 
jobs; and
  (c) Persons involved in setting up and 
managing the ergonomics program, except for 
any outside consultant you may use.

   Employees in problem jobs play a key role 
in the success of an ergonomics program. They 
are the individuals who have developed or are 
at risk of developing MSDs. By reporting MSDs 
and MSD hazards early, making 
recommendations, and following established 
control procedures, these workers can assist 
in protecting themselves.
   Early reporting of the development of MSDs 
would allow the employer to provide 
appropriate MSD management to the affected 
employees. Notification of the existence of 
MSD hazards would alert the employer to the 
necessity of evaluating and implementing 
measures to eliminate or control the hazards. 
The effective control of MSD hazards also 
often requires the active participation of 
employees. For example, a work station that 
can be easily adjusted to accommodate the 
demands of different tasks or the height and 
reach limitations of different workers will 
not be constructively used if the workers are 
not aware of how to make the adjustments. If 
employees are not aware of MSD signs and 
symptoms, or cannot properly use control 
measures, the ergonomic protection process 
will not succeed. It is critical that 
employees have the training they need to 
perform these functions. The proposed 
standard therefore would require in 
Sec. 1910.924(a) that training be provided to 
all employees in problem jobs.
   Supervisors of employees in problem jobs 
are often in a position to observe MSD 
hazards and to recognize when MSDs develop in 
the workers they supervise. As supervisors, 
they are also in a position to ensure that 
employees in problem jobs understand and 
conform with procedures established to 
control MSD hazards. A supervisor, for 
example, may observe an employee operating a 
hand-held vibrating power tool without 
wearing appropriate vibration-resistant 
gloves. The supervisor, when prepared by 
training to understand the significance of 
this oversight, could take corrective action 
by ensuring that gloves are provided and used 
when necessary. If the supervisor was aware 
that this employee was experiencing numbness, 
tingling, and loss of sensation in the 
fingers, training would provide the knowledge 
necessary to recognize these symptoms as 
potential indications of an MSD. Training of 
supervisors would thus provide an additional 
avenue for the protection of employees who 
develop MSDs. MSDs and MSD hazards that may 
be overlooked by the employees who are 
directly affected may be recognized by their 
supervisors. Training is necessary for these 
supervisors to acquire the knowledge 
necessary for these tasks. For this reason, 
the proposed standard would require in 
Sec. 1910.924 (b) that supervisors of 
employees in problem jobs be provided 
training.
   The effectiveness of the ergonomics 
program is also dependent on the abilities of 
those individuals who establish and 
administer the program. These individuals 
must be able to identify MSDs and MSD 
hazards, undertake appropriate interventions 
to control the hazards, and evaluate the 
effectiveness of the ergonomics program and 
controls that have been adopted. The 
individuals who establish and administer the 
ergonomics program may be provided by the 
employer with the authority and resources 
necessary to accomplish these objectives, but 
without effective training it is unlikely 
that they would have sufficient knowledge to 
accomplish them successfully. For example, a 
program administrator assigned the task of 
evaluating the effectiveness of measures 
instituted to materially reduce MSD hazards 
in problem jobs would likely need training in 
order to understand how to assess 
effectiveness. Section 1910.924 (c) of the 
proposed standard would therefore require 
that training be provided to individuals who 
set up and manage the ergonomics program. 
Outside consultants do not need to be trained 
by the employer, because these individuals 
are responsible to preparing themselves to 
perform their professional duties.
   Section 1910.925  What subjects must 
training cover?
   This table specifies the subjects training 
must cover:

------------------------------------------------------------------------
  YOU MUST PROVIDE TRAINING FOR . . .        SO THAT THEY KNOW . . .
------------------------------------------------------------------------
(a) Employees in problem jobs and their  (1) How to recognize MSD signs
 supervisors.                             and symptoms;
                                         (2) How to report MSD signs and
                                          symptoms, and the importance
                                          of early reporting;
                                         (3) MSD hazards in their jobs
                                          and the measures they must
                                          follow to protect themselves
                                          from exposure to MSD hazards;
                                         (4) Job-specific controls
                                          implemented in their jobs;
                                         (5) The ergonomics program and
                                          their role in it; and
                                         (6) The requirements of this
                                          standard.
(b) Persons involved in setting up and   (1) The subjects above;
 managing the ergonomics program.        (2) How to set up and manage an
                                          ergonomics program;
                                         (3) How to identify and analyze
                                          MSD hazards and measures to
                                          eliminate or materially reduce
                                          the hazards; and

[[Page 65835]]

 
                                         (4) How to evaluate the
                                          effectiveness of ergonomics
                                          programs and controls.
------------------------------------------------------------------------

   Training must encompass certain elements 
in order to provide affected individuals with 
sufficient knowledge to recognize and control 
MSDs and MSD hazards in their workplace. The 
proposed standard presents a number of 
elements on which training would be required 
for all employees in problem jobs, their 
supervisors, and persons involved in setting 
up and managing the ergonomics program. For 
persons involved in setting up and managing 
the ergonomics program, several additional 
elements would be required to be covered.
   Training would address recognition of MSD 
signs and symptoms, and the method and 
importance of early reporting when these 
signs and symptoms develop. This is an 
elaboration of the information provided to 
at-risk employees, and an opportunity for the 
employer to relate the general information 
provided to the operations at a specific 
workplace and to site-specific conditions. 
Training is not intended to prepare workers, 
supervisors, or managers to medically 
diagnose or treat MSDs. Rather, the purpose 
is to instill an understanding of what type 
of health problems may be work related so 
that these individuals will be able to 
recognize when MSD management is necessary.
   Since the employees who would be trained 
are in problem jobs, they are exposed to 
factors that are associated with a risk of 
developing MSDs, and may already suffer from 
MSDs. It is thus particularly important that 
they be aware of the MSD signs and symptoms 
that are reasonably likely to occur. The 
supervisors of employees in problem jobs will 
often be in position to observe MSD hazards 
and the development of MSD signs and symptoms 
among the workers they supervise. In many 
instances, supervisors may perform the same 
job tasks as the workers they supervise. 
Early reporting would help the employer 
ensure that intervention in the disease 
process occurs before functional incapacity 
or permanent disability results, and would 
assist in identifying MSD hazards so that 
measures could be taken to eliminate or 
materially reduce those hazards. In many 
instances, the workers who perform tasks that 
involve MSD hazards and their supervisors are 
also the persons most familiar with the 
options for controlling those hazards. The 
recommendations of these individuals are thus 
an important means of identifying actions 
that would alleviate MSD hazards.
   Employees in problem jobs, their 
supervisors, and persons involved in setting 
up and managing the ergonomics program would 
also be trained to recognize the MSD hazards 
in jobs and the measures that must be taken 
to control exposure to these hazards. This 
would include both general measures and those 
specific to the job. This training would 
provide these individuals with the knowledge 
and skills necessary to take actions to 
reduce the potential for developing MSDs. 
Proper understanding of control measures is 
particularly important because the 
effectiveness of these measures is dependent 
on their proper use by employees. All 
affected parties also need to know what their 
role in the ergonomics program is, in order 
to best facilitate the program's successful 
implementation. Employees, for example, must 
understand the provisions for MSD management 
in order to participate appropriately in this 
process.
   The proposed standard includes a 
requirement that employees in problem jobs, 
their supervisors, and persons involved in 
setting up and managing the ergonomics 
program know the requirements of the 
standard. This would ensure that workers are 
aware that specific requirements have been 
established to protect them from MSDs. 
Program administrators would be able to 
ensure that the program meets its legal 
obligations.
   Additionally, program administrators must 
know how to set up and manage an ergonomics 
program, recognize and appraise MSD hazards, 
and select and apply appropriate measures to 
eliminate or materially reduce MSD hazards in 
order for the ergonomics program to be 
effective. The proposed standard would 
require that training be provided to equip 
these individuals to perform these assigned 
functions. The administrators would further 
be trained to evaluate the effectiveness of 
ergonomics programs and controls, in order 
that they be able to identify and rectify any 
deficiencies that may occur in their 
workplace's program.
   While employees in problem jobs may be 
able to take some limited actions 
individually to protect themselves from MSD 
hazards, the primary responsibility for 
providing a safe work environment rests with 
the employer. The individuals who set up and 
administer the ergonomics program act on 
behalf of the employer in controlling MSD 
hazards. Employees cannot be protected from 
MSD hazards unless these hazards are 
identified and effective measures are then 
taken to control them. Accordingly, the 
individuals who administer the ergonomics 
program must be properly trained to discern 
when interventions are needed, decide what 
intervention methods are appropriate, and 
examine the results of interventions to 
determine if further actions are necessary.

   Section 1910.926  What must I do to ensure 
that employees understand the training?
  You must provide training and information 
in language that employees understand. You 
also must give employees an opportunity to 
ask questions and receive answers.

   The proposed standard would allow 
employers to use whatever training 
methodology they consider most useful or 
appropriate for that particular workplace, 
provided that the specified elements are 
addressed. Hands-on training, videotapes, 
slide presentations, classroom instruction, 
informal discussions during safety meetings, 
written materials, or any combination of 
these methods may be appropriate. The primary 
concern is that the training be effective.
   In order for the training to be effective, 
the employer must ensure that the training is 
provided in a manner that the employee is 
able to understand. Employees have varying 
educational levels, literacy, and language 
skills, and training must be presented in a 
language and at a level of understanding that 
accounts for these differences in order to 
meet the proposed requirement that 
individuals being trained understand the 
specified training elements. This may mean, 
for example, providing materials, 
instruction, or assistance in Spanish rather 
than English if the workers being trained are 
Spanish-speaking and do not understand 
English. The employer would not be required 
to provide training in the employee's 
preferred language if the employee understood 
both languages; as long as the employee is 
able to understand the language used, the 
intent of the proposed standard would be met.

[[Page 65836]]

   In order to ensure that employees 
comprehend the actions that they must take to 
protect themselves from exposure to MSD 
hazards, it is critical that trainees have 
the opportunity to ask questions and receive 
answers if they do not fully understand the 
material that is presented to them. When 
videotape presentations or computer-based 
programs are used, this requirement may be 
met by having a qualified trainer available 
to address questions after the presentation, 
or providing a telephone hotline so that 
trainees will have direct access to a 
qualified trainer.
   Section 1910.927  When must I train 
employees?
   This table specifies when you must train 
employees:

------------------------------------------------------------------------
                                THEN YOU MUST PROVIDE TRAINING AT THESE
      IF YOU HAVE . . .                       TIMES . . .
------------------------------------------------------------------------
(a) Employees in problem jobs  (1) When a problem job is identified;
 and their supervisors         (2) When initially assigned to a problem
                                job;
                               (3) Periodically as needed (e.g., when
                                new hazards are identified in a problem
                                job or changes are made to a problem job
                                that may increase exposure to MSD
                                hazards); and
                               (4) At least every 3 years.
(b) Persons involved in        (1) When they are initially assigned to
 setting up and managing the    setting up and managing the ergonomics
 ergonomics program             program;
                               (2) Periodically as needed (e.g., when
                                evaluation reveals significant
                                deficiencies in the program, when
                                significant changes are made in the
                                ergonomics program); and
                               (3) At least every 3 years.
------------------------------------------------------------------------

   Section 1910.927 proposes establishing 
time frames for the provision of training. 
Employees in problem jobs and their 
supervisors would be required to be provided 
training when a problem job is identified, 
when they are initially assigned to a problem 
job, and periodically thereafter as needed, 
but at least every three years.
   The need for initial training is self-
evident: employees and their supervisors must 
be trained prior to the occurrence of covered 
MSDs in order to recognize the hazards, help 
to reduce them, and effectively participate 
in the ergonomics program. If an employee is 
assigned to a problem job prior to receiving 
proper training, that employee is not likely 
to be able to take advantage of protective 
measures that are available to alleviate MSD 
hazards.
   Periodic training under the proposed 
standard would be required to be conducted on 
an as-needed basis. The frequency of routine 
training would be performance oriented; 
individuals would need to be trained 
sufficiently to understand the elements 
specified in Sec. 1910.925. Periodic training 
is needed to refresh and reinforce the 
memories of individuals who have previously 
been trained, and to ensure that these 
individuals are informed of new developments 
in the ergonomics program. For example, 
training after new control measures are 
implemented would generally be necessary in 
order to ensure that employees are able to 
properly use the new controls as they are 
introduced. Employees would likely be 
unfamiliar with new work practices 
undertaken, with the operation of new 
engineering controls, or the use of new 
personal protective equipment; training would 
rectify this lack of understanding. This 
would ensure that employees are able to 
actively participate in protecting themselves 
under the conditions found in the workplace, 
even if those conditions change.
   At a minimum, the periodic training would 
be required to take place every three years. 
This interval is considered by the Agency to 
represent the maximum reasonable interval for 
affected individuals to retain the knowledge 
and understanding initially acquired without 
some form of reinforcement. More frequent 
periodic training, such as annual training, 
has not been proposed because regular 
communication between employees and 
management would be ongoing as a result of 
the proposed requirements for management 
leadership and employee involvement in the 
ergonomics program. Employee involvement in 
developing, implementing, and evaluating each 
element of the ergonomics program, including 
training, is included in the requirements of 
the proposed standard in Sec. 1910.912. 
Prompt reporting by employees of MSD signs 
and symptoms and MSD hazards, effective job 
hazard analysis, and evaluation of the 
ergonomics program will make employers aware 
of additional training needs. Periodic 
training more frequently than every three 
years is likely to be appropriate in many 
work situations, for example in a workplace 
with many problem jobs. A requirement for 
annual training has not been included in this 
proposal in order to avoid encumbering those 
employers whose operations involve more 
limited exposure to MSD hazards.
   Persons involved in setting up and 
managing the ergonomics program would be 
required under the proposed standard to be 
trained upon initial assignment to these 
duties. Knowledge and understanding of the 
identification of MSDs and analysis of MSD 
hazards, measures to eliminate or materially 
reduce MSD hazards, and the ergonomics 
program and its evaluation are all needed for 
the development and operation of the program. 
Periodic training is needed to provide 
program administrators with the skills and 
abilities to adjust the program to account 
for changes in the workplace, and to correct 
any significant deficiencies that may be 
identified in the program. This would assure 
that the ergonomics program is applicable to 
current conditions in the workplace, and is 
optimally effective in protecting workers 
from MSD hazards. Periodic training would 
also allow those individuals setting up and 
managing the program to keep abreast of new 
developments in the evolving field of 
ergonomics.
   In comments received in response to the 
ANPR, some concern was expressed by industry 
regarding the frequency of training. For 
example, the American Meat Institute wrote 
(Ex. 3-147):

  OSHA should not dictate specific training 
requirements. Specifically, training 
frequencies should not be included in a 
standard.

OSHA intends for the performance oriented 
approach adopted in the proposal to provide 
sufficient flexibility so that employees in 
problem jobs, their supervisors, and 
individuals involved in establishing and 
managing the ergonomics program receive 
sufficient training to effectively

[[Page 65837]]

participate in the program, without 
compelling employers to provide training more 
often than the circumstances of the workplace 
dictate.
   Section 1910.928  Must I retrain employees 
who have received training already?

  No. You do not have to provide initial 
training to current employees, new employees 
and persons involved in setting up and 
managing the ergonomics program if they have 
received training in the subjects this 
standard requires within the last 3 years. 
However, you must provide initial training in 
the subjects in which they have not been 
trained.

   Proposed Sec. 1910.928 would allow 
training received within the previous three 
years to fulfill the requirements for initial 
training. Subsequent periodic training would 
still be required at least every three years, 
and more frequently if warranted by the 
circumstances of the workplace. For example, 
a baggage handler who has received training 
from one employer and then moves to another 
employer six months later to perform the same 
job may not need to receive initial training 
in all of the subjects prescribed in 
Sec. 1910.925. Prior training in general 
topics, such as the recognition of MSD signs 
and symptoms, may remain relevant in the new 
workplace. However, site-specific training, 
for example training in how to perform work 
safely using the equipment at the new 
workplace, would generally be required. 
Allowing prior training in covered topics to 
be ``portable'' would apply to both current 
and newly hired employees, including those 
who set up and manage the ergonomics program.
   The employer must be able to demonstrate 
that the employee has retained sufficient 
knowledge to meet the requirements for 
initial training in order for prior training 
to be considered sufficient to meet the 
requirements of Sec. 1910.928. This could be 
determined through discussion of the required 
training subjects with the employee. Merely 
having received training during the previous 
three years would not be sufficient for an 
exemption from the initial training 
requirement. If the employer cannot 
demonstrate that the new employee has been 
trained and knows the required elements, the 
new employer would be obligated to train the 
employee in these elements. In cases where 
understanding of some elements is lacking or 
inadequate, the employer would be required to 
provide training only in those elements. This 
allowance for prior training is intended to 
ensure that employees receive sufficient 
training, without requiring unnecessary 
repetition of that training.
   Evidence in the record clearly shows that 
training is an essential component of an 
effective ergonomics program and can help to 
reduce MSDs. In some instances, training in 
appropriate work practice controls may serve 
to reduce the incidence of MSDs. For example, 
the effectiveness of training in reducing the 
incidence of MSDs has been reported by 
Parenmark et al. (Ex. 26-6). Sixteen newly 
hired assembly workers at a Swedish chain saw 
plant were trained to perform their jobs 
using work practices that maintained the 
muscular load on the upper extremities at 10% 
or less of maximum voluntary contraction. The 
same training was also given to a group of 
assembly workers who had been on the job for 
one year. Training was not provided to a 
control group of new hires. After 48 weeks on 
the job, sick leave due to arm/neck/shoulder 
complaints was reduced by more than 50% among 
the new hires provided ergonomic work 
practice training when compared to the 
control group of new hires; the difference 
was statistically significant. For the 
assembly workers who had been on the job for 
one year, sick leave due to arm/neck/shoulder 
complaints was reduced by over 40% after 
training, although this result was not 
statistically significant.
   Further evidence of the success of 
training in proper work practices in 
controlling MSD hazards in some instances is 
provided by Dortch and Trombly ( Ex. 26-7), 
who examined the effectiveness of training in 
reducing the frequency of movements 
identified as traumatizing to the musculature 
and connective tissue of the hand, wrist, and 
forearm and known to be associated with MSDs. 
Eighteen electronic assembly workers were 
observed performing their jobs, and the 
number of MSD-associated movements was 
recorded for each individual. The workers 
were then divided into two groups. The first 
group received awareness training and a 
printed handout describing job-specific work 
practice controls. In addition to awareness 
training and the printed handout, members of 
the second group discussed the concepts in 
the handout individually with an instructor 
and received hands-on training. Each of the 
groups exhibited statistically significant 
reductions in the frequency of those 
movements associated with MSD development 
during observation one week after the 
training was administered. The group 
receiving more extensive training showed the 
greater reduction, although the difference 
between the two groups after training was not 
statistically significant.
   Engels et al. (Ex. 26-8) studied the 
effectiveness of ergonomic work practice 
training for nurses. Twelve nurses attending 
an ergonomic education course were compared 
to a control group of twelve nurses. 
Participants were videotaped and their 
performance was assessed by scoring ergonomic 
errors on a checklist. Included among the 
activities monitored under standardized 
conditions were such tasks as transferring a 
patient from a bed to a wheelchair, washing a 
patient, and raising a patient from a lying 
position to sitting up. The nurses who had 
received training were found to be less 
likely to make ergonomic errors than the 
control group; this result was statistically 
significant. When the ergonomic work practice 
training was accompanied by other elements of 
an ergonomics program, the likelihood of 
making ergonomic errors was found to continue 
to decrease a year after the training had 
ended; this result was also statistically 
significant.
   Training in work practices, however, 
represents only one of the subjects that 
would be covered in the proposed requirements 
for ergonomic training. Training in the 
recognition of MSD signs and symptoms, and 
methods of reporting development of these 
signs and symptoms, would allow appropriate 
medical management to take place. Ergonomics 
training can also provide employees in 
problem jobs, their supervisors, and 
ergonomics program managers with the 
knowledge necessary to actively participate 
in the development of appropriate methods of 
controlling MSD hazards in their workplace, 
providing a number of benefits for employers. 
The Joyce Institute, a provider of ergonomic 
training and consultation services, reported 
the results obtained by a number of companies 
when ergonomic improvements were made as a 
result of training (Ex. 3-122E-3). Among the 
outcomes:
    Textron-Davidson Interior Trim 
experienced a 42% reduction in OSHA 
recordable injuries, a savings of $440,000 in 
labor and materials, and a reduction in 
employee turnover;
    Spectra-Physics reduced CTDs from 
558 to 150 in three years;
    A food processing company found 
50% fewer CTDs in the plant where training 
had been performed and changes

[[Page 65838]]

made when compared to other plants doing 
similar work; and
    Milton Bradley experienced a 90% 
improvement in quality as measured by 
customer returns due to damaged packaging.
   Responses to the ANPR indicate that the 
need for ergonomic safety and health training 
is widely recognized. For example, the 
National Solid Wastes Management Association 
(Ex. 3-248) stated:

  The Association feels that the training and 
education of workers is the single most 
important element of any general industry 
standard, and is the element most within the 
resources of the majority of employers within 
our industry to provide an effective 
reduction in exposure to ergonomic hazards * 
* *
  If employees are sufficiently educated to 
avoid or minimize ergonomic hazards within 
their personal control, to report symptoms 
early enough to avoid serious medical 
complications and to understand the need to 
communicate to their employer regarding a 
work station, equipment or job duty that 
presents an ergonomic hazard, then the 
employer should be in the best possible 
position to identify and rectify an 
inappropriate situation.

   The Mount Sinai-Irving J. Selikoff 
Occupational Health Clinical Center (Ex. 3-
162) also advocated training for employees:

  We believe that training and education of 
workers about ergonomic hazards should be 
required under the standard. The training 
should emphasize the identification of 
potential ergonomic hazards as well as 
recognition of symptoms of common ergonomic 
disorders. Prevention should be strongly 
emphasized in such programs as part of an 
aggressive company-wide commitment to work to 
eliminate these problems as soon as possible.

   The Telesector Resources Group (Ex. 3-215) 
expressed support for training all employees 
exposed to significant workplace risk 
factors, and indicated what should be 
included in this training, particularly job-
specific training regarding work practices:

  Employees exposed to significant 
occupationally-related CTD risk factors 
should be trained in the broad scope of 
applicable ergonomics principles and in the 
specific operations of their work tasks and 
workstations where such training is required 
to ensure that the task can be performed, and 
equipment operated as intended. These 
employees should understand the significant 
CTD risk factors to which they may be exposed 
and how to prevent or minimize exposure to 
them. Education and training in applicable 
ergonomics principles is especially important 
for new employees and those employees who are 
assuming new job tasks where significant CTD 
risk factors are known to exist.

Similarly, the AFL-CIO also endorsed training 
as part of an appropriate approach to 
addressing ergonomics in the workplace (Ex. 
3-184):

  In order for the standard to be most 
effective in preventing CTDs, workers must be 
trained in early identification of CTDs and 
risk factors for CTDs, proper ways to perform 
the job, and other information related to the 
standard.

   However, not all stakeholders supported a 
training requirement. For example, the 
Society of American Florists (Ex. 3-55) 
commented:

  Additional training and recordkeeping 
requirements would place yet another burden 
and layer of bureaucracy upon small 
businesses and compromise their ability to 
compete.

   Some respondents to the ANPR expressed a 
desire that training requirements be 
adaptable to the specific circumstances of 
the affected employers. US WEST Business 
Resources, Inc. (Ex. 3-91), while endorsing 
training as part of the approach to 
ergonomics, stated that the requirements must 
be flexible:

  US WEST recognizes that employee training 
is an essential cornerstone of any 
occupational health and safety program. As 
with other aspects of an ergonomics program, 
training needs are highly variable and OSHA 
must allow employers a high degree of 
flexibility in establishing training programs 
that best fit the needs of their employees 
and operations.

The Synthetic Organic Chemical Manufacturers 
Association, Inc. (Ex. 3-185) made the same 
point:

  We agree that individuals participating in 
the CTD program should be trained. However, 
the level, frequency, and sophistication of 
the training effort should be performance-
based so that the employer can best determine 
what is appropriate for its workplace.

   In the proposed standard, OSHA seeks to 
provide employees, their supervisors, and 
those involved in administration of the 
ergonomics program sufficient training to 
actively participate in the protective 
process in their workplace, without creating 
any unnecessary or undue burden on employers. 
The Agency recognizes that workplaces vary 
greatly in the scope and magnitude of MSD 
hazards present, the number and complexity of 
control measures implemented, and the extent 
to which affected individuals must be 
involved in the control process. The 
standard, therefore, does not propose a 
specified format or length of time for 
training, allowing employers to adjust 
training to the needs of their workplace. It 
is anticipated that the training would vary 
in duration from facility to facility, 
depending on the extent of the MSD hazards, 
the type of operation, the controls required, 
and the involvement necessary on the part of 
the employee for the control measures to be 
effective.


MSD Management (Secs. 1910.929 through 
1910.935)

   This discussion of MSD management is 
divided into three parts. Part A explains the 
proposed requirements in sections 1910.929 
through 1910.935, all of which address 
aspects of the proposed MSD management 
process. Part B discusses OSHA's legal 
authority to require work restriction 
protection and the Agency's reasons for doing 
so. Part C deals with alternatives to the 
proposed work restriction protection 
requirements that OSHA has considered in 
developing the proposed rule's work 
protection provisions.


Part A--Proposed Requirements for Sections 
1910.929 through 1910.935

   This section of the proposed rule 
establishes the requirements for setting up a 
process to manage MSDs when they occur. MSD 
management is the employer's process for 
ensuring that injured employees are provided 
with:

   Prompt access to health care 
professionals (HCPs) or other safety and 
health professionals as appropriate;
   Effective evaluation, management, 
and follow-up; and
   Appropriate temporary work 
restrictions where needed during the recovery 
period.

   MSD management emphasizes prevention of 
impairment and disability through early 
detection, prompt management and timely 
recovery from covered MSDs (Ex. 26-1264, Ex. 
26-921). This early intervention process is 
important in helping to achieve the goals of 
the proposed standard--reducing the severity 
as well as the number of work-related MSDs.

[[Page 65839]]

   The MSD management provisions in the 
proposed standard are built upon the 
processes that employers with ergonomics 
programs already are using to help employees 
who have work-related MSDs. Evidence in the 
record shows that these companies, through 
early intervention and management of MSDs, 
have achieved substantial reductions in areas 
such as lost-work time, lost-workdays, costs 
per case, and workers' compensation claims 
and costs (see, e.g., Ex. 3-147, Ex. 26-1367, 
Ex. 26-1405).
   The proposed MSD management provisions are 
consistent with and based on OSHA's other 
ergonomics efforts. MSD management provisions 
are included in OSHA's Ergonomics Program 
Management Guidelines for Meatpacking Plants 
(Ex. 26-3). The Guidelines emphasize that 
``proper medical management is necessary both 
to eliminate or materially reduce the risk of 
development of CTD signs and symptoms through 
early identification and treatment and to 
prevent future problems'' (Ex. 26-3). In 
addition, MSD management provisions have been 
included in all of OSHA's corporate 
settlement agreements addressing MSD hazards. 
Finally, to become a member of OSHA's 
Voluntary Protection Program, employers must 
include an ``Occupational Heath Care 
Program'' in their safety and health 
programs. This would address MSDs, along with 
other health hazards.


1. Need for MSD Management

   MSD management is recognized by, among 
others, employers, HCPs, and occupational 
safety and health professionals as an 
essential element of an effective ergonomics 
program (Ex. 26-1, Ex. 26-5, Ex. 26-1264). 
Among employers who told OSHA they have an 
ergonomics program, most reported that their 
programs include MSD management as a key 
element (Exs. 3-56; 3-59; 3-73; 3-95; 3-113; 
3-118; 3-147; 3-175; 3-217; and 26-23 through 
26-26). The draft American Standards 
Committee (ASC) consensus standard on the 
control of work-related MSDs states that a 
program to control MSDs ``shall'' include 
provisions for the evaluation and management 
of MSD cases (i.e., MSD management), because 
such elements ``are either recognized and 
fundamental to injury prevention, or 
considered minimally essential to the control 
of [MSDs]'' (Ex. 26-1264). The draft ASC 
consensus standard was developed by a 
committee comprised of representatives from 
the medical, scientific, and academic 
communities, as well as those representing 
employers and employees.
   There are many reasons why MSD management 
is essential to the success of an ergonomics 
program. MSD management helps to reduce the 
severity of MSDs that occur. As mentioned 
above, MSD management emphasizes the early 
detection of MSDs, followed by prompt and 
effective evaluation and management. 
Identifying and addressing MSD signs and 
symptoms at an early stage helps to slow or 
halt the progression of the disorder. When 
MSDs are caught early they are more likely to 
be reversible, to resolve quickly, and not to 
result in disability or permanent damage. The 
American Meat Institute is on record as 
saying that MSD management programs that 
promote early intervention result in a 
reduction in the number of serious MSDs, 
fewer surgeries, reduced lost-time from work, 
and a quicker return to full duty (Ex. 3-
147). Two studies by Maurice Oxenburgh also 
support this. In one study, Oxenburgh found 
that for employees suffering from upper-
extremity MSDs (UEMSDs), the earlier they 
reported signs and/or symptoms of the UEMSDs, 
the quicker they were able to return fully to 
work (Ex. 26-1367). Specifically, Oxenburgh 
found that UEMSDs resulted in 49 days away 
from work (or on restricted work) for 
employees who reported within 20 days of the 
onset of pain, 66 days for employees who 
reported within 21-50 days of the onset of 
pain, and 84 days for employees who reported 
after 51 days of the onset of pain. In 
another study, Oxenburgh observed two groups 
of video display unit (VDU) workers who were 
exposed to the same ergonomics risk factors. 
One group (``the MSD management group'') 
received medical screening, training, 
workstation redesign, treatment, and 
rehabilitation; the other group (``the 
control group'') received none of these 
interventions. Oxenburgh compared the two 
groups and found:

  1. Twenty-two percent of the control group 
cases had second or third stage injuries, 
compared with 8% for the MSD management 
group;
  2. The mean period of absence from work for 
the control group workers was 33.9 days, 
compared with 3.4 days for the MSD management 
group; and
  3. The total amount of time the average 
worker in the control group lost, either to 
days away or alternate duty, was 124.9 days, 
compared to 34.9 days for the MSD management 
group (Ex. 26-1405).

These studies demonstrate the importance of 
early reporting and intervention as part of 
MSD management in reducing the severity of 
MSDs, as well as accelerating the recovery 
process for injured employees. In so doing, 
MSD management also reduces the costs of MSDs 
to employees and employers alike.
   An MSD management process is also 
important to reduce the use of and need for 
surgery to repair MSDs (Ex. 26-5). Uniformly, 
stakeholders have told OSHA that intervention 
should be made at the earliest possible stage 
when conservative treatment, rather than 
surgery, is most likely to resolve MSDs (see 
Exs. 26-23 through 26-26). For example, the 
Denton Hand Rehabilitation Clinic stated:

  [E]arly intervention and nonsurgical 
intervention is the more appropriate approach 
to carpal tunnel syndrome. It is imperative 
that the high cost of health care be reduced 
and a program which offers early intervention 
and nonsurgical intervention with full 
employer participation, employee 
understanding, and the medical referral would 
certainly offer this (Ex. 3-33).

If MSD management is delayed or not provided 
at all, it may be more difficult to avoid 
surgery because conservative treatment may 
not be able to resolve the MSD.
   MSD management also helps to reduce the 
number of MSDs by alerting employers early 
enough that they can take action before 
additional problems occur. To illustrate, 
many employers with ergonomics programs use 
the report of a single MSD as a trigger for 
conducting a job hazard analysis (Ex. 26-5). 
The purpose of analyzing and fixing the job 
at this stage is to prevent injury to other 
employees in the same job. An MSD management 
process that encourages early reporting and 
evaluation of that first MSD thus helps to 
ensure that the analysis and control of the 
job is done before a second employee develops 
an MSD.
   MSD management also reduces MSDs through 
prevention. Specifically, MSD management 
helps to prevent future problems through 
development and communication of information 
about the occurrence of MSDs. For example, 
where engineering, design and procurement 
personnel are alerted to the occurrence of 
MSDs, they can help to implement the best 
kind of ergonomic controls: controlling MSD 
hazards in the design and purchase phase to 
prevent their introduction into the 
workplace.
   OSHA is using the term ``MSD management'' 
in the proposed rule rather than ``medical 
management.'' ``Medical

[[Page 65840]]

management'' is a term that OSHA has used in 
earlier ergonomics publications (e.g., 
Ergonomics Program Management Guidelines for 
Meatpacking Plants (1990)) and stakeholders 
have become familiar with it. However, OSHA 
believes that ``MSD management'' is a more 
accurate term because it emphasizes that the 
successful resolution of MSDs may involve 
professionals from many disciplines. These 
individuals may include physicians, 
occupational health nurses, nurse 
practitioners, physician assistants, 
occupational therapists, physical therapists, 
industrial hygienists, ergonomists, safety 
engineers, or members of workplace safety and 
health committees. OSHA believes that all of 
these individuals, along with the employer 
and employees, may have a role to play in MSD 
management, depending on the size, 
organizational structure, or culture of the 
particular workplace.
   In addition, OSHA believes that the term 
MSD management indicates that many approaches 
can be successful in resolving MSDs. For 
example, some employers have developed 
successful MSD management programs that are 
built on immediately providing restricted 
work activity at the first report of MSD 
signs or symptoms. These employers have said 
that quick intervention has resulted in 
dramatic reductions in lost workday injuries 
as well as reductions in medical treatment 
costs. Other companies utilize on-site HCPs 
to provide quick front-line health 
interventions. Although these approaches are 
quite different, they have both been shown to 
be successful. Still other organizations rely 
on the training and skill of ergonomics 
committee members to address problems. The 
MSD management provisions of the proposed 
rule have been written to recognize that many 
individuals may be trained and knowledgeable 
about MSDs and MSD hazards. The choice of 
approach to MSD management is left to the 
employer.
   Section 1910.929  What is my basic 
obligation?

  You must make MSD management available 
promptly whenever a covered MSD occurs. You 
must provide MSD management at no cost to 
employees. You must provide employees with 
the temporary ``work restrictions'' and 
``work restriction protection (WRP)'' this 
standard requires.

   The employer's basic obligation, as stated 
in section 1910.929, is to make MSD 
management available promptly to employees 
with covered MSDs. MSD management is a 
process that addresses MSDs promptly and 
appropriately. In other words, MSD management 
means that an employer has established a 
process for assuring that employees with 
covered MSDs receive timely attention for the 
reported MSD, including, if appropriate, work 
restrictions or job accommodation and follow-
up. Where there is no on-site HCP, the 
employer may designate an individual to 
receive and respond promptly to reports of 
MSD signs, symptoms, and hazards. Where there 
is an on-site HCP, he or she would be the 
likely person to have responsibility for MSD 
management, including referral as 
appropriate.
   An effective MSD management program has:

  1. A method for identifying available 
appropriate work restrictions and promptly 
providing them when necessary;
  2. A method for ensuring that an injured 
employee has received appropriate evaluation, 
management, and follow-up in the workplace;
  3. A process for input from persons 
contributing to the successful resolution of 
an employee's covered MSD; and
  4. A method for communicating with the 
safety and health professionals and HCPs 
involved in the process.

   Many stakeholders stated that early 
reporting and intervention is absolutely 
essential for MSD management to be 
successful. To this end, the MSD management 
provisions are crafted to encourage employees 
to report MSDs early and to receive 
appropriate treatment promptly. In 
particular, OSHA's work restriction 
protection requirements (discussed in detail 
below) are included as part of the MSD 
management process to encourage employees to 
report MSDs early.
   In its 1997 primer, Elements of Ergonomics 
Programs, NIOSH stated that, in general, the 
earlier symptoms are identified and treatment 
initiated, the less likely a more serious MSD 
is to develop (Ex. 26-2). Thus, employees 
need to receive prompt, appropriate help 
after reporting the signs or symptoms of MSDs 
that may be work-related. The importance of 
early reporting and intervention has also 
been documented in a number of studies (see 
Exs. 26-912, 26-913, 26-917, 26-914, 26-915, 
26-910, 26-916, 26-911, 26-1367, 26-1405).
   Commenters to OSHA's ANPR also stressed 
the importance of early reporting. Martin 
Marietta attributed a drop in the incidence 
rate of cumulative trauma disorders to early 
reporting and the education of their workers 
(Ex. 3-151). Perdue Farms noted a 15% 
decrease in cumulative trauma disorders, 
which they attributed to early reporting and 
intervention (Ex. 3-56). The Mount Sinai-
Irving J. Selikoff Occupational Health Center 
stated: ``We cannot overemphasize the 
importance of the early reporting of 
symptoms. Based on evaluations of patients 
from a wide variety of work places, we 
believe it is essential to intervene 
medically, and by appropriate modification of 
the work station or job task, as soon as 
possible in order to reduce the potential for 
genesis of permanent impairment `` (Ex. 3-
162). (See also Exs. 3-33; 3-147).
   For MSD management to be effective, it 
must be provided ``promptly,'' as the 
proposed rule requires. By ``promptly,'' OSHA 
means that employers whose employees come 
forward with reports of MSDs or their signs 
or symptoms must as soon as possible assess 
the situation, determine whether temporary 
work restrictions or other measures are 
necessary, and/or refer the employee to the 
ergonomics committee, an ergonomics 
consultant, other qualified safety and health 
consultant or an HCP, as appropriate. These 
actions must be taken promptly to enable the 
MSD to resolve quickly, to prevent worsening 
due to further exposure to MSD hazards. For 
further guidance on what constitutes prompt 
MSD management, OSHA refers employers to 
Sec. 1910.943. In that section, OSHA includes 
start-up deadlines for those employers who 
may not be covered by the ergonomics rule 
initially but whose employees subsequently, 
after the compliance deadlines for the rule 
have passed, develop MSDs that are covered by 
this standard. For those employers, OSHA 
requires that when an employee reports an 
MSD, MSD management must be provided within 5 
days. OSHA believes that this time 
requirement is also appropriate for all cases 
of covered MSDs. This is not meant to imply, 
however, that employers should wait several 
calendar days after an employee reports 
experiencing symptoms before assessing the 
case, providing appropriate work 
restrictions, or referring the employee to 
the ergonomics committee, a safety and health 
professional, ergonomist, or an HCP. OSHA 
reiterates that prompt MSD management 
involves responding to employee reports of 
MSDs as soon as possible to prevent the MSDs 
from worsening.
   MSD management must be provided at no cost 
to employees. The term ``at no cost to 
employees'' includes

[[Page 65841]]

making MSD management available at a 
reasonable time and place, i.e., during 
working hours. In order to increase the 
likelihood that employees will receive the 
full benefits provided by the standard, MSD 
evaluations must be provided in a manner that 
is reasonably convenient for employees. OSHA 
has defined ``at no cost'' the same way in 
its other health standards.
   Employers must also provide employees with 
temporary work restrictions and work 
restriction protection as required by this 
proposed rule. Temporary work restrictions 
and work restriction protection are discussed 
in detail below.
   The term MSD management in the proposed 
standard does not cover particular diagnostic 
tests, treatment protocols, or specific 
treatments but instead refers to the 
employer's process of ensuring that injured 
employees have access to appropriate help 
when they need it. It is not the purpose of 
this standard to dictate professional 
practice for HCPs. An employer is free to 
establish such protocols in consultation with 
an HCP, but this is not required by the 
standard. Many stakeholders urged OSHA to 
leave the establishment of treatment 
protocols and procedures for covered MSDs to 
the HCPs (see, e.g., Ex. 3-154). Where HCP 
evaluation, treatment, and follow-up is 
necessary, OSHA believes that HCPs will 
prescribe treatment and specific therapeutics 
on the basis of the best available knowledge 
at the time that care is provided. In 
addition, OSHA believes HCPs will closely 
monitor the employee's progress to evaluate 
the effectiveness of the prescribed 
treatment. It has also generally not been 
OSHA's practice, in other health standards, 
to dictate specific diagnostic procedures or 
treatment protocols.
   Section 1910.930  How must I make MSD 
management available?

  You must:
  (a) Respond promptly to employees with 
covered MSDs to prevent their condition from 
getting worse;
  (b) Promptly determine whether temporary 
work restrictions or other measures are 
necessary;
  (c) When necessary, provide employees with 
prompt access to a ``health care 
professional'' (HCP) for evaluation, 
management and ``follow-up'';
  (d) Provide the HCP with the information 
necessary for conducting MSD management; and
  (e) Obtain a written opinion from the HCP 
and ensure that the employee is also promptly 
provided with it.

   Paragraph (a) requires employers to 
respond promptly to employees with covered 
MSDs. Whenever an employee reports an MSD, 
the key is to take action quickly to help 
ensure that the MSD does not worsen. As 
discussed above, stakeholders are in 
agreement that early reporting and response 
are the key to resolving MSD problems quickly 
and without permanent damage or disability. 
The term ``promptly,'' as used in this 
section, has the same meaning as in 
Sec. 1910.929, discussed above. Employers 
must respond to employees with covered MSDs 
as soon as possible to determine what action 
is appropriate to prevent the employee's 
condition from becoming more severe.
   Many employers with ergonomics programs 
respond to reports of MSDs by immediately 
placing the employee on restricted work 
activity, either in the same job or in an 
alternative assignment. Limiting further 
exposure to the MSD hazard or hazards 
associated with the employee's job ensures 
that the employee's condition does not worsen 
while the employer analyzes the problem job 
and, if necessary, makes arrangements for the 
employee to be evaluated by a safety and 
health professional, ergonomist, member of 
the ergonomics committee, or an HCP. 
Employers using this approach have discovered 
that the employee's condition will often 
resolve within a few days without further 
intervention. This is especially true if the 
symptom is associated with work hardening or 
conditioning for a new job, new tool, or new 
equipment. It could also be the case if a 
company has instituted a Quick Fix that 
completely eliminates the MSD hazard or 
hazards in the job, which ensures that the 
employee will experience no further exposure 
or aggravation of the condition.
   For other employers, the first response 
may be to have the affected employee 
evaluated by an HCP. Where the employer has 
an on-site HCP, for example, the employee can 
usually be seen immediately. Immediate 
attention is particularly important where the 
employer does not have a policy of 
immediately limiting the work activities of 
employees who report MSDs. However, even when 
employers have on-site HCPs, the HCP may not 
be available when the employee reports an 
MSD.
   In most cases, however, employers will not 
have an on-site HCP. In such cases, OSHA is 
aware that it may take a few days to arrange 
an appointment with an HCP. In order to 
assure a prompt response in these cases, 
employers must ensure that employees have 
access to the HCP as soon as possible. There 
are circumstances where immediate evaluation 
by an HCP is warranted. For example, an 
employee experiencing severe shoulder pain 
with numbness down her arm, an inability to 
sleep due to pain, and decreased range of 
motion of the arm and shoulder should 
immediately be referred to an HCP. An 
employee who describes symptoms that have 
been present continuously for three weeks 
should also be referred at the time of 
initial reporting.
   Paragraph (b) requires employers to make 
an initial determination promptly of whether 
temporary work restrictions or other measures 
are necessary. In many workplaces, work 
restrictions are the first line of defense 
against progression of the disorder. Work 
restrictions include any limitation placed on 
the manner in which an injured employee 
performs a job during the recovery period, up 
to and including complete removal from work. 
Work restrictions are important to resolving 
most MSDs. The purpose of work restrictions 
is to facilitate recovery of the affected 
area by not exposing the injured tissues to 
the same risk factors. The employer, who must 
provide temporary work restrictions, where 
necessary, to employees with covered MSDs, 
and the employee whose work has been 
restricted need to understand (1) What jobs 
or tasks the employee can perform during the 
recovery period, (2) whether the employee can 
perform these jobs or tasks for the entire 
workshift, and/or (3) whether the employee 
needs to be removed from work entirely. 
Employees for whom restrictions have been 
assigned because of a covered MSD must be 
properly matched with those jobs that involve 
task and work activities that accommodate the 
requirements of the restriction and thus 
facilitate healing.
   The employer must also determine whether 
other measures are necessary to protect the 
employee with a covered MSD. A company could 
institute a Quick Fix that completely 
eliminates the MSD hazard or hazards in the 
job, ensuring that the employee will 
experience no further exposure or aggravation 
of the condition. There are also 
circumstances where immediate evaluation by 
an HCP is warranted. In addition, an employer 
who was not able to provide immediate 
temporary work restrictions may be able to 
have an injured employee attend on-site 
training classes

[[Page 65842]]

for a few days. The person(s) assigned 
responsibility for MSD management needs the 
relevant information to make the decision 
about what is appropriate for the affected 
employee.
   Section 1910.930 gives employers 
flexibility to develop an appropriate process 
for responding to employees with covered 
MSDs. The proposed rule allows varied 
approaches because many factors can influence 
the process and procedures employers 
establish to deal with MSDs covered by this 
standard. Such factors may include the 
severity of the employee's condition and the 
interventions readily available. For example, 
some employers immediately place an employee 
on restricted duty. They take a ``wait and 
see approach'' and, if the MSD does not clear 
up in a few days, the employer moves on to 
the next level of intervention. Other 
employers have on-site HCPs. Some employers 
with on-site HCPs place employees who report 
signs or symptoms immediately on work 
restrictions while the HCP does the 
evaluation. Where necessary, the HCP then 
develops a treatment and/or return-to-work 
plan. Whatever the employer's response, it 
needs to be made promptly.
   In paragraph (c) of the proposed rule, 
employers must provide injured employees with 
prompt access to an HCP, when necessary, for 
evaluation, management and follow-up. OSHA 
used the language ``when necessary'' in the 
proposed rule because the Agency recognizes 
that it is not always necessary for an 
employer to send the injured employee to an 
HCP. OSHA recognizes that there are 
situations in which providing work 
restrictions immediately and/or taking other 
measures immediately, such as fixing the job, 
may be an adequate response to the report. 
This is particularly true if the MSD is 
reported very early, that is, before the 
condition becomes severe. In other 
situations, however, it will be necessary to 
send the injured employee to an HCP. For 
example, employers who do not provide work 
restrictions and/or other measures at the 
time the MSD is reported will need to send 
injured employees to the HCP. In addition, 
there will be some cases where the reported 
MSD is so severe that it is essential the 
employee be evaluated by an HCP at the 
earliest possible time.
   The proposed rule defines health care 
professional (HCP) as a physician or other 
licensed health care professional whose 
legally permitted scope of practice (e.g., 
license, registration, or certification) 
allows them to independently provide or be 
delegated the responsibility to provide some 
or all of the MSD management requirements of 
this standard. The proposed rule is flexible 
enough to allow employers to use a broad 
range of HCPs, provided the HCP is capable 
and authorized to provide evaluation, 
management, and follow-up of MSDs. As defined 
by this proposal, HCPs are not limited to 
physicians or nurses. Different HCPs may be 
involved in the process at different points.
   OSHA is proposing a flexible definition of 
HCP, for several reasons. First, this 
approach is responsive to the requests of 
stakeholders, particularly those with 
establishments in rural locations, who 
strongly urged that the rule provide maximum 
flexibility in the selection of HCPs. 
Specifically, these employers urged OSHA not 
to limit employers' choice of HCPs to 
specialists, who are often not available in 
reasonable proximity, which would delay 
prompt evaluation, management, and follow-up 
and make it much more costly. In general, 
most of the commenters made broad, generic 
statements on the qualifications of HCPs that 
were needed to perform MSD management. For 
example, the American College of Occupational 
and Environmental Medicine stated, ``[a] 
health care provider is considered to be a 
licensed/registered health care provider 
practicing within the scope of their license/
registration'' (Ex. 3-105). Other commenters, 
such as Carol Stuart-Buttle, a well-known 
ergonomics consultant, concur with this 
opinion (Ex. 3-59). The American Feed 
Industry Association expressed concern that 
the medical profession in a rural area may 
not have the expertise to deal with work-
related MSDs, and pointed out that compliance 
may be a problem if OSHA stipulates that the 
HCP have a specific background (Ex. 3-73).
   Second, OSHA does not want to limit 
employers' options where the State has 
determined that an individual is authorized 
to provide care. The scope of practice for a 
particular HCP may vary from State to State. 
OSHA believes that issues of HCP 
qualifications and scope of practice are 
adequately addressed by State law and 
professional organizations, and thus it is 
appropriate to allow employers to rely on the 
system developed by the States. OSHA requests 
comments on these issues and specifically 
seeks information on the experience of 
employers in using HCPs with various 
qualifications in their ergonomics programs.
   Some commenters said that the employer 
should be allowed to determine what HCPs 
would best be able to direct their 
occupational health services (Exs. 3-99; 3-
104). For example, physician assistants, 
occupational therapists, and physical 
therapists said that the proposed ergonomics 
program rule should not limit the HCPs that 
are allowed to provide medical management and 
emphasized the role these professionals play 
in the management of work-related MSDs (Exs. 
3-57; 3-47; 3-64).
   Others, however, have urged OSHA to 
require employers to use only HCPs who have 
training in and experience with work-related 
MSDs and MSD hazards. These commenters 
stressed the need for knowledgeable HCPs. 
They said that HCPs should be required to 
have training and experience in occupational 
medicine, MSD hazards, and the disorders 
associated with these hazards (Exs. 3-181; 3-
106). For example, one commenter stated that 
HCPs need a background in occupational health 
and in ergonomics (Ex. 3-59). Another pointed 
out that the skills of the HCP need to be 
updated periodically (Ex. 3-137).
   To the extent possible, employers should 
use HCPs who are knowledgeable in the 
assessment and treatment of work-related MSDs 
to ensure appropriate evaluation, management, 
and follow-up of employees' MSDs. In any 
event, paragraph (d) of the proposed rule 
requires the employer to provide information 
to the HCPs conducting the assessment. If 
these individuals are already on site, they 
are likely to be familiar with the jobs in 
the workplace, the hazards identified in the 
hazard analysis, and what jobs or temporary 
alternative duty may be available. It is 
essential that HCPs charged with the 
responsibility for MSD management know or be 
provided this information if they are to 
successfully manage the cases of the injured 
workers.
   OSHA rules state where an individual other 
than an HCP is responsible for determining 
whether temporary work restrictions or other 
measures are necessary under 
Sec. 1910.930(b), that individual too must be 
provided the information necessary to 
discharge his or her responsibility. This is 
implicit in Sec. 1910.930(b) and is in any 
event required by Sec. 1910.912(b). With 
these materials, the safety and health 
professional or HCP will be better able to 
ensure that the employee is properly assessed 
and is placed in a job that will allow 
healing to occur during the recovery period.
   Paragraph (e) requires the employer who 
has referred the employee to an HCP to obtain 
a written opinion from the HCP so it is clear 
to all parties what needs to be done to

[[Page 65843]]

resolve the employee's MSD. This opinion must 
be written because oral communication is more 
susceptible of misinterpretation. Employers 
must keep a record, and the easiest way to do 
this is if the opinion is in writing. In 
addition, the HCP's opinion is valuable 
information for employers to have when 
identifying MSD hazards in jobs and 
evaluating the ergonomics program and 
controls.
   This paragraph also requires an employer 
to ensure that the employee promptly receives 
a copy of the opinion, which is essential if 
the employee is to participate in his or her 
own protection. It is particularly important 
for the employee to be knowledgeable about 
what work restrictions, if any, he or she has 
been assigned and for how long they will 
apply.
   Section 1910.931  What information must I 
provide to the health care professional?

  You must provide:
  (a) A description of the employee's job and 
information about the MSD hazards in it;
  (b) A description of available work 
restrictions that are reasonably likely to 
fit the employee's capabilities during the 
recovery period;
  (c) A copy of this MSD management section 
and a summary of the requirements of this 
standard; and
  (d) Opportunities to conduct workplace 
walkthroughs.

   Section 1910.931 requires that HCPs 
receive necessary information so the 
evaluation, management and follow-up of the 
injured employee is effective. It is 
important that employers provide information 
to HCPs, regardless of whether the HCP has 
special training or knowledge in dealing with 
occupational injuries and illnesses or in 
managing MSD cases. Requirements to provide 
information to HCPs are not new; they have 
been included in every medical surveillance 
provision in other OSHA health standards. In 
addition, a number of commenters recommended 
that OSHA's ergonomics rule ensure that HCPs 
receive the information they need to be 
familiar with the jobs in the employers' 
workplaces (Exs. 3-23-A; 3-56; 3-89). OSHA 
also notes that if employers provide the HCP 
with the information required in this 
section, they will have satisfied the 
requirement in Sec. 1910.930(d) that they 
provide ``the HCP with the information 
necessary for conducting MSD management.''
   Paragraph (a) requires employers to 
provide a description of the employee's job 
and information about the hazards in it. This 
information is needed to assist HCPs in 
providing both accurate assessment and 
effective management of MSDs. Without such 
information the HCP may not be able to make 
an accurate evaluation about the causes of 
the MSD or may not be able to prescribe 
appropriate restricted work activity. OSHA 
believes that providing HCPs with information 
about the results of any job hazard analysis 
that has been done in that job ensures that 
the HCP has the most complete and relevant 
information for evaluating and managing the 
recovery of the injured employee. Many 
stakeholders have told OSHA that they already 
provide this type of information to the 
treating HCP in order to familiarize the 
provider with the employee's job and 
associated workplace risk factors and 
ultimately to facilitate resolution of the 
MSD (Exs. 26-23 through 26-26).
   Paragraph (b) requires employers to 
provide information on work restrictions that 
are available during the recovery period and 
that are reasonably likely to fit the 
employee's capabilities during the recovery 
period. Providing this information to HCPs 
helps to facilitate the appropriate matching 
of the employee's physical capabilities and 
limitations with a job that allows an 
employee to adequately rest the injured area 
while still remaining productive in other 
capacities. Employers with ergonomics 
programs have discovered that the more 
detailed information and communication 
provided to the HCP about available 
alternative duty jobs, the better the HCP 
understands the causes of the problem and 
knows what work capabilities remain. As a 
result, these employers have found that the 
HCP is more likely to recommend restricted 
work activity rather than removal from work 
during the recovery period. In addition, it 
is more likely that HCPs are able to 
recommend much shorter removal periods when 
removal is combined with restricted work 
activity as a means of facilitating recovery.
   To achieve these kinds of MSD management 
results, the employer must establish a good 
communication process with the injured 
employee and the responsible HCPs, as well as 
with any other safety and health 
professionals involved in the MSD management 
process. In addition, for communication to be 
effective and helpful to the MSD management 
process, it needs to be clear, timely, and 
on-going. The person(s) the employer assigned 
to be responsible for working with the 
injured employee and communicating 
information to the HCP needs to have 
authority to coordinate appropriate placement 
of the affected employee in the workplace 
during the recovery period (Ex. 26-923, Ex. 
26-924).
   Paragraph (c) requires employers to give 
the HCP a copy of the MSD management section 
and a summary of the requirements of the 
standard. This summary must highlight how MSD 
management fits into the ergonomics program 
this standard requires. For example, it is 
especially important that the HCP understand 
that early reporting of MSD signs and 
symptoms is key to the success of the 
ergonomics program and that employers must 
encourage it. HCPs also need to know how 
quickly employers must provide employees with 
access to the HCP and that employers must 
analyze any job in which a covered MSD is 
reported. Moreover, HCPs need to understand 
that the effective resolution of MSDs may 
require the input of different persons, 
including those like safety and health 
professionals, ergonomists, and ergonomics 
committee members, who are in charge of 
analyzing and implementing measures that will 
eliminate or control the hazards that caused 
the MSD.
   OSHA intends, in paragraph (d), that 
employers provide HCPs with opportunities to 
look at the problem job and the available 
alternative duty jobs. Not only is it 
important that the HCP become familiar with 
the physical work activities the injured 
employee performs, but also it is important 
that the HCP see the available alternative 
duty jobs to ensure that such jobs will allow 
the employee to rest the injured area during 
the recovery period. OSHA does not intend to 
require employers to provide HCPs 
walkthroughs throughout the entire facility.
   Many stakeholders support this provision 
and have told OSHA that workplace 
walkthroughs are one of the best ways to 
obtain knowledge regarding the physical work 
activities and workplace conditions in the 
employee's job (Exs. 3-52; 3-107). They are 
also the best way for the HCP to understand 
whether the available alternative duty jobs 
will allow the injured employee to rest the 
affected area and not be exposed to other 
conditions that could aggravate rather than 
resolve the MSD.
   Workplace walkthroughs can be either 
informal or formal. Several stakeholders said 
that they often invite community

[[Page 65844]]

HCPs for a tour of the facility. Others 
conduct the tours one on one. To remain 
knowledgeable about the specific workplace, 
jobs, job tasks, and any changes, employers 
should encourage HCPs to tour the workplace 
periodically. Finally, where workplace 
walkthroughs are not possible (e.g., HCP 
located too far from the workplace), there 
are other ways HCPs can acquire more in-depth 
information about the employee's job and the 
MSD hazards in it. For example, employers can 
provide HCPs with the results of the job 
hazard analysis, photographs of the job, or 
videotapes of the job being performed.
   Where possible, employers should use HCPs 
who have a basic knowledge of the importance 
of the early recognition, evaluation, 
treatment, and prevention of work-related 
MSDs. Since standards of care change over 
time, it is the responsibility of the 
treating health care professional to select 
treatments in accordance with current 
acceptable standards of practice (Kuorinka 
and Forcier, Eds. 1995, Ex. 26-638).
   Section 1910.932  What must the HCP's 
written opinion contain?

  The written opinion must contain:
  (a) The HCP's opinion about the employee's 
medical conditions related to the MSD hazards 
in the employee's job.
  (1) You must instruct the HCP that any 
other findings, diagnoses or information not 
related to workplace exposure to MSD hazards 
must remain confidential and must not be put 
in the written opinion or communicated to 
you.
  (2) To the extent permitted and required by 
law, you must ensure employee privacy and 
confidentiality regarding medical conditions 
related to workplace exposure to MSD hazards 
that are identified during the MSD management 
process.
  (b) Any recommended temporary work 
restrictions and follow-up;
  (c) A statement that the HCP informed the 
employee about the results of the evaluation 
and any medical conditions resulting from 
exposure to MSD hazards that require further 
evaluation or treatment; and
  (d) A statement that the HCP informed the 
employee about other physical activities that 
could aggravate the work-related MSD during 
the recovery period.

   As mentioned above, the HCP must provide a 
copy of the written opinion to the employer 
and injured employee. The written opinion 
must contain the HCP's opinion about the 
employee's medical condition related to MSD 
hazards in the employee's job. The written 
opinion must explain what actions the HCP 
recommends to resolve an MSD. These 
recommendations may include temporary work 
restrictions or the work the employee may do 
during the recovery period as well as the 
medical treatment and follow-up necessary to 
ensure that the MSD resolves.
   It is important that the HCP's opinion be 
provided in writing to the employer or the 
person(s) at the workplace who are 
responsible for carrying out the MSD 
management requirements of the standard. 
Employers need to know about the employee's 
medical condition to ensure that the 
restricted work activity they provide 
satisfies the HCP's recommendations. 
Employers also need to know whether the 
employee requires medical treatment that may 
necessitate his or her absence from work. The 
HCP's written opinion is especially important 
for the on-site person who is responsible for 
follow-up. That person needs to understand 
the HCP's plan for follow-up and how to 
assist in ensuring that follow-up is 
effective.
   Paragraph (a) would require that the HCP's 
written opinion include information on any 
medical condition the employee has that is 
related to the MSD hazards in the employee's 
job. The HCP's opinion addresses issues such 
as whether the employee has a work-related 
MSD, whether work restrictions are needed and 
for how long, and what kind of follow-up is 
needed.

  Note: Some HCPs may classify a medical 
condition under an International Disease 
Classification (ICD) code, while other HCPs 
may provide a more general diagnosis of the 
condition. The proposed rule is not limited 
to providing MSD management only for those 
MSDs that have an ICD-9 classification.

   The HCP's opinion must be limited to 
medical conditions related to MSD hazards in 
the employee's job. This does not mean that 
the HCP must determine whether the MSD is 
work-related (recordable). Rather, this 
provision means that the written opinion must 
not contain medical information about the 
employee that is not related to work or to 
MSD hazards in the employee's job. This 
provision has been included to protect the 
privacy of the employee, who may not, for 
example, want the employer to know that he or 
she has been in treatment for a psychological 
condition.
   As stated, the written opinion the HCP 
provides to the employer must not include 
medical information (e.g., diagnoses, test 
results, medical history) that is not related 
to MSD hazards in the job. Paragraph (a) 
requires employers to instruct the HCP that 
any findings, diagnoses, recommendations on 
treatment or medical follow up, or 
information not related to workplace exposure 
to MSD hazards must remain confidential and 
must not be included in the written opinion 
or communicated in any way to the employer. 
This kind of prohibition is important in 
protecting the employee's privacy, and has 
been a routine feature of OSHA health 
standards. Moreover, HCPs have their own 
independent duty to protect the privacy of 
patients, even patients who work for the same 
employer as the HCP does. Cf. Wilson v. IBP, 
558 N.W.2d 132, 138-39 (Iowa 1996). This 
confidentiality provision is necessary to 
ensure that employees will be willing to 
provide complete information about their 
medical condition and medical history. 
Employees will not divulge this type of 
personal information if they fear that 
employers will see it or use it to the 
employee's disadvantage. For example, 
employees may fear that their employment 
status could be jeopardized if employers know 
that they have certain kinds of medical 
conditions, which may be completely unrelated 
to work or exposure to MSD hazards, or if 
they are taking certain kinds of medication 
(e.g., seizure medication, an anti-
depressant). In this sense, the ergonomics 
rule is consistent with and is intended to be 
consistent with the confidentiality 
requirements of the Americans with 
Disabilities Act. Paragraph (a), however, 
recognizes that there may be times where 
information regarding medical conditions 
related to workplace exposure to MSD hazards 
are required to be revealed by some other 
State or Federal law. The proposed rule does 
not prohibit release of this confidential 
information where expressly required by those 
laws.
   In paragraph (b), OSHA is proposing that 
the written opinion must contain any 
temporary work restrictions and follow-up 
that the employee needs during the recovery 
period. Work restrictions, defined in 
Sec. 1910.945 of this proposed standard, are 
limitations placed on the manner in which an 
employee with a covered MSD performs a job 
during the recovery period. The proposed rule 
defines work restrictions to include 
modifications and restrictions to the 
employee's current job, such as limiting the 
intensity or

[[Page 65845]]

duration of exposure, reassignment to 
temporary alternative duty jobs, and/or 
complete removal from the workplace.
   The written opinion should specifically 
spell out recommended temporary work 
restrictions, what kind of follow-up is 
required, and the specific time frame for the 
follow-up. For example, restrictions on 
lifting during the recovery period should be 
as specific as possible: ``No lifting of more 
than 10 pounds above shoulder level.'' The 
more specific the temporary restrictions are, 
the more likely that the employer will be 
able to identify an alternative duty job that 
fits the employee's capabilities while still 
ensuring that the injured area is rested. 
Specific recommendations give employers 
needed information about whether employees 
can remain in their current job, with 
restrictions on certain of their regular job 
duties, during the recovery period. Finally, 
specific recommendations make it possible for 
on-site safety and health personnel to 
identify alternative jobs or job changes that 
will satisfy the temporary work restriction 
recommendations.
   Paragraph (c) would require that injured 
employees be informed by the HCP about the 
results of the evaluation and medical 
conditions resulting from exposure to MSD 
hazards that may necessitate further 
evaluation or treatment. This provision 
ensures that employees know the information 
that is the basis for the written opinion the 
HCP provides to the employer. For example, it 
may include the test results, or physical 
examination results, that support the 
recommendations regarding treatment and/or 
work restrictions.
   This provision would also ensure that 
there is full disclosure to the employee 
about medical conditions that require the 
employee's further attention. The written 
opinion must include a statement that the 
employee has been informed about the results 
of the evaluation.
   Paragraph (d) is similar to the previous 
provision. It requires that employees be 
informed about other activities, including 
non-work activities, that could aggravate the 
covered MSD and could delay or prevent 
recovery. OSHA is proposing this provision 
because it is important for employees to know 
how they can facilitate and participate in 
their own recovery. Although the employer is 
responsible for ensuring that the employee is 
not exposed during the recovery period to 
workplace conditions and physical work 
activities that are reasonably likely to 
cause MSDs, the employee should be aware of 
the actions he or she should take away from 
work to reduce exposure to ergonomic risk 
factors. This may include reducing or 
stopping certain personal work or 
recreational activities that might be 
associated with MSDs. It also might include 
recommendations to wear immobilization 
devices, such as a wrist brace, during rest 
periods or while asleep. As discussed above, 
paragraph 1910.932(a) would require that 
employers ensure HCPs not include any of 
these recommendations in the written opinion.
   This provision is intended for 
informational purposes only and does not 
require employees to refrain from non-work 
activities that could aggravate the MSD or 
delay recovery. OSHA's authority is ``limited 
to ameliorating conditions that exist in the 
workplace.'' Forging Indus. Ass'n v. 
Secretary of Labor, 773 F.2d 1436, 1442 (4th 
Cir. 1985).
   Section 1910.933  What must I do if 
temporary work restrictions are needed?
  You must:
  (a) Work Restrictions. Provide temporary 
work restrictions, where necessary, to 
employees with covered MSDs. Where you have 
referred the employee to a HCP, you must 
follow the temporary work restriction 
recommendations in the HCP's written opinion;
  (b) Follow-up. Ensure that appropriate 
follow-up is provided during the recovery 
period; and
  (c) Work Restriction Protection (WRP). 
Maintain the employee's WRP while temporary 
work restrictions are provided. You may 
condition the provision of WRP on the 
employee's participation in the MSD 
management this standard requires.

   Section 1910.933 outlines the requirements 
employers must follow when it is determined 
that an employee has a covered MSD that is 
serious enough to require some kind of work 
restriction.
   Paragraph (a) would require that employers 
provide temporary work restrictions, where 
necessary, to employees with covered MSDs. As 
discussed above, work restrictions are 
restrictions on the way in which a job is 
performed or on the activities that the 
injured employee performs during the recovery 
period. Work restrictions include changes to 
the employee's existing job, such as limiting 
the tasks the employee may perform. 
Restrictions also include temporary transfer 
to a restricted duty job or removal from the 
workplace during the recovery period or a 
portion of it.
   If a HCP has recommended restricted work, 
employers should consider such restrictions 
necessary to prevent the employee's condition 
from worsening and to allow the employee's 
injured tissues to recover. In those 
instances where the employer has referred the 
employee to a HCP, the employer must follow 
the temporary work restriction 
recommendations, if any, included in the 
HCP's written opinion.
   The provision of work restrictions to 
injured employees is a vital component of MSD 
management. Work restrictions provide the 
necessary time for the injured tissues to 
recover. They are often considered the single 
most effective means of resolving MSDs, 
especially if they are provided at the 
earliest possible stage. If work restrictions 
are not provided, it may not be possible for 
the employee to recover, and permanent damage 
or disability may result.
   For work restrictions to be effective, 
employers must ensure that they fit the 
physiologic needs of the injured employee. 
For example, work restrictions will only be 
effective if they reduce or prevent the 
employee's exposure to workplace risk factors 
that caused or contributed to the MSD or 
aggravated a pre-existing MSD. To find the 
right fit, employers may need to examine 
potential alternative duty jobs to ensure 
that the employee will still be able to rest 
the affected area while performing the 
alternative job. Identifying appropriate work 
restrictions may require the collaboration of 
different persons such as HCPs, safety and 
health personnel, persons involved in 
managing the ergonomics program, and the 
injured employee.
   Although some covered MSDs are at such an 
advanced stage that complete removal from the 
work environment is the appropriate 
treatment, it usually should be the 
recommendation of last resort. Where 
appropriate, work restrictions that allow the 
employee to continue working (e.g., in an 
alternative job, or by modifying certain 
tasks in the employee's job to enable the 
employee to remain in that job) are 
preferable during the recovery period. These 
types of restrictions allow employees to 
remain within the work environment. Studies 
indicate that the longer employees are off 
work, the less likely they are to return 
(Exs. 26-685, Ex. 26-919, 26-923, 26-924). If 
employers provide accurate and detailed 
information about the job and alternative 
jobs, it is more likely that the safety and 
health professional, ergonomist, or HCP will 
recommend restricted activity at

[[Page 65846]]

work rather than complete removal. Employers 
should communicate with safety and health 
professionals, HCPs, and others to coordinate 
the provision of work restrictions.
   Under this provision, employers are not 
required to provide particular alternative 
jobs or work restrictions that an employee 
requests. Therefore, if a safety and health 
professional, ergonomist, or HCP recommends 
that the employee not perform lifting tasks 
or engage in repetitive motions during the 
recovery period, the employer is free to 
provide any form of work restriction that 
effectuates that work restriction 
recommendation. For example, if the 
recommended work restriction requires fewer 
repetitive motions, the employer may move the 
employee to an alternative duty job as a way 
of achieving this restriction. Or the 
employer could reduce the number of 
repetitions expected to be performed in the 
employee's current job in a number of ways: 
by reducing the amount of time the employee 
performs repetitive motions, by reducing the 
speed at which the employer performs the 
tasks, or by eliminating certain repetitive 
tasks during recovery. In the case of lifting 
jobs, the work restriction may be as simple 
as limiting the types or weights of objects 
the employee must move or lift.
   Paragraph (b) requires that the employee 
receive appropriate follow-up during the 
recovery period. Follow-up is the process or 
protocol the employer, safety and health 
professional, and/or HCP uses to check up on 
the condition of employees with covered MSDs 
when they are given temporary work 
restrictions during the recovery period. 
Follow-up of injured employees is essential 
to ensure that MSDs are resolving and, if 
they are not, that other actions are taken 
promptly. This process helps to ensure that 
injured employees do not ``slip through the 
cracks,'' for example, by being left in 
alternative duty jobs long after they have 
recovered, or by being given work 
restrictions without finding out if the 
restrictions are helping. If follow-up is not 
provided, neither the employer nor the safety 
and health professional or HCP will know that 
an employee's MSD symptoms are not abating or 
are becoming worse. Where follow-up is not 
provided or the healing process is not 
properly monitored, injured employees, in the 
end, may never be able to return to their 
jobs.
   To be effective, follow-up may require the 
efforts of both an HCP and on-site personnel, 
such as the person(s) responsible for 
receiving and responding to employee reports. 
Some employers may use HCPs who already have 
a follow-up process in place. For example, 
some occupational medicine clinics have 
employees contact the clinic almost daily, 
or, alternatively, the clinic may contact the 
employee. In many situations, effective 
follow-up involves a team approach. This is 
especially true where the ergonomist, HCP or 
safety and health professional is not on-site 
and cannot see the employee on a daily basis. 
In these cases an on-site person (e.g., 
nurse, person(s) designated to receive and 
respond to reports, human resources person) 
regularly checks on the employee and reports 
the results back to the HCP, ergonomist, or 
safety and health professional. This approach 
may be very effective because the HCP can be 
provided with almost daily reports on the 
injured employee's condition and respond 
quickly if the condition becomes worse.
   Many stakeholders also recognize the need 
for effective follow-up and have made the 
process a standard company practice. Coors 
Brewing Company, for example, stated that it 
provides follow-up for injured employees as 
often as is necessary until the employee is 
released from care (Ex. 3-95).
   Paragraph (c) requires employers to 
provide work restriction protection (WRP) to 
employees on temporary work restrictions. WRP 
is defined in Sec. 1910.945 of the proposed 
rule as the maintenance of earnings and other 
employment rights and benefits of employees 
who are on temporary work restrictions as 
though the employees had not been placed on 
temporary work restrictions. For employees 
placed on temporary work restrictions short 
of complete removal from work (e.g., an 
alternative duty job), WRP includes 
maintaining 100% of the after-tax earnings 
the employees were receiving at the time they 
were placed on work restrictions. For 
employees removed entirely from the 
workplace, WRP includes maintaining 90% of 
their after-tax earnings; the value of 90 
percent is considered by OSHA to be a 
reasonable estimate of the percentage of 
take-home pay received by workers when 
awarded a worker's compensation claim. Thus, 
if an employee needs to be removed from work 
entirely, either because the employer, an 
ergonomist, a safety and health professional 
or the ergonomics committee has initiated it 
or the employer referred the employee to an 
HCP who recommended it, the employer must pay 
the removed employee 90% of the employee's 
after-tax earnings and maintain the 
employee's full benefits. If an employee is 
placed into an alternative duty job, however, 
that pays less than the employee was earning 
at the time the MSD occurred, the employer 
must maintain 100% of the employee's after-
tax earnings, with full benefits. The 
benefits referred to in Sec. 1910.945 
include, for example, accrual of vacation 
time; employer contributions to health 
insurance; employer contributions to other 
workplace programs such as profit-sharing, 
life insurance, and pension; and seniority or 
``bidding'' rights. Paragraph (c) also 
permits employers to condition the provision 
of WRP benefits upon an employee's 
participation in the MSD management required 
by the proposed standard.
   By requiring employers to provide WRP, 
OSHA intends that employees have some 
economic protection when they are placed on 
temporary work restrictions. OSHA believes 
that this economic protection will encourage 
employees to come forward to report MSDs 
early; such reporting helps to ensure that 
the injured employees, as well as employees 
in the same ``problem'' job, are provided 
with protection from MSD hazards. Because 
early reporting is so critical to the 
proposed rule, OSHA has crafted WRP to 
encourage employees to report as early as 
possible. By requiring employers to maintain 
100% of an employees' after-tax earnings when 
they are placed on temporary work 
restrictions short of complete removal from 
work, OSHA believes employees will have an 
incentive to report the onset of MSDs early, 
before their MSDs become so severe that 
complete removal from work is necessary. OSHA 
predicts that very few employees with covered 
MSDs will need to be removed entirely from 
the workplace during their recovery period. 
OSHA anticipates that restricted work 
activity will be sufficient for a large 
percentage of employees, particularly because 
the proposed standard requires employers to 
establish systems for the early reporting of 
MSDs and to provide prompt MSD management.
   In the proposed standard OSHA is referring 
to this economic protection during temporary 
work restrictions as ``work restriction 
protection (WRP).'' In other OSHA health 
standards, similar provisions have been 
called ``medical removal protection.'' OSHA 
is using the term ``work restriction 
protection (WRP)'' because it more accurately 
describes the typical recovery process for 
most employees with MSDs and the practical 
effect this provision will have on employers 
and employees. Moreover, the term ``medical 
removal protection'' implies that removal is 
necessitated by

[[Page 65847]]

a diagnosis or recommendation by an HCP. In 
the proposed rule, some restricted work 
activity (i.e., immediate placement in 
alternative duty when an employee reports an 
MSD) need not be triggered by an HCP's 
opinion. OSHA does not believe it is 
appropriate to imply that restricted work 
activity can only be triggered by an HCP's 
opinion. OSHA intends that employees who are 
given restricted work activity even before 
seeing an HCP have WRP.
  Note: When ``medical removal protection'' 
provisions in other health standards are 
discussed in this section, the term ``WRP'' 
is also used.

   Section 1910.934  How long must I maintain 
the employee's work restriction protection 
when an employee is on temporary work 
restrictions?

  You must maintain the employee's WRP until 
the FIRST of these occurs:
  (a) The employee is determined to be able 
to return to the job,
  (b) You implement measures that eliminate 
the MSD hazards or materially reduce them to 
the extent that the job does not pose a risk 
of harm to the injured employee during the 
recovery period; or
  (c) 6 months have passed.

   As mentioned above, the proposed rule 
would only require employers to provide work 
restrictions that are temporary, meaning that 
the work restrictions are for MSDs that are 
temporary and reversible. In this section, 
OSHA is proposing a time frame for the length 
of time employers would be required to 
maintain WRP, and identifies the points at 
which the employer's obligation to do so 
would end.
   To ensure that WRP is provided only for 
temporary medical conditions, OSHA is 
proposing three cutoffs that limit the 
employer's obligation to provide WRP. The 
employer's obligation to provide WRP would 
cease when the first of the cutoffs occurs:

   The employee is able to return 
fully to the regular job,
   The job is fixed so the employee 
will not continue to get hurt, and
   WRP has been provided for 6 months

   Although the proposed rule would require 
the employer to maintain WRP for as long as 6 
months, evidence shows that the need to 
provide protection for 6 months is relatively 
rare. Although the median number of lost 
workdays for certain MSDs is quite high, as 
discussed in Chapter IV of the Preliminary 
Economic Analysis (Ex. 28-1) and Section VII 
of this preamble, data show that many MSD 
cases involve only a few days of work 
restriction before employees are able to 
return fully to work. In fact, according to 
the BLS, 50% of all MSD cases that involve 
days away from work result in less than 7 
days away from work (Ex. 26-1413). Assuming 
no change in these lost workday trends, this 
evidence indicates that the first WRP cutoff 
that is likely to occur is that the employee 
is able to return fully to the regular job.
   The second cutoff would occur when the 
employer fixes the job, either by eliminating 
or materially reducing the MSD hazards to the 
extent that the job does not pose a risk of 
harm to the injured employee during the 
recovery period. The second cutoff would 
occur even if the injured employee's MSD has 
not completely recovered. This cutoff is also 
likely to occur early in the process because 
so many ergonomic controls are quick and 
inexpensive. According to David Alexander, an 
ergonomist who has provided consultative 
services for employers in a broad range of 
industries, most jobs can be fixed for less 
than $500 (Alexander, D. and Orr, G. 1999, 
Ex. 26-1407). In addition, a number of 
controls involve making simple, low-cost 
changes in how the job is performed. For 
example, if a person is not tall enough to 
perform the task without reaching 
excessively, the employer could change the 
height at which the employee stands to 
perform the task. Or, if the reach for the 
product is too great, the employer can extend 
the length of the handle of the tool used to 
grab the product. If an employee's arm, leg 
or hand has contact with a hard work surface, 
the employer can wrap the surface with foam. 
In a warehousing area, employees can stack 
smaller amounts of product on each pallet, 
instead of stacking a large amount of product 
on one pallet. If an employer installs a 
fixture or device (a ``jig'') so that it 
maintains the correct relationship between a 
piece of work and the tool used during 
assembly, the employee does not have to use 
force or awkward posture to hold the part. 
Because controls for many jobs are 
inexpensive and cost less than WRP, this 
cutoff should create an incentive for 
employers to implement controls quickly.
   The proposed rule itself facilitates the 
implementation of effective controls. Where a 
covered MSD occurs, the employer may either 
set up an ergonomics program for the employee 
in that job or do a Quick Fix. The Quick Fix 
provision of the proposed rule (see 
Sec. 1910.909) essentially allows employers 
to bypass most of the requirements of the 
program if they can quickly implement 
controls that eliminate the hazard.
   The final cutoff for WRP is 6 months. OSHA 
believes that few employers will be required 
to provide WRP for this length of time, 
because the overwhelming majority of MSDs 
resolve well before 6 months have passed. As 
mentioned above, the median number of days 
away from work for lost workday MSDs is 7. 
The 1998 Liberty Mutual data are consistent 
with the BLS data: only 11% of all UEMSD 
claims were associated with a length of 
disability of more than 6 months (Ex. 26-54). 
With implementation of the early reporting 
requirements in the proposed rule, that 
percentage should decrease.
   Even though most MSDs involve 
substantially less than 6 months of recovery 
time, OSHA is proposing a maximum WRP 
duration of 6 months for several reasons. 
First, OSHA believes this is a ``fallback'' 
cutoff. Some employees with reversible MSDs 
may require longer recovery time. This is 
especially true where employees require 
surgery or where the employer has not 
established an aggressive early reporting 
policy and the MSD was not caught until signs 
or symptoms were more serious (see Oxenburgh 
1984, Ex. 26-1367). Longer recovery time may 
also be necessary for employees who already 
have had an MSD or surgery, have a 
disability, or have other susceptibilities. 
OSHA wants to cover those cases that may 
require more time but nonetheless may still 
have good expectation of recovery.
   At the end of the 6 month WRP period, 
employers should evaluate the employee's 
condition to determine whether work 
restrictions are still necessary and/or 
whether the employee can return to the job. 
OSHA seeks comment from interested parties on 
what protections should be provided to 
employees if their MSDs have not resolved at 
the end of the 6 month WRP period and they 
are not physically able to return to the job.
   Section 1910.935  May I offset an 
employee's WRP if the employee receives 
workers' compensation or other income?


[[Page 65848]]


  Yes. You may reduce the employee's WRP by 
the amount the employee receives during the 
work restriction period from:
  (a) Workers' compensation payments for lost 
earnings;
  (b) Payments for lost earnings from a 
compensation or insurance program that is 
publicly funded or funded by you; and
  (c) Income from a job taken with another 
employer that was made possible because of 
the work restrictions.

   Section 1910.935 specifies the offsets 
employers may make if an injured employee 
receives workers' compensation. This section 
serves two purposes. First, the provision 
helps to strike a balance by providing 
economic protection for employees who are 
placed on temporary work restrictions, while 
ensuring that employers need not provide WRP 
benefits that would result in the injured 
employee receiving more than current 
earnings. OSHA believes that an employer 
should not have to provide WRP benefits that 
duplicate the compensation the injured 
employee receives from other sources for 
earnings lost during the work restriction 
period. Although the most likely ``other'' 
source would most often be workers' 
compensation payments for lost earnings, the 
proposed rule also permits the employer to 
offset other earnings that would not have 
been possible but for the work restrictions, 
for example a job baby-sitting during the day 
because the injured worker is at home. (The 
employer would not be entitled to offset 
earnings the injured employee received from a 
second job held prior to the injury, except 
that the employer may offset any additional 
earnings from a previously held second job if 
such additional earnings were made possible 
by the work restrictions (e.g., as a result 
of the work restrictions, the employee is 
able to work more hours at the previously 
held second job).)
   Second, this section stresses that OSHA's 
intention in proposing WRP is not to 
supersede workers' compensation. If WRP were 
structured without regard to workers' 
compensation eligibility, it could be viewed 
as superseding workers' compensation. The 
offsets allowed in this paragraph are 
consistent with those in other OSHA health 
standards. The offsets for workers' 
compensation payments for lost earnings are 
permitted regardless of whether workers' 
compensation is publicly funded or employer-
funded.


Part B--Work Restriction Protection


1. Legal Authority for WRP

   The OSH Act authorizes WRP. WRP is 
authorized by the OSH Act as necessary to 
protect the health of employees suffering 
from MSDs. Section 6(b)(5) of the OSH Act 
directs OSHA to adopt the health standard 
that ``most adequately assures, to the extent 
feasible, on the basis of the best available 
evidence, that no employee will suffer 
material impairment of health or functional 
capacity'' if exposed to a hazard over a 
working lifetime. 29 U.S.C. 655(b)(5). 
Section 3(8) of the OSH Act explains that an 
``occupational health and safety standard 
[requires] the adoption or use of one or more 
practices, means, methods, operations, or 
processes, reasonably necessary or 
appropriate to provide safe or healthful 
employment and places of employment.'' 29 
U.S.C. 652(8). The statutory provisions give 
OSHA broad authority to require employers to 
implement practices that are reasonably 
necessary and appropriate to provide safe and 
healthful work environments. See United 
Steelworkers of America v. Marshall (Lead), 
647 F.2d 1189, 1230 (D.C. Cir. 1980), cert. 
denied, 453 U.S. 913 (1981) (``A number of 
terms of the statute give OSHA almost 
unlimited discretion to devise means to 
achieve the congressionally mandated 
goal.''). As discussed in greater detail 
below, WRP furthers OSHA's statutory mandate 
to protect the health of workers. By 
providing employees with economic protection 
if they are placed on temporary work 
restrictions, WRP encourages employee 
participation in MSD management and increases 
early reporting of MSDs. This prevents 
injured employees from suffering more severe 
injury, including permanent disability. This 
also helps to protect other employees in the 
same jobs by ensuring that MSD hazards are 
identified and controlled before other 
employees become injured.
   WRP also furthers the broad purposes of 
the OSH Act. In the OSH Act Congress sought 
``to assure so far as possible every working 
man and woman in the Nation safe and 
healthful working conditions.'' 29 U.S.C. 
651(b). To achieve this goal, Congress 
authorized OSHA to:

   ``[Develop] innovative methods, 
techniques, and approaches for dealing with 
occupational safety and health problems.'' 29 
U.S.C. Sec. 651(b)(5). WRP is such an 
innovative technique. WRP is designed to 
encourage early reporting of MSDs, and 
employee participation in MSD management and 
an employer's ergonomics program, thereby 
protecting the health of all employees.
   ``[Build] upon advances already 
made through employer and employee initiative 
for providing safe and healthful working 
conditions.'' 29 U.S.C. Sec. 651(b)(4). WRP 
builds upon advances currently found in 
workplaces. Many employers with existing 
ergonomics programs provide for economic 
protection for employees when they are on 
restricted work activity. In addition, many 
collective bargaining agreements that already 
contain ergonomics programs include WRP 
provisions.
   ``[Provide] medical criteria which 
will assure insofar as practicable that no 
employee will suffer diminished health, 
functional capacity, or life expectancy as a 
result of his work experience.'' 29 U.S.C. 
Sec. 651(b)(7). WRP is a critical component 
of MSD management which helps prevent workers 
from suffering from diminished health and 
functional capacity due to MSDs.

   Courts uphold OSHA's authority to require 
WRP. Judicial decisions have upheld OSHA's 
authority under the OSH Act to require WRP. 
In Lead, the D.C. Circuit directly examined 
OSHA's authority to include WRP in the Lead 
standard and held (1) that the OSH Act gave 
OSHA broad authority to issue WRP, and (2) 
OSHA's inclusion of WRP in the Lead standard 
was necessary and appropriate to protect the 
health of workers. Lead, 647 F.2d at 1228-40.
   In the Lead decision, the D.C. Circuit 
first held that OSHA's inclusion of WRP was 
within its statutory authority. The court 
found that the OSH Act and its legislative 
history ``demonstrate unmistakably that 
OSHA's statutory mandate is, as a general 
matter, broad enough to include such a 
regulation as [WRP].'' Id. at 1230. The court 
relied upon a number of provisions in the OSH 
Act in support of this finding, including 29 
U.S.C. 651(b)(5) and the definition of an 
``occupational safety and health standard'' 
discussed above. In short, the court held 
that OSHA has broad authority to fashion 
regulatory policies that further the goals of 
the OSH Act--enhancing worker safety and 
health and providing for safe and healthful 
working environments. See Id. at 1230 n. 64 
(``[T]he breadth of agency discretion is, if 
anything, at [its] zenith when the action 
assailed related primarily * * * to the 
fashioning of policies * * * in order to 
arrive at maximum effectuation of 
Congressional objectives.'' (citation 
omitted)).
   The court also concluded that the 
legislative history of the OSH Act supported 
reading the statute to authorize WRP. Id. at 
1230-31. The court highlighted a statement by 
Senator Saxbe explaining how both the House 
and Senate versions of the OSH Act did not 
contain a ``list of specific `do's and 
don'ts' for keeping workplaces safe and 
healthful''; rather, both versions tasked 
OSHA with developing regulations to

[[Page 65849]]

address the various complexities of America's 
workplaces. Id. at 1230.
   After concluding that OSHA had the 
statutory authority to promulgate WRP in 
general, the court held that OSHA's inclusion 
of WRP in the Lead standard was a reasonable 
exercise of that statutory authority. OSHA 
established that WRP was a preventive device 
necessary for the effectiveness of the 
standard. Id. at 1237. OSHA demonstrated that 
lead disease is highly reversible if caught 
in its early stages; however, OSHA provided 
evidence that employees ``would resist 
cooperating with the medical surveillance 
program'' absent assurances that they would 
have some economic protection if they were 
removed from their jobs due to high blood-
lead levels. Id. at 1237. For example, 
employees fearing removal from their normal 
work without pay if they showed high blood-
lead levels would tend to try to evade or 
cheat the blood test. The court held that WRP 
in the Lead standard was reasonably necessary 
and appropriate to protect the safety and 
health of workers.
   Further supporting OSHA's authorization to 
include WRP in its standards, the D.C. 
Circuit in International Union v. Pendergrass 
(Formaldehyde), 878 F.2d 389, 400 (D.C. Cir. 
1989)) criticized OSHA for not including any 
WRP in its Formaldehyde standard and remanded 
the standard to OSHA for reconsideration of 
the necessity of including WRP. OSHA had 
claimed that WRP was not appropriate in part 
because the ``nonspecificity of signs and 
symptoms [made] an accurate diagnosis of 
formaldehyde-induced irritation difficult,'' 
and the health effects from formaldehyde 
exposure for these employees quickly 
resolved. Id.
   The court rejected OSHA's justifications 
and remanded the issue to OSHA for further 
examination. OSHA's failure to include WRP in 
the formaldehyde standard represented a 
dramatic ``swerve'' from prior health 
standards that required extensive 
explanation; OSHA's ``allusions to `non-
specificity' of symptoms [were] too vague and 
obscure either to show consistency with 
OSHA's prior stance or to justify a reversal 
of position.'' Id. at 400. The court also 
stated that WRP was particularly appropriate 
in situations where employees recover quickly 
from the signs and symptoms of disease. Id.
   On remand, OSHA included a WRP provision 
in the formaldehyde standard, explaining:

  On reconsideration, the Agency has 
concluded that [WRP] provisions can 
contribute to the success of the medical 
surveillance programs prescribed in the 
formaldehyde standard. Unlike some other 
substance-specific standards, the 
formaldehyde standard does not provide for 
periodic medical examination for employees 
exposed at or above the action level. 
Instead, medical surveillance is accomplished 
in the final rule through the completion of 
annual medical questionnaires, coupled with 
affected employees' reports of signs and 
symptoms and medical examinations where 
necessary. This alternative depends on a high 
degree of employee participation and 
cooperation to determine if employee health 
is being impaired by formaldehyde exposure. 
OSHA believes these new [WRP] provisions will 
encourage employee participation in the 
standard's medical surveillance program and 
avoid the problems associated with 
nonspecificity and quick resolution of signs 
and symptoms that originally concerned the 
agency. 57 FR 22290, 22293, May 27, 1992.

Formaldehyde makes clear that OSHA may not 
decline to include WRP in a health standard 
absent specific findings justifying such a 
change in Agency practice.
   Other health standards support OSHA's 
inclusion of WRP. OSHA has included some form 
of WRP in many other health standards based 
upon findings that WRP is necessary to 
encourage employee participation in medical 
surveillance. See 29 CFR 1910.1025 (Lead); 29 
CFR 1910.1027 (Cadmium); 29 CFR 1910.1028 
(Benzene); 29 CFR 1910.1048 (Formaldehyde); 
29 CFR 1910.1050 (Methylenedianiline); 29 CFR 
1910.1052 (Methylene Chloride). OSHA has 
tailored the WRP provisions in these health 
standards to address the particular hazards 
involved, as well as to effectuate the 
purposes of the standards. In some of these 
standards, for example, WRP is triggered by a 
specific finding. In the Lead standard, WRP 
must be provided when blood-lead levels 
exceed certain limits. In other standards, 
however, WRP is provided even though no 
medical ``triggering'' test is available. In 
these instances, WRP must be provided (1) 
when an employee exhibits signs or symptoms 
of disease (see, e.g., 29 CFR 1910.1048 
(l)(8)(I) (Formaldehyde) ``[WRP applies] when 
an employee reports significant irritation of 
the mucosa of the eyes or the upper airways, 
respiratory sensitization, dermal irritation, 
or dermal sensitization attributed to 
workplace formaldehyde exposure.''), or (2) 
there is a finding by a physician that an 
employee must be removed to avoid material 
impairment of health or functional capacity. 
Providing WRP based upon a finding by a 
physician (or HCP) is included in all other 
OSHA health standards with WRP. OSHA believes 
that this provision serves as a ``backstop'': 
it protects those employees who exhibit signs 
and/or symptoms of disease at particularly 
low exposures.
   OSHA's inclusion of some form of WRP in 
other health standards based on findings that 
WRP is necessary to ensure employee 
participation in medical surveillance 
programs demonstrates an established policy 
that OSHA may not depart from without 
substantial justification. OSHA is aware of 
no such justification. To the contrary, 
OSHA's preliminary view is that WRP is 
necessary to encourage early and full 
employee reporting, which is critical if the 
standard is to reduce the number and severity 
of MSDs.


2. Necessity Of WRP

   As discussed in more detail in the Risk 
Assessment and Significance of Risk sections 
of this preamble, many employees currently 
suffer from MSDs. OSHA believes that WRP is a 
critical component of the proposed rule for 
the following reasons:
   1. WRP encourages employee participation 
in MSD management and the ergonomics program;
   2. WRP encourages early reporting of MSDs, 
and/or signs and symptoms of MSDs;
   3. The actions required of employers by 
the proposed rule are determined by reported 
MSDs; and
   4. There is no justification to deviate 
from past OSHA practice and exclude WRP.
   WRP encourages employee participation in 
MSD management and the ergonomics program.--
There is evidence that many employees at 
present do not report MSDs, and/or signs and 
symptoms of MSDs, because they fear any or 
all of the following will happen to them if 
they report signs and/or symptoms of MSDs, 
and/or are diagnosed with an MSD:
   1. They will be transferred to alternative 
``light'' duty at reduced pay (see Exs. 3-
184; 3-186);
   2. They will be fired or suffer a great 
financial loss and lose their benefits (see 
Exs. 3-151; 3-183; 3-184; 3-186); or
   3. They will suffer other forms of job 
discrimination or retaliation (see Ex. 3-
121).


[[Page 65850]]


   These comments are consistent with those 
comments OSHA received during other health 
standards rulemakings where similar WRP 
provisions were proposed. See, e.g., 43 FR 
54354, 54442, November 21, 1978. These fears 
are particularly acute for the many low-wage 
employees who live ``pay check-to-pay 
check.'' Evidence and data show that many of 
the jobs where ergonomic problems are severe 
are jobs that pay minimum wage or only 
slightly above minimum wage. For example, as 
detailed in the Preliminary Risk Assessment, 
some of the jobs with the highest incidence 
of MSDs are those held by nursing aides, 
orderlies, and attendants; laborers (not 
construction); stock handlers and baggers; 
and maids and housemen.
   OSHA's concern about the pressure on 
workers not to come forward to report their 
MSD signs and symptoms early is heightened by 
two factors: the large number of employees 
who do not receive sick leave, and the 
difficulty employees have in receiving State 
workers' compensation benefits for work-
related MSDs. The BLS reports that only 50% 
of workers are covered by sick leave 
benefits, i.e., were paid for work absences 
due to illness or injury; 64% of blue collar 
workers are not provided this basic benefit 
(BLS 1995, Ex. 26-1406).
   Each State has a statutory workers' 
compensation system that controls eligibility 
for and payment of benefits for State, 
municipal, and private sector employees. The 
Federal government operates a workers' 
compensation system covering Federal workers, 
and there are Federal statutes that create 
special compensation schemes for longshore 
and harbor workers and coal miners. The 
workers' compensation laws in each State are 
the result of legislative enactments and 
interpretations of courts and administrative 
tribunals, and the laws among States often 
vary sharply as to what injuries are covered 
and what benefits are paid.
   All States compensate injured or ill 
workers with MSDs, at least to some degree. 
However, obtaining workers' compensation for 
MSDs is complicated by the difficulty of 
fitting an MSD into the State's definition of 
an injury caused by accident (an acute, 
traumatic injury traceable to a particular 
occurrence at a particular time and place) or 
an illness meeting the State's definition of 
occupational illness (often a specific list 
of diseases or a definition that includes 
only diseases associated with particular 
occupations); by the State-imposed statute of 
limitations on occupational illnesses; and by 
the high level of litigation associated with 
these claims.
   State statutes have increasingly limited 
the compensability of MSD claims. In 
Virginia, for example, the only MSD that is 
covered is carpal tunnel syndrome (CTS); all 
other MSD claims are not accepted. Idaho 
requires the employee to have worked for a 
single employer for 60 days before a claim 
for a non-acute injury is considered. In 
Louisiana, if a claimant was on the job for 
less than 12 months, he or she needs an 
``overwhelming preponderance of the 
evidence'' to receive compensation. In Texas, 
the claimant must prove the disease is 
inherent in that particular type of 
employment. The result of this trend can 
clearly be seen in the substantial 
underreporting of MSDs reported in a number 
of peer-reviewed articles (Cannon, et al. 
1981, Ex. 26-1212; Mazlish, et al. 1995, Ex. 
26-1186; Silverstein, et al. 1997, Ex. 26-
28).
   Those claims that are filed are often 
litigated and may drag on for years. For 
example, the California Workers Compensation 
Institute reported that 94% of the State's 
cumulative trauma claims were litigated and 
that employers in California pay $0.33 in 
litigation costs for every $1 paid in 
benefits for these cases. For other claims, 
this figure is $0.15 per $1 of benefits paid 
(Kohn 1997, Ex. 26-1408).
   OSHA believes that both factors--the low 
level of sick leave benefits available to 
workers and the difficulty employees have in 
receiving workers' compensation benefits for 
work-related MSDs--underscore the importance 
of the proposed standard's WRP provisions. 
OSHA believes that by providing employees who 
must be placed on temporary work restrictions 
with some guaranteed economic protection, WRP 
will reduce employee anxiety about reporting 
signs and/or symptoms of MSDs. Thus, OSHA 
believes that employees will be more willing 
to participate actively in MSD management and 
the ergonomics program.
   WRP encourages early reporting of MSDs, 
and/or signs and symptoms of MSDs. WRP also 
encourages employees to report MSDs, and/or 
signs and symptoms of MSDs, as early as 
possible, so that employers can determine 
whether the MSD is covered and/or whether 
temporary work restrictions are appropriate. 
Early reporting of MSDs leads to early 
detection and successful treatment of 
MSDs.OSHA has substantial evidence that most 
MSDs are reversible if treatment is provided 
early, before the disease becomes 
debilitating (see Exs. 3-56; 3-59; 3-179; 3-
184). In addition, early detection and 
intervention reduces the severity of MSDs, as 
well as the treatment required to address the 
MSDs. An added benefit is that early 
detection, intervention, and treatment reduce 
the costs of MSDs for both employers and 
employees (see Exs. 3-23; 3-33; 3-50; 3-56; 
3-59; 3-121; 3-124; 3-151; 3-162; 3-179; 3-
184). Conversely, when employees do not 
report MSDs, and/or the signs or symptoms of 
MSDs early, they will likely continue working 
until their MSDs become (1) compensable under 
workers' compensation statutes, or (2) more 
severe and/or disabling. This results in more 
damage to the affected employee, higher costs 
for the employer, and reduced productivity.
   Because early reporting is so important, 
the proposed WRP requirements are designed to 
maximize the incentives employees have to 
report signs and/or symptoms of MSDs early. 
As stated above, OSHA is requiring employers 
to maintain 100% of an employee's after-tax 
earnings if the employee is placed on work 
restrictions short of complete removal from 
work. OSHA believes that this will encourage 
employees to report signs and/or symptoms of 
MSDs at the earliest possible point, before 
their conditions become so severe that 
complete removal from work is necessary.
   The early reporting that will result from 
WRP will not only provide protection for 
injured employees, it will provide protection 
to other employees as well. Early reporting 
allows employers to identify problem jobs 
early and to take the necessary steps to 
correct the identified hazards before other 
employees become hurt. In addition, early 
reporting may ensure that job fixes are 
provided more quickly. Since employers bear 
the costs of providing MSD management and 
WRP, they will have an incentive to reduce or 
avoid those costs by implementing effective 
and appropriate ergonomics programs in their 
workplaces. See 43 FR 54354, 54449, November 
21, 1978 (``One beneficial side effect of 
[WRP] will be its role as an economic 
incentive for employers to comply with the 
inorganic lead standard.'').
   OSHA has evidence that in current 
ergonomics programs where employees report 
signs and/or symptoms of MSDs early, the 
number of MSDs and the number of lost-time/
lost-day injuries decreases (see Ranney 1993, 
Ex. 26-913; Day 1987, Ex. 26-914; see also 
Oxenburgh 1984, Ex. 26-1367). This evidence 
demonstrates that where employees report MSDs 
early: (1) the severity of the MSDs 
decreases, and (2)

[[Page 65851]]

greater protection is provided to other 
employees in the workplace, so that they do 
not develop MSDs.
   During OSHA's public outreach process, 
every stakeholder who commented on this 
subject agreed that early reporting of MSDs 
is critical to preventing disease and to 
protecting workers. They confirmed that early 
reporting also reduces the costs to the 
employee and employer (see Exs. 3-197; 3-118; 
3-124; 3-151; 3-56; 3-68; 3-107). Moreover, 
many stakeholders that currently have 
ergonomics programs said that they achieved 
dramatic reductions in the number and 
severity of MSDs once they implemented an 
effective early reporting process (Exs. 26-23 
through 26-26). This experience is consistent 
with the literature and studies conducted on 
ergonomics programs (see NIOSH 1997, Ex. 26-
2; Oxenburgh 1985, Ex. 26-1405).
   WRP is necessary where employer action is 
triggered by reports of MSDs. Whether the 
proposed rule covers certain jobs is 
determined, in part, by the reporting of an 
OSHA recordable MSD. This incident-based 
``trigger'' is unique to OSHA health 
standards. In other OSHA health standards, 
employers are required to monitor their 
workplaces for hazards and control those 
hazards. In this proposed standard, however, 
employers will not have to implement certain 
aspects of an ergonomics program until a 
covered MSD is reported.
   In order for an incident-based rule to be 
as effective as possible in providing 
protection for employees, employees must be 
willing to report MSDs, and/or signs and 
symptoms of MSDs. If employees are not 
willing to come forward and report MSDs, 
serious MSD hazards in that job will go 
uncontrolled, thus potentially placing every 
employee in that job at increased risk of 
harm. Moreover, some stakeholders fear that 
an incident-based ``trigger'' will create an 
incentive for employers to discourage 
employees from reporting MSDs. There is 
strong evidence that there currently is 
significant underreporting of MSDs (see Exs. 
2-2; 2-4; 2-22; 3-159; 3-160; Fine et al. 
1986, Ex. 26-920; Liss 1992, 26-918; 
Silverstein, et al. 1997, Ex. 26-28). OSHA 
believes that WRP in this proposed rule is 
thus particularly necessary to ensure that 
employees come forward and report MSDs early. 
OSHA believes the proposed WRP provision 
provides the necessary economic protection to 
ensure such employee reporting and 
participation.
   No justification to deviate from past OSHA 
practice and exclude WRP. As mentioned above, 
many OSHA health standards include WRP. These 
standards are based on findings that workers 
are less likely to participate in needed 
medical management programs if they may 
suffer severe economic loss as a result. The 
court in Formaldehyde held that this 
principle evinced a clear policy that is to 
be followed unless OSHA gives a persuasive 
justification for deviating from it. Cf. 
Formaldehyde, 878 F.2d at 400. OSHA believes 
that it does not have justification for 
deviating from its past practice of including 
WRP in health standards where necessary and 
appropriate to encourage the participation of 
employees in programs designed to protect the 
safety and health of workers.
   In particular, the fact that there are no 
unambiguous biological monitoring tests for 
diagnosing some MSDs is not a sufficient 
justification for such exclusion. 
Formaldehyde, 878 F.2d at 400. In addition, 
the fact that some MSDs resolve quickly is 
not sufficient to exclude WRP. Id. The court 
in Formaldehyde stated that if affected 
employees have quick recovery periods, they 
``surely could benefit from receiving [WRP] 
during the recovery period.'' Id.


3. Stakeholder Comments on WRP

   The issue of WRP has engendered much 
discussion. OSHA discussed different forms of 
WRP with its stakeholders, and OSHA has 
received many comments from industry, labor, 
and others on WRP generally, as well as on 
the specific elements of WRP. Many 
stakeholders, particularly those in the 
health care profession, support the inclusion 
of some WRP provision in the proposed rule 
(see, e.g., Ex. 3-124). These professionals 
recognize the importance of encouraging 
employee participation in MSD management. 
Employees and their representatives also 
support some form of WRP as being necessary 
to the effectiveness of the proposed standard 
generally, and the effectiveness of MSD 
management specifically (see Exs. 3-184; 3-
164). A large number of stakeholders, 
however, object to the inclusion of any form 
of WRP in the proposed standard. These 
stakeholders contend that WRP:
   1. Is not necessary for the effective 
functioning of the standard;
   2. Violates section 4(b)(4) of the OSH 
Act;
   3. Poses a significant economic hardship 
for employers, especially small employers; 
and
   4. Will be abused by employees.
   Is WRP necessary? Some stakeholders argue 
that WRP is not necessary to get employees to 
report MSDs. They point to the fact that more 
than 600,000 MSDs are reported each year. 
MSDs, they state, account for approximately 
one of every three dollars paid out in 
workers' compensation claims. Given these 
numbers, these stakeholders state that the 
proposed rule does not need WRP to encourage 
employees to report MSDs and participate in 
MSD management. They say that the proposed 
requirements that employers encourage 
reporting, train employees in reporting, and 
refrain from retaliating against employees 
who do report, are sufficient measures to 
achieve the objective of early reporting of 
MSDs.
   While OSHA agrees with stakeholders that 
many MSDs are reported each year, there is 
also strong evidence that MSDs are 
significantly underreported (see Exs. 2-2; 2-
4; 2-22; 3-159; 3-160, 26-920, 26-918, 26-
28). In the last 18 years, many peer-reviewed 
studies that document underreporting of MSDs 
in OSHA logs have been published in the 
scientific literature (Exs. 2-2, 26-1212, 26-
1186, 26-28, 26-1258, 26-920, 26-922, 26-
1259, 26-1261, 26-1260). These studies 
document extensive and widespread 
underreporting on the OSHA logs of 
occupational injuries and illnesses ( Ex. 2-
2) and of MSDs (Exs. 26-28, 26-1258, 26-920, 
26-922, 26-1259, 26-1261, 26-1260). The 
studies also show that a large percentage of 
workers with MSDs that were identified as 
work-related by health care providers do not 
file workers' compensation claims (Exs. 26-
1258, 26-1212, 26-920). In one early study, 
only 47 percent of workers with medically 
diagnosed cases of CTS filed claims (Ex. 26-
1212). Fine and his co-authors found that, in 
two large automobile manufacturing plants, 
workers' compensation claims were filed in 
less than 1 percent of medically confirmed 
cumulative trauma cases in one plant and in 
only 14 percent of such cases in another (Ex. 
26-920). A recent study of 30,000 Michigan 
workers who were identified by a health care 
provider as having a work-related injury 
showed that only 9 to 45 percent of workers 
filed a workers' compensation claim for their 
injuries (Ex. 26-1258). (For a more detailed 
discussion of these studies and a table 
summarizing them, please refer to Section VII 
of this preamble.) OSHA is including WRP in 
the standard to cure underreporting and to 
secure early reporting.

[[Page 65852]]

   OSHA believes that existing State workers' 
compensation systems are not sufficient to 
encourage employees to report MSDs early and 
to cure this underreporting. As stated 
earlier, every State has a different workers' 
compensation system. In many States, 
obtaining workers' compensation for MSDs is 
difficult due to the different definitions of 
``injuries'' or ``illnesses'' in the various 
States, the different State statutes of 
limitation, and the contentious litigation 
that is often associated with claims for 
compensation for MSDs. In addition, some 
States provide no compensation for some MSDs 
(see, e.g., Virginia for rotator cuff 
tendinitis, epicondylitis, etc.). There is 
also another reason workers' compensation 
payments may not be adequate to ensure early 
employee reporting of MSDs. All States have 
waiting periods ranging from 1 to 7 days 
before an injury or illness is compensable 
under workers' compensation. Many employees 
cannot go even a few days without any pay. 
This is particularly true for many low-wage 
employees who live pay check-to-pay check. 
OSHA believes that existing workers' 
compensation systems are not adequate to 
ensure the effectiveness of MSD management.
   Some stakeholders contend that WRP is not 
necessary because many employers do not 
currently reduce the pay or benefits of 
employees when they are placed on restricted 
work duty. OSHA agrees with these 
stakeholders that many employers with good 
ergonomics programs and generous benefits 
policies do not reduce injured employees' pay 
and benefits when they are given, for 
example, alternative duty jobs. Other 
stakeholders, however, have told OSHA that 
many employers do reduce pay in such cases. 
Some stakeholders have also said that to 
create an incentive to return to work 
quickly, employers may not allow employees to 
use sick leave if they develop a workplace 
injury or illness (see Ex. 23). Also, OSHA 
estimates that approximately 50% of 
businesses do not even have a sick leave 
policy (Ex. 26-1406). OSHA believes that 
these kinds of practices would significantly 
deter employee reporting and would persist if 
the ergonomics rule did not include WRP.
   Does WRP violate section 4(b)(4) of the 
OSH Act? Several stakeholders contend that 
the WRP provision in the proposed rule 
violates section 4(b)(4) of the OSH Act 
because it would preempt, replace, and/or 
overwhelm State workers' compensation laws 
and systems.
   Section 4(b)(4) of the OSH Act provides:

  Nothing in this Act shall be construed to 
supersede or in any manner affect any 
workmen's compensation law or to enlarge or 
diminish or affect in any other manner the 
common law or statutory rights, duties, or 
liabilities of employers and employees under 
any law with respect to injuries, diseases, 
or death of employees arising out of, or in 
the course of, employment. 29 U.S.C. 
Sec. 653(b)(4).

   Congress included section 4(b)(4) in the 
OSH Act for a number of reasons. First, the 
section is intended to bar ``workers from 
asserting a private cause of action against 
employers under OSHA standards.'' Lead, 647 
F.2d at 1235. See also Ben Robinson Co. v. 
Texas Workers' Compensation Comm'n., 934 
S.W.2d 149, 156 (Tex. App. 1996) (``Ben 
Robinson'') (Section 4(b)(4) of the OSH Act 
sought ``to prevent injured workers from 
circumventing workers' compensation by 
claiming a private cause of action based on 
the OSH Act'' (citing Pratico v. Portland 
Terminal Co., 783 F.2d 255, 265 (1st Cir. 
1985))). Second, this section of the Act is 
intended to prevent any party in an 
employee's claim under workmen's compensation 
law or other State law from asserting that an 
OSHA regulation or the OSH Act itself 
preempts any element of State law. Lead, 647 
F.2d at 1236. An employee thus cannot obtain 
relief under State law for a disablement that 
is not compensable under that law simply 
because an OSHA standard provides protection 
against that disablement. Similarly, when an 
employee is injured, the employer cannot 
escape liability under State law simply 
because OSHA has not regulated the hazard 
that caused the injury.
   The D.C. Circuit has held that WRP does 
not violate the language or intended purposes 
of section 4(b)(4). See Lead, 647 F.2d at 
1236; cf. Formaldehyde, 878 F.2d 400. In the 
Lead decision, the court squarely addressed 
the issue of whether a similar WRP provision 
violated section 4(b)(4). The WRP provision 
at issue in Lead required employers to 
maintain an employee's ``earnings and 
seniority rights during removal for a period 
of 18 months.'' Lead, 647 F.2d at 1230. In 
Lead, the opponents of WRP argued that WRP 
violated section 4(b)(4) because, in 
practical terms, WRP would ``wholly 
replac[e]'' workers' compensation (i.e., 
federalize workers' compensation). Id. at 
1234. Opponents claimed that WRP violated 
workers' compensation because it provided 
compensation before the point at which 
workers' compensation recognized the 
disability. Id. They also argued that WRP 
would render workers' compensation 
meaningless because disabled employees 
receiving full earnings under WRP would never 
seek workers' compensation. Id.
   The court in Lead found these arguments 
unpersuasive. First, the court held that the 
section's prohibition against ``affecting'' 
or ``superseding'' workers'' compensation 
could not be read too broadly because all 
OSHA standards are meant in some way to 
``affect'' workers'' compensation and 
ultimately to ``supersede'' it in the sense 
that they seek to ensure that employees are 
protected from injury and never have the need 
to seek such compensation. Lead, 647 F.2d at 
1235. Cf. Ben Robinson, 934 S.W.2d at 156. 
The goal of this proposed rule is the same as 
the goal for the Lead standard: to ensure 
that employees are protected from developing 
MSDs and therefore have no need to seek 
workers' compensation.
   Next, the court found that even if WRP 
were available, injured employees would have 
incentives to seek workers' compensation 
because: (1) Workers' compensation would 
reimburse them for the medical treatment 
expenses that WRP would not cover; and (2) 
WRP would only last for several months (e.g., 
18 months in the Lead standard; 6 months in 
the proposed rule), while workers' 
compensation would compensate them for longer 
periods of disability, and in certain cases 
indefinitely. Lead, 647 F.2d at 1235. The 
court's finding is particularly applicable to 
the proposed rule. Employees with MSDs would 
still have several incentives to seek 
workers' compensation. The only way employees 
with severe disorders could get reimbursement 
for medical expenses such as prescription 
medicines, physical therapy, and surgery, 
would be by filing a workers' compensation 
claim. (The proposed rule does not require 
that employers pay for the medical treatment 
costs, such as those for surgery or physical 
therapy, of employees who have covered MSDs.) 
In fact, employees with MSDs have an even 
greater incentive to file claims than 
employees covered by the Lead standard 
because the proposed rule limits WRP to 6 
months (compared to 18 months for the Lead 
standard).
   The court in Lead held that even if WRP 
has a ``great practical effect'' on workers'' 
compensation, it does not violate section 
4(b)(4) as long as it ``leaves the state 
scheme wholly intact, as a legal matter.'' 
Lead, 647 F.2d at 1236. The proposed WRP 
provision does not touch the legal scheme of 
existing State workers' compensation laws, 
even though it may result in a reduction in 
workers' compensation claims and payments. 
The proposed WRP provision would not

[[Page 65853]]

require States to cover MSDs that they have 
excluded from coverage. The proposed WRP 
provision would not require States to change 
the percentage of lost wages it will replace. 
The proposed WRP provision also would not 
change the legal tests for compensability; 
that is, it would not require that 
compensation be awarded when work 
``contributed'' to the MSD if State workers'' 
compensation laws only allow it when work is 
the ``primary cause'' of the MSD.
   The stakeholders who oppose WRP state that 
the Lead decision's reference to ``great 
practical effect'' is not applicable to the 
proposed WRP provision. They contend that the 
``practical effect'' this provision would 
have is much greater than that anticipated by 
the Lead court. They argue that this 
standard, and thus the WRP provision, will 
cover a significantly greater number of 
employers and employees than previous OSHA 
standards. This means, they state, that a 
significantly larger number of employees will 
receive WRP. This degree of ``practical 
effect,'' they state, would either overwhelm 
workers'' compensation or render it 
meaningless or insignificant.
   Although stakeholders are correct that the 
proposed rule is likely to cover more 
establishments than many other health 
standards, OSHA believes that these 
stakeholders overstate the ``practical 
effect'' that the proposed WRP provision 
would have on workers'' compensation as well 
as individual employers. While the median 
number of lost workdays for certain MSDs is 
quite high, as discussed in Sections IV and 
VII, the median number of lost workdays for 
all MSDs is 7 (Ex. 26-1413). Thus, in many 
cases the impact of WRP will be limited 
because a large percentage of MSDs resolve in 
a matter of days and many employers allow 
workers who must stay away from work or be on 
restricted work to use their sick leave for 
this purpose. By contrast, in other health 
standards, such as lead, it usually takes 
longer, for example, for blood lead levels to 
decline to acceptable levels. Once the 
ergonomics standard is final, the percentage 
of MSDs involving less than 6 days away from 
work should increase as employees are 
informed about the importance of early 
reporting, and employers implement better 
controls to reduce MSD hazards.
   Second, as mentioned above, most MSDs 
resolve if employees are simply placed in 
alternative work duty during the recovery 
period. Where employers provide such work 
duty, only a very small number of cases ever 
require complete removal from work for any 
significant period of time. This suggests 
that the impact on workers' compensation will 
be much more limited than the stakeholders 
contend. Furthermore, as employers identify 
and fix problem jobs and employees are 
trained to report MSDs as early as possible, 
the numbers of injured employees requiring 
complete removal from work during the 
recovery period should decrease 
significantly. Companies that have 
implemented effective ergonomic programs 
report that lost-time/day injuries have 
decreased significantly or have been 
eliminated (Ex. 26-5; Ex. 3-147). In 
addition, the WRP provision itself is crafted 
to encourage employees to report signs and/or 
symptoms of MSDs as early as possible, 
thereby decreasing the number of employees 
with MSDs that will require complete removal 
from work.
   Third, for many employers, WRP should have 
little impact. Many employers who have told 
OSHA that they already have an alternative 
duty program for employees with MSDs also 
said that they do not reduce employee pay 
when employees are placed on restricted work 
duty during the recovery period.
   Finally, the type of ``practical effect'' 
many employers believe WRP will have on 
workers'' compensation systems is precisely 
the effect that the courts have said OSHA 
standards are intended to have. Lead, 647 
F.2d at 1234-35. Cf. Ben Robinson, 934 S.W.2d 
at 156. The goal of WRP, as well as other 
provisions of the proposed rule, is to 
protect employees from suffering material 
impairment of health or functional capacity. 
Achieving that goal will result in reducing 
or eliminating the need to seek workers' 
compensation. This effect, however, does not 
violate section 4(b)(4) of the OSH Act. Lead, 
647 F.2d at 1234-35.
   Will WRP impose substantial economic 
hardship on employers? Some stakeholders 
argue that WRP will impose a substantial 
economic hardship on employers, especially 
small employers, because it will be so 
expensive to implement. Stakeholders argue 
that small employers will not be able to 
remain in business if they must provide 
employees with WRP.
   OSHA is aware of the stakeholders' 
concerns, but the Preliminary Economic 
Analysis and Initial Regulatory Flexibility 
Analysis show that the proposed rule, which 
includes the WRP provision, is economically 
feasible for all of the industries that OSHA 
is proposing to cover, including small 
employers in those industries. Available data 
discussed above indicate that these 
stakeholders may be overstating the economic 
impact of the proposed rule. While the median 
number of lost workdays for certain MSDs is 
quite high, as discussed above, OSHA 
estimates that most MSDs do not result in any 
days away from work, and data on those that 
do indicate that half of all such reported 
MSDs (i.e., lost workday MSDs) resulted in 7 
or fewer days away from work (Ex. 26-1413). 
Once the proposed rule's provisions stressing 
the importance of early reporting become 
effective, the number of MSDs requiring more 
than 7 days away from work should decrease 
further. Thus, OSHA believes that the 
requirement to provide WRP will encourage 
employers to more quickly implement an 
effective ergonomics program (1) to detect 
MSDs, (2) to institute effective controls, 
and (3) to prevent other employees in the 
same job from developing a covered MSD. These 
actions will reduce the number and severity 
of MSDs, thus reducing WRP costs.
   Will WRP be abused? Some stakeholders 
stated that WRP will be abused by employees. 
These stakeholders contend that MSDs are too 
difficult to reliably diagnose; thus, they 
contend that WRP will give employees an 
incentive to report injuries that occur 
``off-the-job'' as injuries that are work-
related. Certain stakeholders also fear that 
an employee could persuade an HCP to write a 
medical recommendation for six months of 
removal, even though the employee is not 
injured or not injured to the extent that 
such a period of removal is necessary.
   OSHA has drafted the proposed standard to 
reduce any potential for employee abuse that 
may exist. First, OSHA is only requiring 
employers to maintain 90% of employees' 
after-tax earnings if they are removed form 
work entirely. If an employee is placed in 
work restrictions short of complete removal, 
the employer must maintain 100% of the 
employee's after-tax earnings. OSHA believes 
that this scheme provides little incentive 
for employees to persuade an HCP to write an 
unnecessary removal recommendation for six 
months or otherwise abuse WRP. To the 
contrary, OSHA believes that WRP will 
encourage employees to report signs and/or 
symptoms of MSDs as early as possible to 
avoid complete removal from work.
   Second, OSHA emphasizes that employers 
have the ability to prevent abuse. Under the 
proposed rule, employers make the 
determination as to whether a reported MSD is 
covered by the standard, i.e., whether the 
MSD is an OSHA

[[Page 65854]]

recordable MSD and meets the screening 
criteria in Sec. 1910.902. This gives 
employers the ability to prevent employees 
from receiving WRP benefits for injuries that 
are not work-related and covered by this 
standard. In addition, OSHA believes that 
implementation of an ergonomics program under 
this standard will decrease significantly any 
opportunity for abuse as MSD hazards are 
removed from the workplace.
   Third, the proposed standard only requires 
that employers provide temporary work 
restrictions (and thus WRP) where necessary 
or when recommended by an HCP to whom the 
employee was referred by the employer. The 
employer need not remove the employee from 
work based only on a request made by the 
employee.
   Fourth, when an employer refers an 
employee to an HCP and that HCP provides 
recommended temporary work restrictions, the 
proposed rule only requires the employer to 
provide the temporary work restrictions that 
the HCP actually recommends. This means that 
if the HCP recommends restricted duty, the 
employee is not entitled to time-off from 
work. Where employers provide the HCP with 
information and communicate with them about 
alternative duty jobs, OSHA believes that the 
HCP will be more likely to recommend 
restricted work activity than complete 
removal. Recent BLS statistics bear this out: 
since 1992, the percentage of restricted 
workdays for all occupational injuries and 
illnesses has increased by 50%, while the 
percentage of lost workdays has decreased by 
a substantial amount. This trend, which 
reflects the influence of return-to-work 
programs among other factors, shows no signs 
of abating.
   Finally, the proposed standard does not 
require employers to provide WRP if they 
correct the hazards associated with the MSD 
such that there is no risk of harm to the 
employee during the recovery period. A 
workplace with hazard controls further 
reduces any potential for employee abuse 
associated with WRP.
   For all of these reasons, OSHA believes 
that WRP will not provide employees with an 
incentive for abuse.


Part C--Alternatives

   A number of stakeholders, including some 
who participated in the SBREFA process, and 
the SBREFA panel, have recommended that OSHA 
look at various alternatives to the proposed 
WRP provisions. OSHA has examined the 
following alternatives:

   Require employers to maintain 100% 
of an employee's after-tax earnings whenever 
the employee is placed on temporary work 
restrictions, including complete removal from 
work;
   Reduce the amount of time an 
employer would be required to provide WRP to 
an employee with an MSD;
   Propose a WRP provision that 
includes special provisions or an exemption 
for small businesses such as those included 
in the Methylene Chloride standard;
   Phase-in WRP over a period of time 
ranging from a number of months to as long as 
three years; and
   Require employers to provide 
employees with non-monetary incentives to 
report MSDs, instead of requiring WRP.
   OSHA has carefully considered these 
alternatives. For the reasons that follow, 
OSHA has preliminarily decided not to include 
these provisions in the proposed ergonomics 
rule.
   Require employers to maintain 100% of an 
employee's after-tax earnings whenever the 
employee is placed on temporary work 
restrictions, including complete removal from 
work. As stated, WRP requires employers to 
maintain 100% of an employee's after-tax 
earnings, plus full benefits, if the employee 
is placed on temporary work restrictions 
short of complete removal from work; however, 
if an employee is removed entirely from work, 
the employer must maintain 90% of the 
employee's after-tax earnings, plus full 
benefits. This differs from the WRP 
provisions in other health standards. In 
other health standards, OSHA requires that 
employers maintain an employee's full 
earnings, rights, and benefits when an 
employee is medically removed from work. See, 
e.g., 29 CFR 1910.1025 (Lead); 29 CFR 
1910.1027 (Cadmium). OSHA considered 
requiring employers to maintain an employee's 
full take-home pay and benefits whenever the 
employee is placed on any temporary work 
restrictions, including complete removal from 
work, but OSHA preliminarily has decided not 
to include this alternative in the proposed 
rule. As discussed in the Preliminary 
Economic Analysis (Ex. 28-1), this 
alternative would increase the costs of WRP 
by 36 percent.
   OSHA believes that the proposed WRP 
provision provides the requisite economic 
protection to encourage employees to 
participate fully in the MSD management 
program. OSHA anticipates that few employees 
will require complete removal from work 
during the recovery period. For those few 
employees requiring complete removal, 
maintenance of 90% of their after-tax 
earnings (and full benefits), coupled with 
the cost savings from the elimination of such 
expenditures as commuting expenses, will 
provide them the requisite economic 
protection to effectuate the purposes of WRP: 
encouraging employee participation in MSD 
management. As stated, OSHA also believes 
that the proposed WRP design is uniquely 
suited to encourage employees to report MSDs 
as early as possible, a critical aspect of 
the proposed rule.
   Reduce the length of time an employer 
would be required to provide WRP to an 
employee with an MSD. OSHA is proposing that 
employers may stop providing WRP benefits 
when the first of certain cutoff points 
occurs. The cutoff points are: the ability of 
the employee to return fully to the job; the 
successful control of the job; and, as a last 
resort, 6 months of WRP. OSHA considered 
reducing the length of time employers would 
have to provide WRP.
   The vast majority of MSDs resolve in 
substantially less than six months. According 
to the Liberty Mutual Insurance Company, the 
largest workers' compensation insurer in the 
United States, 75% of all UEMSD claims in 
1994 did not involve any days away from work 
and only about 11% of those involving lost 
workdays resulted in more than 6 months away 
from work (Ex. 26-54). This evidence 
indicates that most MSDs, if detected early, 
can be resolved very quickly. Even for CTS 
cases, the injury and illness with the 
highest number of median days away from work, 
the median number of days away from work in 
1996 was 25 days, according to BLS (see 
Section VII). (The average number of lost 
workdays for CTS cases is likely to be higher 
since more than 42% of all CTS cases resulted 
in more than 30 days away from work.)
   For claims for MSDs of the lower back, the 
most prevalent of all work-related MSDs, 
according to Liberty Mutual, the median 
number of days away from work was 7 days in 
1996 (Ex. 26-54). Therefore, although the 
proposed rule provides 6 months of WRP 
protection, the evidence indicates that it is 
unlikely that 6 months would be the first 
cutoff event to occur.
   However, there is also evidence that some 
employees may require an extended period to 
recover, and that a small percentage may 
require even more than 6 months. According to 
Liberty Mutual, for the one-quarter of the 
UEMSDs that

[[Page 65855]]

did involve at least one day away from work, 
the average length of disability was 294 days 
and the median was 99 days (Ex. 26-54). One 
reason for the longer disability period may 
be that a high percentage of these cases 
involved surgeries, such as carpal tunnel 
release surgery, which would require a longer 
recovery period.
   In other health standards that have WRP 
provisions, OSHA has set the length of WRP 
based primarily on its ``best estimate'' as 
to the rate (i.e., time) at which employees 
will recover from the adverse health effect. 
In the Lead standard, the length of the WRP 
represented the rate at which employees with 
high blood-lead levels would naturally 
excrete lead if removed from lead exposure. 
See 43 FR 54354. 54469, November 21, 1978. 
Applying that principle, OSHA said in the 
preamble to the Lead standard that a maximum 
of 18 months was a reasonable and appropriate 
length of time, particularly since some 
workers had high blood lead levels: ``Very 
few workers should require longer than 18 
months to decline to acceptable blood lead 
levels, and 18 months is not in excess of 
what some long-term lead workers may 
require.'' Id. at 54469.
   The criterion OSHA applied in the Lead 
standard also supports OSHA's preliminary 
determination that employers should be 
required to provide up to 6 months of WRP for 
employees with MSDs, if necessary. According 
to BLS, 42% of all reported CTS cases 
involved more than 30 days away from work in 
1992 (see Section VII). Data from Liberty 
Mutual confirm this. Liberty Mutual reported 
that for those UEMSDs involving lost-work 
time, the typical disability duration was 
more than 3 months (Ex. 26-54). Given these 
data, OSHA believes that the 6-month maximum 
time is reasonable because it would allow the 
majority of employees time to recover before 
losing WRP benefits. The six-month period is 
appropriate because this phase of the 
ergonomics rule is focusing on those jobs 
where employees have the highest numbers and 
rates of MSDs that are serious enough to 
result in days away from work.
   In the Preliminary Economic Analysis, OSHA 
has provided preliminary cost estimates for 
three alternatives to the 6-month time period 
for WRP:
    A 3-month WRP provision;
    No WRP during the average 
workers' compensation waiting period (3 
days);
    Providing WRP only for a limited 
number of days.
   3-month WRP Provision. Cutting the WRP 
period in half to 3 months would reduce WRP 
costs somewhat. This alternative, however, 
would not cut the costs of WRP in half. This 
is because the vast majority of MSDs (75%) do 
not involve days away from work and the 
percentage of cases involving employees who 
are out of work for 3 months is not 
substantially less than the percentage out of 
work for 6 months. To illustrate, Liberty 
Mutual found that 89% of all workers' 
compensation indemnity cases for UEMSDs 
involved less than 6 months away from work, 
while 85% involved less than 3 months away 
from work--a difference of only 4% (Ex. 26-
54).
   If the WRP period were reduced to 3 
months, however, many employees with UEMSDs 
that involve more than 3 months away from 
work would not receive WRP after the original 
3 month period. According to Liberty Mutual, 
a majority of UEMSD workers' compensation 
claims resulted in more than 3 months away 
from work. In addition, the median number of 
lost workdays for these cases was 99 days and 
the mean was 294 days (Ex. 26-54). Thus, even 
looking only at UEMSDs, a 3-month WRP period 
would provide no WRP benefits after the first 
3 months to more than 12% of all lost workday 
cases. This percentage of cases is hardly the 
equivalent to the ``very few'' cases of lead-
poisoned workers who were estimated to need 
more than 18 months to recover. If the WRP 
period is significantly shortened, injured 
employees may have to return to their jobs 
before their condition resolves, which 
increases the likelihood of reinjury or 
aggravation of the MSD.
   No WRP during the average workers' 
compensation waiting period (3 days). Under 
this option, WRP would not be provided until 
an employee has missed three days of work. 
All State workers' compensation systems have 
a waiting period. The waiting periods range 
from 1 to 7 days; most States have a waiting 
period of either 3 or 7 days. This 
alternative would not require employers to 
cover the expenses of an injured employee for 
the first 3 days, the average workers' 
compensation waiting period. While this 
alternative may reduce the costs of WRP 
somewhat, if adopted, it would reduce 
employee protection by 75%. Once again, this 
is because the vast majority of all reported 
MSDs involve no lost workdays or only a few 
lost workdays.
   OSHA believes that, particularly for 
employees in low-wage jobs, this alternative 
would not achieve the goal of WRP: the early 
reporting of all MSDs. Stakeholders have told 
OSHA that workers in these low wage jobs are 
so fearful of the consequences of losing up 
to a few days of wages that they would not 
report MSDs or participate in MSD management 
if faced with the threat of this economic 
loss. Under this alternative, employers would 
not be prohibited from sending an employee 
with an MSD home after three days, even if an 
alternative duty job would be an effective 
way of managing the employee's recovery. 
While OSHA is aware that some employers 
currently pay employees during the State 
workers' compensation waiting period (see 
Exs. 26-23 through 26-26), stakeholders also 
said that a number of employers do not pay 
employees during this period, even if they 
are sent home (see Exs. 26-23 through 26-26). 
Some employers have policies to send any 
employee who reports an MSD home without pay 
for some number of days (see Exs. 26-23 
through 26-26). Other employers told OSHA 
that they do not permit employees to use 
their sick leave to cover work-related 
injuries (see Ex. 23). These types of 
practices indicate that this alternative to 
the proposed WRP provision is unlikely to 
reduce employee fears of reporting MSDs 
early. Again, if employees do not report, it 
could result in increased harm to that 
employee and others in the same job. Indeed, 
this alternative would have the perverse 
effect of encouraging employees to wait until 
an MSD is serious enough to warrant more than 
three days away from work before reporting 
the MSD.
   In only one standard has OSHA delayed the 
removal of injured employees and the 
application of WRP benefits. In the 
Formaldehyde standard, OSHA allows employers 
to wait two weeks before removing an employee 
from exposure. 29 CFR 1910.1048 (l)(8). In 
the preamble to that standard OSHA explained 
that the delay in removing employees was to 
give employers an opportunity to ascertain 
whether the signs or symptoms would subside 
without treatment or with the use of PPE and 
first aid (which imposes a barrier between 
the skin and the irritant). The two-week 
delay was based on evidence that the initial 
irritation exposure effects sometimes 
disappeared as employees became accustomed to 
working with compounds containing 
formaldehyde. The opposite exists in dealing 
with this hazard. WRP is particularly 
necessary at the onset of an MSD, because 
that is when the MSD is the least likely to 
result in permanent damage or disability. As 
exposure continues, MSD signs and

[[Page 65856]]

symptoms get worse rather than abating (with 
the exception of initial work conditioning 
periods). As such, limiting WRP until after 
the employee has additional exposure to 
workplace risk factors could result in 
adverse health effects.
   WRP only for a limited number of days. 
Under this option, WRP would only be provided 
for a limited number of days (e.g., three, 
five, or seven days). This alternative is 
designed to provide protection for employees 
for the short period of time before workers' 
compensation payments begin.
   As stated, the median number of lost-work 
days from MSDs is 7; thus, requiring 
employers to provide WRP benefits for three, 
five, or seven days may provide protection 
for some employees. At the same time, 
however, many MSDs are not resolved in those 
time periods. Even for those MSDs where the 
median number of days away from work is five, 
for example, statistically, 50 percent of 
those cases involve more than five days away 
from work. In addition, as indicated above, 
the median number of days away from work for 
CTS is 25 (see Section VII).
   OSHA believes that this alternative would 
not provide the requisite protection to 
employees to encourage them to report MSDs 
early and to actively participate in MSD 
management. For those employees who have MSDs 
that do not resolve within the short time 
period called for by this alternative, this 
alternative leaves workers only with workers' 
compensation. In addition, many workers' 
compensation waiting periods extend beyond 
three or five days. For those employees in a 
state with a longer waiting period, if their 
MSDs do not resolve within the short time 
period covered by this alternative, they may 
be without any protection for several days 
(even though their injury may be covered by 
their State's workers' compensation system). 
The loss of even a few days pay is 
devastating to many employees. Furthermore, 
for those injured employees whose MSDs are 
not covered by their respective workers' 
compensation systems, this alternative would 
only provide protection for three, five or 
seven days. Because of this great financial 
strain, these employees may return to work 
too early, before their MSD is fully 
resolved, and reinjure themselves. OSHA 
believes that this alternative would have a 
chilling effect on early reporting of MSDs.
   This alternative also reduces the 
employer's incentive to fix the job quickly. 
Under OSHA's proposal, one way an employer 
can avoid paying for WRP for 6 months is to 
fix the job so the injured employee can 
perform it. Under this alternative, however, 
the WRP payments would generally end before 
the employer is able to identify and fix the 
MSD hazards. Without that incentive, 
employers may opt for a longer timeline for 
controlling the job.
   Apply Methylene Chloride WRP provision to 
small businesses covered by the ergonomics 
standard. The proposed WRP provision applies 
WRP universally to large and small employers. 
In this respect, WRP is similar to the WRP 
requirements in other health standards. See, 
e.g., 29 CFR 1910.1025 (Lead); 29 CFR 
1910.1027 (Cadmium); 29 CFR 1910.1028 
(Benzene); 29 CFR 1910.1048 (Formaldehyde). 
To illustrate, the Lead standard applies the 
WRP requirements to all employers even though 
a substantial number of industries with lead 
exposures contain small businesses (e.g., 
non-ferrous foundries, construction). In 
construction, for example, more than 75% of 
all establishments have fewer than 10 
employees; however, the Lead standard (29 CFR 
1926.62) applies to all employers, regardless 
of size. OSHA examined applying the 
feasibility limitations in the WRP provision 
in the Methylene Chloride standard to small 
businesses that would be covered by the 
ergonomics rule.
   The Methylene Chloride standard allows 
small businesses to make a case-by-case 
analysis regarding the feasibility of WRP if 
one or more employees are already receiving 
WRP benefits and the employer is informed 
that removal is appropriate for a second 
employee. 63 FR 50712, 50717, September 22, 
1998. If a second employee required removal 
while the first employee was being paid WRP 
benefits, the Methylene Chloride standard 
would not require the employer to remove the 
second injured employee from the job and pay 
WRP if:

comparable work is not available and the 
employer is able to demonstrate that removal 
and the costs of extending [WRP] benefits to 
an additional employee, considering 
feasibility in relation to the size of the 
employer's business and the other 
requirements of the standard, make further 
reliance on [WRP] an inappropriate remedy * * 
*. Id. at 50730 (citing 29 CFR 
1910.1052(j)(11)(I)(B)).

   In each of the standards that have a WRP 
provision, the costs of the standards, 
including those of WRP, were found to be 
economically feasible for both large and 
small businesses in all affected industries. 
The same is true for the proposed ergonomics 
standard. The Preliminary Economic Analysis 
discussed below indicates that the proposed 
standard, including the 6-month WRP 
provision, is economically feasible for all 
industries. This is true even for very small 
businesses (those with fewer than 20 
employees). OSHA's Preliminary Economic 
Analysis indicates that for very small 
businesses affected by the proposed standard, 
the impacts of the proposed rule are not 
likely to affect the viability of firms.
   The WRP provision in the Methylene 
Chloride standard resulted from a settlement 
resolving several challenges to the final 
standard. OSHA and the parties to the 
settlement agreed that the WRP provision 
noted above was appropriate to the hazards 
posed by exposure to methylene chloride. The 
WRP provision agreed to in the settlement is 
limited to the unique characteristics of 
methylene chloride exposure. OSHA does not 
believe that a similar WRP provision would be 
appropriate here.
   Delay or phase-in implementation of the 
WRP provision. OSHA also considered delaying 
or phasing-in implementation of WRP, perhaps 
by up to three years. The proposed standard 
does not delay or phase-in implementation of 
either MSD management or WRP. OSHA believes 
that, because so many workers already are 
experiencing MSDs every year, it is critical 
that both MSD management and WRP be 
implemented as soon as possible. Delaying WRP 
could result in serious damage or disability 
for employees who have MSD signs and symptoms 
but fear severe economic loss if they report 
an MSD. Moreover, if WRP were delayed for the 
recommended 3 years, as many as 1.8 million 
employees that are likely to have lost-
workday MSDs over that time period would not 
have WRP protection. While OSHA acknowledges 
that some of these employees may be able to 
use sick leave pay during a recovery period, 
many employers either do not offer sick leave 
or prohibit employees from using sick leave 
for work-related MSDs. In fact, delaying the 
implementation of WRP could result in injured 
employees receiving less protection than they 
currently have. For example, employers who 
currently do not reduce the wages of 
employees on restricted duty would not be 
prohibited from changing their policies in 
the future, particularly since reports of 
MSDs will, after the standard's effective 
date, impose costs on employers for job 
analysis and control.

[[Page 65857]]

   With regard to phasing-in WRP, some 
members of the SBREFA panel recommended that 
the phase-in be done according to 
establishment size, that is, phase-in large 
employers first and delay implementation of 
WRP for small businesses. However, such a 
phase-in would not be consistent with past 
OSHA practice (Ex. 23). The Lead standard is 
the only rule in which WRP has been phased-
in. In that standard, OSHA determined that 
phase-in was necessary because seriously 
elevated blood levels were so persistent in 
the lead-using industries that removal 
presented feasibility problems:

  The weight of the evidence in the lead 
record demonstrates that immediate imposition 
of the entire ultimate [WRP] program is not 
feasible. Put simply, existing worker blood 
lead levels are so high that major segments 
of the lead industry would have to 
immediately remove at least 25 percent to 40 
percent of their productive work force from 
lead exposure. Sufficient transfer 
opportunities would not exist thus extensive 
layoffs would result with accompanying [WRP] 
costs.

* * * * *
  OSHA is persuaded that several industry 
segments could not reasonably be expected to 
comply with an immediate imposition of the 
overall [WRP] program. 43 FR 54354, 54452, 
November 21, 1978.

   Given this, OSHA decided to phase-in WRP 
based on the severity of employees' blood 
lead levels. By contrast, there is no 
evidence that immediate implementation of WRP 
in the ergonomics standard would present 
feasibility problems for employers, even for 
very small employers. The Preliminary 
Economic Analysis indicates that it would be 
feasible to apply the WRP provision to all 
covered employers. The Preliminary Economic 
Analysis shows that the proposed standard 
will neither affect the economic viability of 
any industry as a whole, nor of the small or 
very small establishments in those 
industries.
   Delaying or phasing-in WRP would also 
render the proposed standard's hazard 
identification system ineffective. The hazard 
identification system in the proposed rule 
does not consist of assessing each job in the 
workplace to see if employees have excessive 
exposure to workplace risk factors. Instead, 
the hazard identification system is based on 
employees coming forward with reports of 
MSDs. In order for this hazard identification 
system to produce accurate results, it is 
essential that employees voluntarily come 
forward with their reports. However, if they 
fear severe economic loss for reporting, 
employees will not come forward. Phasing in 
WRP would have a chilling effect on 
employee's willingness to report MSDs and/or 
signs and symptoms of MSDs. This ``chilling 
effect'' will delay job hazard analysis and 
identification and the implementation of 
controls, subjecting employees to workplace 
risk factors and MSD hazards.
   Finally, delaying or phasing-in WRP is not 
necessary to ease employers' transition 
because OSHA is already proposing to phase in 
all but the MSD management provisions of the 
standard. OSHA is proposing that employers be 
given a start-up time of up to 3 years to set 
up a full program and implement controls. 
These proposed start-up times are longer than 
the corresponding provisions in almost all 
other OSHA health standards. If job control 
is delayed while employers plan ergonomics 
changes and work those changes into their 
production cycle changes, it becomes even 
more important that employees not be without 
WRP protection in the interim.
   Also, OSHA is proposing that general 
industry employers who are not brought under 
the scope of the standard until after all 
compliance deadlines have passed (e.g., there 
are no covered MSDs among their employers 
until after compliance deadlines have passed) 
be given additional time to come into 
compliance. At that point, employers would 
have up to one year to put in controls and 
determine if their program is effective. This 
extension of compliance deadlines has not 
been included in other OSHA standards. In 
other standards, once the deadlines occur, 
employers must be in compliance from that 
point forward. For example, in many other 
OSHA standards, employers who build new 
facilities must be in compliance with OSHA 
standards from the very start (e.g., the 
employer must be in compliance with the PEL 
when the facility first opens). This would 
not be the case under this proposed standard. 
Rather, employers in general industry are 
given additional time to come into compliance 
with the standard's requirements after an 
employee develops a covered MSD.
   Use non-monetary incentives, instead of 
WRP, to increase employee reporting and 
participation in MSD management. OSHA also 
considered replacing WRP with non-monetary 
incentives for employees to report MSDs.
   OSHA decided to propose a WRP provision 
because non-monetary incentives do not appear 
to be working. Section 11(c) of the OSH Act 
already includes a prohibition against 
employers retaliating against employees who 
report MSDs and MSD hazards:

  No person shall discharge or in any manner 
discriminate against any employee because 
such employee has filed any complaint or 
instituted or caused to be instituted any 
proceeding under or related to this Act or 
has testified or is about to testify in any 
such proceeding or because of the exercise by 
such employee on behalf of himself or others 
of any right afforded by this Act. 29 U.S.C. 
660(c).

   However, despite this provision, several 
studies show that MSDs are significantly 
underreported. Although the reasons for such 
underreporting are believed to be many 
(including, for example, unintentional and 
intentional discouragement by employers, 
failure on the part of employers and 
employees to recognize the work-relatedness 
of many MSDs), OSHA believes the fear of 
severe economic loss is one of the primary 
reasons for the underreporting. The proposed 
rule includes a provision prohibiting 
employers from having practices that 
discriminate against employees who make a 
report. Nonetheless, there is evidence that 
non-monetary incentives can result in 
increased rather than decreased 
underreporting.
   A number of stakeholders have said that 
employers use various non-monetary incentives 
to achieve a safer and more healthful 
workplace (see Exs. 26-23 through 26-26; Ex. 
23). Some of these incentives include 
recognition and nominal rewards (company 
caps, plaques) for reporting hazards or 
presenting ideas to fix problem jobs or 
reduce severity rates. These types of 
incentives can increase employee reporting. 
There are also other incentives such as 
``safety bingo'' and bonuses for supervisors 
and/or employees reporting low numbers of 
injuries or no injuries. According to 
stakeholders, incentives of this second type 
can have the unintended result of pressuring 
employees not to report injuries or other 
problems. For example, in Wilson v. IBP, 558 
N.W.2d 132, 143-44 (Iowa 1996), the court 
found that the defendants had engaged in the 
following conduct which could discourage 
employee reporting and result in 
discrimination of employees who did report an 
MSD:

  [The registered nurse who was the plant 
manger of occupational health services] had 
another reason for responding to workers' 
injuries as she did. IBP had a financial 
incentive program,

[[Page 65858]]

somewhat disingenuously called `the safety 
award system.' As part of the safety award 
system, IBP recorded the number and severity 
of injuries and the number of work days 
missed by employees due to work-related 
injuries. Employees of the division with the 
lowest injury statistics received gifts or 
extra year-end bonuses. Through its financial 
incentives, the safety award system provided 
strong motivation for management to reduce 
the number of lost time days.

* * * * *
  From the evidence in this record, a 
reasonable juror could have found the 
following: [the plant nurse] lied to Dr. 
Hamsa to keep him from referring [the injured 
employee] to a neurosurgeon, that IBP and 
[the plant nurse] would profit financially by 
getting workers back to work quickly (via 
IBP's safety award system), and that [the 
plant nurse] maliciously manipulated [the 
injured employee's] medical treatment for 
personal profit, knowing that he had an 
unstable disc in his back * * *.
  A reasonable juror could also have found as 
follows: IBP actively sought ultra-
conservative physicians to avoid surgery 
costs; it hired a staff of investigators to 
spy on injured employees, one of whom looked 
into [the injured employee's] apartment 
windows; workers who were uncooperative in 
the company's planned medical treatment were 
assigned by [the plant nurse] to a light duty 
job, watching gauges in the rendering plant, 
where they were subjected to an atrocious 
smell while hog remains were boiled down into 
fertilizers and blood was drained into tanks.
  This climate of suspicion toward the 
legitimacy of injuries to workers and their 
treatment, well known to [the plant nurse], 
could be found by a reasonable juror to 
corroborate a finding of willful and wanton 
disregard for the rights and safety of [the 
injured employee].

   At this point, OSHA has not been able to 
identify non-monetary incentives that would 
be as effective as WRP in encouraging 
employees to report MSDs early and in 
protecting employees who do come forward 
voluntarily.


Requests for Comment

   OSHA requests information and comments on 
the WRP provision in the proposed standard. 
Specifically, OSHA requests information and 
comments on the alternatives to WRP discussed 
in this section as well as other non-monetary 
alternatives that would achieve the same 
goals and be as protective as WRP. OSHA is 
particularly interested in whether commenters 
believe that for WRP to be effective in 
encouraging employee participation in MSD 
management and encouraging early reporting, 
employees must be guaranteed 100% of after-
tax earnings and benefits if they are placed 
on any type of temporary work restriction, or 
whether a guarantee of 90 percent or less is 
sufficient to accomplish this goal.


Program Evaluation (Secs. 1910.936-1910.938)

   Sections 1910.936-1910.938 of the proposed 
Ergonomics Program standard would require 
that employers evaluate their ergonomics 
program to ensure that it is effective. Good 
management, as well as common sense, suggest 
that periodic review of a program's 
effectiveness is necessary to ensure that the 
resources being expended on the program are, 
in fact, achieving the desired results and 
that the program is achieving these results 
in an efficient way. Additionally, program 
evaluation is a tool that can be used to 
ensure that the program is appropriate for 
the specific MSD hazards in the employer's 
problem jobs.
   OSHA has long considered program 
evaluation to be an integral component of 
programs implemented to address health and 
safety issues in the workplace. For example, 
the Ergonomics Program Management Guidelines 
for Meatpacking Plants (``Meatpacking 
Guidelines'') recommend regular program 
review and evaluation (Ex. 2-13). These 
guidelines suggest that procedures and 
mechanisms be developed to evaluate the 
implementation of the ergonomics program and 
to monitor progress accomplished. Program 
evaluation is included in the Meatpacking 
Guidelines as a program component that 
involves both management commitment and 
employee involvement. OSHA's 1989 voluntary 
Safety and Health Program Management 
Guidelines also recommend regular program 
evaluation as an integral program component 
(Ex. 2-12). Furthermore, OSHA's Voluntary 
Protection Programs (VPP) and its 
Consultation Program also require periodic 
evaluations of an employer's safety and 
health program. The following discussion 
presents OSHA's reasons for proposing the 
three program evaluation provisions described 
below.
   Section 1910.936  What is my basic 
obligation?

  You must evaluate your ergonomics program 
periodically, and at least every 3 years, to 
ensure that it is in compliance with this 
standard.

   Proposed section 1910.936 informs 
employers of their basic obligation. This 
section would require employers to ``evaluate 
[their] ergonomics program periodically, and 
at least every 3 years, to ensure that it is 
in compliance with this standard.'' This 
means that employers would have to, at a 
minimum, analyze the functioning of the 
ergonomics program, compare it to the 
requirements of this standard, and identify 
any deficiencies in the program. Employers 
would be required to make sure that the 
ergonomics program they have implemented 
controls the MSD hazards in the problem jobs 
in their workplace. A program designed for a 
large site with many different problem jobs, 
for example, is likely to be more formal and 
extensive than one designed for a small site 
with one or two problem jobs. Similarly, an 
ergonomics program that fits a manufacturing 
facility may not be appropriate for a work 
environment in the service sector.
   Program evaluation goes beyond a mere 
inspection or audit of problem jobs. It must 
ask questions to determine whether the 
required ergonomics program elements have 
been adequately implemented and whether they 
are integrated into a system that effectively 
addresses covered MSDs and MSD hazards. Such 
questions include:
    Has management effectively 
demonstrated its leadership?
    Are employees actively 
participating in the ergonomics program?
    Is there an effective system for 
the identification of MSDs and MSD hazards?
    Are identified hazards being 
controlled?
    Is the training program providing 
employees with the information they need to 
actively participate in the ergonomics 
program?
    Are employees using the reporting 
system?
    Are employees reluctant to report 
covered MSDs or MSD hazards because they 
receive mixed signals from their supervisors 
or managers about the importance of such 
reporting?
    Is prompt and effective MSD 
management available for employees with 
covered MSDs?
   Program evaluation, in other words, 
involves a review of how various aspects of 
an employer's ergonomics program are working 
together to ensure that employees are 
protected from MSD hazards.
   Program evaluations can be conducted by 
those responsible for carrying out the 
employer's program, but

[[Page 65859]]

evaluations performed by persons who are not 
involved in the day-to-day operation of the 
program are often even more valuable because 
these individuals bring a fresh perspective 
to the task. They can often identify program 
weaknesses that those routinely involved in 
program implementation may fail to see. In 
any event, it is important that the 
ergonomics program be evaluated regularly for 
effectiveness and that program evaluation be 
routinely integrated into the program.
   The extent of the evaluation that would be 
required by proposed section 1910.936 will 
vary from one workplace to another. However, 
the basic tools of evaluation are the same, 
even though their application may range from 
informal to formal. These tools include:
    Review of pertinent records, such 
as those related to covered MSDs and MSD 
hazards;
    Consultations with affected 
employees (including managers, supervisors, 
and employees) regarding the ergonomics 
program; and
    Reviews of MSD hazards and 
problem jobs.
   The records to be reviewed would include 
all available documentation of covered MSDs 
and MSD hazards. These records might include:
    The OSHA 200 log;
    Reports of workers' compensation 
claims;
    Reports of job hazard analyses 
and identification of MSD hazards;
    Employee reports to management of 
covered MSDs or, for employers with 
manufacturing or manual handling jobs, 
persistent MSD symptoms;
    Insurance company reports and 
audits; and
    Reports from any ergonomic 
consultants engaged by the employer.

If the employer has a written ergonomics 
program, it should be included in the review 
of pertinent records.
   Some employers may have very few of these 
records and will have to rely on other 
methods to assess effectiveness. For example, 
under Sec. 1904.15 and Sec. 1904.16 of OSHA's 
recordkeeping regulation (29 CFR part 1904), 
employers with fewer than 10 employees and 
employers in certain low-hazard Standard 
Industrial Classification (SIC) codes are 
exempt from the requirement to maintain an 
OSHA log. Therefore, these employers will 
have fewer records for review and will need 
to place more emphasis on employee interviews 
and surveys of MSD hazards and problem jobs 
when they perform ergonomics program 
evaluations.
   Record review can also reveal valuable 
information on the effectiveness of an 
ergonomics program when comparisons are made 
from year to year and trends are identified. 
For example, if an employer compares the list 
of MSD hazards during consecutive program 
evaluations and finds that the number of 
identified hazards has decreased over time, 
then the employer may conclude that the 
program's job hazard analysis and control 
activities have been effective. Similarly, a 
reduction in the number of covered MSDs from 
year to year suggests that the program may be 
effective. However, program evaluation must 
include consideration of the accuracy and 
reliability of the records under review. It 
is essential to be sure that the identified 
trends are real and not the product of 
underreporting, loss of interest, or 
carelessness. For example, a downward trend 
in covered MSDs or MSD hazards may indicate 
that employees are being discouraged from 
reporting or that the employees performing 
job hazard analysis and control are not 
adequately trained to do so.
   Another essential tool in any ergonomics 
program evaluation is interviews of employees 
doing, supervising, or managing problem jobs 
at all levels of the organization. Interviews 
of employees are designed to elicit 
information on how well the ergonomics 
program has been communicated to the people 
who rely on it the most. If employees cannot 
explain what MSD hazards they are exposed to 
in the course of their work, do not know what 
steps their employer is taking to eliminate 
or control these hazards, are unclear about 
the procedures they should follow to protect 
themselves from these hazards, or do not 
understand how to report covered MSDs or MSD 
hazards, the hazard information and reporting 
and training components of the program are 
not working. If a supervisor is unclear about 
how to reinforce proper work practices, the 
management leadership and training components 
of the program need improvement. Similarly, 
if managers are not aware of the covered MSDs 
and MSD hazards employees are reporting and 
what corrective actions are being taken, the 
management leadership and training components 
of the ergonomics program should be improved. 
Because interviews allow the program 
evaluator to assess how the program is 
actually working, there is no substitute for 
direct input from employees in the evaluation 
process.
   Program evaluation must also include a 
review of MSD hazards and problem jobs at the 
worksite. This review goes beyond inspection 
and analysis of problem jobs because it is 
concerned not only with identifying hazards 
but with identifying the ergonomic program 
deficiencies that resulted in the 
continuation of these hazards. If the program 
evaluation identifies problem jobs that have 
not been evaluated for ergonomic hazards, the 
job hazard analysis component of the program 
needs to be improved. Further, if a 
previously identified MSD hazard remains 
uncorrected, the evaluator should conclude 
that the job hazard control component of the 
program is not effective. Likewise, if a MSD 
hazard is identified and controlled in one 
part of the facility but the same job has not 
been properly controlled in another part of 
the facility, two program components may need 
attention: the management leadership 
component, which failed to coordinate and 
disseminate MSD hazard information throughout 
the facility, and the training component, 
which failed to provide the employees 
performing the job hazard analyses with 
adequate training.
   Proposed section 1910.936 also specifies 
the frequency of the program evaluations. It 
would require ergonomics program evaluations 
to be conducted periodically and at least 
every three years. Given the diversity of 
workplaces covered by this proposed rule, 
OSHA has chosen a flexible approach for the 
frequency of program evaluations. In 
Sec. 1910.945 of this standard, the section 
that defines key terms, OSHA defines 
periodically as meaning a process or activity 
that is ``performed on a regular basis that 
is appropriate for the conditions in the 
workplace.'' The definition of periodically 
further clarifies that ``the process or 
activity is conducted as often as needed, 
such as when significant changes are made in 
the workplace that may result in increased 
exposure to MSD hazards.'' It is OSHA's 
intention to reduce unnecessary burden while 
ensuring that program evaluations, which are 
essential to program effectiveness, are 
conducted at some minimal frequency.
   OSHA believes that the employer is in the 
best position to determine how often the 
ergonomics program at a particular worksite 
needs to be evaluated to ensure its 
effectiveness. A site undergoing process or 
production changes, or one experiencing high 
turnover, may need more frequent evaluations 
to ensure program effectiveness.

[[Page 65860]]

Similarly, an increase in covered MSDs in the 
workplace should suggest that a program 
evaluation is warranted. In work environments 
with a stable workforce and work operation, 
program evaluations conducted once every 
three years may be sufficient.
   Guidance on the frequency of ergonomics 
program evaluations is also available from 
other sources. For example, the Meatpacking 
Guidelines (Ex. 2-13) recommends semi-annual 
reviews by top management to evaluate the 
success of the program in meeting its goals 
and objectives. The NIOSH publication, titled 
Elements of Ergonomics Programs (Ex. 26-2), 
distinguishes between short-term indicators 
and long-term indicators for evaluating the 
effectiveness of controls. According to 
NIOSH, subsequent to the implementation of 
controls to eliminate or reduce MSD hazards, 
a follow-up evaluation is necessary to ensure 
that the controls were effective and did not 
introduce new ergonomic risk factors. The 
follow-up evaluation should use the same 
measurement tools, for example MSD hazard 
checklists or MSD symptom surveys, that were 
used to document the original problem job. 
NIOSH recommends that this follow-up 
evaluation take place no sooner than one to 
two weeks after implementation, with one 
month being the most preferable time 
interval.
   Section 1910.937  What must I do to 
evaluate my ergonomics program?

  You must:
  (a) Consult with employees in problem jobs 
to assess their views on the effectiveness of 
the program and to identify any significant 
deficiencies in the program;
  (b) Evaluate the elements of your program 
to ensure they are functioning properly; and
  (c) Evaluate the program to ensure it is 
eliminating or materially reducing MSD 
hazards.

   Proposed section 1910.937 provides 
employers with the procedures that would be 
required to evaluate the effectiveness of the 
ergonomics program. It answers the question: 
``What must I do to evaluate my ergonomics 
program?'' Through this proposed requirement, 
OSHA intends to inform employers of the 
minimal evaluation procedures necessary to 
assess whether or not their ergonomics 
program is working.
   Proposed paragraph (a) would require 
employers to ``consult with employees in 
problem jobs to assess their views on the 
effectiveness of the program.'' Additionally, 
employers would be required to consult with 
employees ``to identify any significant 
deficiencies in the program.'' OSHA believes 
that employee participation in the ergonomics 
program is critical for success, and the 
involvement of employees in program 
evaluation is just one more way that 
employees can take an active role in the 
program. A requirement that employers consult 
with employees regarding program evaluation 
is not unique to the proposed Ergonomics 
Program standard. OSHA promulgated a similar 
provision in the Respiratory Protection final 
rule (29 CFR 1910.134).
   Employees in jobs that have been 
identified as problem jobs are in the best 
position to judge whether or not job hazard 
analysis and control measures are effectively 
reducing or eliminating MSD hazards. Perhaps 
even more importantly, they will be most 
knowledgeable about whether the implemented 
controls have introduced new, unintended MSD 
hazards to the job. By consulting with 
employees, employers can also have direct 
feedback on the effectiveness of other 
ergonomics program elements, such as 
opportunities for employee participation, 
hazard information and reporting, and 
training. OSHA is aware that employers 
sometimes act in good faith to implement 
ergonomics program elements, but that the 
actual result experienced by employees can 
differ markedly from the intention. Thus, by 
checking directly with their employees, 
employers can be sure that their ergonomics 
program resources are being effectively 
invested.
   Through collaboration with their 
employees, employers will also have the 
opportunity for input on major program 
shortcomings. If an ergonomics program is not 
successfully reducing the incidence of 
covered MSDs or MSD hazards, employees in 
problem jobs will most likely have valuable 
information to share on identifying and 
correcting the program weaknesses. OSHA 
believes that employers should have the 
opportunity to access this input from their 
employees and use it, together with their own 
independently collected information, to 
improve the effectiveness of their ergonomics 
program.
   Proposed paragraph (b) would require 
employers to ``evaluate the elements of 
[their] program to ensure they are 
functioning properly.'' These elements, as 
identified in this proposed Ergonomics 
Program standard, include:
    Management leadership and 
employee participation;
    Hazard information and reporting;
    Job hazard analysis and control;
    Training; and
    MSD management.

OSHA believes that employers are best able to 
determine which evaluation criteria for these 
elements are most appropriate for their 
workplaces. Additionally, OSHA believes that 
employers should be able to define 
``functioning properly'' according to the 
specific characteristics of their problem 
jobs, in particular, and their work 
environment in general. Thus, OSHA has not 
proposed specific evaluation criteria or 
goals for each ergonomics program element.
   Proposed paragraph (c) would require 
employers to ``evaluate the program to ensure 
it is eliminating or materially reducing MSD 
hazards.'' The intention of this proposed 
paragraph is to require employers to evaluate 
the overall effectiveness of their ergonomics 
program, in addition to evaluating the 
individual program elements, as required in 
proposed paragraph (b). The primary purpose 
for implementation of an ergonomics program 
is the elimination or material reduction of 
MSD hazards. Thus, OSHA would expect 
employers to establish evaluation criteria to 
assess success in meeting this goal. There 
are a wide variety of methods available to 
employers that will facilitate the 
observation of trends that document program 
performance. OSHA believes that employers are 
best able to determine the specific 
evaluation criteria that will most 
effectively tell the story of their efforts 
to eliminate and materially reduce MSD 
hazards.
   Section 1910.938  What must I do if the 
evaluation indicates my program has 
deficiencies?

  If your evaluation indicates that your 
program has deficiencies, you must promptly 
take action to correct those deficiencies so 
that your program is in compliance with this 
standard.

   Proposed section 1910.938 informs 
employers of what to do if their ergonomics 
program has deficiencies. This proposed 
section would require that employers 
``promptly take action to correct those 
deficiencies so that [their]

[[Page 65861]]

program is in compliance with this 
standard.'' Deficiencies are findings that 
indicate that the ergonomics program is not 
in compliance with the standard because, for 
example, it is not successfully controlling 
MSD hazards or is not providing needed MSD 
management. Employers would be required to 
respond to deficiencies in the ergonomics 
program by identifying appropriate corrective 
actions to be taken, assigning the 
responsibility for these corrective actions 
to an individual who will be held accountable 
for the results, setting a target date for 
completion of the corrective actions, and 
following up to make sure that the necessary 
actions were taken. This proposed requirement 
will help employers to improve their 
ergonomics program on an ongoing basis.
   In anticipation of concerns that employers 
will be ``liable'' if their evaluations 
reveal deficiencies, OSHA emphasizes that the 
Agency's primary goal is to protect employees 
from MSD hazards, not to hold employers 
liable for ergonomics program deficiencies. 
In fact, OSHA expects that in the process of 
complying with the requirements of this 
standard, most employers will find 
deficiencies in their ergonomics program at 
one time or another. OSHA's concern will be 
whether or not employers act on the 
information obtained during the program 
evaluation. Employers who act in good faith 
to correct identified program deficiencies 
will satisfy this requirement. On the other 
hand, employers who identify ergonomics 
program deficiencies through the evaluation 
process and then do not act on this 
information may not be in compliance with 
this requirement.
   In order to provide employers with maximum 
flexibility, OSHA has not specified a time 
frame in which identified program 
deficiencies must be corrected. OSHA 
recognizes that the time needed to correct a 
program deficiency will vary according to 
many factors. Such factors include:
    The nature of the MSD hazard;
    Previous attempts to correct the 
problem;
    The complexity of the needed 
controls;
    The expense of the needed 
controls;
    Whether the hazard is a higher or 
lower priority in the list of identified 
program deficiencies; and
    The expertise needed to control 
the hazard.
However, OSHA expects that employers will use 
good faith efforts to correct program 
deficiencies as quickly as possible.


What Records Must I Keep? (Secs. 1910.939-
1910.940)

   Occupational injury and illness records 
are a vital part of any ergonomics program. 
These records provide employers, employees, 
and consultants with valuable information on 
conditions in the workplace and can be used 
to identify trends over time and to pinpoint 
problems. Nevertheless, OSHA recognizes the 
need to reduce paperwork burdens for all 
employers, especially small employers, to the 
extent that this can be done without reducing 
safety and health protection. The proposal 
accordingly limits the records this proposal 
requires employers to keep. Also, the 
proposed standard limits the applicability of 
the proposed recordkeeping requirements to 
employers with 10 or more employees, which is 
consistent with the Act's emphasis on 
minimizing paperwork burdens on small 
employers.
   OSHA is exempting employers with fewer 
than 10 employees from the proposed 
standard's recordkeeping requirements 
because, in these very small workplaces, 
information can be communicated and retained 
informally. Larger employers must keep 
records of employee reports of MSDs and the 
employer's responses to them; the results of 
job hazard analysis; records of Quick Fix 
controls; records of controls implemented in 
problem jobs; program evaluations; and 
records of the MSD management process.
   The following paragraphs discuss the 
specific requirements of the recordkeeping 
sections of the proposed standard.
   Section 1910.939  Do I have to keep 
records of the ergonomics program?
   The proposal states, ``You only have to 
keep records if you had 10 or more employees 
(including part-time employees and employees 
provided through personnel services) on any 
one day during the preceding calendar year.'' 
In section 1910.939, OSHA is thus proposing 
to exempt employers with fewer than 10 
employees from having to keep any records for 
this proposed standard. Most of the small 
business representatives on the SBREFA panel 
said that they would choose to keep records 
even if they were not required to do so (Ex. 
23). However, OSHA's experience indicates 
that, because of the absence of management 
layers and multishift work, informal 
communication is effective and formal 
recordkeeping systems are not necessary in 
very small companies. A small establishment 
may have a very simple ergonomics program 
that does not need written records.
   This section indicates that part-time 
employees and employees provided through 
personnel services must be included in the 
count of employees for the purpose of this 
section. These workers are personnel retained 
and supervised on a daily basis by an 
employer for a limited time, and they include 
personnel under contract, written or oral, 
with the employer. OSHA believes that these 
employees should be included in the count of 
employees because many employers today have 
workforces composed largely of part-time or 
temporary employees. If these employees were 
not counted toward the size threshold for 
recordkeeping, large workplaces that operate 
with few permanent employees but many 
temporary employees would not be required to 
keep records even though the workplace had 
several levels of management and complex 
methods of communication.
   By ``any one day during the preceding 
calendar year,'' OSHA means that so long as 
there are fewer than 10 employees, including 
employer-supervised part-time and temporary 
employees, at all times during preceding one-
year period, the employer is not required to 
keep written records under this proposed 
standard.
   Section 1910.940  What records must I keep 
and for how long?
   This proposed section describes the 
records of the ergonomics program that 
employers would have to keep. It reflects 
OSHA's preliminary conclusion that 
recordkeeping is necessary for employers to 
measure their progress in establishing an 
effective program and in controlling MSD 
hazards.
   The proposed standard requires employers 
to keep records of employee reports, employer 
responses, the results of job hazard analyses 
and controls, records of quick fix controls, 
and MSD management records for the purposes 
of musculoskeletal injury and illness 
prevention.
   The following paragraphs discuss the 
specific requirements of the recordkeeping 
section of the proposed standard.
   Section 1910.940  What records must I keep 
and for how long?
   This table specifies the records you must 
keep and how long you must keep them:

[[Page 65862]]



------------------------------------------------------------------------
  YOU MUST KEEP THESE RECORDS . . .           FOR AT LEAST . . .
------------------------------------------------------------------------
 Employee reports and your    3 years
 responses
------------------------------------------------------------------------
 Job hazard analysis          3 years or until replaced by
 Hazard control records        updated records, whichever comes
 Quick Fix control records     first
 Ergonomics program
 evaluation
------------------------------------------------------------------------
 MSD management records       The duration of the injured
                                       employee's employment plus 3
                                       years
------------------------------------------------------------------------

  Note to Sec. 1910.939: The record retention 
period in this standard is shorter than that 
required by OSHA's rule on Access to Employee 
Exposure and Medical Records (29 CFR 
1910.1020). However, you must comply with the 
other requirements of that rule.

   The period the employer is required to 
keep exposure and medical records (e.g., MSD 
management records) under this proposed 
standard is much shorter than is the case for 
other health standards. Health standards 
generally require exposure records to be kept 
for 30 years and medical surveillance records 
to be kept for the duration of employment 
plus 30 years, as required by 29 CFR 
1910.1020, Access to employee exposure and 
medical records. These lengthy retention 
periods are appropriate for many toxic 
substances and harmful physical agent 
standards because of the long latency between 
exposure on the job and the onset of disease. 
However, for ergonomic disorders, there is a 
shorter latency period than for many of the 
chronic conditions and illnesses covered by 
these other rules. Also, changes in the 
workplace may make old ergonomics records 
irrelevant to current jobs and the present 
workplace environment. An employer's 
ergonomics program will continue to evolve, 
with the most recent aspects of that 
evolution being the most relevant for 
employee protection.
   The three-year retention period in the 
proposed standard coincides with the required 
frequency of program evaluations mandated by 
the proposed standard. OSHA believes that 
employers will use these records to perform 
the required evaluations of the effectiveness 
of their program under this standard, and 
that records prior to the last evaluation 
would be of little use.
   A note to section 1910.940 states that 
employers must continue to comply with the 
other requirements of the records access rule 
(29 CFR 1910.1020; Access to employee 
exposure and medical records), although the 
proposed ergonomics program rule permits a 
shorter records retention period than would 
otherwise be required by the records access 
rule.


When Must My Program be in Place? 
(Secs. 1910.941-1910.944)

   Sections 1910.941 through 1910.944 propose 
both compliance start-up deadlines and 
provide future compliance deadlines for 
certain situations, i.e., for employers who 
are ``triggered'' into the scope of the 
standard after the compliance dates have 
passed.
   OSHA is proposing certain variations in 
the approach to compliance deadlines that 
differ from the approach taken in other 
standards. First, OSHA is proposing a long 
start-up period so employers have time to get 
assistance before the compliance deadline 
comes due. Second, even after the compliance 
deadlines come due, OSHA is proposing to give 
employers newly covered by the standard 
additional time to set up a program and put 
in controls in certain situations. In other 
OSHA standards, once the compliance deadlines 
have occurred, employers must be in 
compliance with the standard continuously, 
even on the first day they open a new 
facility. Third, OSHA is proposing to allow 
employers to discontinue large portions of 
their program if no further MSDs are reported 
for a period of time.
   Section 1910.941  When does this standard 
become effective?

  This standard becomes effective 60 days 
after [publication date of final rule].

   Proposed section 1910.941 establishes the 
effective date of the standard. The effective 
date is the date on or past which the 
standard is in effect and the date from which 
the compliance deadlines in this section are 
counted. In addition, only covered MSDs 
reported after the effective would be covered 
by the ergonomics standard.
   Section 1910.942  When do I have to be in 
compliance with this standard?

  This standard provides start-up time for 
setting up the ergonomics program and putting 
in controls in problem jobs. You must comply 
with the requirements of this standard, 
including recordkeeping, by the deadlines in 
this table:

------------------------------------------------------------------------
  YOU MUST COMPLY WITH THESE REQUIREMENTS
      AND RELATED RECORDKEEPING . . .            NO LATER THAN . . .
------------------------------------------------------------------------
 MSD management                     Promptly when an MSD is
                                             reported
------------------------------------------------------------------------
 Management leadership and          [1 year after the effective
 employee participation                      date]
 Hazard information and reporting
------------------------------------------------------------------------
 Job hazard analysis                [2 years after the effective
                                             date]
 Interim controls
 Training
------------------------------------------------------------------------
 Permanent controls                 [3 years after the effective
                                             date]
 Program evaluation
------------------------------------------------------------------------

  Note to Sec. 1910.942: The compliance 
deadlines in this section do not apply if you 
are using a Quick Fix.

   In Sec. 1910.942, OSHA is proposing to 
give long phased-in start-up times ranging 
from one to three years for meeting various 
requirements of the ergonomics program 
standard. OSHA believes that the long start-
up period is appropriate for several reasons.
   First, OSHA plans to provide extensive 
outreach and consultation as soon as the 
final ergonomics rule is published. OSHA 
believes that the 3-year start-up period will 
allow employers to take full advantages of 
these materials and services, as well as 
those developed by others, without concern 
that enforcement action would already be 
underway.
   Second, OSHA also believes that giving 
employers additional time to comply with the 
rule will reduce the compliance burden for 
small employers and will facilitate

[[Page 65863]]

compliance for all employers. OSHA recognizes 
that it takes time to put an ergonomics 
program in place and that small employers, in 
particular, need additional time to learn 
about the details of the rule and how to 
implement it in their workplace. Small 
employers, in particular, should take full 
advantage of OSHA's outreach, compliance 
assistance, and consultation services in 
meeting the standard's requirements.
   At the same time, this section would 
require employers to begin setting up their 
ergonomics program step by step so they will 
have an effective process in place by the 
time compliance comes due. Without phased 
start-up, OSHA is concerned that some 
employers may wait until the last minute to 
take action. The phase-in of compliance is 
also important to ensure that those employees 
who report MSD signs and symptoms during the 
start-up period are provided with prompt 
intervention (both MSD management and work 
restrictions) in order to help the problem 
resolve quickly and without permanent damage. 
Finally, the longer start-up period would 
also allow employers to work needed job 
modifications into their regular production 
change schedules or processes. Because the 
best way to control MSD hazards is often in 
the design process, allowing additional 
compliance time will allow establishments of 
all sizes to make needed changes to their 
processes as part of regular production 
changes, and thus to make those changes at 
less cost.
   Finally, the phase-in compliance deadlines 
fit the structure of the proposed rule. The 
rule itself envisions two levels of 
ergonomics programs: a basic program (for 
manual handling and manufacturing jobs) and 
the full program, and the compliance start-up 
deadlines track those phases. The basic 
program addresses management leadership and 
employee involvement and hazard information 
and reporting. Accordingly, the compliance 
deadlines for these preliminary requirements 
occur first. Later compliance deadlines 
correspond with elements of the full program, 
which requires job hazard analysis, job 
controls, training, and program evaluation if 
a covered MSD is reported. (The MSD 
management deadline is also consistent with 
this approach. The first start-up deadline 
for MSD management requires that MSD 
management be put into place ``promptly when 
an MSD is reported.'')
   The proposed standard does not contain 
different compliance deadlines for small and 
larger employers, because OSHA believes that 
the proposed deadlines already build in 
enough time even for very small employers to 
get information about the rule and ways to 
implement an ergonomics program. OSHA also 
believes that the 3-year period is adequate 
for larger employers who may have more 
complex processes, more employees, more 
problem jobs, and more controls to implement.
   Section 1910.943  What must I do if some 
or all of the compliance start-up deadlines 
have passed before a covered MSD is reported?

  If the compliance start-up deadline has 
passed before you must comply with a 
particular element of this standard, you may 
take the following additional time to comply 
with that element and the related 
recordkeeping:

------------------------------------------------------------------------
     YOU MUST COMPLY WITH THESE
      REQUIREMENTS AND RELATED                   WITHIN . . .
         RECORDKEEPING . . .
------------------------------------------------------------------------
 MSD management               5 days
------------------------------------------------------------------------
 Management leadership and    30 days (In manufacturing and
 employee participation                manual handling jobs, these
 Hazard information and        requirements must be implemented
 reporting                             by [1 year after the effective
                                       date])
------------------------------------------------------------------------
 Job hazard analysis          60 days
------------------------------------------------------------------------
 Interim controls             90 days
 Training
------------------------------------------------------------------------
 Permanent controls           1 year
 Program evaluation
------------------------------------------------------------------------

  Note to Sec. 1910.943: The compliance 
deadlines in this section do not apply if you 
are using a Quick Fix.

   In section 1910.943, OSHA is proposing to 
give additional compliance time to those 
employers who do not have any problem jobs 
until after some or all of the compliance 
deadlines established in Sec. 1910.942 have 
passed. This is because the first occurrence 
of an MSD in a job is unpredictable and may 
not occur until years after the standard is 
in effect.
   The additional time OSHA is proposing is 
appropriate in those situations in which 
employers who do not have any covered MSDs 
reported until after certain deadlines have 
passed. The standard permits employers who do 
not have manufacturing or manual handling 
jobs to refrain from implementing an 
ergonomics program until after a covered MSD 
is reported. Even for employers who have 
manual handling or manufacturing jobs, 
extended dates are needed for the 
requirements that would not be triggered 
until after a covered MSD occurs.
   OSHA believes that the additional time 
this section proposes is reasonable. This 
section would require that employers take 
certain critical preliminary actions very 
quickly after a covered MSD occurs (i.e., 
provide MSD management within 5 days, analyze 
the job with 2 months and put in at least 
interim controls within 3 months). At the 
same time, it would allow employers up to a 
year to get effective permanent controls into 
place. OSHA believes this time period would 
be sufficient to allow employers to use the 
standard's incremental process of trying out 
one or more controls first to see if they 
work before moving on to other controls. 
Finally, to ensure that the additional time 
is reasonable in those cases in which some of 
the compliance deadlines have passed, this 
section would allow employers to comply by 
the compliance deadlines in this section or 
those in section 1910.942, whichever comes 
later.
   Section 1910.944  May I discontinue 
certain aspects of my program if covered MSDs 
no longer are occurring?

  Yes. However, as long as covered MSDs are 
reported in a job, you must maintain all the 
elements of the ergonomics program for that 
job. If you eliminate or materially reduce 
the MSD hazards and no covered MSD is 
reported for 3 years, you only have to 
continue the elements in this table:

[[Page 65864]]



----------------------------------------------------------------------------------------------------------------
 IF YOU ELIMINATE OR MATERIALLY REDUCE THE HAZARDS    THEN YOU MAY STOP ALL EXCEPT THE FOLLOWING PARTS OF YOUR
 AND NO COVERED MSD IS REPORTED FOR 3 YEARS IN . .                    PROGRAM IN THAT JOB . . .
-------------------------.--------------------------------------------------------------------------------------
A manufacturing or manual handling job               Management leadership and employee participation,
                                                     Hazard information and reporting, and
                                                     Maintenance of implemented controls and training
                                                     related to the controls.
----------------------------------------------------------------------------------------------------------------
Other jobs in general industry where a covered MSD   Maintenance of controls and training related to the
 had been reported                                   controls.
----------------------------------------------------------------------------------------------------------------

   In section 1910.944, OSHA is proposing to 
allow employers to discontinue some 
significant portions of their ergonomics 
program when no covered MSD has been reported 
in a problem job for 3 years after the 
problem job was controlled. OSHA is proposing 
this provision because, where employers have 
implemented controls and those controls have 
eliminated or materially reduced the MSD 
hazard to the extent that a covered MSD is 
not reported for several years, it is 
reasonable to conclude that the physical work 
activities and conditions in that job are no 
longer reasonably likely to cause or 
contribute to an MSD. When this level of 
control has been reached, OSHA believes it is 
appropriate for employers to focus their 
efforts on maintaining the controls that have 
corrected the problem (along with the 
training related to those controls).
   OSHA is proposing a 3-year time period to 
coincide with the timing of other 
requirements of the proposed standard. For 
example, in the proposed rule periodic 
program evaluation must be done every three 
years, and the start-up deadlines for 
implementing permanent controls and initially 
evaluating the program is 3 years. OSHA 
believes that employers should only be 
permitted to discontinue parts of the program 
where permanent controls have been 
implemented and an evaluation of the program 
and controls shows that the program and 
controls have been effective in eliminating 
or materially reducing the MSD hazards in the 
job. Without this type of information, 
employers would not have the knowledge and 
information necessary to make a determination 
about whether another MSD is reasonably 
likely to occur. Allowing employers to 
discontinue certain elements only after a 
program evaluation has been done will help to 
ensure that the employer's decision is based 
on knowledge that the MSD reporting system 
has been effective, that the job hazard 
analysis did identify all of the MSD hazards, 
and that the permanent controls are in place 
and working.
   If a covered MSD has not been reported in 
a problem job for 3 years, employers would 
only be required to maintain the controls in 
the problem job (including the training 
related to those controls) and to continue 
those elements of the program they must have 
even where no covered MSDs have been 
reported. Employers with manufacturing and 
manual handling jobs would be required to 
implement the management leadership and 
employee participation, and hazard 
information and reporting elements of the 
program. Employers with jobs other than 
manufacturing and manual handling would not 
be required to do anything beyond maintaining 
the controls (and related training).


Definitions (Sec. 1910.945)

   Section 1910.945  What are the key terms 
in this standard?
   The proposed ergonomics program standard 
includes a number of definitions which should 
be consulted to properly understand the terms 
used in the standard. Most of the definitions 
are straightforward and self-explanatory. 
Clarification of many terms is provided in 
the summary and explanation of the sections 
where those terms are used. Other definitions 
are explained in greater detail in the 
following paragraphs.
   Musculoskeletal disorders (MSDs) are 
defined in the proposal as injuries and 
disorders of the muscles, nerves, tendons, 
ligaments, joints, cartilage and spinal 
disks. Examples of some of the more 
frequently occurring occupationally induced 
MSDs are given in the definition. These are 
medical conditions that generally develop 
gradually over a period of time, and do not 
typically result from a single instantaneous 
event. This definition specifically states 
that MSDs do not include injuries caused by 
slip, trips, falls, or other similar 
accidents. They can differ in severity from 
mild periodic symptoms to severe chronic and 
debilitating conditions.
   No cost to employees means that the 
employer must bear any costs associated with 
the proposed requirements. Employees must be 
compensated at their regular rate of pay for 
time spent receiving training and medical 
management, or obtaining personal protective 
equipment. Where these activities require 
employees to travel, the employer must pay 
for the cost of travel, including travel time 
when the activities are not scheduled during 
the employee's normal work hours. The intent 
of this definition is to include any 
financial or other cost which, if borne by 
the employee, would serve as a disincentive 
to participating in the proposed rule's 
training, medical management, and personal 
protective equipment activities.
   Periodically means on a regular basis 
appropriate for the conditions in your 
workplace, or as needed. The proposed 
standard would require that certain 
activities occur periodically; these 
activities include hazard identification, 
evaluation of the ergonomics program and the 
effectiveness of controls, and provision of 
information and training. The term 
periodically does not establish a specific 
frequency that is acceptable for conducting 
these activities; rather, the activities must 
be performed as often as necessary in order 
for them to be effective in the particular 
workplace in question. In some work 
environments with relatively few MSD hazards 
and little or no change in the work process 
over time, for example, refresher training 
may be adequate if performed every three 
years. A workplace with more substantial 
hazards or more complex controls may require 
training at more frequent intervals to ensure 
employee retention of information. If 
significant changes to the job occur, if new 
MSDs or MSD hazards are identified in the 
job, or if unsafe work practices are 
observed, then additional training would be 
necessary. The same performance orientation 
would apply to the other activities that the 
proposed standard would require to be 
provided periodically.

[[Page 65865]]

   Physical work activities include any 
movements of the body or any static exertion 
involved in performing a job. This term is 
intended to cover all activities that have 
the potential to stress or strain muscles, 
nerves, tendons, ligaments, joints, cartilage 
or spinal disks.
   Work restrictions are limitations 
prescribed by the employer, other qualified 
individuals, or health care professional on 
the work activities of an employee who is 
recovering from a MSD. Work restrictions are 
designed to prevent the employee from futher 
exposure to the MSD hazards that gave rise to 
the covered MSD. Work restrictions may 
involve limitations on activities the 
employee is permitted to perform in the 
current job, assignments to an alternative 
job (light duty), or complete removal from 
the workplace.


V. Health Effects

   Activity-related disorders of the 
musculoskeletal and neuromuscular systems, 
acquired in the course of adult working life, 
are common in the population. Unlike acute 
injuries, these chronic conditions usually 
cannot be attributed to a single traumatic 
event. Instead, they often result from 
repeated episodes of exposure to causal and 
exacerbating factors.
   The purpose of the Health Effects Section 
is to summarize knowledge in the field of 
musculoskeletal disorder (MSD) etiology and 
provide an overview of the multidisciplinary 
evidence that has established the 
relationship between work and these 
disorders. This body of evidence also 
provides the basis for the growing literature 
of intervention studies. These studies 
demonstrate the practical value of applying 
this well-established etiological knowledge 
to the reduction of the incidence of 
musculoskeletal disorders.
   A more complete analysis of the studies 
underlying OSHA's Health Effects section is 
identified as Exhibit 27-1 in the docket for 
this rulemaking, (Docket S-777).
   Following this introduction are five 
sections detailing the concepts of risk 
factors and their effects:
    Section A, Issues of Causation. 
This section discusses the etiology of MSDs 
and describes the multifactoral causation and 
exacerbation of MSDs by exposure to workplace 
risk factors, the role of personal factors 
and pre-existing disease, and medical and 
diagnostic issues.
    Section B, Biomechanical Risk 
Factors for MSDs. This section begins with an 
examination of the epidemiological criteria 
used to strengthen the argument for a causal 
relationship between a risk factor and an 
adverse health outcome. This is followed by a 
discussion of the basic biomechanical risk 
factors and modifying factors involved in MSD 
etiology.
    Section C, Evidence for the Role 
of Basic Risk Factors and Modifying Factors 
in the Etiology of MSDs. This section 
presents an overview of three bodies of 
evidence supporting the causal relationship 
between these risk factors and disease 
development: epidemiological studies, 
laboratory/medical studies, and 
psychophysical research. The Health Effects 
Section demonstrates that the sheer volume of 
evidence, plus the congruence of evidence 
from very different research traditions, 
makes a very strong case implicating of 
workplace biomechanical risk factors in the 
causation and/or exacerbation of MSDs. The 
Appendices provide a more detailed treatment 
of this evidence.
    Section D, Pathogenesis and 
Pathophysiologic Evidence for Work-Related 
MSDs. This section presents an overview of 
the mechanisms through which the risk factors 
detailed in Section B may cause physiological 
alterations, anatomical alterations, and 
disease in different types of soft tissues. 
Because one of the criteria useful in 
establishing a causal relationship between a 
risk factor and disease is the existence of a 
plausible biologic mechanism, the 
pathophysiological evidence in this section 
is an important link in the argument 
establishing such a relationship between 
workplace exposures and MSDs. Some redundancy 
exists between this generic discussion of 
risk factors and target tissues and the site-
specific disorders examined in the 
Appendices. However, the goal is to underline 
common exposure and injury patterns without 
trivializing the complexity of tissue 
function and remodeling in disease and in 
health. For example, the ligamentures of the 
knee and the carpal bones are highly 
dissimilar in function and structure, 
requiring both generic and site-specific 
discussion.
    Section E, Glossary and List of 
Acronyms. This section provides definitions 
of terms and acronyms used throughout the 
document.
   These basic overview sections are 
supported by set of Appendices (Ex. 27-1) 
that present, in much greater detail, the 
evidence linking workplace risk factors to 
outcomes of musculoskeletal disease:
    Appendix I, Epidemiology of MSDs, 
examines in more detail the epidemiologic 
evidence for work-related causation and 
exacerbation of MSDs. The Appendix begins 
with a summary of the NIOSH publication 
Musculoskeletal Disorders and Workplace 
Factors and continues to detail research in 
specific body areas. This section also 
contains a detailed overview of individual 
factors associated with work-related MSDs.
    Appendix II, A Review of 
Biomechanical and Psychophysical Research on 
Risk Factors Associated with Upper Extremity 
Disorders, details laboratory and 
psychophysical studies as well as the value 
of using biomechanical modeling to estimate 
risk associated with low-back and upper-
extremity disorders.
    Appendix III, Pathophysiology of 
Regional MSDs, examines the pathophysiology 
of common MSDs by body region.
   The Health Effects Section focuses on 
research in which investigators have found 
sizable and consistent results associating 
clinical disorders, such as chronic low back 
pain and injuries to muscle-tendon units in 
the forearm, with identifiable (extrinsic) 
work characteristics such as force and 
posture. There is less attention to 
conditions in which personal (intrinsic) risk 
factors or underlying disease status 
predominate, or in which there is conflict 
over disease etiology. However, there is 
widespread agreement in the literature that 
workplace risk factors play the major, 
although not the only, role in the 
development of work-related MSDs.
   The Health Effects Section concentrates on 
external factors or stressors, because this 
is where the causes of human disease and 
discomfort in the workplace have been most 
clearly identified and where interventions 
have produced the greatest reduction in 
injury and illness. Intrinsic or personal 
factors, such as anthropometry, gender, age, 
physical conditioning, and general health are 
treated within each major subject area, where 
appropriate. Intrinsic predispositions are 
treated as modifiers of effect, reflecting 
the variability of their influence and the 
primacy of the basic risk factors.
   The case of aging provides an example. The 
important body of information on physical 
performance and injury risk evolving from 
Finland (Tuomi, 1997) invalidates the notion

[[Page 65866]]

of a simple relationship between dysfunction 
and age, even when the complex issues of 
survivorship are taken into account. Further, 
it is difficult to separate the effects of 
aging from the effects of years of exposure 
to workplace risk factors. The ergonomic 
literature in general, and the materials 
cited in this section specifically, have not 
been designed to explore associations between 
subtle predisposition and observed risk. 
Moreover, much of the literature on acquired 
physical injury has identified particular 
patterns of susceptibility within each age 
stratification (Krause et al., 1997).
   Finally, the Health Effects Section 
concentrates on well-recognized studies and 
common disorders, and does not address the 
more unusual disorders and patterns of 
injury. The study of MSDs is an evolving 
field that requires improved and broad-based 
surveillance techniques to identify less 
common patterns of association between 
exposure and disease. However, the body of 
evidence in this Health Effects section makes 
a convincing case for the work-relatedness of 
many MSDs and the effectiveness of 
interventions designed to reduce the risk 
factors that caused the MSD in the first 
place.


A. Issues Of Causation


1. Multifactoral Causation and Exacerbation 
by Extrinsic Risk Factors at Work

   MSDs usually result from exposure to 
multiple risk factors (Putz-Anderson, 1988; 
Kourinka and Fourcier, 1995, Ex. 26-432; 
Bernard and Fine, 1997, Ex. 26-1), with the 
possible exception of vibration-related 
disorders, which are discussed in Section D. 
The present state of knowledge does not allow 
a clear determination of whether these 
multiple risk factors act additively or 
synergistically (i.e., in a true, 
multiplicative interaction) within the 
workplace, although some studies suggest the 
latter (e.g., Silverstein, Fine, and 
Armstrong, 1986, 1987, Exs. 26-1404 and 26-
34). The combination of this multifactoral 
causation, lack of knowledge about 
interaction, and the unavoidable difficulty 
of studying risk factors in isolation makes 
it difficult to determine a numerical limit 
for a given type of biomechanical exposure.
   A more practical approach, accepting the 
intricate interplay of risk factors in MSD 
causation, may be to simultaneously assess 
all the risk factors in a given workplace. 
Punnett (1998) has demonstrated the 
effectiveness of predicting MSD prevalence 
using an exposure index that combines 
assessment of multiple risk factors: work 
pace, grip force, postural stressors, contact 
(compressive) stress, vibration, and machine-
pacing of work. This research found that the 
prevalence of MSDs (whether defined by 
symptom reports or physical examination) 
increased markedly as the number of risk 
factors contributing to the index increased. 
The obvious corollary is that multifactoral 
interventions will reduce MSD incidence more 
effectively than interventions targeting only 
a single risk factor or a small subset of the 
risk factors actually present in the 
workplace.


2. Multifactoral Etiology and Other 
Contributions to MSD Causation and 
Exacerbation

   The concept of multifactoral etiology of 
MSDs can easily lead to confusion. Various 
literatures define the concept in at least 
three different ways, as follows:
    ``Multifactoral etiology'' means 
that MSDs generally result from simultaneous 
exposure to, and often synergy among, several 
different risk factors--e.g., high force 
requirements and awkward postures. (This is 
the meaning of ``multifactoral'' in Section 
A.2.a above.)
    ``Multifactoral etiology'' means 
that MSDs often result from exposure to and 
interplay between both work and non-work risk 
factors, although work factors are the 
greater influence in most cases (see Section 
A.2.b below).
    ``Multifactoral etiology'' means 
that MSD incidence and severity are affected 
by personal characteristics (physiological 
susceptibility and repair capacity, 
anthropometry, psychological characteristics, 
level of fitness, etc.) and underlying or 
preexisting disease (see Section A.2.b.ii 
below).

This Health Effects Section primarily uses 
the first of these definitions, which focuses 
on the contribution of multiple risk factors 
in the workplace to MSD etiology. Because the 
other two definitions can complicate the 
establishment of worksite MSD causation, the 
contribution of non-work exposures, personal 
(intrinsic) factors, and underlying or 
preexisting disease are briefly addressed 
here. Other parts of the Health Effects 
Section address issues of work-relatedness in 
detail, by specific body location, and also 
discusses personal factors where appropriate.
   a. Non-Work-Related Risk Factors. The risk 
factors presented in Section B are not 
encountered solely in the work environment. 
Non-work risk factors obviously may 
contribute to disease causation, but they are 
as likely to exacerbate existing or work-
related disease as to cause new disorders. 
Most non-work activities are not performed 
with the duration or intensity, or under the 
time constraints characteristic of 
occupational exposures. In addition, certain 
industries, such as meatpacking (OSHA, 1990, 
Ex. 26-3), demonstrate disease clusters and 
rates of disease that are substantially above 
population background rates and rates found 
in other industries. Franklin et al. (1991, 
Ex. 26-948) reviewed Washington State 
workers' compensation claims from 1984 to 
1988. These investigators found that, 
compared to industry-wide carpal tunnel 
syndrome (CTS) incidence rates, oyster and 
crab packers demonstrated a relative risk 
(RR) of 14.8 (95% CI: 11.2-19.5) and the meat 
and poultry industries had an RR of 13.8 (95% 
CI: 11.6-16.4). The recent NAS report 
(National Academy of Sciences, 1998, Ex. 26-
37) concludes, ``There is a higher incidence 
of reported pain, injury, loss of work, and 
disability among individuals who are employed 
in occupations where there is a high level of 
exposure to physical loading than for those 
employed in occupations with lower levels of 
exposure'' (p. 23). The existence of these 
elevated rates, despite the random variety of 
non-work risk factors experienced by 
employees in all industries, suggests the 
primacy of workplace risks in MSD causation.
   MSD genesis represents a complex 
combination (and possibly interaction) of 
exposures to work and non-work risk factors, 
modified by the individual's ability to 
tolerate physical job stress. It is not the 
intent of this document to attribute sole 
causation to the workplace, but to establish 
work-relatedness. Non-work exposures 
certainly contribute to disease, but OSHA's 
mandate to create a safe and healthy 
workplace does not require that the only 
diseases to be controlled are those caused 
solely by work. Since the goal of the Health 
Effects Section is the clarification of 
workplace risk factors involved in MSD 
causation or exacerbation, the 
epidemiological studies cited generally 
represent research carried out in 
occupational settings.
   b. Personal Factors and Underlying 
Disease. The third meaning of 
``multifactoral,'' which includes personal 
factors and pre-existing disease, is also 
generally beyond the scope

[[Page 65867]]

of this document. Again, these factors are 
irrefutably implicated in MSD development and 
recovery, as factors that modify the body's 
response to external risk factors and its 
ability to recover from insult. But their 
presence in the equation of etiology does not 
remove the primary necessity to identify and 
control external, workplace-based risk 
factors.
   Reparative Capacity of Individuals. The 
physiological effects of the risk factors and 
modifiers presented in Section D are 
themselves modified by the worker's 
individual capacity to accept and repair the 
damage caused. This capacity may be likened 
to the ability of the body to process a 
chemical exposure. Depending on the body's 
defenses, a given atmospheric concentration 
of toxin will result in cells and tissues 
receiving a particular dose of the toxin. 
Over time, this dose, modified by the body's 
capacity to detoxify and/or clear the 
substance and its metabolites, will result in 
a measurable body burden.
   Although the analogy is simplistic, and 
other disease mechanisms are probable, it is 
possible to visualize certain effects of 
biomechanical risk factors through this 
model. An exposure to a biomechanical risk 
factor of given intensity, duration, and 
temporal profile can result in an internal 
``dose'' that makes demands on the body's 
reparative capacity for ``detoxification'' of 
the dose. The cumulative trauma model 
suggests that the resultant ``body burden'' 
may be seen as partly the result of exposure 
and repair capacity. Armstrong et al. (1993) 
proposed a model (called a ``cascade'' model) 
of this process that also incorporates a 
staged series of challenges to the body. The 
body's response to a particular biomechanical 
``dose'' can itself generate new 
physiological or anatomical stressors; the 
effectiveness of the body's response to these 
new stressors also depends partly on 
individual capacity. Likewise, pre-existing 
or underlying disease can also compromise 
reparative capacity as well as predisposing 
tissues to further injury.
   The components of individual reparative 
capacity include:
    Genetic factors. These include 
basic inherited characteristics of the 
individual, such as body dimensions 
(anthropometry), physiological variables, and 
gender. Genetically based personal 
differences include variation in bone length 
and tendon attachment points (which affect 
the mechanical advantage of a muscle in a 
given posture), muscle mass and distribution 
of fiber types, laxity of ligaments, 
intervertebral disk cross-sectional area and 
nucleus fluidity, tendon size, and carpal 
tunnel size (Radwin and Lavender, NRC 1998, 
Ex. 26-37).
   Gender may be seen partly as representing 
anatomical and physiological differences 
among workers (see summary in Faucett and 
Werner, 1998, Ex. 26-425). Women's 
anthropometry may not fit many jobs designed 
originally for the average male. It is 
important to understand, however, that gender 
is also a surrogate for a large complex of 
social and economic differences among 
workers, as well a differences in exposure 
between males and females. Many of these 
differences influence patterns of disease and 
recovery (Messing, Chatigny, and Courville, 
1998a, Ex. 26-566; Messing et al., 1998b, Ex. 
26-300).
    Acquired characteristics. 
Acquired characteristics include physical 
conditioning, previous or concurrent disease 
status, and the effects of aging. The aging 
process is strongly influenced by both 
genetic and acquired characteristics. In any 
case, OSHA's mandate to assure a safe and 
healthy workplace is not limited to workers 
below an arbitrary age threshold but 
encompasses workers of all ages. Acquired 
characteristics can modify some genetically 
based characteristics. For example, type and 
intensity of exercise can alter muscle mass 
and fiber type distribution. Likewise, a 
worker's level of skill and work habits can 
substantially affect the impact of 
biomechanical stressors on body tissues.
   It is important to recognize that the 
effects of risk factors and modifiers found 
in the work environment are modified at the 
individual level by these personal factors. 
However, the primary purpose of job analysis 
and workplace interventions is to make work 
safe for as many workers as possible. Hence, 
this document considers the measurement, 
characterization, and reduction of work 
environment risks and modifiers to be the 
most important objective of the ergonomics 
program rule.
   Work Techniques and Skill Level. Personal 
factors also include work technique and skill 
level. In some situations, the predominant 
factors influencing MSDs are individual 
anatomy, work style, posture, and technique. 
For example, the well-recognized upper 
extremity disorders of sign language 
interpreters (Feuerstein and Fitzgerald, 
1992, Ex. 26-1284), or the hand problems of 
musicians (Amadio and Russotti, 1990, Ex. 26-
925; Fry, 1986, Ex. 26-850), are usually 
addressed on an individual (intrinsic) basis, 
because either no tool is involved, or the 
potential for tool modification is limited.
   Other situations clearly preclude 
addressing problems on an individual basis. 
For example, the vascular and neurologic 
problems produced by hand-arm vibration occur 
with such high attack rates and 
predictability that an effective control 
strategy necessarily addresses the tool and 
extrinsic exposure rather than individual 
susceptibility (Pyykko 1986, Ex. 26-662). In 
some industries, such as meatpacking, hand 
and wrist problems have been so prevalent and 
associated so strongly with particular tasks 
that identifying cause in a work process is 
unambiguous (Schottland et al., 1991, Ex. 26-
1001; Masear, Hayes, and Hyde, 1986, Ex. 26-
983).
   In still other settings, the multi-
dimensional pattern of personalized risk 
factors, non-work risk factors, and external, 
work-related risk factors complicates 
etiology identification. As with other 
chronic and sub-chronic diseases, it may be 
difficult, and sometimes impossible, to 
differentiate between underlying morbidity 
and causative, exacerbating, or even 
disabling features (stressors) in the 
external environment.


3. Medical and Diagnostic Issues

   The development of an ergonomics standard 
for U.S. workplaces poses specific challenges 
for disease identification. The relationship 
between MSDs and exposure to even well-
recognized risk factors, such as heavy 
repetitive lifting and hand-arm vibration, 
poses different sets of challenges for the 
recognition of exposures and their control 
than has been the case for many more 
traditional workplace exposures and 
disorders. The inhalation of asbestos fibers, 
for example, has well-defined and accepted 
endpoints, such as lung cancer and 
mesothelioma, and intermediate health effects 
at the tissue or cellular level are less 
important objects of dust control. 
Formaldehyde and other irritants have 
immediate and recognizable effects on mucosa, 
so that overexposure is often obvious, and 
the parameters of acute effects and detection 
thresholds all fall within a limited range of 
measurements. Physical hazards such as noise 
and radiation are highly organ-specific or 
have universally accepted risk profiles. For 
such hazards, exposure assessment does not 
require significant attention to individual 
work factors or personal factors, or there 
may be a consensus test for disease (as for 
noise).

[[Page 65868]]

   For MSDs, on the other hand, microanatomic 
injury and repair is often sub-clinical and 
generally invisible to clinical testing or 
surveillance measures. Although, the object 
of much active research, the relationship 
between sub-threshold injury and the onset of 
recognized clinical disorders is imprecisely 
understood. Because of regional and 
individual differences in diagnosis and 
treatment, disease recognition depends on 
professional practice, diagnosis, and 
treatment patterns.


4. References

  1. Amadio, P.C., Russoti, G.M. (1990). 
Evaluation and treatment of hand and wrist 
disorders in musicians. Hand Clinics, 6:405-
416.
  2. Armstrong, T.J., Buckle, P., Fine, L.J., 
Hagberg, M., Jonsson, B., Kilbom, A., 
Kuorinka, I.A.A., Silverstein, B.A., 
Sjogaard, G., Viikari-Juntura, E.R.A. (1993). 
A conceptual model for work-related neck and 
upper-limb musculoskeletal disorders. 
Scandinavian Journal of Work, Environment and 
Health, 19:73-84.
  3. Bernard, B., Fine, L., eds. (1997). 
Musculoskeletal Disorders and Workplace 
Factors. Cincinnati, OH: U.S. Department of 
Health and Human Services, Public Health 
Service, Centers for Disease Control, 
National Institute for Occupational Safety 
and Health. DHHS (NIOSH) Publication ##97-
141.
  4. Bovenzi, M., Petronio, L., Di Marino, F. 
(1980). Epidemiological survey of shipyard 
workers exposed to hand-arm vibration. 
International Archive of Occupational 
Environmental Health, 46:251-266.
  5. Faucett, J., Werner, R.A. (1998). Non-
Biomechanical Factors Potentially Affecting 
Musculoskeletal Disorders. In: National 
Academy of Sciences. Work-Related 
Musculoskeletal Disorders: The Research Base. 
Washington, DC: National Academy Press.
  6. Feuerstein, M., Fitzgerald, T. (1992). 
Biomechanical factors affecting upper 
extremity cumulative trauma disorders in sign 
language interpreters. Journal of 
Occupational Medicine, 34:257-264.
  7. Franklin, G.M., Haug, J., Heyer, N., 
Checkoway, H., Peck, N. (1991). Occupational 
carpal tunnel syndrome in Washington State, 
1984-1988. American Journal of Public Health, 
81(6):741-746.
  8. Fry, H.J.H. (1986). Overuse syndrome of 
the upper limb in musicians. Medical Journal 
of Australia, 144:182-185.
  9. General Accounting Office (1997). Worker 
Protection: Private Sector Ergonomics 
Programs Yield Positive Results. GAO/HEHS 
Publication #97-163.
  10. Kourinka, I., Forcier, L., eds. (1995). 
Work Related Musculoskeletal Disorders 
(WMSDs): A Reference Book for Prevention. 
London: Taylor and Francis.
  11. Krause., N., Lynch, J., Kaplan, G.A., 
et al. (1997). Predictors of disability 
retirement. Scandinavian Journal of Work, 
Environment and Health, 23:403-413.
  12. Masear, V.R., Hayes, J.M., Hyde, A.G. 
(1986). An industrial cause of carpal tunnel 
syndrome. Journal of Hand Surgery, 11A:222-
227.
  13. Messing, K., Chatigny, C., Courville, 
J. (1998a). ``Light'' and ``Heavy'' work in 
the housekeeping service of a hospital. 
Applied Ergonomics, 29(6):451-459.
  14. Messing, K., Tissot, F., Saurel-
Cubizolles, M.J., Kaminski, M., Bourgine, M. 
(1998b). Sex as a variable can be a surrogate 
for some working conditions: factors 
associated with sickness absence. Journal of 
Occupational and Environmental Medicine, 
40(3), 250-260.
  15. National Academy of Sciences (1998). 
Work-Related Musculoskeletal Disorders: A 
Review of the Evidence. Washington, DC: 
National Academy Press.
  16. Occupational Safety and Health 
Administration (1990). Ergonomics Program 
Guidelines for Meatpacking Plants. U.S. 
Department of Labor. OSHA Publication #3123.
  17. Punnett, L. (1998). Ergonomic stressors 
and upper extremity disorders in vehicle 
manufacturing: cross sectional exposure-
response trends. Occupational and 
Environmental Medicine, 55:414-420.
  18. Putz-Anderson, V., ed. (1988). 
Cumulative Trauma Disorders: A Manual for 
Musculoskeletal Diseases of the Upper Limbs. 
New York: Taylor and Francis.
  19. Pyykko, I. (1986). Clinical aspects of 
the hand-arm vibration syndrome: a review. 
Scandinavian Journal of Work, Environment and 
Health, 12:439-447.
  20. Radwin, R.G., Lavender, S.A. (1998). 
Work Factors, Personal Factors, and Internal 
Loads: Biomechanics of Work Stressors. In: 
National Academy of Sciences. Work-Related 
Musculoskeletal Disorders: The Research Base. 
Washington, DC: National Academy Press.
  21. Schottland, J.R., Kirschberg, G.J., 
Fillingim, R., Davis, V.P., Hogg, F. (1991). 
Median nerve latencies in poultry processing 
workers: an approach to resolving the role of 
industrial ``cumulative trauma'' in the 
development of carpal tunnel syndrome. 
Journal of Occupational Medicine, 33:627-631.
  22. Silverstein, B.A., Fine, L.J., 
Armstrong, T.J. (1986). Hand wrist cumulative 
trauma disorders in industry. British Journal 
of Industrial Medicine, 43:779-784.
  23. Silverstein, B.A., Fine, L.J., 
Armstrong, T.J. (1987). Occupational factors 
and the carpal tunnel syndrome. American 
Journal of Industrial Medicine, 11:343-358.
  24. Tuomi, K., ed. (1997). Eleven-year 
follow-up of aging workers. Scandinavian 
Journal of Work, Environment and Health, 23 
(Supplement 1):1-71.
  25. Webster, B.S., Snook, S.H. (1994). The 
cost of compensable upper extremity 
cumulative trauma disorders. Journal of 
Occupational Medicine, 36:713-727.
  26. World Health Organization (1985). 
Identification and Control of Work-Related 
Diseases. Report Series 714. Geneva, 
Switzerland, World Health Organization.


B. Biomechanical Risk Factors and Modifiers


1. Overview

   This section has two purposes:
    To present a framework for and 
classification of major observable and 
quantifiable workplace risk factors for 
neuromuscular and musculoskeletal disorders 
(MSDs).
    To define and explain these risk 
factors and to briefly explore possible 
mechanisms by which exposure to these 
stressors could cause MSDs.

The section begins with a summary exploration 
of the issues involved in establishing a 
causal relationship between aspects of the 
work environment/process and musculoskeletal 
disorders (Section B.1). It then presents the 
classification scheme used in the section, 
with brief reference to possible mechanisms 
of effect. Sections B.2 and B.3 present 
current knowledge of the basic physical risk 
factors and modifying factors identified by 
epidemiological and laboratory research.
   a. Epidemiological Criteria for 
Establishing Causation. Good epidemiology 
requires accurate and consistent 
identification and quantification of both 
exposure and outcome. In the rapidly evolving 
fields of research relevant to MSD etiology, 
there are still problems with measurement, 
quantification, and even recognition of 
particular risks and disease outcomes. 
However, the research referenced in this 
document demonstrates substantial agreement 
over a wide range of research methodologies 
concerning the causal association between a 
set of commonly recognized stressors and MSD 
outcomes.
   The risk factors discussed in this section 
have been shown to cause or contribute to 
MSDs, in accordance with generally accepted 
criteria for assessing a cause-effect 
relationship.

[[Page 65869]]

The following list of such criteria (based on 
Hill, 1965, Ex. 26-376; Hennekens, Buring, 
and Mayrent, 1987, Ex. 26-428; Bernard and 
Fine, 1997, Ex. 26-1; Rothman and Greenland, 
1998, Ex. 26-870) is not exhaustive but 
represents consensus in the field of 
epidemiology. Note that, with the exception 
of temporality, none of these criteria is a 
necessary or sufficient basis for determining 
causality: the absence of any criterion other 
than temporality in a study does not 
necessarily invalidate a causal hypothesis. 
But the presence of each factor, while not 
proving causality, does strengthen that 
hypothesis. Any given study may not satisfy 
each criterion, but the cumulative burden of 
evidence, from the many studies cited in this 
document, strongly argues for a causal 
relationship between the risk factors 
presented in this section and MSDs. These 
criteria are:
    The strength of the association. 
The larger the association, the less likely 
is an interpretation invoking undetected bias 
or unmeasured confounders. If bias or 
confounding are operative, they would have to 
be of a larger magnitude to explain the size 
of the association, making it less likely 
that the study would have overlooked them.
    Biological plausibility. 
Knowledge of a known or understandable 
proposed mechanism aids determination of 
causality.
    Consistency with other research. 
Similar results from independent studies, 
especially with different measurement 
techniques, strengthen a causality 
hypothesis.
    Temporality or appropriate time 
sequence. The proposed exposure (the risk 
factor) should be present prior to the 
proposed effect or outcome (here, indicators 
of MSDs).
    Dose-response relationship 
(biologic gradient). If higher levels of 
exposure are associated with higher levels of 
outcome, this can indicate causality. 
However, a causal relationship may exist but 
be hidden by a non-linear dose-response 
relationship. The presence of a dose-response 
relationship can also indicate a confounder 
with its own biologic gradient.

A sixth criterion, specificity of 
association, is often added to this list. 
This term refers to the degree to which a 
particular outcome is always associated with 
a particular risk factor. Because of the 
overwhelming evidence for multifactoral 
causation of MSDs, the specificity of 
association is low for most risk factors and 
musculoskeletal outcomes (Kourinka and 
Forcier, 1995, Ex. 26-432). Thus, this 
criterion is generally not useful in 
assessing causality in MSD etiology (with the 
possible exception of the specific 
association of vibration exposure with 
neurovascular disorders in the hands). In 
general, a specific risk factor can be 
associated with a number of different 
outcomes.
   b. Classification of Risk Factors and 
Modifiers. As much as possible, the risk 
factor classification employed in this 
document uses the definitions and concepts 
defined by NIOSH in the publication, 
``Musculoskeletal Disorders and Workplace 
Factors'' (Bernard and Fine, 1997, Ex. 26-1), 
combined with definitions and concepts 
developed in the draft ANSI ergonomics 
standard, Z-365 (1998, Ex. 26-1264). This 
discussion separates the risk factors into 
two basic families of concepts: basic risk 
factors and modifiers. The basic risk factors 
presented here are the aspects of work that 
most researchers agree cause or exacerbate 
MSDs. The modifiers are characteristics of a 
specific exposure to a risk factor that may 
affect the level or type of strain produced 
within tissues. Although there is a growing 
body of evidence linking psychosocial and 
work organization factors with the 
development of MSDs, those factors are not 
addressed here (other than the obvious impact 
of work organization on work pace). The 
following sections focus on the biomechanical 
or physical risk factors:

    Basic Biomechanical Risk Factors 
(Section B.2):
    --Force
    --Awkward Postures
    --Static Postures
    --Repetition
    --Dynamic Factors
    --Compression
    --Vibration
    Modifying Factors (Section B.3):
    --Intensity
    --Duration
    --Temporal Profile
    --Cold Temperatures

   Other classification systems are possible 
and valid. For instance, Kourinka and Forcier 
(1995, Ex. 26-432) present a broader system 
that links force, repetition, and duration as 
components of ``musculoskeletal load.'' 
Radwin and Lavender (in NAS, 1998, Ex. 26-37) 
and the ANSI draft standard Z-365 (1998, Ex. 
26-1264) prefer to list repetition as a 
modifier or ``characteristic property'' 
rather than as a basic risk factor. The 
system used here represents one useful 
classification scheme; the component terms 
maintain essentially the same definition in 
any of the frameworks currently in use. Most 
importantly, these differences in 
classification are relatively trivial and do 
not affect the evidence showing that all of 
these factors are implicated in the etiology 
of work-related MSDs.


2. Basic Risk Factors

   This section details the definitions, 
measurement issues, and some of the proposed 
effect mechanisms associated with basic 
biomechanical risk factors. No attempt is 
made to prioritize risk factors by 
importance, because the relative contribution 
of each stressor to MSDs depends on the 
particulars of the work environment and task 
structure, including the presence or absence 
of other risk factors. For instance, Radwin 
and Lavender (in NAS, 1998, Ex. 26-37) note 
that for a primarily static task, postural 
risks merit the closest attention in job 
analysis, while a dynamic manual material 
handling job requires more attention to 
dynamic stressors, such as range of motion, 
velocity, and acceleration of movement. 
Evidence for the relationship between these 
risk factors and MSDs is presented in detail 
in Section V.C of this preamble and the 
Appendices (Ex. 27-1). This section provides 
only cursory treatment of the mechanism of 
tissue injury attributable to these risk 
factors; Section V-C presents this aspect of 
MSD etiology in detail.
   a. Force. Force is the mechanical effort 
required to carry out a movement or to 
prevent movement. Force may be exerted 
against a work piece or tool, or against 
gravity, to stabilize body segments. Force 
does not necessarily imply motion. The 
dynamic act of lifting a work piece and the 
static act of holding that work piece in 
position both require force, generated by 
muscles, transmitted through tendons, and 
exerted by body segments on the work piece. 
In determining the risk posed by force 
requirements of the task, it is useful to 
consider muscle force and output force of 
body segments separately.
   Muscle Force. Muscle force is the actual 
mechanical effort exerted by the combined 
contraction of muscle fibers. The total force 
generated by any one muscle is a function of 
many factors, including the cross-sectional 
area of the muscle, the length of the muscle 
during contraction (i.e., where the length 
range falls between full contraction and

[[Page 65870]]

full extension), and the degree of fatigue. 
Research generally characterizes muscle force 
by surrogate measures of muscle activity 
(e.g., amplitude of electromyographic [EMG] 
signals, generally expressed as a percentage 
of the amplitude measured at maximum 
voluntary contraction [MVC]). Because of the 
electrical activity associated with muscle 
contraction, muscle force is the most easily 
measured aspect of tissue involvement. But 
full characterization of potential tissue 
damage requires attention to all links in the 
pathway through which muscle force is 
transmitted to output force (Section 2.a). 
Thus, force requirements affect tension on 
tendons (which transmit muscle force to 
bones), shear force, friction, and irritation 
induced by lateral forces on tendons and 
tendon sheaths (as they are pressed against 
surrounding anatomical structures) and the 
strain at the insertion of tendons on bones.
   Estimating muscle force from external 
characteristics of the task can be 
complicated compared to measuring muscle 
activity (such as taking EMG measurements 
with deep wire electrodes implanted directly 
in the muscle fibers of interest). First, 
many external job characteristics can affect 
muscle force requirements, and some of these 
characteristics may not be recognized in a 
job analysis. For example, Kourinka and 
Forcier (1995, Ex. 26-432) note several 
factors that affect muscle force required for 
a grip: presence of other risk factors (such 
as awkward postures required by grip type and 
handle size), the coefficient of friction of 
the work piece surface, whether gloves are 
required, and individual variations in 
technique.
   Second, the lever arm (the distance from 
point of force application to the fulcrum--
the joint center) for most muscles is 
generally much smaller than that of the 
external load (Radwin and Lavender, in NAS, 
1998, Ex. 26-37). This means that muscle 
forces are usually several times greater than 
the external load. Thus, accurate modeling 
requires precise estimation or modeling of 
actual lever arm lengths.
   Third, fatigue affects muscle fiber 
recruitment patterns within a single muscle, 
as well as recruitment (substitution) 
patterns of alternative muscles (Parnianpour 
et al., 1988, Ex. 26-1150). When secondary 
muscles are recruited to assist a fatigued 
primary muscle, the recruited secondary 
muscles may be more vulnerable to injury due 
to less-advantageous lever arm length, 
smaller size, or less-than-optimal fiber 
length in the work posture (see Section 2.b).
   Despite these difficulties, modeling 
approaches can often predict internal force 
requirements accurately. For instance, Marras 
and Granata (1997a, Ex. 26-1380) showed that 
measured pressures in the L5S1 intervertebral 
disk generally match values predicted by 
modeling. (Internal disk pressure is a result 
of forces exerted on the disk by muscles and 
gravity.)
   Output Force. The force exerted by body 
parts to move or hold the work piece (often 
against gravity) is obviously a function of 
muscle force. However, the relationship is 
strongly affected by other variables, the 
most important being posture. Deviations from 
a so-called ``neutral posture'' (see Section 
2.b) can dramatically reduce the amount of 
muscle force translated into output force. 
The ``lost'' force is generally seen in 
inefficient coupling of the contractile 
proteins in muscle fibers or in force exerted 
by muscles and tendons against adjacent 
anatomical structures as the force 
transmission changes direction. In addition, 
most holding and moving tasks involve input 
from several muscles, often working in 
opposition. Skilled, small-motor activities 
involve co-contraction of antagonist muscles 
to generate precisely graded movements, joint 
stabilization, or holding forces. Thus, 
substantial muscle activity can be associated 
with very little net output force. In 
addition, these co-contractile forces act 
additively on the joint components 
(ligaments, cartilage, and bone). For the 
researcher, this has important implications. 
For example, measurements of the weight of a 
work piece or the finger forces necessary to 
move a computer mouse may substantially 
underestimate the potential damage to the 
muscles, tendons, joints and other soft 
tissues involved.
   Guidelines for manual materials handling 
(e.g., Snook and Ciriello, 1991, Ex. 26-1008; 
NIOSH, 1981, 1994, Exs. 26-393 and 26-572) 
clearly note that the weight of the load, in 
isolation, is not a sufficient measure of 
musculoskeletal stress.
   b. Awkward Postures. This risk factor is 
generally conceptualized as postures deviated 
from a neutral position. In this document, 
``posture'' means the angle between two 
adjacent body segments. A so-called ``neutral 
posture'' angle can be determined for each 
joint. This term seems to suggest the resting 
position of the joint, but it actually 
encompasses two biomechanical criteria 
necessary for optimal development of muscle 
force:
    The biomechanical relationship of 
the two body segments that presents the 
largest lever arm upon which the muscle force 
acts.
    The length of the muscle that 
allows it to develop the greatest force most 
rapidly. For most muscles, the physiological 
and physical relationships between the two 
contractile proteins, known as the length-
tension and the length-velocity 
relationships, mean that maximum force and 
speed of contraction can be developed when 
the muscle is in a position between greatest 
extension and greatest contraction.
   However, the term ``non-neutral posture'' 
should only be seen as a first approximation 
of a stressful, awkward posture, for several 
reasons. First, neutral posture is generally 
defined in terms of muscle length, although 
joint angles have implications for other 
tissues: what is optimal for one tissue may 
not be the optimal joint angle for another. 
For example, a roughly 90-degree elbow angle 
satisfies both criteria above for optimal 
biceps activity. But that posture may stretch 
the ulnar nerve against the elbow, suggesting 
that a more open elbow angle is necessary for 
optimal nerve function and safety.
   Second, most body exertions involve more 
than one muscle, each of which may be in 
optimal biomechanical and length relationship 
at a different joint angle. Third, the body 
can adopt postures that are not necessarily 
the optimal biomechanical or length-tension 
relationships for muscles, but that result in 
the lowest sum of muscle activation to 
stabilize body parts against gravity.
   Fourth, non-neutral postures are sometimes 
defined in relation to their association with 
tissue damage, not to a biomechanically sub-
optimal joint angle. For example, a 90-degree 
abduction of the upper arm may put some 
shoulder muscles (e.g., the deltoids) in a 
relatively ``neutral'' posture, but can 
expose the brachioplexus to compressive 
forces from other muscles and anatomical 
structures. This posture can also entrap the 
tendon of the supraspinatus muscle between 
the acromion and the head of the humerus 
(Hagberg, 1984, Ex. 26-1271). To fully 
characterize the degree to which a posture is 
``awkward,'' it is necessary to take an 
integrated overview of the tissues involved, 
defining which muscles and other tissues are 
involved in the position and what the 
implications are for tissue damage.
   With these concerns in mind, Kourinka and 
Forcier (1995, Ex. 26-432) separate the term 
``awkward postures'' into

[[Page 65871]]

three concepts, which may characterize a 
particular posture in combination or alone:
    Extreme postures. This term is 
used in the NIOSH review of epidemiological 
evidence (Bernard and Fine, 1997, Ex. 26-1). 
Extreme postures are joint positions close to 
the ends of the range of motion. They require 
more support, either by passive tissues 
(e.g., ligaments and passive elements of the 
muscles) or increased muscle force. These 
positions may also exert compressive forces 
on blood vessels and/or nerves. Note, 
however, that some joints, such as the knee, 
are designed to be used close to the range-
of-motion extremes.
    Non-extreme postures that expose 
the joint to loading from gravitational 
forces, requiring increased forces from 
muscles and/or load on other tissues. For 
instance, holding the arm at 90 degrees to 
the body does not represent an extreme 
posture in terms of muscle length. But the 
position allows gravitational forces to exert 
a pull requiring roughly 10% of maximal 
strength from the associated muscles (Takala 
and Viikari-Juntura, 1991, Ex. 26-1014).
    Non-extreme postures that change 
musculoskeletal geometry, increasing loading 
on tissues or reducing the tolerance of these 
tissues. This third factor includes the 
reduction in available lever arm for muscles, 
described above. An example of increased 
loading is provided by experiments (Smith, 
Sonstegard, and Anderson, 1977, Ex. 26-1006) 
demonstrating that even non-extreme wrist 
flexion can press the finger flexor tendons 
against the median nerve. Experiments by 
Adams et al. (1980, Ex. 26-701) indicate that 
combined flexion and twisting or bending of 
the spine reduces tissue tolerance of the 
intervertebral disks, predisposing them to 
rupture.
   c. Static Postures. Static postures--
postures held over a period of time to resist 
the force of gravity or to stabilize a work 
piece--are particularly stressful to the 
musculoskeletal system. More precisely, 
static postures are usually defined as 
requiring isometric muscle force--exertion 
without accompanying movement. Even with some 
movement, if the joint does not return to a 
neutral position and continual muscle force 
is required, the effect can be the same as a 
non-moving posture. Since blood vessels 
generally pass through the muscles they 
supply, static contraction of the muscle can 
reduce blood flow by as much as 90%. The 
consequent reduction in oxygen and nutrient 
supply and waste product clearance results in 
more rapid onset of fatigue and may 
predispose muscles and other tissues to 
injury. The increased intramuscular pressure 
exerted on neural tissue may result in 
chronic decrement in nerve function. The 
viscoelastic ligament and tendon tissues can 
exhibit ``creep'' over time, possibly 
reaching failure thresholds beyond which they 
are unable to regain resting length.
   d. Repetition. Appendix I lists repetition 
as a basic risk factor. This section follows 
that categorization. However, repetition can 
have characteristics of both a basic risk 
factor and a modifier (the ANSI draft 
standard, Z-365, 1998, Ex. 26-1264, gives 
repetition modifier or ``characteristic 
property'' status). High repetition may act 
as a modifying factor, exacerbating the basic 
risk factors of force and posture. But high 
repetition also may have its own tissue 
effects (combined with the dynamic factors 
described in Section 2.e). For example, 
increased friction-induced irritation of 
finger flexor and extensor tendons in their 
sheaths can result in tendinitis and lead to 
increased pressure in the carpal canal. A 
moderate level of repetition can be seen as 
protective, since it can increase muscle 
strength and flexibility (this is the concept 
behind exercise). It can also assist blood 
flow through muscles, thus relieving the 
stressful nature of static muscle 
contractions. Ideal work cycles keep overall 
repetition rates in a middle zone between the 
injurious extremes of static contraction and 
excessive repetition.
   e. Dynamic Factors (Motion). Motion of 
body segments consists of both linear motion 
and rotational motion around a joint. Present 
research addresses the effects of kinematic 
measures of posture: both angular and linear 
velocity (speed of motion) and acceleration 
(rate at which velocity increases or 
decreases). It is possible that, to a degree, 
measured acceleration and velocity are 
surrogates for increased force and postural 
risk factors. For example, Marras and Granata 
(1995, 1997b Exs. 26-1383 and 26-169) find 
that increased velocity and acceleration in 
trunk lateral bending and twisting result in 
measurable increases in both compressive and 
shear forces experienced by the 
intervertebral disks. But dynamic factors 
themselves may result in increased tendon 
travel and irritation. Viscoelastic soft 
tissues, such as tendons, spinal discs, and 
ligaments, have a fixed, intrinsic capacity 
to regain resting dimensions after 
stretching. Brief movement cycles may involve 
peak accelerations that can exceed tissue 
elasticity limits during an otherwise 
moderate task. The biodynamic literature 
suggests that, even in tasks performed for a 
short time, the acceleration and velocity of 
movements may pose risks that would not be 
predicted by the muscle forces or joint 
angles alone.
   f. Compression. Compression of tissues can 
result from exposure that is external or 
internal to the body. Depending on the tissue 
compressed, the effects are manifested in 
quite different ways (see Section V-D of this 
preamble).
   External Compression. Moderately sharp 
edges, such as tool handles, workbench edges, 
machine corners, and even poorly designed 
seating, concentrate forces on a small area 
of the anatomy, resulting in high, localized 
pressure. This pressure can compress nerves, 
vessels, and other soft tissues, resulting in 
tissue-specific damage (e.g., degraded nerve 
transmission, reduced blood flow, and 
mechanical damage to tendons and/or tendon 
sheaths). These changes may themselves result 
in disease or predispose other tissues to 
damage.
   The most common sites for compression MSDs 
are in the hands and wrists. Since natural 
selection has resulted in well-developed, 
padded gripping areas on the hands (in 
particular, finger pads and the thenar and 
hypothenar pads on the palm), injury is most 
often seen outside these areas: the sides of 
the fingers, the palm, and the ventral side 
of the wrist. For instance, the prolonged use 
of scissors can cause nerve damage on the 
sides of the fingers. Compression MSDs have 
also been identified in the forearm, elbow, 
and shoulder.
   Internal Compression. Nerves, vessels, and 
other soft tissues may be internally 
compressed under conditions of high-force 
exertions, awkward postures, static postures, 
and/or high velocity or acceleration of 
movement. For example, strong abduction or 
extension of the upper arm, as well as 
awkward postures of the neck, can compress 
parts of the brachioplexus under the scalene 
muscles and other anatomical structures. This 
compression can result in nerve and/or blood 
vessel damage or in eventual damage to the 
tissues served by these nerves and vessels.
   There are other sources of internal 
compression, also the secondary result of 
exposure to other risk factors noted in this 
document. Examples include:
    Intramuscular pressure developed 
during forceful contraction. (This is the 
main mechanism resulting in

[[Page 65872]]

compression of blood vessels internal to the 
muscles during static contraction).
    Pressure due to reparative 
swelling of tissues injured in work 
processes. (For example, the inflammatory 
swelling of flexor tendon synovial sheaths, 
in response to friction and irritation, can 
increase pressure in the carpal tunnel and 
compress the median nerve.)
   g. Vibration. Vibration is normally 
divided into two categories:
    Segmental vibration or vibration 
transmitted through the hands. Segmental 
vibration appears to damage both the small, 
unmyelinated nerve fibers and the small blood 
vessels in the fingers, resulting in two 
specific diseases: vibration-induced white 
finger (VWF) and vibratory neuropathy. 
Together, these are called the hand-arm 
vibration syndrome (see below). Segmental 
vibration has also been implicated in carpal 
tunnel syndrome.
    Whole-body vibration, or 
vibration transmitted through the lower 
extremities and/or the back. Whole-body 
vibration is implicated in low back disorders 
and a host of less well-understood symptoms.
   Recent research suggests that vibration 
should be further subdivided into two types:
    Harmonic or oscillatory vibration 
(due to a constant driving source, such as a 
grinding wheel or holding a powered tool such 
as an electric drill)
    Impact vibration (due to single 
impact, such as hammering a nail)
    Percussive vibration (bursts of 
separable impacts, such as those produced by 
a pneumatic riveting tool or a jackhammer)

It is possible that the thresholds for 
effects of these three types of vibration are 
quite different, with impact and percussive 
vibration having physiological effects at 
much lower measured exposure times.
   Three classes of effect due to vibration 
are discussed in Section V-D and the 
Appendices (Ex. 27-1):
    Vascular damage, leading to 
premature vasoconstriction and insufficient 
circulation in the fingers. These effects 
give rise to the original name for 
occupationally induced Raynaud's syndrome: 
vibration-induced white finger (VWF). In 
1987, a consensus panel, meeting in 
Stockholm, coined the term hand-arm vibration 
syndrome (HAVS) to give equal weighting to 
neurological symptoms (Gemne et al., 1987, 
Ex. 26-624).
    Neurological effects. These 
effects involve damage to both the median 
nerve and to the small, unmyelinated nerve 
fibers in the fingers.
    Musculoskeletal effects. Kourinka 
and Forcier (1995, Ex. 26-432) list a number 
of possible effects in this category, 
including impaired muscle strength and 
osteoarthrosis of some upper extremity 
joints.
   Finally, some research suggests that 
vibration received aurally (i.e., noise) can, 
itself, result in increased static muscle 
loading (Kjellberg, Skoldstrom, and Tesaiz, 
1991, Ex. 26-432).


3. Modifying Factors

   This section elaborates on the definitions 
and measurement issues associated with the 
classification of modifying factors presented 
in Section B.1. Evidence for the relationship 
between these modifying factors and MSDs is 
presented in Section C. The following 
measures are not risk factors in themselves; 
rather, they modify the effects of the basic 
risk factors. To fully characterize exposure, 
investigators measure both the basic risk 
factors and the relevant modifiers.
   a. Intensity or Magnitude. Intensity or 
magnitude is a measure of the strength of 
each risk factor: how much force, how 
deviated the posture, how great the velocity 
or acceleration of motion, how much pressure 
due to compression, how great the 
acceleration level of vibration, etc.
   b. Duration. Duration is the measure of 
how long the risk factor was experienced. 
This is a task-specific measure and is 
generally combined with a comprehensive, job-
specific characterization of the temporal 
profile of the exposure (Section 3.c). 
Frequency and duration are related, i.e., the 
more frequently a task is performed, the 
greater the duration of exposure.
   c. Temporal Profile (Recovery Time and 
Pattern of Exposure). The combined effects of 
the basic risk factors, modified by intensity 
and duration, tax the recovery and repair 
capacities of the body. Recovery capacity is 
strongly related to the time available for 
tissue repair. Thus, accurate exposure 
assessment takes into account the way that 
risk factors vary over time. Excessive 
metabolic load and inadequate rest schedules 
deprive the body of recovery time to 
accomplish repair on strained tissues. The 
pattern of exposure can be as important as 
total magnitude or cumulative exposure. For 
instance, a cumulative exposure duration of 4 
hours, spread over two 8-hour work days, can 
be associated with substantially different 
health effects than a single, one-time 
exposure of 4 hours. Kourinka and Forcier 
(1995, Ex. 26-432) note that assessment of 
temporal profile would include:
    Task variation over a given time 
period (hour, day, week)
    Characteristics of the duty 
cycle: the proportion of the task in which 
stressors are high, compared to when they are 
low
    Schedule of micropauses (of a few 
seconds) every few minutes
    Distribution of formal rest 
breaks
    Shift and overtime schedules
   d. Cold Temperatures. Cold is a well-
established exacerbating factor in the 
development of vibration-related disease. In 
addition to aggravating pre-existing disease 
and injury, cold environments compromise 
muscle efficiency. Cold-related injuries to 
the hands result in several vascular and 
neurological disorders. Perhaps the most 
common effect of cold is its ability to 
reduce cutaneous sensory sensitivity and thus 
compromise manual dexterity. Workers with 
cold-desensitized fingers may grasp loads 
with more force than necessary, due to 
reduced sensory feedback, thus exposing 
muscles, soft tissues, and joints to 
increased tensile and compressive forces.


4. References

   Adams, M.A., Hutton, W.C., Stott, 
J.R.R. (1980). The resistance to flexion of 
the lumbar intervertebral joint. Spine, 
5(3):245-253.
   American National Standards 
Institute. (1998). ANSI Z-365 Control of 
Work-Related Cumulative Trauma Disorders 
(Draft). New York: ANSI.
   Bernard, B., Fine, L., eds. 
(1997). Musculoskeletal Disorders and 
Workplace Factors. Cincinnati, OH: U.S. 
Department of Health and Human Services, 
Public Health Service, Centers for Disease 
Control, National Institute for Occupational 
Safety and Health. DHHS (NIOSH) Publication 
#97-141.

[[Page 65873]]

   Gemne, G., Pyykko, I., Taylor, W., 
Pelmear, P. (1987). The Stockholm Workshop 
scale for the classification of cold-induced 
Raynaud's phenomenon in the hand-arm 
vibration syndrome (revision of the Taylor-
Pelmear scale). Scandinavian Journal of Work, 
Environment and Health, 13:275-278.
   Hagberg, M. (1984). Occupational 
musculoskeletal stress and disorders of the 
neck and shoulder: a review of possible 
pathophysiology. International Archives of 
Occupational and Environmental Health, 
53(3):269-278.
   Hagberg, M., Morgenstern, J., 
Kelsh, M. (1992). Impact of occupations and 
job tasks on the prevalence of carpal tunnel 
syndrome: a review. Scandinavian Journal of 
Work, Environment and Health, 12:337-345.
   Hennekens, C.H., Buring, J.E., 
Mayrent, S.L. (1987). Epidemiology in 
Medicine. Boston: Little, Brown.
   Hill, A.B. (1965). The environment 
and disease; association or causation? 
Proceedings of the Royal Society of Medicine, 
58:295-300.
   Kjellberg, A., Skoldstrom, B., 
Tesaiz, M. (1991). Equal EMG Response Levels 
to a 100 and 1000 Hz Tone. In Proceedings of 
Internoise, pp. 847-850.
   Kourinka, I., Forcier, L., eds. 
(1995). Work Related Musculoskeletal 
Disorders (WMSDs): A Reference Book for 
Prevention. London: Taylor and Francis.
   Marras, W.S., Granata, K.P. 
(1995). A biomechanical assessment and model 
of axial twisting in the thoracolumbar spine. 
Spine, 20:1440-1451.
   Marras, W.S., Granata, K.P. 
(1997a). The development of an EMG-assisted 
model to assess spine loading during whole-
body free-dynamic lifting. Journal of 
Electromyography and Kinesiology, 17(4):259-
268.
   Marras, W.S., Granata, K.P. 
(1997b). Spine loading during trunk lateral 
bending motions. Journal of Biomechanics, 
30:697-703.
   National Institute for 
Occupational Safety and Health (1981). Work 
Practices Guide for Manual Lifting. 
Cincinnati, OH: U.S. Department of Health and 
Human Services, Public Health Service, 
Centers for Disease Control, National 
Institute for Occupational Safety and Health. 
DHHS (NIOSH) publication #81-122.
   National Institute for 
Occupational Safety and Health (1994). 
Revised NIOSH Lifting Equation. Cincinnati, 
OH: U.S. Department of Health and Human 
Services, Public Health Service, Centers for 
Disease Control, National Institute for 
Occupational Safety and Health. DHHS (NIOSH) 
Publication #94-110.
   Parnianpour, M., Nordin, M., 
Kahanovitz, N., Frankel, V. (1988). The 
triaxial coupling of torque generation of 
trunk muscles during isometric exertions and 
the effect of fatiguing isoinertial movements 
on the motor output and movement patterns. 
Spine, 13:982-992.
   Radwin, R.G., Lavender, S.A. 
(1998). Work Factors, Personal Factors, and 
Internal Loads: Biomechanics of Work 
Stressors. In National Academy of Sciences. 
Work-Related Musculoskeletal Disorders: The 
Research Base. Washington, DC: National 
Academy Press.
   Rothman, K.J., Greenland, S. 
(1998). Modern Epidemiology. Philadelphia: 
Lippincott-Raven.
   Smith, E.M., Sonstegard, D., 
Anderson, W. (1977). Carpal tunnel syndrome: 
contribution of the flexor tendons. Archives 
of Physical and Medical Rehabilitation, 
58:379-385.
   Snook, S.H., Ciriello, V.M. 
(1991). The design of manual handling tasks: 
revised tables of maximum acceptable weights 
and forces. Ergonomics, 34(9):1197-1214.
   Takala, E., Viikari-Juntura, E. 
(1991). Muscle force endurance and neck-
shoulder symptoms of sedentary workers: an 
experimental study on bank cashiers with and 
without symptoms. Amsterdam, The Netherlands: 
Elsevier Science Publishers, B.V., pp. 123-
132.


C. Evidence for the Role of Basic Risk 
Factors and Modifying Factors in the Etiology 
of MSDs

   This section summarizes the extensive body 
of evidence for the involvement of workplace 
stressors in musculoskeletal disorder (MSD) 
causation. For each of the basic risk factors 
and modifying factors described in Section V-
B, this section presents highlights from the 
relevant epidemiological, laboratory, and 
psychophysical studies, as well as a summary 
of the evidence. Section V-D and the 
Appendices (Ex. 27-1) explore this body of 
evidence in much greater detail.


1. Quality of the Evidence

   The evidence from epidemiologic, 
laboratory, and psychophysical studies in the 
Health Effects Section supports a causal 
relationship between workplace stressors and 
MSD outcomes. The proposed mechanisms of 
effect, detailed in Section V-D of the 
preamble and in the Appendices (Ex. 27-1), 
support the biological plausibility of the 
link between stressors and disease--one of 
the five criteria useful in establishing 
causality (see Section B.1.a). These criteria 
require attention to population studies 
relating exposure and effect (epidemiology), 
to physiological measurements that show a 
plausible mechanism for disease causation or 
exacerbation (laboratory studies), and to 
subjective perceptions of fatigue and pain 
(psychophysical studies).
   The epidemiological studies in this field 
have been criticized because they tend to 
feature cross-sectional research design and 
rely on worker self-reports. These studies 
may have an increased risk of common-
instrument bias (if based on self-report) and 
present obstacles to determining causality, 
due to their inability to establish 
temporality. The NIOSH review discussed below 
(Bernard and Fine, 1997, Ex. 26-1) selected 
the studies with the best design and further 
weighted these studies' contributions to the 
review's conclusions by methodological 
quality. Still, some investigators feel that 
NIOSH was not exclusive enough in its 
selection of acceptable studies. (Note that 
although Gerr [1998, Ex. 26-426] makes this 
criticism in the NAS symposium [1998, Ex. 26-
37], he also states that he doubts whether 
the exclusions he suggests would make a 
substantial difference in the overall 
conclusions NIOSH reaches about work-
relatedness.) NIOSH notes that ``The document 
represents a first step in assessing work-
relatedness of MSDs.''
   It is useful, however, to look more deeply 
at the criticisms of self-reported studies. 
Punnett (1998, Ex. 26-442) reviews the wide 
variety of studies that demonstrate the 
validity of self-report measures. These 
studies further suggest that common-
instrument bias (the notion that a worker's 
perception of high exposure might lead him/
her to report higher symptom status, or vice 
versa) may pose less of a problem than 
critics suppose. Punnett notes that a number 
of well-designed keyboard studies found 
differences between self-reported and 
observed keying times, but these differences 
were non-differential between cases and 
controls. Symptom status, in other words, did 
not bias overall reporting of exposure one 
way or the other. The NIOSH summary of 
epidemiological evidence for low-back MSDs 
(Bernard and Fine, 1997, Ex. 26-1) does not 
support the assumption that self-reported 
bias inflates associations. Of the 13 studies 
(out of 18 reviewed) with a positive 
relationship between work-related lifting and 
forceful movements, those relying on 
objective measures of exposure showed higher 
odds ratios (ORs) (2.2-11) than those relying 
on subjective measures (1.2-5.2).

[[Page 65874]]

   Likewise, looking at objectively measured 
as opposed to self-reported MSD outcomes, 
self-reported symptoms do correlate with 
objectively measured disease. Bernard et al. 
(1993, Ex. 26-439), for example, found that 
when compared to non-cases for increased 
median nerve latency, subjects defined as CTS 
cases on the basis of self-reported symptoms 
showed an OR of 42.5 (with a wide 95% CI: 
1.61-1122, due to small sample size).
   Although other types of bias are difficult 
to detect in cross-sectional studies, when 
they occur they are likely to underestimate 
rather than overestimate the relationship 
between exposure to stressors and disease. 
For instance, the ``healthy worker'' bias, 
the preferential departure of symptomatic 
workers from high-exposure jobs, artificially 
lowers the disease prevalence in these jobs, 
reducing the calculated association of 
stressor exposure to MSD in analysis. The 
clear association noted by the NAS report 
(1998, Ex. 26-37) between MSDs and jobs with 
high physical load is thus derived despite 
the effect-reducing influence of the 
``healthy worker'' bias. This example also 
demonstrates that a researcher can make 
plausible hypotheses about the direction of 
effect in some cross-sectional studies. It is 
highly unlikely that workers experiencing MSD 
symptoms would preferentially transfer into 
jobs with higher physical exposure (which 
would artificially elevate epidemiological 
estimates of effect). It has, in fact, been 
shown that symptomatic workers do tend to 
leave jobs that have high levels of MSD risk 
(Punnett, 1998, Ex. 26-442). Silverstein et 
al. (1988, Ex. 26-1004), in a follow-up study 
at one of the plants examined in their 
earlier studies, found that those subjects in 
the high-force/high-repetition exposure 
category who were symptomatic in the original 
study were no longer in that exposure 
category at the time of follow-up.
   This section does not evaluate the growing 
body of intervention research relating 
reduction in the number and severity of MSDs 
to intentional reductions in exposures. 
However, the recent NIOSH study of MSDs and 
workplace factors (Bernard and Fine, 1997, 
Ex. 26-1) includes studies that demonstrate a 
reduction in disease as a result of 
interventions that reduce exposures. 
Goldenhar (1994, Ex. 26-126) and Smith, 
Karsh, and Moro (1998, Ex. 26-445) carried 
out reviews of the intervention literature. 
While noting the potential value of 
intervention research, both reviews note 
substantial deficits in research sample size 
and study design. Despite these drawbacks, 
Smith, Karsh, and Moro find evidence for the 
injury-reduction potential of redesigned hand 
tools, weight-handling devices (e.g., hoists, 
articulated arms), and other work station 
alterations, as well as exercise and 
training. The General Accounting Office study 
(1997, Ex. 26-5) of ergonomic program 
effectiveness (focusing on five case studies) 
found that successful programs were based on 
a core set of elements: management commitment 
and employee involvement, identification of 
problem jobs, development of solutions, 
training and education, and medical 
management. Programs based on these elements 
showed reductions in injuries, illnesses, 
lost work days, and associated workers' 
compensation costs. Qualitative evidence from 
these case studies showed improvements in 
worker morale, productivity, and product 
quality.
   Psychophysical experiments, explored in 
Appendix II, (Ex. 27-1) measure subjective 
responses of individuals performing various 
laboratory tasks designed to mimic real work 
procedures. The measures are self-reports of 
discomfort, fatigue, level of exertion, etc. 
These measures have been found to correlate 
well with objective measures of injury 
frequency in workplaces (Snook, Campanelli, 
and Hart, 1978, Ex. 26-35; Herrin, Jaraiedi, 
and Anderson, 1986, Ex. 26-961).


2. NIOSH Summary of the Epidemiological 
Evidence

   The following sections present selected 
epidemiological evidence organized by risk 
factor. However, it is helpful first to look 
at a summary of this evidence, taken from the 
very thorough analysis carried out by NIOSH 
(Bernard and Fine, 1997, Ex. 26-1). NIOSH 
lists reasonable and consistent criteria for 
including studies in this summary. The 
Workshop Summary and Papers document from the 
recent NAS symposium on MSDs (National 
Academy of Sciences, 1998, Ex. 26-37) 
contains assessments of the NIOSH analysis by 
seven respected epidemiologists. This group 
noted the drawbacks to many of the studies 
included in the analysis:
    Difficulty in establishing causal 
direction from any one study.
    Variability in assessment 
measures (also a strength of the combined 
body of studies).
    Lack of information concerning 
disease prevalence in non-working 
populations.
    The common epidemiological 
problem of possible unmeasured factors 
contributing to the effects seen.
   However, the group concluded that:
    The NIOSH criteria for study 
inclusion in the summary were, in general, 
adequate.
    The preponderance of evidence, 
particularly from studies with high exposure 
contrasts among study groups, supports the 
association between work-related stressors 
and MSD development.
    The demonstrated reduction of 
MSDs in workplaces where stressors were 
reduced also strongly supports this 
association.
   Bernard and contributors (1997, Ex. 26-1) 
established a four-part classification system 
to characterize the strength of evidence for 
work-relatedness, examining the contribution 
of each risk factor to MSDs, categorized by 
body location (see Tables V-1 and V-2).

[[Page 65875]]



                                        Table V-1.--Upper-Extremity MSDs
----------------------------------------------------------------------------------------------------------------
                                                                 RISK FACTOR
                           -------------------------------------------------------------------------------------
MSD LOCATION    NUMBER OF                 STATIC OR
OR DIAGNOSIS     STUDIES       FORCE       EXTREME       REPETITION          VIBRATION           COMBINATION
                                          POSTURES                          (SEGMENTAL)
----------------------------------------------------------------------------------------------------------------
Neck and              >40          ++           +++                ++                 +/0                  (--)
 Neck/
 Shoulder
Shoulder              >20         +/0            ++                ++                 +/0                  (--)
Elbow                 >20          ++           +/0               +/0                (--)                   +++
Carpal                >30          ++           +/0                ++                  ++                   +++
 Tunnel
Hand/Wrist              8          ++            ++                ++                (--)                   +++
 Tendinitis
Hand-Arm               20        (--)          (--)              (--)                 +++                  (--)
 Vibration
----------------------------------------------------------------------------------------------------------------
Note: (--) means the association is not reported in the NIOSH publication.


                                                               Table V-2.--Lower-Back MSDs
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                     RISK FACTOR
                                                            --------------------------------------------------------------------------------------------
          MSD LOCATION OR DIAGNOSIS              NUMBER OF                        LIFTING AND
                                                  STUDIES     HEAVY PHYSICAL        FORCEFUL      STATIC  POSTURES  AWKWARD POSTURES   VIBRATION (WHOLE
                                                                   WORK            MOVEMENTS                                                 BODY)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low Back                                               >40                ++                +++               +/0                ++                 +++
--------------------------------------------------------------------------------------------------------------------------------------------------------

   In this determination, the investigators 
weighted the contribution of individual 
studies by the quality of the study design:
    Strong evidence of work-
relatedness (+++): a very likely causal 
relationship between exposures of high 
intensity and/or duration and an MSD, using 
the epidemiologic criteria for causality 
(similar to those presented above).
    Evidence of work-relatedness 
(++): some convincing evidence of a causal 
relationship.
    Insufficient evidence of work-
relatedness (+/0): some suggestion of 
causality, but most studies lack sufficient 
quality, consistency, or statistical power; 
study quality may be lower.
    Evidence of no effect of work 
factors (-): Adequate studies consistently 
and strongly show a lack of association 
between a risk factor and MSDs.
   The study considered five categories of 
risk factors for upper-extremity MSDs (see 
Table V-1):
    Forceful exertions.
    High levels of static 
contraction, prolonged static loads or 
extreme working postures (termed ``awkward 
postures'' in Section B).
    Highly repetitive work.
    Vibration.
    A combination of these factors.

Table V-1 also shows that there is evidence 
or strong evidence of work-relatedness for 
most MSDs and risk factors.
   The NIOSH study presents a somewhat 
different set of risk factors for low-back 
MSDs (see Table V-2). The classification:
    Looks at static and awkward 
postures separately, explicitly substituting 
``awkward postures'' for extreme postures.
    Inserts ``heavy physical work'' 
and ``lifting and forceful movements'' in 
place of ``force.''
    Assesses whole-body vibration 
instead of segmental vibration.
    Removes assessment of repetition 
as a separate risk factor.
    Does not address combinations of 
risk factors.

This modified selection of risk factors is, 
overall, appropriate to the particular nature 
of back exposures and injury and reflects the 
foci of attention in the epidemiological 
research literature. The last two omissions 
are unfortunate, however, because both 
repetition rate and combined exposures to 
stressors are relevant to the etiology of 
low-back disorders. In practice, the studies 
that assessed heavy physical work used 
definitions of this stressor that include 
``high energy demands * * * heavy tiring 
tasks, manual materials handling tasks, and 
heavy, dynamic, or intense work'' (Bernard 
and Fine, 1997, p. 6-4, Ex. 26-1). These 
stressors probably implicitly include both 
repetition and a combination of risk factors. 
Table V-2, like Table V-1, shows that there 
is evidence or strong evidence of work-
relatedness for low back MSDs. Due to the 
multifactoral nature of MSD causation, the 
separation of evidence by individual risk 
factor is artificial. But this separation is 
useful for clarity and is continued in this 
section, which presents other epidemiological 
studies as well as evidence from laboratory 
and psychophysical studies pointing to the 
role of workplace stressors in the causation 
or exacerbation of MSDs.


3. Workplace Risk Factors and MSDs

   a. Force.
   Epidemiological Evidence. The NIOSH 
summary (Bernard and Fine, 1997, Ex. 26-1) of 
upper-extremity MSDs found evidence of a 
causal relationship between exposure to force 
and disorders of the neck and elbow, as well 
as carpal tunnel syndrome (CTS) and hand/
wrist tendinitis. (In general, the evidence 
for work-related MSDs at the elbow has been 
less convincing than that for other body 
locations. Although the NIOSH review finds 
evidence for a relationship between force and 
epicondylitis, Kourinka and Forcier (1995, 
Ex. 26-

[[Page 65876]]

432) conclude that the evidence is not yet 
convincing.) Silverstein, Fine, and Armstrong 
(1987, Ex. 26-34), studying CTS as an 
outcome, found an OR of 15.5 (95% CI: 1.7-
142) for high-force/high-repetition jobs, 
compared to jobs with low levels of both. The 
interaction of force and repetition was 
important in this study; in separate models, 
force alone had a non-significant OR of 2.9 
and repetition alone had an OR of 5.9 (p < 
.05). Nathan et al. (1988, Ex. 26-990) also 
found elevated prevalences of CTS in workers 
holding high-force/high-repetition jobs. The 
case definition of these authors did not 
include self-reported symptoms but only 
measurable decrements in nerve conduction 
velocity. This is a stricter case definition 
than that of Silverstein et al. (1987, Ex. 
26-34), which was based on self-reported 
symptoms and physician examinations. This 
stricter case definition resulted in a 
smaller but more rigorously defined set of 
cases; the calculated OR was correspondingly 
lower (2.0, 95% CI: 1.1-3.4, comparing the 
highest-force/repetition group to the 
lowest). Note that this author did not find 
significant relationships between force and 
CTS in subsequent work (Nathan et al., 1992, 
Ex. 26-988).
   In addition to the NIOSH summary, other 
epidemiological studies point to an 
association between force requirements and 
work-related MSDs. Silverstein's 1985 cross-
sectional research on male and female 
industrial workers is suggestive, although 
the NIOSH summary found insufficient evidence 
for an association between force and shoulder 
MSDs and did not include this study (Ex. 26-
1173). The study compared workers in jobs 
characterized by a combination of high force 
and high repetition, measured at the wrist, 
to those in jobs with low levels of both 
exposures; the authors calculated an OR of 
5.4 (95% CI: 1.3-23) for prevalence of 
shoulder tendinitis and degenerative joint 
disease (thus using wrist measurements as a 
surrogate for shoulder exposure, a possible 
source of criticism). This study also found 
an OR for hand/wrist tendinitis of 29 (CI not 
reported).
   Vingard et al. (1991, Ex. 26-1400), in a 
registry-based cohort study of people 
hospitalized for osteoarthrosis over 3 years, 
compared men and women with high exposure to 
dynamic and static forces at the knee to 
those with low exposure. Occupations with 
significantly elevated relative risk were 
firefighter, farmer, and construction worker 
for men, and cleaner for women.
   Coggon et al. (1998, Ex. 26-1285) carried 
out a case-control study of 611 subjects with 
hip replacements due to osteoarthritis, 
compared to matched controls. Men who 
reported lifting more than 25 kilograms at 
least 10 times per week for 10 years prior to 
age 30 or for more than 20 years over their 
working life had higher rates of surgery (OR 
2.7 and 2.3, respectively significant at a 
0.05 level). The association did not hold for 
females.
   Laboratory Evidence. Ashton-Miller (1998, 
Ex. 26-414), summarizing a large body of 
laboratory evidence assessing the effects of 
loading on body tissues, concludes that 
muscle, tendon, and ligamentous tissues can 
fail when subjected to sufficient force under 
certain conditions. Faulkner and Brooks 
(1995, Ex. 26-1410) found that excessive 
force can cause muscle fiber damage, either 
by disruption of the actin-myosin (the 
contractile proteins) interdigitation or of 
the Z-lines between single sarcomeres (the 
contractile units in the muscle fibril). 
Muscles are particularly likely to be injured 
through exertion of excessive force in 
eccentric contractions (i.e., as the muscle 
is being lengthened, such as when stopping 
the motion of the body or an external object) 
(Brooks, Zerba, and Faulkner, 1995, Ex. 26-
87). Ashton-Miller (1998, Ex. 26-414) 
suggests that these injuries, although 
seemingly traumatic, commonly occur in 
combination with accumulated strain from 
lower levels of repeated forceful exertions 
(Wren, Beaupre, and Carter, 1998, Ex. 26-
245).
   Laboratory evidence for viscoelastic 
strain in tendons and ligaments under 
forceful loading is suggestive (e.g., 
Goldstein et al., 1987, Ex. 26-953; Crisco et 
al., 1997, Ex. 26-1373). However, more 
research is necessary to establish whether 
this strain progresses to MSDs. Animal 
studies have shown that forceful loading of 
tendons can produce structural changes 
similar to those found in MSDs (Rais, 1961, 
Ex. 26-1166; Backman et al., 1990, Ex. 26-
251).
   Forceful muscle contraction raises intra-
muscular pressure, potentially increasing 
pressure on nerves and vessels within the 
active muscle. Abundant animal studies (see 
summary, Rempel et al., 1998, Ex. 26-444) 
demonstrate that increased pressure on 
neurons can reduce blood flow around, and 
inhibit transport in, axons. Pressure 
elevations can impair nerve function, 
increase neural edema, and even alter myelin 
sheath structure. Many of these changes can 
occur over relatively short exposure times 
and in the presence of relatively low 
pressure elevations. These changes 
demonstrate a dose-response relationship. 
This suggests that elevated pressure around 
nerves during work tasks might cause 
decrements in nerve function. Both human 
cadaver studies (Cobb et al., 1996, Ex. 26-
98) and work with healthy volunteers (Rempel 
et al., 1997, Ex. 26-889; Keir et al., 1998, 
Ex. 26-289) demonstrate that forceful loading 
of fingertips results in elevated carpal 
tunnel pressures, well within the range 
demonstrated to cause damage to animal 
neurons.
   Psychophysical Evidence. Experiments 
performed over many years at the Liberty 
Mutual laboratories in Hopkinton, 
Massachusetts (Snook, 1996, Ex. 26-1353), 
have examined, in detail, the effects of 
different biomechanical stressors on 
subjects' reports of acceptable lifts, 
carries, pushes, pulls, etc. In general, the 
experimenter sets all parameters of a 
simulated task, with the exception of the 
load, which can be varied by the subject. The 
subjects are asked to rate task acceptability 
as if they were performed for a full day, so 
that the ratings of acceptable load include 
allowances for fatigue over the course of a 
workday. The research group has published 
extensive tables of these acceptable loads 
(Snook and Ciriello, 1991, Ex. 26-1008). 
Although there is great individual variation, 
these experiments generally show the 
subjects' ability to precisely estimate and 
regulate the load that would allow them to 
work a full day without becoming overtired or 
out of breath. These studies demonstrate the 
interrelatedness of the biomechanical 
stressors examined in the Health Effects 
Section. They show that acceptable load 
estimates are very sensitive to variations in 
posture, frequency, and the distance the load 
is moved.
   Klein and Fernandez (1997, Ex. 26-1357) 
administered a variant of this study design, 
allowing subjects to adjust the frequency of 
a repeated pinch grip (determining the 
maximum acceptable frequency [MAF]) under 
varying conditions of force, wrist posture, 
and pinch duration. They found that, as the 
force of the pinch grip was experimentally 
increased, the MAF fell.
   Summary: Force and Work-Related MSDs. The 
NIOSH findings of evidence for force-related 
MSDs in most upper-extremity locations, 
combined with the few studies addressing 
lower-extremity MSDs, make a case for a 
causal association of between increased 
workplace force requirements and disease. The 
large number of laboratory studies (see 
Appendix II, Ex. 27-1) provides evidence for 
several plausible and repeatable mechanisms 
by which

[[Page 65877]]

forceful exertions could cause MSDs. The 
psychophysical studies lend support to these 
conclusions, due to the demonstrated 
correlation between subjective workload 
estimates (discomfort, fatigue, and level of 
exertion) and objectively measured outcomes 
of injury frequency in workplaces (Snook et 
al., 1978, Ex. 26-35; Herrin et al., 1986, 
Ex. 26-961). These studies also demonstrate 
the interrelatedness of force exposures with 
several other risk factors for MSDs--in 
particular, repetition and awkward postures. 
Taken as a whole, the evidence is consistent 
and makes a strong case for force as a risk 
factor for work-related MSDs.
   b. Awkward Postures.
   Epidemiological Evidence. The NIOSH 
summary of upper-extremity MSDs (Bernard and 
Fine, 1997, Ex. 26-1; see Table V-1 above) 
did not separate static and awkward postures 
in their conclusions. The summary found 
evidence of a causal relationship between 
exposure to static or extreme postures and 
disorders of the shoulder and hand/wrist 
tendinitis. There is strong evidence of a 
causal relationship between postural 
stressors and neck MSDs. The summary found 
insufficient evidence for a relationship 
between these risk factors and elbow 
disorders or CTS. Of the 15 studies that 
addressed postures, many with positive 
results were carried out on VDT workers 
(e.g., Bernard et al., 1993, Ex. 26-439; 
Kukkonen et al., 1983, Ex. 26-1138). The 
research on the largest study population 
(Linton, 1990, Ex. 26-977) examined combined 
biomechanical and psychosocial exposures. The 
study looked at 22,180 Swedish employees 
undergoing screening examinations at their 
occupational health care service. Combined 
exposures to ``uncomfortable posture'' and 
poor psychosocial work environment showed an 
OR of 3.5 (95% CI: 2.7-4.5) for neck pain 
cases (defined as those who reported a visit 
to a health care professional in the last 
year for neck pain) compared to low-exposure 
jobs. The studies in the NIOSH summary 
support the conclusion that a combination of 
risk factors carries increased risk. In 
particular, the studies reviewed provide 
strong evidence for the causal relationship 
of combined risk factors (especially force, 
postural stressors, and repetition) with 
disorders of the elbow, CTS, and hand/wrist 
tendinitis.
   Other epidemiological studies demonstrate 
an association between awkward or extreme 
postures and work-related MSDs. Bjelle et al. 
(1979, Ex. 26-1112) found a strong 
relationship between industrial work with 
hands at or above shoulder level and outcomes 
of shoulder tendinitis (OR: 11; 95% CI: 2.7-
42). Similar findings appeared in studies by 
Herberts et al. (Ex. 26-960) on shipyard 
welders (1981; OR: 13; 95% CI: 1.7-95) and 
shipyard plate workers (1984; OR: 11; 95% CI: 
1.5-83). The referent group in these studies 
consisted of office workers. A cross-
sectional study of female assembly line 
packers, compared with department store shop 
assistants (Luopajarvi et al., 1979, Ex. 26-
56), found an OR of 7.1 for hand/wrist 
tendinitis (95% CI: 3.9-12.8). In this study, 
exposure was a combination of awkward 
postures, static postures and repetitive 
motions.
   The bulk of the NIOSH-reviewed studies 
(Bernard and Fine, 1997, Ex. 26-1) do not 
provide sufficient evidence for the link of 
postural factors with CTS. However, de Krom 
et al. (1990, Ex. 26-102) found associations 
between awkward (flexed and extended) wrist 
postures and CTS. The strength of association 
increased with hours of exposure. Marras and 
Schoenmarklin (1993, Ex. 26-172) were able to 
distinguish between jobs carrying a high and 
low risk of CTS, using a combination of 
measured wrist flexion and two dynamic 
factors (wrist extension angular velocity and 
wrist flexion angular acceleration).
   Laboratory Evidence. Ashton-Miller (1998, 
Ex. 26-414) cites a number of studies 
demonstrating that a change of force 
direction over bony or ligamentous structures 
creates transverse or shear forces and 
increases in friction experienced by tendons 
and tendon sheaths. Increased angles adopted 
by tendons as they pass around a tendon 
pulley (related to awkward posture) and 
increased longitudinal tension (related to 
the required muscle force) combine to 
increase friction on the tendon (Uchiyama et 
al., 1995, Ex. 26-339).
   In addition, extreme postures can require 
elevated muscle activity simply to overcome 
the resistance of passive tissues. Zipp et 
al. (1983, Ex. 26-1270) found that adopting 
an extremely pronated forearm position (such 
as that required by computer keyboard 
operation) requires high muscle activity, 
even without any external loading. Non-
extreme postures can still trap tissues in 
injurious positions. Smith, Sonstegard, and 
Anderson (1977, Ex. 26-1006) demonstrated 
that even non-extreme wrist flexion can cause 
the finger flexor tendons to compress the 
median nerve. Buchholz et al. (1988, Ex. 26-
1297) detail a sophisticated modeling 
approach that explains the measured increased 
muscle force demands associated with non-
optimal grip diameters (putting the fingers 
into awkward biomechanical relationships).
   Nerve tissue may also be at risk in 
anatomical sites associated with awkward 
posture. Any posture that compresses or 
crushes a nerve may cause the histological 
changes noted in Section C.3.a. Human studies 
(Armstrong et al., 1984, Ex. 26-1293) have 
shown that histological changes (edema, 
thickening, fibrosis) occur in nerves at the 
site of compression injury and possibly at 
sites of bending (e.g., the ulnar nerve at 
the elbow). The human cadaver studies (Cobb 
et al., 1996, Ex. 26-98) and healthy 
volunteer studies (Rempel et al., 1997, Ex. 
26-889; Keir et al., 1998, Ex.26-289) cited 
above also demonstrate that non-neutral hand 
postures, combined with forceful loading of 
fingertips, result in elevated carpal tunnel 
pressures, well within the range demonstrated 
to cause damage to animal neurons. Rempel et 
al. (1998, Ex. 26-444) cite eight human 
studies measuring pressure in the carpal 
tunnel when the wrist is in a flexed or 
extended posture relative to a neutral 
posture. Most of these studies show elevation 
of carpal pressure, again into the range that 
causes damage in the animal studies.
   Studies of the spine demonstrate similar 
negative effects of awkward postures. Marras 
et al. (1993, Ex. 26-170) include maximum 
sagittal trunk flexion angle as one of the 
five predictors of high risk for low-back 
injury. In a study by Hutton and Adams (1982, 
Ex. 26-1381), intervertebral disks in 
undeviated cadaver spines did not fail until 
loads exceeded 10,000 Newtons (N). However, 
disks in extremely flexed spines failed at 
roughly half that loading (average 5400 N--
Adams and Hutton, 1982, Ex. 26-1379). 
Repetitive loading reduced this average 
failure point to 3800 N (Adams and Hutton, 
1985, Ex. 26-1315). Although the relative 
magnitude of these forces is important, they 
may suggest lifting limits that are too high 
for many living workers. NIOSH, noting the 
large variability in compression forces 
associated with disc failure, estimated that 
21% of spinal segment specimens would fail at 
the 3400 N level used as a basis for the 
NIOSH lifting equation (Waters et al., 1991, 
Ex. 26-521). Adams et al. (1980, Ex. 26-701) 
report experimental and modeling evidence 
suggesting that combined forward flexion and 
lateral bending of the lumbar

[[Page 65878]]

spine reduce the injury tolerance of 
intervertebral disk fibers, possibly 
increasing chance of rupture. A possible 
mechanism for disk injury may relate to the 
fact that lateral flexion and axial rotation 
of the lumbar spine increase antagonistic 
muscle activity, thereby increasing the 
overall disk loading. This is consistent with 
observations that the combination of lifting, 
twisting, and bending is one of the most 
frequent causes of low-back pain (Rowe, 1983, 
Ex. 26-699).
   Psychophysical Evidence. The Liberty 
Mutual studies cited in Section C.3.a also 
demonstrate the subjective effect of awkward 
postures. The maximum acceptable weight (MAW) 
arrived at by the subjects in these 
experiments decreased if the lifts were 
carried out above shoulder height. The MAW 
was also inversely related to object size 
(reflecting the fact that moving bulkier 
loads generally requires more awkward 
postures).
   As described in Section C.3.a, Klein and 
Fernandez (1997, Ex. 26-1357) allowed 
subjects adjust to the frequency of a 
repeated pinch grip (determining the MAF) 
under varying conditions of force, wrist 
posture, and pinch duration. They found that 
the MAF at two-thirds the maximum wrist 
flexion was significantly less than in a 
neutral wrist posture. Wrist flexion angle 
was a significant factor for several 
variables.
   Marley and Fernandez (1995, Ex. 26-863), 
looking at the stressors associated with 
hand-held tools, assessed MAF for a simulated 
drilling task. Compared to ratings in a 
neutral wrist posture, when the wrist was at 
one-third maximum flexion, MAF was 88%; at 
two-thirds maximum flexion, MAF was 73% of 
the neutral posture value. Subjects used Borg 
RPE ratings (self-reported ratings of 
perceived exertion) (Borg, 1982, Ex. 26-705) 
to estimate required exertion at various body 
locations. Compared to a neutral wrist 
position, subjects performing the task with 
the wrist in two-thirds maximum flexion 
reported increases in exertion in the wrist, 
forearm, shoulder, and whole body.
   Asymmetrical lifting postures also 
resulted in a reduction in the MAW. Garg and 
Badger (1986, Ex. 26-121) asked subjects to 
carry out a floor-to-table lift twisted 30, 
60 and 90 degrees from neutral trunk posture. 
The MAWs showed significant decreases of 7%, 
15%, and 22%, respectively.
   Summary: Awkward Postures and Work-Related 
MSDs. The epidemiological evidence for a 
causal association between awkward postures 
and MSDs is strong, especially for neck 
disorders. Although the NIOSH review (Bernard 
and Fine, 1997, Ex. 26-1) found insufficient 
evidence that posture alone can cause CTS, 
the studies found strong evidence for CTS 
causation by a combination of risk factors. 
This suggests that the harmful effects of 
exposure to awkward posture may be 
experienced primarily in combination with 
other risk factors. The numerous laboratory 
studies examining the relationship between 
postural stressors and CTS, in particular, 
strengthen the evidence for a combination of 
awkward postures and force as risk factors 
for this outcome. Likewise, extensive 
epidemiological and laboratory evidence for 
increased risk of low-back injury due to 
bending and twisting also demonstrates the 
important role that postural stressors play 
in MSD causation.
   This evidence is further strengthened by 
the sensitivity to postural variables of 
subject-estimated safe loads in the 
psychophysical literature. These 
psychophysical studies lend support to these 
conclusions, due to the demonstrated 
correlation between subjective workload 
estimates (discomfort, fatigue and level of 
exertion) and objectively measured outcomes 
of injury frequency in workplaces (Snook et 
al., 1978, Ex. 26-35; Herrin et al., 1986, 
Ex. 26-961). These studies also demonstrate 
the interrelatedness of postural exposures 
with several other risk factors for 
musculoskeletal disorders, in particular, 
repetition and force. The convergent evidence 
from these diverse areas, with very different 
methodological approaches, strongly supports 
the hypothesis that awkward postures have a 
causal role in the etiology of MSDs.
   c. Static Postures.
   Epidemiological Evidence. Since the NIOSH 
summary (Bernard and Fine, 1997, Ex. 26-1) 
did not distinguish between awkward and 
static postures, the summary in section C.3.b 
applies here as well. In addition to the 
NIOSH summary (see Tables V-1 and V-2 above), 
other epidemiological studies demonstrate an 
association between static contractions or 
prolonged static load and work-related MSDs. 
In a review of the epidemiological evidence 
for three neck-related MSDs, the contributors 
to Kourinka and Forcier (1995, Ex. 26-432) 
report consistent associations between 
exposures to static head and arm postures and 
outcomes of tension neck syndrome. Grieco et 
al. (1998, Ex. 26-627) also report 
associations between static work and tension 
neck syndrome in several different 
occupations. Looking at the neck region more 
generally, Hales and Bernard (1996, Ex. 26-
896) report several studies showing 
consistent association between neck disorders 
and work involving static or constrained 
postures. A review of neck studies by Hidalgo 
et al. (1992, Ex. 26-631) proposes that 
prolonged static contraction of neck muscles 
be limited to force levels at or below 1% of 
maximum voluntary contraction (MVC). In an 
intervention study, Aaras et al. (1998, Ex. 
26-597) found that introduction of a 
workstation arrangement that allowed forearm 
support (thus lowering static load on the 
shoulders) reduced trapezius muscle activity 
from 1.5% to 0.3% of MVC and was associated 
with a reduction in neck pain.
   A cross-sectional study of 152 female 
assembly line packers, compared with 
department store shop assistants (Luopajarvi 
et al., 1979, Ex. 26-56), found an OR of 7.1 
for hand/wrist tendinitis (95% CI: 3.9-12.8). 
In this study, exposure was a combination of 
static postures, awkward postures and 
repetitive motions.
   A population-based case-control study 
(Cooper et al., 1994, Ex. 26-460), comparing 
cases with knee osteoarthritis to matched 
controls with non-arthritic knee pain, found 
that squatting more than 30 minutes per day 
was associated with an increased prevalence 
of osteoarthritis (OR: 6.9, 95% CI 1.8--
26.4). Vingard et al. (1991), in a registry-
based cohort study of people hospitalized for 
osteoarthrosis over 3 years, compared men and 
women with high exposure to static and 
dynamic forces at the knee to those with low 
exposure. Occupations with significantly 
elevated relative risk were firefighter, 
farmer, and construction worker for men, and 
cleaner for women.
   Laboratory Evidence. In general, the 
laboratory literature cited above for force 
and awkward posture is relevant to the 
prolonged exposures involved in static 
postures (Zipp et al., 1983, Ex. 26-1270; 
Buchholz et al., 1988, Ex. 26-1297; Smith, 
Sonstegard, and Anderson, 1977, Ex. 26-1006). 
Many of the same mechanisms apply, but the 
duration is increased and the temporal 
profile of exposure is made worse by the 
reduction in rest breaks and opportunity for 
recovery time. Lundborg et al. (1982, Ex. 26-
979) showed that a constant hydrostatic 
pressure (i.e., during a static muscle 
contraction) of between 30 and 60 mm Hg 
reduces microcirculation of the nerve and 
compromises nerve conduction.

[[Page 65879]]

   Rohmert (1973, Ex. 26-580) found that 
muscle contractions can be maintained for 
prolonged periods if kept below 20% of MVC. 
But other investigators (Westgaard and Aaras, 
1984, Ex. 26-1026) found chronic deleterious 
effects of contractions even if they are 
lower than 5% of MVC. This latter finding is 
supported by the observation that low-level 
static loading (such as shoulder loading in 
keyboard tasks) is associated with shoulder 
MSDs (Aaras et al., 1998, Ex. 26-597). The 
supraspinatus muscle, a muscle severely 
constrained by bone and ligamentous tissue, 
demonstrates increased intramuscular pressure 
during small amounts of shoulder abduction or 
flexion (Jarvholm et al., 1990, Ex. 26-285). 
This suggests the possibility of chronic 
blood vessel and nerve compression during 
static tasks.
   Chronic reduction of blood flow may be a 
mechanism by which static muscle contractions 
lead to MSDs. Several studies have found that 
the small, slow motor units in patients with 
chronic muscle pain show changes consistent 
with reduced local oxygen concentrations 
(Larsson et al., 1988, Ex. 26-1140; Dennett 
and Fry, 1988, Ex. 26-104). Reduced blood 
flow and disruption of the transportation of 
nutrients and oxygen can produce 
intramuscular edema (Sjogaard, 1988, Ex. 26-
206). The effect can be compounded in 
situations where recovery time between static 
contractions is insufficient. Eventually, a 
number of changes can result: muscle membrane 
damage, abnormal calcium homeostasis, an 
increase in free radicals, a rise in other 
inflammatory mediators, and degenerative 
changes (Sjogaard and Sjogaard, 1998, Ex. 26-
1322).
   Psychophysical Evidence. Several studies 
have evaluated the maximum acceptable weight 
( MAW) in conditions requiring prolonged 
stooping (low ceiling height). Smith et al. 
(1992, Ex. 26-1007) performed laboratory 
experiments on 100 subjects (50 male, 50 
female) recruited from a college-age 
population at Texas Tech University. The 
study collected data on a number of awkward 
postures, such as twisting, lying down, 
kneeling, squatting, and carrying loads with 
a restricted ceiling. The authors found that 
the MAW decreased with decreasing ceiling 
height (which requires forward flexion during 
lifting) as well as with twisted postures.
   Klein and Fernandez (1997, Ex. 26-1357) 
allowed subjects to adjust the frequency of a 
repeated pinch grip (determining the MAF) 
under varying conditions of force, wrist 
posture and pinch duration. They found that, 
as the pinch grip was held for longer 
increments of time (1, 3, and 7 seconds), the 
MAF fell.
   Summary: Static Postures and Work-Related 
MSDs. The epidemiological evidence is 
particularly strong for the causal role of 
static postures in MSDs of the neck and 
shoulder region. This evidence is suggestive 
but less convincing for disorders of the 
distal upper extremities. Laboratory evidence 
for muscle and tendon damage in these areas, 
as well as secondary compression of blood 
vessels and nerves, lends support to the 
connection between work-related static 
postural requirements and the development of 
these disorders. The psychophysical studies 
have not generally focused on static 
postures, but the two studies cited in 
section C.3.c provide evidence of increased 
fatigue and discomfort related to static 
postures of the back and fingers. These 
psychophysical studies lend support to the 
conclusions of work-relatedness, due to the 
demonstrated correlation between subjective 
workload estimates (discomfort, fatigue, and 
level of exertion) and objectively measured 
outcomes of injury frequency in workplaces 
(Snook et al., 1978, Ex. 26-35; Herrin et 
al., 1986, Ex. 26-961). These studies also 
demonstrate the interrelatedness of postural 
exposures with several other risk factors for 
musculoskeletal disorders, in particular 
repetition and force. Taken as a whole, the 
evidence suggests that static postures are 
causal factors in the etiology of MSDs, both 
through exacerbation of the mechanisms 
explored under other risk factors (e.g., 
awkward postures, force) and through chronic 
reductions in blood flow and neural function 
caused by prolonged elevations of 
intramuscular pressure.
   d. Repetition. Repetition has qualities of 
both a risk factor and a modifying factor (or 
``characteristic property'' (ANSI, 1998, Ex. 
26-1264)). Because of this borderline 
position, repetition is often reported as an 
exposure intensifier (e.g., Radwin and 
Lavender, 1998, Ex. 26-37) and often as a 
risk factor in itself (e.g., Kourinka and 
Forcier, 1995, Ex. 26-432). Thus, a 
substantial portion of the evidence presented 
in subsequent sections, supporting the 
association of repetition with work-related 
MSDs, examines repetition in combination with 
other risk factors. In fact, the NIOSH 
summary (Bernard and Fine, 1997, Ex. 26-1) 
found that a combination of risk factors 
increases the strength of the evidence for 
work-relatedness. This suggests that each 
individual risk factor has characteristics of 
both a basic risk factor and a modifier, and 
the distinction becomes somewhat academic.
   Epidemiological Evidence. The NIOSH 
summary (Bernard and Fine, 1997, Ex. 26-1; 
see Table V-1 above) found evidence for work-
related MSDs connected with exposure to 
repetitive work for all body locations 
considered except the elbow. Of the 16 
selected studies that addressed repetition 
exposure and found a positive association 
with neck disorders, 11 found associations 
that were statistically significant. Ohlsson 
et al. (1995, Ex. 26-868) compared 82 female 
industrial workers exposed to short-cycle 
tasks (less than 30 seconds) to 64 referents 
with no exposure to repetitive work. The OR 
for tension neck syndrome was 3.6 (95% CI: 
1.5-8.8), and the OR for shoulder symptoms 
(several types of tendinitis, frozen 
shoulder, acromioclavicular syndrome) was 5.0 
(95% CI: 2.2-11.0). Silverstein et al. (1987, 
Ex. 26-34), studying CTS as an outcome, found 
an OR of 15.5 (95% CI: 1.7-142) for high-
force/high-repetition jobs, compared to jobs 
with low levels of both. Jobs with only high-
repetition exposure still demonstrated an OR 
of 5.5, compared to low-force/low-repetition 
jobs. Nathan et al. (1988, Ex. 26-990) also 
found an elevated prevalence of CTS in 
workers holding high-force/high-repetition 
jobs. Their stricter case definition was 
based on nerve conduction velocity 
decrements, and the calculated OR was 
correspondingly lower (2.0, 95% CI: 1.1-3.4). 
Note that subsequent investigations by this 
investigator did not find a significant 
association of repetition with CTS (Nathan et 
al., 1992, Ex. 26-988).
   Other epidemiological studies demonstrate 
an association between repetitive movements 
and work-related MSDs. The contributors to 
Kourinka and Forcier (1995, Ex. 26-432), in a 
review of the epidemiological evidence for 
three neck-related MSDs, report weak-to-
moderate, but consistent associations between 
exposures to repetitive work and outcomes of 
tension neck syndrome and thoracic outlet 
syndrome (TOS). They and other reviewers 
(e.g., Grieco et al., 1998, Ex. 26-627) did 
not find convincing evidence of a connection 
between repetition and cervical 
radiculopathy. Looking at the neck region 
more generally, Hales and Bernard (1996, Ex. 
26-896) report several studies showing 
consistent association between neck disorders 
and repetitive work/forceful repetitive work.
   Silverstein's (1985, Ex. 26-1173) cross-
sectional study of male and female industrial 
workers compared workers in

[[Page 65880]]

jobs characterized by a combination of high 
force and high repetition to those in jobs 
with low levels of both exposures. She 
calculated a risk ratio of 5.4 (95% CI: 1.3-
23) for prevalence of shoulder tendinitis and 
degenerative joint disease. This study found 
an OR for hand/wrist tendinitis of 29 (CI not 
reported). A cross-sectional study of female 
assembly line packers, compared with 
department store shop assistants (Luopajarvi 
et al., 1979, Ex. 26-56), found an OR of 7.1 
for hand/wrist tendinitis (95% CI: 3.9-12.8). 
In this study, exposure was a combination of 
awkward postures, static postures and 
repetitive motions. Other studies have also 
demonstrated a strong association between CTS 
and repetition (reviewed in Kourinka and 
Forcier, 1995, Ex. 26-432).
   A population-based case-control study 
(Cooper et al., 1994, Ex. 26-460), comparing 
cases with knee osteoarthritis to matched 
controls with non-arthritic knee pain, found 
that climbing more than 10 flights of stairs 
per day was associated with increased 
prevalence of osteoarthritis (OR: 2.7, 95% CI 
1.2-6.1).
   Laboratory Evidence. In 1951, Sperling 
(Ex.26-1411) subjected his own fingers to a 
series of prolonged, repetitive movements, 
against resistance. In all cases, the area 
around the affected tendon became tender and 
swollen, and in most cases, he began to 
notice snapping and thickening. These 
symptoms remained for several months. 
Sperling concluded that tendon injury could 
be caused by simple, repetitive loading, 
without the necessity for traumatic injury. 
Rais (1961, Ex. 26-1166) performed two 
experiments subjecting rabbits to varying 
degrees of stressful, repetitive leg 
movement. Overall, he found evidence of 
peritendinitis, localized to the area of the 
myotendinous junction. The changes indicated 
cellular damage and restorative activities. 
In the muscles themselves, he also observed 
degeneration of varying degrees, fibrin 
deposition, and evidence of regeneration.
   Experimentally, Hagberg (1981, Ex. 26-955) 
demonstrated that a 1-hour course of 
repetitive shoulder flexion movements could 
induce acute shoulder tendinitis. Several 
investigators found an increase in shoulder 
muscle activity and/or pain when assembly 
line work pace was increased (e.g., Odenrick 
et al., 1988, Ex. 26-576; Ohlsson et al., 
1989, Ex. 26-1290). These findings should be 
interpreted with caution: Shoulder tension is 
strongly affected by psychosocial factors 
(although it should be noted that the overall 
effect is still the increase of shoulder 
muscle activity).
   A few investigators have studied the 
effects of repeated loading on cadaver spinal 
segments (Brinckmann, et al., 1987, Ex. 26-
1318; 1988; Hansson, et al., 1987, Ex. 26-
279). These studies applied a submaximal load 
(a percentage of the load associated with 
failure in a single application). A strong 
dose-response relationship emerged. Even with 
compressive loads set at 55% of the single 
trial failure load, mechanical failure 
occurred in 92% of the specimens after 5000 
cycles. At 65% of this load, 91% of the 
specimens failed after only 500 cycles. At 
75% of this load, some specimens failed after 
only 10 cycles. Although cadaver tissue 
probably acts differently from living tissue, 
these results do suggest that repetition is a 
risk factor for spinal injury.
   Psychophysical Evidence. The Liberty 
Mutual studies cited in Section C.3.a.iii 
also demonstrate the subjective effect of 
repetition rates on subject estimates of 
tasks that could be performed over the course 
of a work day without undue fatigue, 
discomfort, or overexertion (Snook, 1996, Ex. 
26-1353). As noted above, the experimenter 
sets all parameters of a simulated task, with 
the exception of the load, which can be 
varied by the subject. The subjects are asked 
to rate task acceptability as if they were 
performing the task for a full workday, so 
the ratings of acceptable load include 
allowances for fatigue over the course of a 
workday. The research group has published 
extensive tables of these acceptable loads 
(Snook and Ciriello, 1991, Ex. 26-1008). 
Although there is great individual variation, 
these experiments in general show the 
subjects' ability to precisely estimate and 
regulate the load that would allow a full day 
of work without becoming overtired or out of 
breath. These studies show that acceptable 
load estimates are very sensitive to 
variations in the repetition rate of the 
task. In all variations, the MAW that was 
estimated by the subjects in these 
experiments decreased as the frequency of the 
lift, lower, push, or pull increased.
   Separate studies by Garg and Banaag (1988, 
Ex. 26-951) and Mital and Fard (1986, Ex. 26-
182), in addition to replicating the MAW 
decrements attributable to asymmetric lifting 
noted under ``awkward postures,'' also found 
that increased frequency of lifting reduced 
the MAW reported by their subjects. Klein and 
Fernandez (1997, Ex. 26-1357) administered a 
variant of this study design, allowing 
subjects to adjust the frequency of a 
repeated pinch grip (determining the MAF) 
under varying conditions of force, wrist 
posture, and pinch duration. They found that, 
as force of the pinch grip was experimentally 
increased, the MAF fell.
   Summary: Repetition and Work-Related MSDs. 
Despite the difficulties in assessing 
repetition in isolation from other risk 
factors, the epidemiological evidence 
strongly implicates repetitive motions in the 
etiology of work-related MSDs. A large body 
of laboratory studies demonstrates a 
biological plausibility for this 
relationship. The psychophysical research 
lends support to the epidemiological and 
laboratory results: it demonstrates a 
correlation between subjective workload 
estimates (discomfort, fatigue, and level of 
exertion) and objectively measured outcomes 
of injury frequency in workplaces (Snook et 
al., 1978, Ex. 26-35; Herrin et al., 1986, 
Ex. 26-961). These studies also demonstrate 
the interrelatedness of repetition with 
several other risk factors for 
musculoskeletal disorders, in particular, 
force and awkward postures. In sum, the 
congruence of evidence from several different 
research traditions, with different 
methodologies, strongly implicates repetition 
in the etiology of work-related MSDs.
   e. Dynamic Factors.
   Epidemiological Evidence. The contributors 
to the NIOSH summary (Bernard and Fine, 1997, 
Ex. 26-1) did not examine evidence linking 
dynamic factors with work-related MSDs. Most 
research on dynamic factors has been carried 
out on low-back injury. Sudden maximal 
lifting effort and unguarded movements appear 
to be risks for developing work-related low-
back pain (Magora and Schwartz, 1976, Ex. 26-
389). Marras and Granata (1995, Ex. 26-1383) 
categorized jobs into three levels of risk 
(meaning risk of low-back injury, assessed by 
medical reports). They then calculated ORs of 
a job, characterized by five measures of 
exposure falling into the high-risk category. 
The OR of a job with the highest combined 
exposure score, compared to the lowest 
combined score, was 10.7 (95% CI: 4.9-23.6). 
These exposure measures (assessed by 
sophisticated electrogoniometry) include 
dynamic factors: linear and angular velocity 
and acceleration of the lumbar spine. Marras 
and Schoenmarklin (1993, Ex. 26-172) also 
implicate dynamic factors in wrist MSDs. 
Using a similar, job-based analytic design, 
they found that angular velocity of wrist

[[Page 65881]]

extension and angular acceleration of wrist 
flexion could distinguish between jobs having 
high and low prevalence of CTS.
   Laboratory Evidence. The most persuasive 
evidence for the risks associated with 
dynamic factors comes from work on the 
intervertebral disks. Marras and Granata 
demonstrated that the magnitude of 
compressive and shear forces on the disks is 
related to the speed and acceleration of 
movement in both lateral bending (1997, Ex. 
26-169) and twisting (1995, Ex. 26-1383). 
Degree of asymmetry also affects the trunk 
motion characteristics associated with 
increased risk of back injury (Marras et al., 
1993, Ex. 26-170). Velocity and acceleration 
measures were all higher with one-handed 
lifts, the size of increase being 
proportional to the angle of asymmetry.
   Szabo and Chidgey (1989, Ex. 26-1168) 
found that repetitive, passive wrist flexion 
and extension resulted in higher pressures in 
the carpal tunnel. These elevated pressures 
took longer to return to normal in their CTS 
patients than in normal subjects. These 
investigators also found evidence that, if 
the wrist and finger motions are active (in 
other words, if the subject rather than the 
investigator moves the wrist), the effect may 
be larger.
   Psychophysical Evidence. The 
psychophysical laboratory studies have not 
explicitly examined the impact of dynamic 
factors, although it is likely that the 
studies of repetition (Section C.3.d) do 
address dynamic factors by proxy (Snook, 
1996, Ex. 26-1353; Snook and Ciriello, 1991, 
Ex. 26-1008; Garg and Banaag, 1988, Ex. 26-
951; Mital and Fard, 1986, Ex. 26-182; Klein 
and Fernandez, 1997, Ex. 26-1357). Increased 
repetition rates necessarily entail increases 
in angular and linear velocity and 
acceleration of some body segments. The 
resultant increases in forces experienced by 
body tissues (e.g., Marras and Granata, 1995, 
1997 Exs. 26-1383 and 26-169) might explain 
the subjective perceptions of fatigue and 
discomfort that result in a particular 
estimated MAW.
   Summary: Dynamic Factors and Work-Related 
MSDs. Attention to dynamic factors in their 
own right (as opposed to the proxy 
representation of repetition) is very recent. 
The bodies of epidemiological and laboratory 
evidence relating dynamic stressors to MSD 
development are consistent with each other 
and with research centered on the other risk 
factors. But the existing studies are limited 
in number and in scope. As a result, the 
literature does not allow quite as much 
confidence in connecting these factors with 
work-related MSDs as can be demonstrated for 
the other risk factors addressed in this 
section. Further research is needed to more 
firmly establish the link between dynamic 
factors and work-related MSDs.
   f. Compression. The classification of risk 
factors presented in Section B separated 
compression into external and internal 
compression. Internal compression has been 
addressed above, as the consequence of other 
biomechanical exposures, such as force, 
awkward and static postures, and repetition. 
This section only addresses externally 
applied compressive forces.
   Epidemiological Evidence. The NIOSH 
summary (Bernard and Fine, 1997, Ex. 26-1) 
did not examine the association of 
compressive forces with MSDs. A few 
epidemiological studies have assessed the 
role of compression as a risk factor. 
Hypothenar hammer syndrome, characterized by 
signs of blood deprivation in the fingers, is 
caused by thrombosis or aneurysm in the ulnar 
artery or the superficial palmar arterial 
arch. This condition has been linked to the 
practice of using the palm as a hammer, 
exposing the palm to repetitive, forceful 
compression. Little and Ferguson (1972, Ex. 
26-1144) calculated an OR of 16.3 (95% CI: 
2.7-100) for objectively verified (by a 
Doppler flow detector) ulnar artery block, 
comparing vehicle maintenance workers who 
used their hands as a hammer (n=79) to those 
who did not (n=48). Nilsson et al. (1989, Ex. 
26-1148) found a smaller effect (OR: 2.8; 95% 
CI: 1.3-6.2), comparing 890 plate workers to 
61 office workers in the same plant. This 
study also found a dose-response 
relationship, with the OR increasing with 
increasing years on the job. However, 
inappropriate palm use and vibration exposure 
occurred together in this population.
   Two studies also link bursitis of the knee 
with jobs that require a substantial amount 
of time in a kneeling position. Thun et al. 
(1987, Ex. 26-60) found a non-significant 
prevalence ratio for bursitis of 3.2 (90% CI: 
0.8-3.9), comparing tile and terrazzo setters 
to bricklayers and millwrights. Kivimaki et 
al. (1992, Ex. 26-1137), comparing carpet 
layers to painters, calculated an OR of 11.2 
(95% CI: 3.4-38) for doctor-diagnosed 
prepatellar bursitis. A population-based 
case-control study (Cooper et al., 1994, Ex. 
26-460) compared cases with knee 
osteoarthritis to matched controls with non-
arthritic knee pain. They found that kneeling 
more than 30 minutes per day was associated 
with increased prevalence of osteoarthritis 
(OR: 3.4; 95% CI: 1.3-9.1).
   Laboratory Evidence. Most of the research 
concerning the relationship of mechanical 
compression to MSDs has been conducted in the 
laboratory. Researchers have known for years 
that tools with inappropriately short 
handles, such as pliers and paint scrapers, 
can apply substantial compressive force to 
the blood vessels and nerves in the palmar 
area, resulting in occlusion of the ulnar 
artery, in particular, and possible 
neuropathy (Tichauer; 1966, Ex. 26-1172; 
Tichauer and Gage, 1977, Ex. 26-1269). There 
is medical evidence for compression-related 
MSDs. Finelli (1975, Ex. 26-115) describes 
the compression of an ulnar nerve branch in 
the palm by both occupational (tool handles) 
and non-occupational (bicycle handle grips) 
exposures. Sauter et al. (1987, Ex. 26-199) 
present a case example of injury due to wrist 
compression at a keyboard job. Several 
investigators describe compression of the 
ulnar nerve at the elbow, caused by leaning 
the ulnar side of the elbow on a hard surface 
(e.g., Aguayo, 1975, Ex. 26-702). Nevasier 
(1980, Ex. 26-394) found examples of shoulder 
tenosynovitis in individuals who habitually 
carried heavy loads (such as lumber) on their 
shoulder.
   Psychophysical Evidence. Psychophysical 
studies have not examined the effects of 
compression.
   Summary: Compression and Work-Related 
MSDs. Despite the long history of recognition 
(particularly the relationship between tool 
handles and palmar compression), relatively 
little research has been performed on this 
risk factor. The existing epidemiological and 
laboratory evidence is congruent in 
suggesting the linkage between compression 
and at least two medical conditions. 
Particularly in the case of hypothenar hammer 
syndrome, a plausible physiologic mechanism 
exists.
   g. Vibration.
   Epidemiological Evidence. The NIOSH 
summary (Bernard and Fine, 1997, Ex. 26-1; 
see Table V-1 above) finds strong evidence 
for a causal relationship between segmental 
vibration and hand-arm vibration syndrome 
(HAVS). The only study to meet all four of 
the NIOSH inclusion criteria (Bovenzi et al., 
1995, Ex. 26-354) compared forestry workers 
with more than 400 hours of sawing to 
shipyard workers

[[Page 65882]]

with no vibration exposure. These authors 
found increasing effect sizes, depending on 
the intensity of vibration exposure. The OR 
for forestry workers using anti-vibration 
saws was 6.2 (95% CI: 2.3-17.1); the OR for 
workers using no anti-vibration measures was 
32.3 (95% CI: 11.2-93). This study also found 
a dose-response relationship to number of 
years exposed. Nilsson et al. (1989, Ex. 26-
1148), comparing platers with current 
vibration exposure to office workers in the 
same workplace, calculated an OR of 85 (95% 
CI: 15-486). The high ORs in these studies 
have large confidence intervals but 
demonstrate the strength of effect that is 
characteristic of many vibration studies.
   Other epidemiological studies demonstrate 
an association between vibration and work-
related MSDs. Most work reported in the 
Health Effects Section addresses segmental 
vibration exposure of HAVS or occupational 
Raynaud's syndrome. Studies of select 
populations using vibrating tools find high 
concentrations of vascular and neurological 
symptoms compared to these in other working 
populations. Examples include shipyard 
workers (Cherniack et al., 1990, Ex. 26-
1116), surgeons (Cherniack and Mohr, 1994, 
Ex. 26-1341), and dental technicians 
(Hjortsburg, 1989, Ex. 26-1131).
   The NIOSH summary also found evidence for 
a causal link between segmental vibration and 
CTS. Chatterjee et al. (1982, Ex. 26-941) 
compared 16 rock drillers to 15 controls 
unexposed to vibration. The OR for CTS, 
identified by nerve conduction studies, was 
10.9 (95% CI: 1.02-524). Weislander et al. 
(1989, Ex. 26-1027), comparing 32 male CTS 
patients to population referents, found an OR 
for vibrating tool use of 6.1 (95% CI: 2.4-
15). Several other studies have also found an 
association between CTS and vibration 
exposure in jobs involving the use of 
vibrating tools, such as grinders and 
chipping hammers (e.g., Nathan et al., 1988, 
Ex. 26-990; Hagberg et al., 1992, Ex. 8-1). 
In this literature, however, it is extremely 
difficult to separate the association of CTS 
and vibration from the association of CTS and 
the other biomechanical stressors that often 
are associated with these tools: awkward and 
static postures, repetition, and high force 
requirements.
   Some literature has addressed the 
consequences to other body parts of whole-
body vibration exposure to other body parts. 
Hedlund (1989, Ex. 26-1279) found a foot 
analogue of HAVS in miners exposed to whole-
body and segmental vibration. However, other 
research suggests that foot symptoms may be a 
more generalized sympathetic nervous system 
response to segmental exposure in the upper 
extremities (Sakakibara et al., 1991, Ex. 26-
1356). Other studies of whole-body vibration 
have suggested links to driving. Jensen et 
al. (1996, Ex. 26-145), studying a cohort of 
more than 89,000 drivers hospitalized for 
prolapsed cervical disks over 10 years, found 
a Standardized Hospitalization Ratio (SHR) of 
142 (95% CI: 126.8-159.6), compared to other 
male workers. They also reported a prevalence 
ratio for self-reported vibration exposure of 
7.1 (95% CI: 4.1-11.7) for the drivers. This 
research did not directly link vibration 
exposure with outcomes of prolapsed cervical 
disk.
   Laboratory Evidence. Short-term and long-
term changes to human neural tissue have been 
demonstrated by a number of researchers. 
These effects include intraneural edema, 
structural changes in non-myelinated fibers, 
demyelination, fibrosis, and even loss of 
axons (Takeuchi et al., 1988, Ex. 26-682; 
Stromberg et al., 1997, Ex. 26-894). Chang et 
al. (1994, Ex. 26-357) found similar changes 
in rat peripheral nerves. Finger biopsies of 
workers heavily exposed to local vibration 
have shown signs of significant endothelial 
injury (Takeuchi et al., 1986, Ex. 26-681).
   In the back, vibration may diminish the 
blood flow to the intervertebral disks. This 
has been demonstrated by Hirano, Tsuji, and 
Oshima (1988, Ex. 26-140) in rabbit 
intervertebral disks exposed to in vivo 
vibration. This could predispose the spine to 
injury by reducing both the transport of 
nutrients to the disk interior and the degree 
of hydration necessary to support the spine 
under load.
   Psychophysical Studies. Although the 
weighting curves established for vibration 
exposure rely heavily on perceived 
discomfort, no formal psychophysical 
laboratory work has been performed on 
vibration.
   Summary: Vibration and Work-Related MSDs. 
Vibration is the one biomechanical stressor 
that may be able to cause a specific disease 
(HAVS) as the only exposure. The 
epidemiological evidence is considered strong 
for vibration as the only causal factor for 
this outcome. Epidemiological evidence also 
exists for a causal link between vibration 
exposure and CTS.
   The laboratory evidence supports these 
conclusions with findings of anatomical and 
physiological changes, due to segmental 
vibration, that are consistent with the 
symptoms and signs of HAVS. This congruent 
evidence strongly supports the implication of 
segmental vibration as the risk factor for 
the development of HAVS.
   The evidence supporting the association 
between whole-body vibration exposure and 
disk degeneration is not as strong, but it is 
suggestive. More research into this 
association is required.


4. Modifying Factors and MSDs

   Many of the studies cited above also 
indicate the importance of the modifying 
factors in this section's classification 
scheme: intensity/magnitude, duration, 
temporal profiles, and cold temperatures. 
Much of the research summarized by Bernard 
and Fine (1997, Ex. 26-1) finds that 
exposures characterized by high intensity 
and/or duration are associated with higher 
levels of MSD outcome than those with lower 
levels of these modifiers. These two 
modifiers are examined more fully in Section 
C.5, below.
   a. Intensity. Intensity is included in 
many of the epidemiological and laboratory 
studies cited above. In particular, studies 
assessing the effects of high and low force 
are based in measures of intensity. The 
evidence for intensity as an important 
modifier of exposure in MSD etiology is 
presented below, in Section C.5.
   b. Duration. As with intensity, duration 
is often the measure of high and low exposure 
in studies cited above. Much epidemiologic 
research measures the hours of exposure and 
has documented a dose-response relationship 
between duration and MSD outcomes. For 
example, Brisson et al. (1989, Ex. 26-937) 
found that the length of exposure to 
piecework in the garment industry was 
associated with increased MSD levels. de Krom 
et al. (1990, Ex. 26-102) found that hours of 
exposure increased the association of 
awkward, flexed wrist postures with CTS. 
Hagberg et al. (1990, Ex. 26-1317) 
demonstrated a duration/MSD association for 
vibration exposure. Kourinka and Forcier 
(1995, Ex. 26-432) summarize a collection of 
similar studies, all of which find that 
length of exposure, either per day or over a 
lifetime, increases the size of the 
association between exposure and work-related 
MSD outcome.
   Duration may be measured in much longer 
time spans than hours. Anderson and Felson 
(1988, Ex. 26-926), analyzing the First 
National Health and Nutrition

[[Page 65883]]

Examination Survey (HANES I) data, found that 
an increased risk of osteoarthritis related 
to job characteristics appeared only in older 
workers, suggesting that lifelong exposure 
may be a part of the etiology.
   The evidence linking duration with MSD 
causation is presented in detail below, in 
Section C.5.
   c. Temporal Profile (Fatigue/Inadequate 
Recovery Time). In general, repeated damage 
to body tissues without adequate recovery 
time for repair may create permanent 
structural damage. Fatigue has been shown to 
modify muscle response to external load. As 
noted above, when muscles fatigue, the 
characteristics and effects of internal 
muscle loading can be changed in two ways. 
Within a given muscle, fiber recruitment 
generally proceeds from small to large 
fibers. Some small, slow-twitch fibers may be 
almost constantly in use and become fatigued 
and possibly injured, even during very-low-
force contractions (see Section C.3.c) 
(Radwin and Lavender, in NAS, 1998, Ex. 26-
37). This phenomenon, termed the ``Cinderella 
fiber theory,'' is discussed in more detail 
in later sections. This theory suggests one 
physiological reason that adequate rest 
cycles in work activities are important.
   d. Cold Temperatures. Research has 
strongly linked cold to the exacerbation of 
effects due to vibration exposure. Lundstrom 
and Johansson (1986, Ex. 26-164) demonstrated 
the reduction in mechanoreceptor sensitivity 
with combined exposure to vibration and cold. 
This was accompanied by an increase in finger 
force exerted by subjects, creating better 
coupling between hand and vibration source 
and increasing the amount of vibration 
absorbed by the upper extremities. 
Simultaneously, this increased force is 
itself a possible risk factor for CTS.
   Cold temperatures may also increase muscle 
activation required for a given task. 
Hammerskjold et al. (1992, Ex. 26-957) found 
increased EMG signals in carpenters after 
hand exposure to cold, as well as increased 
perceived exertion and increased time 
required to carry out nailing tasks. Riley et 
al. (1983, Ex. 26-1358) showed that exposure 
to cold temperatures resulted in decreased 
performance on an assembly task. The 
experimentally demonstrated decrease in 
strength and coordination of the hands after 
exposure to cold (e.g., Vangaard, 1975, Ex. 
26-506; Vincent and Tipton, 1988, Ex. 26-592) 
may be the mechanism through which greater 
force requirements are made on muscles and 
tendons, causing or exacerbating MSDs.
   e. Summary: Modifiers and Work-Related 
MSDs. The evidence for the effects of these 
modifying factors is contained within each 
risk factor section, as well as in the brief 
review above. Section C.5 below explores the 
evidence for the roles of intensity and 
duration in modifying the relationship of 
stressors to MSD outcomes. This evidence 
makes a strong case for the impact that each 
of these workplace modifiers has on the way 
the body tissues receive a given ``dose'' of 
a biomechanical stressor and the way in which 
that tissue can process, repair, and recover 
from this dose.


5. Evidence for the Relationships Between 
Exposure Intensity and MSD Prevalence

   This section reviews studies designed to 
examine the relationships between intensity 
and/or duration of exposure to workplace risk 
factors and the magnitude of the risk for 
developing a work-related MSD (typically 
measured as an OR). In this capacity, the 
section reviews some of the studies presented 
above in greater detail. Data demonstrating a 
positive relationship between exposure and 
response provide evidence for a causal 
relationship between exposure to the hazard 
in the workplace and an increase in the 
occurrence and/or severity of the adverse 
response. Often, regression analysis is used 
to verify that the relationship is 
statistically significant even when potential 
confounding factors, such as gender and age, 
are taken into consideration. The strength of 
the association between exposure and response 
is reflected in the slope of the exposure-
response curve; as the slope increases, the 
strength of the association increases and 
provides greater evidence of a causal 
relationship between exposure to the hazard 
of interest and increased risk of injury or 
illness.
   Generalized models do not exist that would 
permit OSHA to use these data to quantify 
risk across all working populations. 
Nevertheless, these studies are useful to 
illustrate the extent to which risk can be 
reduced by reducing the intensity and 
duration of exposures to workplace risk 
factors.
   The relationship between duration of 
exposure to workplace risk factors and 
prevalence of MSDs has been demonstrated in 
numerous studies. For example, the 1988 
Occupational Health Supplement to the 
National Health Interview Survey (NHIS-OHS) 
conducted by the National Center for Health 
Statistics (NCHS) showed a clear dose-
response relationship between hours engaged 
in manual handling and episodes of back pain 
lasting 7 days or longer. NCHS interviewed 
27,408 currently employed workers between 18 
and 64 years of age to gather information on 
the health conditions of the currently 
employed noninstitutionalized civilian 
population and to develop weighted national 
estimates of the incidence of health 
conditions, including episodes of back pain, 
known to occur in association with 
employment. All estimates were based on self-
reports.
   NIOSH (Exs. 26-1104, 26-1105, 26-1106) 
used the NCHS data to develop weighted 
national estimates of the number of currently 
employed workers by the status of back pain 
episodes lasting 1 week or longer, and by 
number of hours exposed to some of the 
workplace risk factors associated with MSDs 
of the back: strenuous physical activity and 
repeated bending, twisting, or reaching. 
Exposure was divided into categories of 0 
hours, 0 to less than 2 hours, 2 to less than 
4 hours, 4 to less than 6 hours, 6 to less 
than 8 hours, and 8 hours or more.
   Of particular interest were:
    The number of currently employed 
workers experiencing no episodes of back 
pain.
    The number of currently employed 
workers experiencing an episode of back pain 
lasting 1 week or longer due to repeated 
activities at their current or most recent 
job and not due to any accident.

With these data categorized by hours of 
exposure to workplace risk factors, ORs could 
be calculated for episodes of back pain due 
to repeated activities at work for each of 
the exposure categories and each of the 
workplace risk factors considered.
   Table V-3 presents the estimated number of 
currently employed workers engaged in 
strenuous physical activity such as lifting, 
pushing, or pulling heavy objects. Table V-4 
presents the estimated number of currently 
employed workers engaged in repeated bending, 
twisting, or reaching. In each table the 
estimated numbers are broken down by hours 
per day engaged in each of the work 
activities, and by back pain status (either 
none or an episode lasting at least 1 week 
due to repeated activities at a current or 
most recent job and not due to any accident). 
In addition, ORs are presented.

[[Page 65884]]

   The ORs in Table V-3 clearly indicate that 
exposure to strenuous physical activity 
increases the risk of episodes of back pain. 
The data show a clear positive exposure-
response trend: the risk of episodes of back 
pain increases with an increase in the daily 
number of hours engaged in strenuous physical 
activity. Table V-4 shows the same results: 
the risk of episodes of back pain increases 
as the number of hours engaged in repeated 
bending, twisting, or reaching increases. 
These results are shown graphically in Figure 
V-1. They indicate that the risk of severe 
back pain can be reduced substantially by 
reducing the daily duration of exposure to 
these risk factors. For example, the risk can 
be reduced by about half if exposure to these 
risk factors is reduced from 6 to 8 hours to 
2 hours or less per day.
   Table V-3 shows that for some exposure 
categories, the ORs do not increase as 
exposure increases. The OR for workers 
engaged in strenuous physical activity for 6 
to 8 hours is lower than the OR for workers 
engaged in strenuous physical activity for 4 
to 6 hours. This deviation from an increasing 
trend, however, does not mean that there is 
no such trend. NIOSH used its estimated 
numbers to conduct a logistic regression of 
episodes of back pain on duration of 
exposure, adjusting for age and gender. The 
parameter estimates for each of the two types 
of exposure were positive and highly 
statistically significant (p < .01). This 
means that the increasing trend observed in 
the relationships between episodes of back 
pain and duration of each type of exposure is 
statistically significant.

    Table V-3.--Estimated Number of Currently Employed Workers Engaged in Strenuous Physical Activity Such as
                Lifting, Pushing, or Pulling Heavy Objects, by Duration and Back Pain Status \1\
----------------------------------------------------------------------------------------------------------------
                                                     BACK PAIN
                            ----------------------------------------------------------
                                         NONE                AT LEAST 1 WEEK DUE TO
       HOURS ENGAGED        ----------------------------- REPEATED ACTIVITIES AT WORK     PERCENT     ODDS RATIO
                                                                      \3\                                \4\
                                    #           % \5\    -----------------------------
                                                                 #           % \5\
----------------------------------------------------------------------------------------------------------------
0                                70.960,000         71.7       1,233,700         26.8          1.7          1.00
----------------------------------------------------------------------------------------------------------------
0-2                               7,431,700          7.5         549,200         11.9          6.9          4.25
----------------------------------------------------------------------------------------------------------------
2-4                               5,776,000          5.8         566,100         12.3          8.9          5.64
----------------------------------------------------------------------------------------------------------------
4-6                               4,955,800          5.0         749,500         16.3         13.1          8.70
----------------------------------------------------------------------------------------------------------------
6-8                               3,235,600          3.3         431,800          9.4         11.8          7.68
----------------------------------------------------------------------------------------------------------------
Over 8                            6,669,300          6.7       1,072,200         23.3         13.9          9.25
----------------------------------------------------------------------------------------------------------------
      Total                      99,028,400                    4,602,500                       4.4
----------------------------------------------------------------------------------------------------------------
\1\ Numbers estimated by NIOSH using data from the 1988 NHIS-OHS conducted by NCHS (Exs. 26-1104, 26-1105, 26-
  1106).
\2\ Estimated number of currently employed workers experiencing no episodes of back pain every day for 1 week or
  more during the 12 months prior to the survey.
\3\ Estimated number of currently employed workers experiencing an episode of back pain every day for 1 week or
  more due to repeated activities at their current or most recent job during the 12 months prior to the survey.
\4\ The odds ratio approximates the risk of an episode of back pain lasting 1 week or more due to repeated
  activities at work for workers engaged in strenuous physical activity such as listing, pushing, or pulling
  relative to the risk of an episode of back pain for workers with no such exposure.
\5\ Percentage may not add to 100 due to rounding.


 Table V-4.--Estimated Number of Currently Employed Workers Engaged in Repeated Bending, Twisting, or Reaching,
                                      by Duration and Back Pain Status \1\
----------------------------------------------------------------------------------------------------------------
                                                     BACK PAIN
                            ----------------------------------------------------------
                                         NONE                AT LEAST 1 WEEK DUE TO
       HOURS ENGAGED        ----------------------------- REPEATED ACTIVITIES AT WORK     PERCENT     ODDS RATIO
                                                                      \3\                                \4\
                                    #           % \5\    -----------------------------
                                                                 #           % \5\
----------------------------------------------------------------------------------------------------------------
0                                57,020,000         58.1         501,100         11.0          0.9          1.00
----------------------------------------------------------------------------------------------------------------
0-2                               5,664,100          5.8         288,200          6.3          4.8          5.79
----------------------------------------------------------------------------------------------------------------
2-4                               7,478,000          7.6         553,500         12.2          6.9          8.42
----------------------------------------------------------------------------------------------------------------
4-6                               8,088,800          8.2         736,600         16.2          8.3         10.36
----------------------------------------------------------------------------------------------------------------
6-8                               6,556,800          6.7         766,500         16.9         10.5         13.30
----------------------------------------------------------------------------------------------------------------

[[Page 65885]]

 
Over 8                           13,340,000         13.6       1,697,100         37.4         11.3         14.08
----------------------------------------------------------------------------------------------------------------
      Total                      98,148,600                    4,543,000                       7.1
----------------------------------------------------------------------------------------------------------------
\1\ Numbers estimated by NIOSH using data from the 1988 NHIS-OHS conducted by NCHS (Exs. 26-1104, 26-1105, 26-
  1106).
\2\ Estimated number of currently employed workers experiencing no episodes of back pain every day for 1 week or
  more during the 12 months prior to survey.
\3\ Estimated number of currently employed workers experiencing an episode of back pain every day for 1 week or
  more due to repeated activities at their current or most recent job during the 12 months prior to the survey.
\4\ The odds ratio approximates the risk of an episode of back pain lasting 1 week or more due to repeated
  activities at work for workers engaged in repeated bending, twisting, or reaching relative to the risk of an
  episode of back pain for workers with no such exposure.
\5\ Percentage may not add to 100 due to rounding.


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   The ORs calculated from the data provided 
by NIOSH are very conservative. It is highly 
likely they underestimate the true ORs for 
the currently employed population. Only 
workers suffering episodes of back pain due 
to repeated activities at their current or 
most recent job are included. Workers who 
suffered episodes of back pain at a previous 
job are excluded. Workers who suffered 
episodes of back pain due to repeated 
activities on the job and due to an accident 
are also excluded. Finally, as observed by 
Bernard et al. (1993, Ex. 26-439), workers 
tend to overestimate the amount of time they 
spend daily at specific activities, 
particularly when such activities are hard 
and/or painful. Therefore, exposure is likely 
to be overestimated, meaning that risks at 
the lower exposure levels are likely to be 
underestimated. Despite the limitations of 
this analysis, the NCHS data clearly show a 
relationship between episodes of back pain 
lasting 1 week or longer and duration of 
exposure to workplace risk factors.
   A similar analysis was conducted by 
Punnett et al. (1991, Ex. 26-39), using data 
from a case-control study of automobile 
assembly workers. To determine the 
relationship between back disorders and both 
postural stress and daily duration of 
exposure, the authors estimated the ORs from 
a logistic regression analysis. Duration of 
exposure was divided into two categories: 0 
to 10% of cycle time and 10% or more of cycle 
time. Three types of postural stress were 
examined: any postural stress, mild flexion, 
and severe flexion. The results of this 
study, presented in Table V-5 and Figure V-2, 
show that for any postural stress and for 
mild flexion, the risk of back disorders was 
approximately 1.4 times greater for workers 
exposed for 10% or more of cycle time 
compared to workers exposed less than 10% of 
cycle time. For severe flexion, the risk of 
back disorders was approximately 2 times 
greater for workers exposed for 10% or more 
of cycle time than it was for workers exposed 
less than 10% of cycle time. The greatest 
increase in risk was seen among workers 
exposed to severe trunk flexion for more than 
10% of cycle time (OR = 8.9 compared to 
unexposed workers). Thus, this study suggests 
that reductions in severity or duration of 
exposure to awkward trunk postures, even 
where exposure cannot be eliminated, may 
reduce risk of back disorders up to 2-fold.
   Holmstrom, Lindell, and Moritz (1992, Ex. 
26-36) estimated age-standardized prevalence 
rate ratios to examine the relationship 
between duration of exposure to different 
working postures and low-back and neck/
shoulder pain in construction workers. Age 
standardization ia a statistical approach 
that controls for the effect of age on the 
health outcome being studied. This is usually 
done by selecting control subjects that match 
the ages of the individuals in the study 
cohort, or by using standardized illness 
rates for local or national populations. 
Controlling for age permits the investigator 
to compare the effect of age on the health 
outcome of interest with the effect of other 
variables, such as degree of exposure to a 
hazard. The age-standardized prevalence ratio 
is comparable to an age-adjusted odds ratio.

  Table V-5.--Estimated Odds of Back Disorders in Workers With Varying
                Durations and Severities of Exposure \1\
------------------------------------------------------------------------
                                   PERCENT OF CYCLE
         TRUNK  POSTURE                  TIME             ODDS RATIO
------------------------------------------------------------------------
Any posture                                   0-10%                 3.8
                                 ---------------------------------------
                                               >10%                 5.5
------------------------------------------------------------------------
Mild Flexion                               0 to 10%                 4.2
                                 ---------------------------------------
                                               >10%                 6.1
------------------------------------------------------------------------
Severe Flexion                             0 to 10%                 4.4
                                 ---------------------------------------
                                               >10%                 8.9
------------------------------------------------------------------------
\1\ Punnett et al., 1991, Ex. 26-39.


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   The results of the Holmstrom study are 
presented in Tables V-6 and V-7, and in 
Figure V-3. Three working postures were found 
to be associated with low-back pain: hands 
above shoulder level, stooping, and kneeling. 
In each case, the risk of severe back pain 
increases with exposure, with the largest 
increases in risk being associated with more 
than 4 hours per day of exposure to kneeling 
or stooping. Table V-6 shows that the 
greatest risk, associated with kneeling more 
than 4 hours per day, is 3.5 times greater 
among exposed workers than among workers with 
no exposure. These three working positions 
are also associated with considerable neck/
shoulder pain. For this outcome, risk 
increases with duration of exposure as well. 
Table V-7 shows that for neck/shoulder pain, 
however, the greatest risk is associated with 
a posture of hands above shoulder level for 
more than 4 hours per day.

    Table V-6.--Estimated Prevalence Rate Ratios of Severe Low-Back Pain in Construction Workers Engaged in a
                                Variety of Postures, by Duration of Exposure \1\
----------------------------------------------------------------------------------------------------------------
                                                                   HOURS OF
                           POSTURE                               EXPOSURE PER     ODDS  RATIOS      CONFIDENCE
                                                                     DAY                             INTERVAL
----------------------------------------------------------------------------------------------------------------
Hands Above Shoulder Level                                                 <1             1.09          0.8-1.5
                                                              --------------------------------------------------
                                                                          1-4             1.46          1.1-2.0
                                                              --------------------------------------------------
                                                                           >4             1.61          1.0-2.6
----------------------------------------------------------------------------------------------------------------
Stooping                                                                   <1             1.31          0.9-1.8
                                                              --------------------------------------------------
                                                                          1-4             1.88          1.4-2.6
                                                              --------------------------------------------------
                                                                           >4             2.61          1.7-3.8
----------------------------------------------------------------------------------------------------------------
Kneeling                                                                   <1             2.4           1.7-3.3
                                                              --------------------------------------------------
                                                                          1-4             2.6           1.9-3.5
                                                              --------------------------------------------------
                                                                           >4             3.5           2.4-4.9
----------------------------------------------------------------------------------------------------------------
\1\ Holmstrom, Lindell, and Moritz, 1992, Ex. 26-36.


 Table V-7.--Estimated Prevalence Rate Ratios of Neck/Shoulder Pain in Construction Workers Engaged in a Variety
                                    of Postures, by Duration of Exposure \1\
----------------------------------------------------------------------------------------------------------------
                                                                   HOURS OF
                           POSTURE                               EXPOSURE PER     ODDS  RATIOS      CONFIDENCE
                                                                     DAY                             INTERVAL
----------------------------------------------------------------------------------------------------------------
Hands Above Shoulder Level                                                 <1              1.1          0.8-1.5
                                                              --------------------------------------------------
                                                                          1-4              1.5          1.2-1.9
                                                              --------------------------------------------------
                                                                           >4              2.0          1.4-2.7
----------------------------------------------------------------------------------------------------------------
Stooping                                                                   <1              1.0          0.8-1.3
                                                              --------------------------------------------------
                                                                          1-4              1.4          1.1-1.8
                                                              --------------------------------------------------
                                                                           >4              1.5          1.1-2.1
----------------------------------------------------------------------------------------------------------------
Kneeling                                                                   <1              1.4          1.1-1.8
                                                              --------------------------------------------------
                                                                          1-4              1.4          1.1-1.8
                                                              --------------------------------------------------
                                                                           >4              1.5          1.1-2.1
----------------------------------------------------------------------------------------------------------------
\1\ Holmstrom, Lindell, and Moritz, 1992, Ex. 26-36.


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   A prospective study by Liles et al. (1984, 
Ex. 26-33) demonstrated a clear relationship 
between intensity of exposure to manual 
handling risk factors and incidence of both 
total and lost-work-day back injuries. The 
study is unusual in that healthy workers were 
followed for over 1 year to determine the 
annual rate of back disorders. Exposure to 
manual handling risk factors was measured 
using a job severity index (JSI). A JSI is a 
measure of musculoskeletal strain based on 
weight handled, frequency of lifting, and a 
worker's physical capacity for lifting. A JSI 
of 1 or less means that the work task 
involved handling loads at or less than the 
worker's physical capacity for lifting. There 
was no apparent increase in either total or 
lost-work-day back injuries among workers 
whose jobs scored below a JSI of 1.5. Above 
this level, both total and lost-work-day 
injury rates increased dramatically, about 5-
fold. The authors interpreted this finding as 
indicating that there is a threshold exposure 
level for back injuries due to manual 
handling and that back injuries can be 
expected to increase when workers handle 
loads exceeding their capacities by 50%. 
These data also suggest that back injury 
rates can be reduced by as much as 5-fold in 
manual handling tasks if they are designed to 
impart a physical load below 1.5 times the 
physical capacity of the worker, either by 
reducing duration of exposure or by reducing 
load weights or geometries. Figure V-4 
graphically presents the relationship between 
the JSI and back injury rates.
   Exposure-response relationships have also 
been demonstrated for upper-extremity MSDs. 
As with back disorders, studies have 
demonstrated that the risk of these illnesses 
increases dramatically with increasing daily 
duration of exposure to risk factors. For 
example, de Krom et al. (1990, Ex. 26-102) 
used ORs from a case-control study to assess 
the relationship between duration of exposure 
and MSDs. The authors estimated ORs from a 
logistic regression analysis that controlled 
for sex, age, and the interaction between age 
and sex to determine whether there was a 
relationship between CTS and the amount of 
time workers were engaged weekly in 
activities requiring a flexed wrist position, 
and between CTS and the amount of time 
workers were engaged weekly in activities 
requiring an extended wrist position. The 
results of this study, presented in Table V-8 
and in Figure V-5, show that for both of 
these workplace risk factors--activities 
requiring a flexed wrist position and 
activities requiring an extended wrist 
position--the risk of CTS clearly increases 
as the number of hours spent each week in 
these activities increases.

   Table V-8.--Estimated Odds of Carpal Tunnel Syndrome in Workers Engaged in Flexed Wrist and Extended Wrist
                                     Activities, by Duration of Exposure \1\
----------------------------------------------------------------------------------------------------------------
                                                      HOURS OF  EXPOSURE                          CONFIDENCE
                      ACTIVITY                             PER WEEK           ODDS RATIOS          INTERVAL
----------------------------------------------------------------------------------------------------------------
Flexed Wrist                                                          0                 1.0
                                                     -----------------------------------------------------------
                                                                    1-7                 1.5             1.3-1.9
                                                     -----------------------------------------------------------
                                                                   8-19                 3.0             1.8-4.9
                                                     -----------------------------------------------------------
                                                                  20-40                 8.7            3.1-24.1
----------------------------------------------------------------------------------------------------------------
Extended Wrist                                                        0                 1.0
                                                     -----------------------------------------------------------
                                                                    1-7                 1.4             1.0-1.9
                                                     -----------------------------------------------------------
                                                                   8-19                 2.3             1.0-5.2
                                                     -----------------------------------------------------------
                                                                  20-40                 5.4            1.1-27.4
----------------------------------------------------------------------------------------------------------------
\1\ de Krom et al., 1990, Ex. 26-102.


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   For workers engaged in activities 
requiring flexed wrists for as few as 8 to 19 
hours per week (averaging approximately 1.5 
to 4 hours per day), the odds of suffering 
CTS were three times greater than for workers 
engaged in activities that did not require 
flexed wrists. In contrast, the odds of 
suffering CTS in workers with average daily 
exposure to activities requiring flexed 
wrists in excess of 4 hours per day was 8.7 
times greater than in workers with no 
exposure, or almost 3 times greater than for 
workers exposed less than 4 hours per day. 
Similarly, for workers engaged in activities 
requiring extended wrists for as few as 8 to 
19 hours per week, the odds of suffering CTS 
were 2.3 times greater than for workers 
engaged in activities that did not require 
extended wrists. The odds of suffering CTS in 
workers with average daily exposure to 
activities requiring flexed wrists in excess 
of 4 hours per day was 5.4 times greater than 
in workers with no exposure. Thus, for 
workers engaged in tasks involving flexed or 
extended wrists for more than 4 hours daily, 
this study suggests that the risk of CTS can 
be reduced 2- to 3-fold by reducing daily 
exposure to less than 4 hours.
   The duration of exposure to workplace risk 
factors is not the only factor associated 
with increased risk of work-related MSDs. 
Exposure to multiple workplace risk factors 
has also been found to be associated with 
increased risk. For example, in a study of 
workers at six industrial sites, Silverstein 
et al. (1986, Ex. 26-1404) studied the 
relationship between hand/wrist cumulative 
trauma disorders and exposure to activities 
requiring low force and low repetition, high 
force and low repetition, low force and high 
repetition, and high force and high 
repetition. Using logistic regression 
analysis to estimate ORs, these authors 
reported that the odds of suffering hand/
wrist cumulative trauma disorders were 1.0 
for workers engaged in low-force and low-
repetition activity (i.e., the control 
group), 3.3 for workers engaged in low-force 
and high-repetition activity, 5.2 for workers 
engaged in high-force and low-repetition 
activity, and 29.1 for workers engaged in 
high-force and high-repetition activity (see 
Figure V-6).

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   Similar findings for CTS were reported for 
workers in seven industrial sites (also shown 
in Figure V-6). Using logistic regression 
analysis to estimate ORs, these authors 
reported that the odds of suffering CTS were 
1.0 for workers engaged in low-force and low-
repetition activity (i.e., the control 
group), 1.8 for workers engaged in high-force 
and low-repetition activity, 2.7 for workers 
engaged in low-force and high-repetition 
activity, and 15.5 for workers engaged in 
high-force and high repetition activity. 
Thus, the risk to workers exposed to two risk 
factors (high repetition and high force) was 
7 to almost 10 times higher than the risk to 
workers exposed to only one risk factor. 
These data also suggest that risk increases 
more than linearly with increasing duration 
or intensity of exposure. Moore and Garg 
(1994, Ex. 26-1033) reported a similar 
finding among meat processing workers at risk 
for upper-extremity disorders. They found 
that the incidence of all upper-extremity 
disorders increased by the square of the 
amount of hand force applied in the job.
   Loslever and Ranaivosoa (1993, Ex. 26-161) 
examined 17 jobs at high risk for CTS. For 
each job, they measured the amount of time 
the workers spent with flexed or extended 
wrists, the degree of flexion or extension, 
and the amount of force exerted. They found 
that the prevalence across jobs of CTS in 
both wrists increased in a dose-dependent 
manner as the combined exposure to force and 
flexion across jobs increased. In addition, 
the combination of force and flexion 
explained approximately 39% of the total 
variation in the prevalence of bilateral CTS 
across jobs.
   Other supporting evidence for the 
existence of exposure-response relationships 
for upper-extremity disorders includes 
studies by Viikari-Juntura et al. (1994, Ex. 
26-873) of neck disorders among machine 
operators, construction carpenters, and 
office workers, and a case-control study by 
English et al. (1995, Ex. 26-848) showing an 
exposure-response relationship between the 
rate of wrist flexion/extension and the ORs 
for disorders of the thumb.
   Punnett (1998, Ex. 26-442) conducted a 
cross-sectional study in an automobile 
stamping plant and an engine assembly plant 
using an exposure-scoring protocol that 
reflected the intensity and duration of 
exposure to any of several workplace risk 
factors (e.g., lifting/lowering, pushing/
pulling, repetitive hand motion, awkward 
postures). The total exposure score had a 
possible range from 0 to 25 and was divided 
into quartiles, as indicated in Tables V-9 
and V-10. The results are quite consistent, 
indicating that regardless of whether a case 
was defined by a physical examination or by 
self-reported symptoms, the prevalence of 
illness increased in a dose-dependent manner 
through exposure levels 13 to 18. Above that 
level, prevalence appears to hit a plateau. 
The author suggests that this plateau may be 
due to a ``healthy worker'' effect. By this 
she means that exposures at this level are so 
severe that workers move out of these jobs 
quickly, either to other jobs or to 
disability status. As a result of this 
relatively high turnover, healthy workers are 
frequently moved into these jobs. Thus the 
observed prevalence does not conform to a 
monotonic dose-response model.

                                     Table V-9.--Prevalence Ratios for MSDs
                                            [Based on Physical Exam]
----------------------------------------------------------------------------------------------------------------
  EXPOSURE SCORE BASED ON
         CHECKLIST             SHOULDER/UPPER-ARM MSDs          HAND/WRIST MSDs        ALL UPPER- EXTREMITY MSDs
----------------------------------------------------------------------------------------------------------------
                 0-6                            1.0                         1.0                         1.0
----------------------------------------------------------------------------------------------------------------
                  7-12                          2.6                         1.9                         2.0
----------------------------------------------------------------------------------------------------------------
                 13-18                          3.6                         2.4                         2.6
----------------------------------------------------------------------------------------------------------------
                 19-25                          2.3                         2.3                         2.8
----------------------------------------------------------------------------------------------------------------


                                     Table V-10.--Prevalence Ratios for MSDs
                                          [Based on Symptom Reporting]
----------------------------------------------------------------------------------------------------------------
  EXPOSURE SCORE BASED ON
         CHECKLIST             SHOULDER/UPPER-ARM MSDs          HAND/WRIST MSDs        ALL UPPER- EXTREMITY MSDs
----------------------------------------------------------------------------------------------------------------
                 0-6                            1.0                         1.0                         1.0
----------------------------------------------------------------------------------------------------------------
                  7-12                          2.5                         2.0                         1.8
----------------------------------------------------------------------------------------------------------------
                 13-18                          3.8                         2.5                         2.4
----------------------------------------------------------------------------------------------------------------
                 19-25                          3.5                         2.5                         2.3
----------------------------------------------------------------------------------------------------------------
Source: Punnett, 1998, Ex. 26-442.

   Taken together, these studies provide 
compelling evidence of a causal relationship 
between exposure to workplace risk factors 
and an increased risk of developing MSDs. 
Furthermore, these studies demonstrate that 
the risk of work-related MSD can be 
substantially reduced by reducing the 
frequency or duration of exposure to any 
workplace risk factor, and by reducing the 
number of workplace risk factors to which 
workers are exposed.


6. Summary

   The evidence summarized in this section is 
convincing and consistent. Studies from very 
different research traditions, and 
incorporating very different research

[[Page 65897]]

methodologies, strongly support the causal 
association of force, awkward postures, 
static postures, repetition, and vibration 
with work-related MSD outcomes. The evidence 
also strongly supports the effects of the 
four modifying factors on the impact of the 
exposures and the body's ability to repair 
the damage. The evidence is less strong in 
the case of external compression and dynamic 
factors, partly because of a relative 
shortage of studies in these areas. But the 
evidence that does exist is congruent.
   In sum, although not all the 
epidemiological studies reviewed demonstrate 
significant associations, the overwhelming 
majority justify a conclusion that the risk 
factors noted in this section, with effects 
adjusted by the four modifying factors, cause 
or exacerbate work-related MSDs. The 
laboratory evidence in each case provides 
plausible and demonstrable biologic 
mechanisms through which these exposures can 
cause the anatomical and physiological 
changes characteristic of these disorders. 
The psychophysical evidence, relying on 
research that has linked subjective reports 
of fatigue, discomfort, and exertion to 
measurable disease rates in industry, further 
strengthens this conclusion.


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D. Pathogenesis and Pathophysiologic Evidence 
for Work-Related Musculoskeletal Disorders


1. Overview

   An extensive body of scientific research 
and information has led to the conclusion 
that specific work factors, combinations of 
these factors, and modifying attributes or 
conditions contribute to the development and 
manifestation of work-related musculoskeletal 
disorders (MSDs). The term ``work-related'' 
refers to the performance of work tasks or 
working in a specific work environment that 
significantly contributes to the pathogenesis 
or manifestation of these multifactoral 
conditions (World Health Organization, 1985, 
Ex. 26-1040). The multifactoral nature of 
many of these MSDs, including the potential 
contribution of pre-existing or non-work 
factors to the pathogenesis of some work-
related MSDs, is recognized. Other sections 
of this document present epidemiologic and 
biomechanical evidence that addresses the 
association of work factors and certain MSDs. 
This section describes the pathogenic and 
pathophysiologic mechanisms that establish 
the biological plausibility of the findings 
of the epidemiologic and biomechanical 
observations included in the earlier sections 
and in the Appendices (Ex. 27-1).
   The pathogenesis of work-related MSDs can 
refer to either single, point-in-time 
injuries, associated with work tasks that 
result in activities in which tissue 
tolerance is acutely exceeded, or 
circumstances in which the performance of 
specific work tasks or combinations of tasks 
over a prolonged period of time results in 
small and repeated tissue damage to muscles, 
tendons, joints, or nerve structures 
(Association of Schools of Public Health/
NIOSH, 1986, Ex. 26-1323; Putz-Anderson, 
Doyle, and Hales, 1992, Ex. 26-419; Rempel, 
Harrison, and Barnhart, 1992, Ex. 26-520). 
Work activities suggested as potential 
factors in the development or expression of 
work-related MSDs include high rates of task 
repetition; excessive force requirements; 
static postures; awkward work postures; 
vibration; cold temperatures; weight of loads 
lifted, pushed, or pulled; position of a load 
in relationship to the spinal axis; frequency 
and duration of materials handling task 
performance; hand coupling; dynamics of 
lifting (e.g., muscle velocity and 
acceleration); lack of sufficient rest or 
recovery periods; overtime; piecework; and 
other issues (Armstrong, 1986, Ex. 26-928; 
Armstrong et al., 1987, Ex. 26-48; Bergquist-
Ullman and Larsson, 1977, Ex. 26-933; Chaffin 
and Park, 1973, Ex. 26-1115; Frymoyer et al., 
1980, Ex. 26-707; Johanning et al., 1991, Ex. 
26-1228; Klein et al., 1984, Ex. 26-972; 
Marras et al., 1993, Ex. 26-170; Rempel, 
Harrison, and Barnhart, 1992, Ex. 26-520; 
Silverstein, 1985, Ex. 26-1173; Silverstein, 
Fine, and Armstrong, 1986a, Ex. 26-1153, 
1986b, Ex. 26-1404; Snook, Campanelli, and 
Hart, 1978, Ex. 26-35; Stock, 1991, Ex. 26-
1010; Waters et al., 1993, Ex. 26-521; 
Waters, 1994, Ex. 26-1403).
   To accomplish motion and work, muscle, 
nerves, connective tissue, and skeleton are 
affected by a number of external and internal 
physical demands causing metabolic and 
compensatory tissue reactions. For example, 
the forceful, static, continuous, and/or 
repetitive demands made by manufacturing 
assembly work or manual materials handling 
can alter the function and integrity of 
specifically affected tissues. This can lead 
to the development and

[[Page 65901]]

clinical manifestation of MSDs such as 
tendinitis, epicondylitis, rotator cuff 
syndrome, or low-back pain. External demands 
can include direct pressure or tissue 
friction. As an illustration, prolonged or 
excessive force exerted over the base of the 
palm (by tools, handles, etc.) during 
assembly tasks can damage the median nerve in 
the palm, causing signs and symptoms of 
carpal tunnel syndrome (CTS). Internal 
responses can include inflammatory responses 
to tissue injury, neurochemical changes, and 
altered metabolism. For example, a lumbar 
disc herniation from repetitive lifting of 
heavy loads can compress a spinal nerve root, 
with subsequent nerve root edema, altered 
tissue metabolism, production of inflammatory 
mediators, and expressed signs and symptoms 
of lumbar radiculopathy.
   The consequences of these external and 
internal demands associated with work 
activities can include a spectrum of symptoms 
or clinical findings, such as subtle or 
obvious inflammation, pain, swelling, 
restricted movement, and tissue damage 
diagnosed as muscle strain or tear, 
ligamentous or cartilage injury, tendinitis 
or tenosynovitis, bursitis, nerve entrapment, 
disc herniation, or degenerative joint or 
disc disease. This does not mean that a 
precise dose-response relationship between 
task factor exposure and disease exists for 
each of these work-related MSDs. Clear and 
consistent patterns exist, however, among the 
epidemiologic studies, biomechanical models, 
and pathogenetic and pathophysiologic 
explanations for many work-related MSDs 
(Gordon, Blair, and Fine, 1994, Ex. 26-1399; 
National Academy of Sciences, 1998, Ex. 26-
37; Bernard and Fine, 1997, Ex. 26-1).
   Factors specific to the individual can 
also affect the development and/or 
manifestation of pathology. These include, 
for example, preexisting injuries or 
illnesses (such as diabetes, degenerative 
joint disease, or rheumatoid joint disease); 
individual susceptibility to injury or tissue 
damage (related to anthropometric 
characteristics, physical conditioning, age, 
or genetics); and avocational activities or 
hobbies. These can interact in a complex 
fashion, such that work acts either as a 
causative, contributing, or accelerating 
factor in the development and/or 
manifestation of disease (Putz-Anderson, 
Doyle, and Hales, 1992, Ex. 26-419; Rempel, 
Harrison, and Barnhart, 1992, Ex. 26-520). 
However, although non-work risk factors can 
influence the development or expression of 
MSDs, their role is generally not as 
important as workplace risk factors because 
the duration and intensity of work are seldom 
matched in the non-work settings. Additional 
important considerations pertain to 
interactions between co-existing MSDs. For 
example, once an MSD is established, 
subsequent physical compensatory changes can 
further predispose an individual to the 
development of additional MSDs. When injury 
causes an altered posture, decreased range of 
motion, or weakness or ability to respond to 
tactile feedback to one joint or region, 
there is often increased risk of injury to 
another joint or region due to compensatory, 
increased loading. One example is the loss of 
tactile feedback from CTS, leading to greater 
hand force output that in turn contributes to 
the development of tendinitis or 
epicondylitis.
   Section D.2 discusses the interaction 
between work demands and the responses of 
skeletal muscle, tendon, ligament, nerve, 
blood vessels, joint, and cartilage. It 
reviews the biological plausibility of an 
association between workplace factors and 
work-related MSDs of the spine and upper and 
lower extremities. It also considers the 
contributions of age, genetics, gender, 
cigarette smoking, and avocational activities 
to the pathogenesis and pathophysiology of 
work-related MSDs.
   Section D.3 focuses on vibration. A 
separate section on vibration is included 
here because real specificity exists for this 
risk factor. Vibration can be reliably linked 
with specific outcomes: damage to vessels and 
small, unmyelinated nerve fibers in the 
fingers. In contrast, most of the other 
tissue disorders discussed in Section D 
result from a combination of exposures.


2. Pathogenesis and Pathophysiology of Work-
Related Tissue Injury

   a. Skeletal Muscle. There are several 
explanations for the development of work-
related skeletal muscle disorders. Acute 
muscle tears, an extreme example of work-
related skeletal muscle disorders, may 
develop when task demands exceed muscle 
tissue tolerance. While this may occur during 
any type of muscle contraction, it is much 
more common during eccentric contraction 
(i.e. during muscle lengthening to control, 
rather than initiate, an action), perhaps due 
to the nature of muscle recruitment of fibers 
with less oxidative capacity (Friden and 
Lieber, 1994, Ex. 26-546). Yet even low-
force, static, or prolonged muscle activities 
commonly noted in a variety of manufacturing 
and office settings have the potential to 
cause or contribute to the development of 
work-related skeletal muscle disorders (Hagg, 
1991, Ex. 26-427; Henneman and Olson, 1965, 
Ex. 26-139; Herberts et al., 1984, Ex. 26-51; 
Jarvholm et al., 1989, Ex. 26-967; Murthy et 
al., 1997, Ex. 26-307; Sjogaard, 1988, Ex. 
26-206; Sjogaard and Sjogaard, 1998, Ex. 26-
1322). Muscle recruitment patterns with low-
extension, repetitive, or static activities 
may selectively injure low-threshold and more 
easily recruited muscle fibers, which have 
been referred to as ``Cinderella fibers'' 
because of their constant activity (Henneman 
and Olson, 1965, Ex. 26-134; Lieber and 
Friden, 1994, Ex. 26-559). Alternatively, 
hypoxia and metabolic abnormalities 
(fatigue), inflammatory responses, inadequate 
rest pauses, and repair mechanisms appear to 
explain some of these skeletal muscle 
disorders associated with certain jobs or 
tasks (Armstrong et al., 1993, Ex. 26-1110; 
Bigland-Ritchie, 1983, Ex. 26-76; Faulkner 
and Brooks, 1995, Ex. 26-1440; Herberts et 
al., 1984, Ex. 26-51; Sjogaard, 1988, Ex. 26-
206; Sjogaard and Sogaard, 1998, Ex. 26-
1322). Electromyography (EMG) has helped 
researchers to better understand skeletal 
muscle responses to work tasks, estimate 
muscle loading with activity and 
intramuscular pressure generation, and 
comprehend the development of muscle fatigue 
(Chaffin, 1973, Ex. 26-876; Chaffin and 
Andersson, 1991, Ex. 26-420; Dolan et al., 
1999, Ex. 26-819; Lieber and Friden, 1994, 
Ex. 26-559; Nieminen et al., 1993, Ex. 26-
1382; NIOSH, 1992, Ex. 26-1325). In addition, 
at least one study has demonstrated a 
significant impact of ergonomic interventions 
on diminishing both EMG-observed trapezius 
loading and sick time due to skeletal muscle 
morbidity (Aaras, 1994a, 1994b, 1987, Exs. 
26-892, 26-62, 26-1034).
   Skeletal muscle is a highly evolved tissue 
with specialized contractile properties and 
an exceptional capacity to adapt and change. 
The bodybuilder's ability to rapidly build 
muscle bulk and the weakness and atrophy that 
come with prolonged bed rest or disuse are 
two examples of this ``plasticity.'' 
Individual muscle fibers have a unique 
capacity to convert chemical energy into a 
specific level of time-limited mechanical 
work (capacity and endurance). There are 
hundreds of skeletal muscles in the human 
body, each responsible for specific motions 
of bone and joints, that permit work 
performance. In the setting of normal 
physiologic responses, the central nervous 
system (CNS)

[[Page 65902]]

releases nerve impulses which activate motor 
units, causing muscle contraction, tendon 
tension, and movement of bones and joints. 
Each skeletal muscle is attached to a site of 
origin, transitions through a myotendinous 
junction, and attaches to bone as tendon, 
sometimes crossing joints along the way.
   The components of each skeletal muscle 
include muscle fibers, connective tissue, and 
nerve endings. Muscle fibers, in turn, are 
composed of contracting elements called 
myofibrils. These myofibrils contain thin 
(actin, troponin, and tropomyosin proteins) 
and thick (myosin protein) filaments that 
slide over each other, resulting in muscle 
contraction. The myofilaments are arranged in 
compartments (sarcomeres) separated from each 
other by thin zones of dense material (Z-
lines). Upon stimulation from a motor nerve 
impulse, altered muscle membrane permeability 
(depolarization) releases calcium ions, which 
subsequently create cross-bridging between 
muscle filaments and resultant contraction. 
Skeletal muscle is covered by a connective 
tissue called the epimysium, which is 
contiguous with the perimysium, a septum that 
separates the muscle into muscle fiber 
bundles. These muscle fiber bundles further 
subdivide into individual muscle fibers 
surrounded by an endomysium. The connective 
tissue permits the passage of blood vessels 
and nerves through the skeletal muscle to the 
muscle fibers, and also contributes to the 
mechanical characteristics of the muscle, 
especially with respect to resistance to 
stretching or deformation.
   Peripheral nerves traverse the connective 
tissue to carry (motor) impulses from the CNS 
to the muscle, attaching at the neuromuscular 
junction. The functional unit of a muscle is 
called the motor unit, and is composed of 
motor neurons and the muscle fibers they 
control. Small motor units, with a nerve 
fiber controlling a few muscle fibers, are 
located in areas such as the hand where fine 
motor tasks are performed. These smaller 
units allow contraction at lower forces. 
Larger units are located in the leg, where a 
single nerve fiber can activate hundreds or 
thousands of muscle fibers to permit gross 
motor tasks. When a nerve impulse activates a 
motor unit, all of the fibers in that unit 
contract simultaneously. The response of the 
entire muscle depends on several factors. 
After a nerve impulse, a certain number of 
motor units will contract in response. As the 
impulse increases, more units are recruited 
and greater force results. When stimulation 
occurs prior to relaxation, a larger 
contraction (or summation) will evolve. The 
size, temporal sequencing, and frequency of 
the stimulus will determine if a muscle 
reaches maximal contraction, with responses 
maintained until stimulation ceases or 
fatigue occurs. Sensory feedback control 
occurs via muscle spindles that sense the 
length and speed of contraction or stretch of 
the muscle fibers.
   Muscle power also depends on the 
composition of the fibers and muscle length. 
Type I (slow) fibers are smaller, have a 
large capacity for aerobic work, take a 
longer time to reach peak tension, and permit 
sustained, low-level muscle activity. Type II 
(fast) fibers quickly reach peak tension and 
help with short-duration, intensive activity. 
Type II fibers, however, fatigue quickly. 
With disuse, type II fibers are the first to 
atrophy (Chaffin and Andersson, 1991, Ex. 26-
420). Skeletal muscles at their relaxed 
length generate the greatest amount of 
tension. At resting length, there is optimal 
overlap between the thick and thin filaments 
to permit maximal shortening. As the muscle 
contracts, there is greater overlap and less 
potential to contract further. When muscles 
are stretched, there is less overlap, and 
therefore, less tension can be generated 
(Chaffin and Andersson, 1991, Ex. 26-420). As 
discussed above, the amount and 
characteristics of the passive connective 
tissue in the specific muscle also determine 
the tension developed when muscles are 
stretched.
   Individual muscle fibers have a unique 
capacity to convert chemical energy into a 
specific level of time-limited mechanical 
work (capacity and endurance). This chemical 
energy is transported in the form of 
activated phosphorylated molecules, primarily 
adenosine triphosphate (ATP). Energy release 
to accomplish muscle contraction is provided 
by the splitting off of a phosphate group 
from adenosine triphosphate (ATP), which 
converts the ATP to adenosine diphosphate 
(ADP). Phosphocreatine enables ADP to be 
converted back to ATP, thereby re-supplying 
the muscle fiber with energy and permitting 
the contraction to continue for brief 
periods. With persistent contraction, ATP 
resynthesis occurs under aerobic (with 
oxygen) or anaerobic (without oxygen) 
conditions. During low to moderate exertion, 
aerobic conditions predominate. The 
exhaustion of these energy stores can lead to 
fatigue, and in extreme cases, injury to the 
muscle tissue itself (Armstrong, Warren, and 
Lowe, 1994, Ex. 26-525; Chaffin and 
Andersson, 1991, Ex. 26-420; Lieber and 
Friden, 1994, Ex. 26-559). Heat is also 
generated and expended as a result of this 
metabolic activity.
   Researchers have described several types 
of muscle contraction. In isometric (static) 
contraction, the external length of the 
muscle remains fixed, despite sliding of 
myofibrils. High muscle tension is generated 
because there is no expenditure of energy to 
shorten the muscle. During isotonic 
contraction, muscle length changes while the 
tension remains constant. Energy is expended 
to permit this change in muscle length to 
occur. Concentric contraction involves muscle 
shortening. An example of this is when the 
biceps muscle contracts and shortens during 
elbow flexion. Eccentric contraction 
describes contraction during muscle 
lengthening, as when muscle activity is 
required to control an action rather than to 
initiate it. Velocity of contraction affects 
the tension a muscle generates, with less 
force generated as the velocity of shortening 
increases. This relates to the length of the 
muscle, discussed above, and friction. 
Endurance depends on the composition of 
fibers and the percentage of maximal muscle 
force (Chaffin and Andersson, 1991, Ex. 26-
420; Lieber and Friden, 1994, Ex. 26-559). At 
efforts under 15% of maximal force, endurance 
can reach 45 minutes (Lieber, 1992, Ex. 26-
433). As muscle approaches 35% of maximal 
force, endurance time decreases to 
approximately two minutes, and as exertion 
approaches 100%, endurance time approaches 
zero (Chaffin and Andersson, 1991, Ex. 26-
420, p. 49). Gradual exercise programs, 
however, have the capacity to improve muscle 
strength and endurance.
   Muscle proteins allow muscle fibers to 
stretch and to elastically recoil to their 
resting length. If a muscle is stretched 
excessively, these mechanoelastic properties 
of muscle fiber are exceeded and observable 
physical damage is incurred. There is an 
important distinction between injuries that 
are the result of muscle activities that 
exceed these mechanoelastic capacities of 
muscle, and injuries that have their origins 
in activities that are below maximum muscle 
capacity. The latter may involve sequential 
or stereotyped patterns of work, whose 
execution becomes compromised by pain or 
fatigue. In fact, the bulk of modern work 
involves activities that neither challenge 
nor exceed the mechanical limits of muscle 
fibers.
   The types of injury acquired during more 
routine function involve potentially complex 
metabolic and neurologic processes. Changes 
in muscle morphology and fiber type

[[Page 65903]]

(gene expression), in muscle fatigue and 
failure (metabolic function), and in loss of 
centrally mediated coordinated movement 
(dystonia) are all examples of the 
biochemical and neurologic origins of some 
types of muscle injury. These mechanisms, 
rather than gross patho-anatomic injury and 
repair, are a major focus of current research 
on work-related muscle injury.
   Muscle tissue has a high intrinsic repair 
capacity and can effectively adapt to diverse 
biomechanical loads. Understanding the 
divergent paths of successful learning and 
adaptation or injury and degeneration 
requires an understanding of physiology 
(Pette, 1980, Ex. 26-1304).
   There are three events associated with 
muscle injury. While injury related to 
mechanical contraction is usually caused by 
stretch (eccentric contraction), injury may 
also occur during muscle shortening 
(concentric contraction), or while 
maintaining the muscle at a constant level of 
stretch and tension (isometric contraction). 
The basic mechanism is a mismatch between 
external load and internal contractile 
capacity. This results in mechanical 
disruption between the sarcomeres along the 
Z-lines. The outcome is inflammation, the 
sensation of muscle soreness, and triggering 
of repair processes.
   A second injury mechanism is fatigue, in 
which there is an activity-related perception 
of raised effort or an inability to sustain 
force. Muscle fatigue occurs when physical 
tasks require high-power, short-duration 
repetitive contractions, or when there are 
low-power, sustained or repetitive 
contractions (Faulkner and Brooks, 1995, Ex. 
26-1410). Fatigue has consequences for task 
performance and includes both rapidly 
reversible and non-reversible manifestations.
   As a muscle becomes fatigued, it produces 
a distinct electrical signal that can be 
picked up by electromyography (EMG). The EMG 
signal is measured by placing electrical 
transducers on the skin surface over the 
muscle, or by inserting a needle or small 
wire directly into the muscle. EMG 
measurements are most often taken where 
muscles are well-defined and accessible. EMG 
has other uses. EMG has been an important 
tool in measuring effort and fatigue in the 
large muscles of the neck and shoulders. 
Recorded EMG voltage reflects the sum of 
several motor unit potentials. The primary 
usefulness of surface EMG in work settings is 
to estimate muscle tension associated with 
task performance from measured myoelectric 
activity. Since many factors affect the 
relationship between muscle force and the 
amplitude of myoelectric activity, several 
methods are used to improve the correlation 
(Chaffin and Andersson, 1991, Ex. 26-420; 
Dolan et al., 1999, Ex. 26-819; NIOSH, 1992, 
Ex. 26-1325). Individual-and activity-
specific calibration can be performed by 
measuring myoelectric activity and external 
moments while a subject performs graded 
activity. Normalization can be employed by 
measuring one isometric maximum voluntary 
contraction (MVC) and reporting the activity 
as a percentage of MVC. This appears to 
correlate reasonably with load moments 
calculated from other models (Nieminen, 1993, 
Ex. 26-1382). Measurements of myoelectric 
activity can then be used to estimate load 
moments or forces during the performance of 
more complex tasks in a variety of work 
settings. Fatigue can also be assessed: 
muscle activity is observed to show an 
increased amplitude and decreased frequency 
in the myoelectric signal with fatigue 
(Chaffin and Andersson, 1991, Ex. 26-420; 
Chaffin, 1973, Ex. 26-876; Lieber and Friden, 
1994, Ex. 26-559). This is consistent with 
laboratory observations of the response in 
fatigued muscle fiber (Bigland-Ritchie et 
al., 1983); the authors hypothesize that this 
may be a physiologic adaptation'slower 
muscles are able to generate higher forces.
   Dolan et al. (1999, Ex. 26-819) recently 
validated the usefulness of this technique in 
evaluating dynamic lumbar spine loading. The 
authors studied eight male subjects who 
performed lifting tasks from floor height 
(boxes weighing 6.7 and 15.7 kg). L5-S1 joint 
moments were assessed using force plates and 
by measuring the EMG activity of the erector 
spinae muscles. The two assessment methods 
yielded similar peak extensor moments, 
equivalent to spinal compressive forces of 
2.9 to 4.8 kN. The researchers did note, 
however, that there were small deviations 
during lifts requiring a vigorous upward 
thrust from the legs, and that additional 
force-plate data would mildly improve 
correlation in these settings.
   A third injury mechanism (after mechanical 
contraction-related injury and muscle 
fatigue) is the release of neuro-humoral 
substances and changes in electrolyte 
balance. Neuro-humoral substances are 
chemicals that affect cell membranes and cell 
function and excite afferent nerves. Muscle 
pain, inflammation, and ischemia, or 
sustained static contraction, lead to release 
of potassium chloride, lactate, arachidonic 
acid, bradykinins, serotinin, and histamine. 
In addition to producing pain, these agents 
can excite chemosensitive afferents--gamma 
muscle spindles--that respond to stretch. It 
is hypothesized that increased spindle 
excitation can cause the stiffness and pain 
of ``myalgia'' (Johannson and Sojka, 1991, 
Ex. 26-968). There is substantial evidence 
that these mechanisms of tissue injury can 
produce a distinct MSD pattern, particularly 
when the work stressors are not sufficiently 
intense to produce outright mechanical 
injury. At even 10% of MVC, muscle oxidation 
declines significantly (Murthy et al., 1997, 
Ex. 26-307). Proprioceptive accuracy and 
efficiency are also significantly limited 
under conditions of fatigue. The loss of 
accuracy and fine control in hand-intensive 
tasks, such as manual tool use, requires 
greater muscle recruitment and correction, 
further increasing demands on muscle.
   Several mechanical and physiologic muscle 
responses are involved in the generation of 
muscle forces and motion of skeletal 
structures that relate to the development of 
pathology. Coordination of muscle activity to 
manipulate bones and joints involves 
initiation by agonist muscles, with 
regulatory contributions from synergistically 
and antagonistically acting muscles. The 
forces generated by these muscles around a 
joint produce load moments on the joint. This 
can cause compression or rotation at the 
joint with secondary effects on the joint 
cartilage or bone.
   An acute muscle tear is a point-in-time 
injury that results when the force demands 
exceed the muscle tissue mechanical 
tolerance. This can occur during rapid 
intentional movement or during a loss of 
balance, such as in a fall. Often there is 
rapid stretching of muscle in addition to 
contraction (Lieber and Friden, 1993, Ex. 26-
160), and injuries are generally worse when 
muscle is in its stretched position 
(Macpherson, Shork, and Faulkner, 1996, Ex. 
26-165). Healing requires 1 to 4 weeks 
(Ashton-Miller, 1999, Ex. 26-414; Brooks and 
Faulkner, 1990, Ex. 26-85), and there is 
potential for decreased strength after 
healing is achieved.
   After injury, satellite cells proliferate 
to repair the muscle damage. As people age, 
fewer satellite cells are observed in muscle 
tissue; this may explain the delayed recovery 
in injured older workers (Carlson, 1994, Ex. 
26-530). However, muscle rupture may also 
occur when mechanical disruption of 
sarcomeres produces an inflammatory response 
(free radicals, cytosolic enzymes, 
phagocytosis) with an increased

[[Page 65904]]

susceptibility to delayed muscle tear 
(Faulkner and Brooks, 1995, Ex. 26-1410).
   Reduced blood flow and increased 
transmural muscle pressure appear to be 
important predisposing factors to injury 
(Armstrong et al., 1993, Ex. 26-1110; Kilbom, 
1994, Ex. 26-1352; Sjogaard and Sogaard, 
1998, Ex. 26-1322). The reduced blood flow 
that is characteristic of static contraction 
and increased transmural pressure is 
reversible. However, there is additional 
evidence that the pattern of reduced flow, 
injury and diminished repair, and chronic 
fiber damage all contribute to muscle pain 
(Lindman et al., 1991, Ex. 26-976). 
Sufficient blood flow to skeletal muscle is 
essential for contraction, since force 
development depends on the conversion of 
chemical to mechanical energy. EMG studies 
show increased EMG activity in repetitive and 
stereotyped work in the setting of myalgia. 
All of this points to the particular problems 
of continued use of muscle that has already 
sustained injury, since the normal processes 
of adequate blood supply and oxygenation, 
ability to sustain contraction, and the 
capacity for repair are all compromised. 
Prolonged skeletal muscle contraction can 
produce other complications related to 
elevated intramuscular pressure. Secondary 
ischemia and disruption of the transportation 
of nutrients and oxygen can produce 
intramuscular edema (Sjogaard, 1988, Ex. 26-
206). This is compounded when recovery time 
between contractions is insufficient. 
Eventually, muscle membrane damage, abnormal 
calcium homeostasis, free radicals, other 
inflammatory mediators, and degenerative 
changes can occur (Sjogaard and Sjogaard, 
1998, Ex. 26-1322).
   It is also important to recognize that 
sustained injury appears to involve the 
excitation of specific neural pathways, 
rather than occurring as the result of simple 
repetitive tonic activities. The implications 
are that simple overuse is remediable and 
apparent functional loss is often a 
protective mechanism against depleting muscle 
cells' energy stores. However, more complex 
muscle injury involves changes in nerve-
muscle interaction and inflammatory changes, 
and continued use and insult can cause more 
chronic aggravation.
   Several studies appear to support belief 
in these pathogenic mechanisms. Veiersted et 
al. (1993, Ex. 26-1154) performed EMG studies 
on subjects performing machine-paced packing 
work. Individuals with symptoms of trapezius 
pain had fewer rest pauses and a shorter 
total duration of rest pauses, suggesting 
higher levels of muscle fiber activity. Aaras 
(1987, Ex. 26-1034) demonstrated that 
reduction of trapezius muscle activity to 
less than 2% of MVC in assembly workers 
reduced sick time. Interesting 
pathophysiologic findings were noted by 
Larsson et al. (1990, Ex. 26-1141) when they 
evaluated trapezius muscle biopsies and blood 
flow in assembly workers with localized 
chronic myalgia related to static loading 
during assembly work. In symptomatic workers, 
reduced muscle blood flow and pathologic 
changes (ragged red fibers indicating 
disturbed mitochondrial function were 
confined to the type I fibers) were recorded. 
Myalgia was correlated with reduced local 
blood flow and the presence of mitochondrial 
changes.
   Other authors have noted elevated serum 
levels of muscle enzymes, particularly 
creatine kinase, in delayed onset muscular 
soreness following unaccustomed muscle 
exertion (Armstrong, 1990, Ex. 26-703; Newham 
et al., 1983a, Ex. 26-395; Schwane et al., 
1983, Ex. 26-716). This is followed by 
degenerative changes in sarcomeres followed 
by regeneration and repair within about 2 
weeks (Newham et al., 1983b, Ex. 26-741; 
Ogilvie et al., 1988. Ex. 26-189).
   It must also be appreciated that work does 
not have to be repetitive or forceful to 
cause MSDs. Static postures involve repeated 
and prolonged low force contraction of low-
threshold motor units. Although the total 
workload is low, the individual muscles and 
muscle fibers may approach their maximal 
capacity, which can lead to injury (Hagg, 
1991, Ex. 26-427). For example, intramuscular 
pressures associated with static muscle 
contraction have the potential to cause 
muscle tissue injury. The magnitude of 
intramuscular pressure varies significantly 
depending on individual muscle 
characteristics (there are greater pressures 
in contracting bulky muscles as opposed to 
thin ones) and location (constricting fascial 
compartments and adjacent bony structures may 
increase pressures reached during 
contraction) (Sjogaard and Sogaard, 1998, Ex. 
26-1322). Muscle activity and position also 
determine intramuscular pressures. Herberts 
et al. (1984, Ex. 26-51) demonstrated that 
increased hand loads and larger degrees of 
arm elevation will increase EMG activity and 
intramuscular pressures in shoulder girdle 
muscles (deltoid, infra- and supraspinatus, 
trapezius). This may be noted during static 
work tasks adopted to stabilize hand tools 
near shoulder heights during assembly or 
construction. While very forceful muscle 
contractions may produce intramuscular 
pressures that exceed systemic blood 
pressure, supravenous intramuscular pressures 
exceeding 40 to 60 mm Hg have even been 
observed in the supraspinatus muscle during 
static contractions of less than 10% of MVC 
(Jarvholm et al., 1989, Ex. 26-967; Sjogaard 
et al., 1996, Ex. 26-213). Therefore, muscle 
pressures during low-force static work may 
approach the range of diastolic pressures. Of 
importance, diastolic pressures are more 
significant than mean blood pressures for 
maintaining blood flow in low-flow situations 
(Sjogaard et al., 1986, Ex. 26-207), 
resulting in the potential for damage to 
muscle tissues. The mechanism of muscle 
injury associated with elevated intramuscular 
pressures relates to secondary abnormalities 
of microcirculatory regulation caused by 
these pressure increases. As a result, 
several changes are noted. Diminished oxygen 
supply to muscle tissue will reduce its 
capacity to convert chemical to mechanical 
energy. Persistent contraction may increase 
tissue edema, potentially increasing tissue 
pressures and further impairing 
microcirculation.
   In other circumstances, the recruitment of 
only a limited number of fibers can result in 
high fiber stress distributed across the few 
fibers involved in the contraction, although 
total muscle forces may be low. Because 
highly repetitive tasks can only be sustained 
for prolonged periods when low force is 
involved, type I fibers are more likely to be 
involved in repetitive injury.
   Increasing attention has been paid to 
metabolic and neuroregulatory factors to 
better understand the relationship between 
acute muscle fatigue and the development of 
chronic muscle disorders, as well as to 
characterize the pattern of pain symptoms 
that affect the neck, shoulders, forearms, 
wrists, and fingers in manually intensive 
tasks that occur well below the MVC. Higher 
subjective levels of fatigue as well as 
electrophysiological evidence of fatigue are 
more common in large muscle groups, such as 
the neck and shoulder muscles, when 
activities are static and repetitive rather 
than dynamic (Sjogaard, 1988, Ex. 26-830). 
During low levels of exertion, skeletal 
muscle recruitment primarily activates the 
slower and less fatigable type I muscle 
fibers because of their lower thresholds 
(Henneman and Olson, 1965, Ex. 26-139) Lieber 
and Friden (1994, Ex. 26-559) have 
demonstrated an activation sequence by which 
these smaller, more fatigue-resistant muscle 
units are first

[[Page 65905]]

recruited, followed by stronger, more easily 
fatigued fibers. These smaller fibers are the 
``Cinderella fibers,'' so named because they 
are always working in lower-threshold 
activity, which can be insufficient to 
recruit stronger fibers (Henneman and Olson, 
1965, Ex. 26-139).
   The concerns with sustained low-level 
activity are multifold. Limited muscle fiber 
recruitment can result in higher individual 
fiber stresses distributed across the few 
fibers involved in the contraction, although 
total muscle forces may be low. Because 
highly repetitive tasks can only be sustained 
for prolonged periods of time when low force 
is involved, type I fibers are more likely to 
be involved in repetitive injuries. The 
prolonged recruitment of limited numbers of 
motor units, even during situations with low 
stress on these muscle fibers, can deplete 
available energy, producing eventual fatigue 
and injury (Lieber and Friden, 1994, Ex. 26-
559). At low contraction levels, membrane 
resting potential is maintained in all 
fibers, including activated fibers (Sjogaard 
et al., 1996, Ex. 26-213). Potassium-flux--
induced fatigue is an important homeostatic 
mechanism for protecting essential ATP 
stores, but this essential mechanism is 
bypassed at lower activity levels. A fatigued 
muscle that will not contract prevents direct 
tissue damage. Otherwise, the infusion of 
cytosolic calcium continues. Although calcium 
is essential for contraction, its build-up is 
directly damaging to membrane lipids and 
mitochondria. There is mounting evidence that 
types of lower-output activity that bypass 
homeostatic protection can dispose active 
muscle to silent but significant injury. 
Skeletal muscle recruitment may also explain 
the observation that eccentric muscle 
contraction more commonly causes muscle 
injury than does concentric contraction 
(Friden and Lieber, 1994, Ex. 26-559), since 
this type of contraction primarily involves 
the fastest fibers with the lowest oxidative 
capacity.
   Finally, age effects on skeletal muscle 
generally result in greater susceptibility to 
injury with repeated loading. With aging, 
muscle contractility is diminished (Thelen et 
al., 1996a, Ex. 26-219), muscle mass and 
maximum isometric force declines (Faulkner 
and Brooks, 1995, Ex. 26-1410), and the rate 
of developing force and power is lower 
(Thelen et al., 1996b, Ex. 26-220). In older 
individuals, physical conditioning has more 
impact on power than it does on force. Age-
related changes appear to be an intrinsic 
function of muscle fibers themselves, rather 
than a change in muscle recruitment patterns. 
Injuries from eccentric contractions in older 
animals heal more slowly and show a greater 
force deficit (injury effect) than in younger 
animals.
   In summary, a significant body of evidence 
supports the conclusion that conditions often 
present at work can be pathogenetic and 
pathophysiologic links with many muscular 
disorders. There is strong physiologic 
evidence that sub-maximal muscle contraction, 
which is the prevailing pattern in the 
American manufacturing and office workplace, 
can produce patterns of chronic muscle 
injury. Potential etiologies include 
abnormalities in motor unit recruitment, 
tissue loading in susceptible positions, 
altered muscle metabolism and blood flow, 
energy depletion and fatigue, inflammation, 
and altered tissue repair. This is especially 
true when work evolves away from tasks that 
approach the limit of contractile forces, and 
specific pathways of injury, rather than 
force itself, become the critical elements in 
understanding disease. Applying ergonomic 
principles to muscle physiology is intended 
to preserve mechanical output while 
preventing tissue injury.
   b. Tendons and Ligaments. Work-related 
tendon disorders develop for several reasons. 
Tendon has viscoelastic properties that may 
be exceeded when workers perform excessively 
forceful work activities, carry tasks that 
overstretch tendons, or have rest periods 
that are not sufficient to enable normal 
repair mechanisms to occur (Ashton-Miller, 
1999, Ex. 26-414; Chaffin and Andersson, 
1991, Ex. 26-420; Moore, 1992a, Ex. 26-985; 
Woo et al., 1994, Ex. 26-596). Unfortunately, 
many jobs and tasks in manufacturing and 
other work settings associated with excessive 
hand force, machine paced or piece work, 
overtime, poor tool design, etc. have these 
associated risks. In addition, repetitive 
tendon loading may cause tendon deformation 
and eventual tissue failure at a lower limit 
during subsequent loading cycles (Goldstein 
et al., 1987, Ex. 26-953; Moore, 1992a, Ex. 
26-985; Thorson and Szabo, 1992, Ex. 26-
1171). Compression and friction of tendons as 
they cross joints or move through tight 
compartments (e.g., the carpal canal or first 
dorsal compartment of the wrist) may result 
in inflammation, degeneration, and 
metaplastic changes with symptoms and signs 
of tendon pathology (e.g., stenosing 
tenosynovitis, tenosynovitis, tendinitis) 
(Ashton-Miller, 1999, Ex. 26-414; Azar et 
al., 1984, Ex. 26-1031; Backman et al., 1990, 
Ex. 26-251; Finkelstein, 1930, Ex. 26-266; 
Flint et al., 1975, Ex. 26-268; Goldstein et 
al., 1987, Ex. 26-953; Hart, Frank, and Bray, 
1994, Ex. 26-551; Kilbom, 1994, Ex. 1352; 
Rais, 1961, Ex. 26-1166; Rathburn and McNab, 
1970, Ex. 26-1376; Sampson et al., 1991, Ex. 
26-322; Uchiyama et al., 1995, Ex. 26-339; 
Vogel, 1994, Ex. 26-593; Wilson and Goodship, 
1994, Ex. 26-241).
   Tendons and ligaments are connective 
tissues that connect either muscle to bone 
(tendons), or bone to bone (ligaments). 
Tendons and ligaments are relatively 
uncomplicated tissues, with a simple 
structure subject to a limited set of 
stresses: tensile forces from muscle 
contraction, shear forces from friction 
against obstructing anatomic structures, and 
compressive forces from entrapment. Injuries 
to the muscle and tendon unit are common in 
the upper extremity.
   Tendon structure consists of parallel-
oriented collagen bundles in a water-
mucopolysaccharide matrix. In ligament, 
bundles are primarily parallel, with some 
bundles arranged in a non-parallel fashion. 
This results in different mechanical 
properties for these tissues, with more 
elasticity noted in ligamentous structures 
(Chaffin and Andersson, 1991, Ex. 26-420).
   Tendons. Skeletal muscle, unlike tendon, 
is composed of non-parallel fibers. 
Therefore, as the muscle-tendon unit proceeds 
from muscle to tendon (myotendinous 
junction), intracellular contractile muscle 
proteins transition to extracellular collagen 
in the tendon, and the arrangement of 
collagen fibers becomes more parallel. 
Extensive infolding of fibers in the 
myotendinous junction increases the surface 
area of the muscle-tendon interface and 
decreases the stress from tensile loading in 
this area (Chaffin and Andersson, 1991, Ex. 
26-420). The myotendinous junction then 
proceeds to a region called the aponeurosis, 
where tendon connective tissue predominates. 
Peritenon, a thin membranous sheath, 
separates the aponeurosis from the 
surrounding fascia.
   Microscopically, the distal tendon 
consists of multiple bundles of collagen 
tissue surrounded by epitenon, endotenon, and 
peritenon membranes. The extracellular matrix 
of healthy tendon includes water, 
glycosaminoglycans, and glycoproteins. Blood 
vessels, lymphatics, and nerves may traverse 
the epitenon or endotenon layers. However, 
avascular regions are observed in healthy 
tendons, and it is presumed that these 
regions are nourished by diffusion. The 
distal tendon has a synovial sheath that 
produces lubricating fluid (synovial fluid). 
In the

[[Page 65906]]

hand, transverse ligaments called pulleys are 
present near the distal metacarpal and permit 
flexor tendons to flex the finger through a 
fibroosseous canal without bowing out.
   The primary function of tendon is to 
transmit forces from muscle to bone. 
Accordingly, its principal injuries involve 
forces causing stretch, deformation, or 
inadequate recovery (i.e., return to resting 
length), on the one hand, and frictional 
damage due to shear and extrinsic 
compression, on the other. The tendon is 
subject to both uniaxial tensile forces from 
muscles and transverse forces from anatomic 
pulleys, bursae, and extended range of 
motion. Tensile and transverse forces produce 
shear and influence tendon gliding. This 
phenomenon draws particular attention to 
awkward or extreme posture, particularly at 
the wrist (Armstrong et al., 1984, Ex. 26-
1293).
   Pathophysiologically, four main types of 
non-acute tendon disorders have been 
suggested (Leadbetter, 1992, Ex. 26-157). 
Paratenonitis (tenosynovitis) is the 
inflammation of the peritenon. Signs and 
symptoms can include pain, swelling, warmth, 
and tenderness. Tendinosis involves 
intratendinous degeneration with fiber 
disorientation, scattered vascular ingrowth, 
occasional necrosis, and calcification; 
tendon nodularity may be noted, but swelling 
of the tendon sheath is absent. Paratenonitis 
may be observed with tendinosis. 
Corresponding signs of inflammation and 
nodularity are possible. Tendinitis (tendon 
strain or tear) can range from inflammation 
with acute hemorrhage and tear to 
inflammation with chronic degeneration. 
Clinical symptoms and signs relate to the 
contributions of inflammation vs. 
degeneration. This classification into four 
types, however, is not universally accepted.
   To understand how tendons become diseased, 
one must understand tendon function and 
repair mechanisms. As muscles contract, 
tendons are subjected to mechanical loading 
and viscoelastic deformation. Tendons must 
have both tensile resistance to loading (to 
move attached bones) and elastic properties 
(to enable them to move around turns, as in 
the hand). When collagen bundles are placed 
under tension, they first elongate without 
significant increase in stress. With 
increased tension, they become stiffer in 
response to this further loading. If the load 
on these structures exceeds the elastic limit 
of the tissue (its ability to recoil to its 
original configuration), permanent changes 
occur (Ashton-Miller, 1999, Ex. 26-414; 
Moore, 1992a, Ex. 26-985; Chaffin and 
Andersson, 1991, Ex. 26-420). During 
subsequent loading of the damaged tendon, 
less stiffness is observed. The ultimate 
strength of normal tendon and ligament is 
about 50% of that of cortical bone (Frankel 
and Nordin, 1980, Ex. 26-1125), but 
structures that have exceeded the elastic 
limit fail at lower limits. In addition, if 
recovery time between contractions is too 
short, deformation can result in pathologic 
changes that decrease the tendon's ultimate 
strength (Thorson and Szabo, 1992, Ex. 26-
1171; Goldstein et al., 1987, Ex. 26-953).
   Tendon exhibits additional viscoelastic 
properties of relaxation and creep. That is, 
when a tendon is subjected to prolonged 
elongation and loading, the magnitude of the 
tensile force will gradually decrease 
(relaxation) and the length of the tendon 
will gradually increase (creep) to a level of 
equilibrium (Chaffin and Andersson, 1991, Ex. 
26-420; Moore, 1992a, Ex. 26-985; Woo et al., 
1994, Ex. 26-596). During repetitive loading, 
the tendon exhibits these properties and then 
recovers if there is sufficient recovery 
time. If the time interval between loadings 
does not permit restoration, then recovery 
can be incomplete, even if the elastic limit 
is not exceeded (Goldstein et al., 1987, Ex. 
26-953).
   Tendons are also subject to 
perpendicularly oriented compressive loading. 
This is seen when tendons are loaded as they 
turn corners around pulleys or bony surfaces. 
Friction is generated at these locations as 
the tendon slides against adjacent surfaces, 
causing a shearing force. This is significant 
in the hand and wrist, as demonstrated by 
Goldstein et al. (1987, Ex. 26-953). The 
authors noted that higher levels of muscle 
tension are required to achieve a specific 
level of strength at the fingertip during 
non-neutral wrist postures, and that tendons 
are subject to greater shear stress with non-
neutral wrist postures. Similarly, 
compressive force in the A1 pulley has been 
demonstrated to rise dramatically from the 
neutral posture (0 to 50 mm Hg) to full 
flexion (500 to 700 mm Hg) (Azar, Fleeger, 
and Cluver, 1984, Ex. 26-1031). Tendon 
friction is proportional to the axial tension 
of the tendon, the coefficient of friction 
between the tendon and its adjacent surface, 
and the angle of the tendon as it turns about 
a pulley (Uchiyama et al., 1995, Ex. 26-339). 
Ashton-Miller, Ex. 26-414, suggests that this 
may be a cause of surface degeneration in 
tendons. Internal degeneration may be the 
result of friction-induced internal heat 
generation (Wilson and Goodship, 1994, Ex. 
26-241). One study in exercising racehorses 
demonstrated that tendon core temperature in 
the superficial digital flexor tendon was 5.4 
degrees above tendon surface temperature, 
enough to kill fibroblasts in vitro (Wilson 
and Goodship, 1994, Ex. 26-241).
   Clinically, tendon compression in the hand 
may manifest as stenosing tenosynovitis. 
Initially, examination in patients with 
stenosing tenosynovitis may reveal impaired 
motion, tenderness, pain on resisted 
contraction or passive stretch, swelling, or 
crepitation. With time, swelling and 
thickening of the tendon may occur from 
fibril disruption, partial laceration, 
impairment of blood flow and diffusion of 
metabolites, and the localized repair 
process. Ultimately, this limits the normal 
smooth passage of the tendon through its 
fibroosseous canal. These chronic tissue 
changes are recognized as triggering. At 
surgery, findings may include tightness and 
thickening of the pulley, nodular fusiform 
tendon swelling, fibrocartilaginous 
metaplasia, or fraying of the tendon 
(Finkelstein, 1930, Ex. 26-266; Sampson et 
al., 1991, Ex. 26-322)
   These conceptualized patterns of tendon 
injury have practical clinical significance, 
relating to some of the most common MSDs 
encountered in clinical practice. Micro-tears 
and gross trauma to the tendon produce an 
acute inflammatory condition with 
regeneration and removal of tissue debris. As 
noted, when the tendon load is great and 
there is insufficient recovery time between 
deformations for the tendon to recover its 
resting length, viscous strain can exceed 
elastic strain (Goldstein et al., 1987, Ex. 
26-953), causing tendon deformation (Thorson 
and Szabo, 1992, Ex. 26-1171). These are the 
mechanisms most often involved in the common 
``sprain.''
   A different injury mechanism occurs when 
tendon and tendon sheaths are forced over 
hard anatomic surfaces, producing either an 
inflammatory tendinitis or a zone of 
avascularity (lack of blood flow) due to 
compression (Rathburn and McNab, 1970, Ex. 
26-1376). This has been experimentally 
demonstrated by electrically stimulating 
muscles to contract, causing friction and 
tendinitis (Rais, 1961, Ex. 26-1166). 
Impaired circulation, hard tissue 
compression, and degenerative change are 
pertinent to rotator cuff injuries, where 
tendon insertions on the greater tuberosity 
of the humerus can be compressed under the 
coracoacromial arch. Muscle tension, itself, 
can also restrict circulation when the 
tendon's supply of arterial blood runs

[[Page 65907]]

through the contracted muscle, as is the case 
with the supraspinata (Herberts et al., 1984, 
Ex. 26-51). Common rotator cuff diagnoses 
that fall short of surgical intervention 
often fall under these pathophysiologic 
mechanisms.
   A more subtle friction-related injury is 
de Quervain's Syndrome, in which a narrowed 
first dorsal compartment juxtaposes crossed 
tenosynovium of the abductor pollicis longus 
and extensor pollicis brevis (Witt et al., 
1991, Ex. 26-242). Injury in the first dorsal 
compartment in de Quervain's Syndrome is 
actually a disorder of the retinaculum, a 
specialized ligamentous tissue acting as an 
anatomic pulley to prevent tendon 
bowstringing, and involves the fingers and 
the toes. ``Bowstringing'' refers to the 
tendency of a tendon, under tension, to 
assume the shortest distance between its 
proximal and distal insertion, unless it is 
tethered and damped. The disorder is a 
hypertrophy of this retinaculum. Tendon and 
ligament are elastic and will ``creep'' 
(i.e., stretch) in response to tensile 
loading. Creeping involves progressive fiber 
recruitment and loss of the natural waviness 
of collagen fibers.
   A diversity of clinical terms complicates 
the description of tendon injuries. As 
Waldron points out (1989, Ex. 26-509), the 
traditional peritendinitis crepitans, 
characterized by an edematous or swollen 
musculo-tendinous junction, is more limited 
than the variety of soft tissue pains that 
are currently described as tendinitis or 
tenosynovitis. In the older usage, tendinitis 
was an uncommon and severe condition in which 
the injured tissues were swollen and crackled 
under compression. Currently, ``tendinitis'' 
is used to describe a wide variety of soft 
tissue pain and is the most widely used term 
employed to characterize MSDs. Tendons have 
very different structures, depending on 
anatomic location and function, so as a 
general term for a diseased tendon, 
``tendinitis'' groups together several 
different pathologies. In the case of 
epicondylitis, the insertional tears seen in 
young athletes playing racket sports have 
little in common with the non-inflammatory 
degeneration seen in older populations, 
whether or not work is implicated as a risk 
factor (Chaard et al., 1994, Ex. 26-458). The 
frequent lack of connection between observed 
gross pathology and clinical or reported 
symptoms is another consideration. In autopsy 
series, the majority of cadavers have tears 
at the TFCC (triangulate fibro-cartilage 
complex) in the wrist or degeneration of the 
ECRB (extensor carpi radialis brevis) 
insertion at the elbow (Mooney and Poehling, 
1991, Ex. 26-304; Cherniack, 1996, Ex. 26-
258). However, the occurrence of perceptible 
symptoms is comparatively uncommon.
   Tendons and ligaments also undergo 
significant modification where they turn 
corners or insert onto bone. Evidence exists 
that the tendon matrix is reformulated in 
response to mechanical forces, implying an 
active process of cell response. However, it 
has not been determined whether this reaction 
definitively alters the mechanical properties 
of the tendon, or what its role is in future 
injury. Experimental work with rabbit flexor 
digitorum profundus tendon compressed by 
adjacent calcaneum and talus (Flint et al., 
1975, Ex. 26-268) has demonstrated that 
fibrocartilagenous metaplasia occurs in 
response, and that after surgical 
translocation of the tendon, this will 
improve. The presence of sex hormone and 
neurotransmitter receptors in tendon tissues 
indicates that tissue responses are complex 
(Hart, Frank, and Bray, 1994, Ex. 26-551). 
This implies that tendon is affected by 
internal signals and is subject to regulation 
beyond stress and strain. The proinflammatory 
neurotransmitters substance P and calcitonin 
gene-related peptide are located in the nerve 
endings present in tendons and ligaments 
(Goldstein et al., 1987, Ex. 26-953) and 
constitute a pathway for neurologically 
mediated tendon injury. The current notion of 
tendons and ligaments, which are structurally 
closely related, describes them as dynamic 
tissues subject to biomechanical strain and 
the effects of endocrine hormones and 
neurotransmitters. This suggests potentially 
complex patterns of injury and pain, and also 
of adaptation. Although a complete view of 
tendon function remains to be articulated, 
for now it seems clear that remodeling of 
tendons, inflammation, and the response to 
injury are mediated systemically as well as 
locally.
   Additional experimental evidence relates 
to a more chronic or cumulative process 
through which tendon injury can evolve. Much 
is unknown about underlying pathophysiologic 
mechanisms in even such common mechanical 
tendon-and tenosynovium-related disorders as 
breakdown of the ECRB in lateral 
epicondylitis and tendinitis of the flexor 
digitorum in CTS. However, the provocation of 
a tissue response characterized by 
proinflammatory mediators in laboratory 
animals exposed to continuous motion (Backman 
et al., 1990, Ex. 26-251) strongly suggests 
that biomechanical loading and stresses 
induce mechanical tissue injury and acquired 
micro-structural changes. Although this 
provides a useful direction, laboratory 
tendon loading experiments have not permitted 
a human threshold for repetitions causing 
tendon injury to be quantified.
   Experience suggests that resolution of 
tendinitis can be surprisingly time-
consuming. The reasons can be found in the 
pathophysiology of tendon repair. Following 
flexor tendon laceration, tendon healing 
follows three phases. Initially, inflammation 
is observed, with cells arising from the 
epitenon, endotenon, and peritendinous 
tissue. This stimulates migration and 
proliferation of fibroblasts and the removal 
of damaged tissue. The inflammatory phase 
ends long before tissue remodeling has been 
completed. Within the first week, collagen 
synthesis is initiated, though fiber 
orientation may be chaotic. By the fourth 
week, fibroblasts predominate and collagen 
content increases. Maturation of collagen and 
functional alignment occurs by the second 
month, with maximum functional restoration 
requiring exposure of the healing tendon to 
renewed loading. Exercise and movement are 
fundamental to the therapeutic process of an 
injured tendon. But premature exercise can be 
detrimental; movement of a deformed, 
devascularized, or inflamed tendon will 
provoke further injury and breakdown. 
Mechanical loading that results in a stiffer 
tendon development can provide structural 
integrity but a loss of mobility. Pain is an 
important indicator of either gross or 
microscopic abnormal tissue responses. In 
considering MSDs involving tendon and 
ligament it is especially important to 
differentiate between aggravation of an 
injury and exercise, which can be 
therapeutic. Exercise has proven to be an 
important component in the remodeling and 
strengthening of the ligaments of the rat 
knee (Frank, McDonald, and Shrive, 1997, Ex. 
26-623). However, tendon and ligament 
adaptation and repair are inevitably slow 
processes'a knee injury can take up to 2 
years to fully repair. Thus, although tendon, 
in particular, can effect a considerable but 
slow adaptational response to increased 
physical demand, a progressive increase in 
loading demands can easily exceed remodeling 
capacity, increasing the likelihood of re-
injury. The slow natural rate of tendon and 
ligament repair also highlights the 
importance of prevention and early 
intervention. Established injuries can 
persist for weeks and months even after 
ergonomic review of the workplace and 
remediation.

[[Page 65908]]

   In summary, clear evidence exists to 
support the conclusion that conditions often 
present at work can be pathogenic for some 
tendon disorders, as discussed above. 
Potential etiologies include mechanical 
disadvantage or tendon related to changes in 
joint position, changes in tensile and 
viscoeastic properties of tendon with 
excessive or repetitive loading, interference 
with normal repair mechanisms, and the 
effects of compression and friction leading 
to internal and external degeneration and 
inflammatory responses.
   Ligaments. Work exposures may contribute 
to the development of ligament and joint 
disorders as the result of many pathogenic 
and physiologic mechanisms. Ligaments, like 
tendons, have viscoelastic properties that 
may be exceeded by repetitive loading or 
deformation, resulting in possible subsequent 
failure during lower levels of loading 
(Chaffin and Andersson, 1991, Ex. 26-420). On 
the one hand, ligamentous laxity has been 
demonstrated in the wrist after continuous 
exercise (Crisco et al., 1997, Ex. 26-1373). 
This type of stress is commonly observed in 
highly repetitive work settings. On the other 
hand, immobilization may result in decreased 
ligamentous tensile strength (Woo et al., 
1987, Ex. 26-243). The significance of this 
finding in workers who perform prolonged, 
sedentary work merits further investigation.
   Although tendon and ligament have many 
structural similarities, they also have 
important differences. Ligament structure 
consists of type I and type III collagen with 
elastin and glycosaminoglycans. Ligamentous 
structures are somewhat more elastic than 
tendon, in part because of the occurrence of 
non-parallel fibers. As in tendon, there are 
length and velocity tension relationships, 
and relaxation and creep are noted (Chaffin 
and Andersson, 1991, Ex. 26-420). The ability 
of ligaments to adapt to changes in 
physiologic loading has been studied in the 
rabbit medial collateral ligament. After 9 
weeks of immobilization, a 50% decline in 
tensile strength was noted (Woo et al., 1987, 
Ex. 26-243). With remobilization, stiffness 
improved, but after 9 weeks was still 20% 
below initial values. Viscoelastic changes 
have been reported with repetitive loading, 
with a 30% increase in wrist laxity in 
subjects performing 1 hour of exercise. After 
24 hours, tissue laxity had returned to 
baseline (Crisco et al., 1997, Ex. 26-1373). 
Ligament healing and remodeling is, 
unfortunately, rather slow and limited. After 
injury, a vascular response is rather 
prolonged, and can last for several months 
(Bray et al., 1996, Ex. 26-773). With aging, 
a decrease in elastic stiffness and failure 
can occur at lower loads, as demonstrated in 
a study comparing tissue samples from old 
(mean age 76 years) and young (mean age 35 
years) subjects (Woo et al., 1991, Ex. 26-
244).
   Joint hypermobility, the familiar double-
jointedness, appears to be more common in 
women than in men (Bridges et al., 1992, Ex. 
26-1312), and appears to have a strong 
genetic basis (Child, 1986, Ex. 26-358). It 
is more an anthropometric factor, or effect 
modifier, than a predisposition to disease. 
That is, hypermobility is not an 
intrinsically morbid condition, but it can 
increase musculo-tendinous loading and 
effort. It has been recognized as a risk 
factor for musculotendinous injury in hand-
intensive tasks, presumably because of the 
co-contractive effort required to stabilize 
small joints in the hand (Pascarelli et al., 
1993, Ex. 26-1164). Hyper-mobility means that 
opposing muscle groups must be simultaneously 
and antagonistically contracted to maintain 
the position of a finger or a wrist against 
resistance. There is considerable speculation 
that hormones, as well as mechanical 
stresses, may influence knee and other tendon 
and ligament injuries in women. Although it 
is premature to ascribe these factors to the 
risk of developing a work-related knee 
injury, it is important to recognize that 
ligamentous laxity can usually be 
accommodated through changes in work 
technique and job design.
   Ligamentous laxity is also acquired in the 
course of continuous work. A 30% increase in 
wrist laxity (due to visco-elastic 
stretching) has been observed after 1 hour of 
continuous exercise (Crisco et al., 1997, Ex. 
26-1373). There is a return to normal length 
and function within 4 hours. This observation 
highlights the point that maintenance of 
ligamentous function requires periods of rest 
and disuse.
   c. Nerve. Work-related nerve disorders 
include compression, entrapment, and 
vibration-induced and toxic neuropathies. It 
is the first two that are within the scope of 
this document. Compression most commonly 
occurs adjacent to joints or as nerves pass 
through muscle or connective tissue. This may 
result in mechanical deformation of nerves, 
perineural edema, nerve ischemia, and 
inflammation with secondary nerve damage and 
delayed conduction (Feldman et al., 1983, Ex. 
26-949; Gelberman et al., 1983, Ex. 26-465; 
Lundborg and Dahlin, 1994, Ex. 26-561; Moore, 
1992b, Ex. 26-984; Rydevik et al., 1989, Ex. 
26-198; Szabo et al., 1983, Ex. 26-333). 
Examples of this include carpal tunnel 
syndrome, cubital tunnel syndrome, entrapment 
at Guyon's canal, and tarsal tunnel syndrome 
(Bozentka, 1998, Ex. 26-82; Delisa and Saeed, 
1983, Ex. 26-364; Feldman et al., 1983, Ex. 
26-949; Moore, 1992b, Ex. 26-984; Terzis and 
Noah, 1994, Ex. 26-587). External compression 
with impairment of nerve function may occur 
from contact stress between body parts and 
hard work surfaces or sharp edges (e.g., 
carpal tunnel syndrome, cubital tunnel 
syndrome) (Feldman et al., 1983, Ex. 26-949; 
Hoffman and Hoffman, 1985, Ex. 26-141). 
Alternatively, internal compression may occur 
from increased compartmental pressures or 
from contact against bones, tendons, or 
ligaments (e.g., cubital tunnel syndrome, 
carpal tunnel syndrome) (Bozentka, 1998, Ex. 
26-82; Feldman et al., 1983, Ex. 26-949; 
Moore, 1992b, Ex. 26-984; Skie et al., 1990, 
Ex. 26-328). At times, workers may experience 
anatomic and tissue changes with multiple 
sites of nerve compression that cause greater 
damage than would be experienced with a 
single site of compression (``double crush 
syndrome'') (Lundborg and Dahlin, 1994, Ex. 
26-949; Mackinnon, 1992, Ex. 26-646; Novak 
and Mackinnon, 1998, Ex. 26-1310). 
Furthermore, whole-body vibration transmitted 
by vehicles or segmental vibration from hand 
tool use may damage nerves directly or 
indirectly because of ischemia or adjacent 
tissue changes (Hjortsberg et al., 1989, Ex. 
26-1131; McLain and Weinstein, 1994, Ex. 26-
1347; NIOSH, 1989, Ex. 26-392; Takeushi et 
al., 1986, Ex. 26-681; Rempel et al., 1998, 
Ex. 26-444).
   Peripheral nerve is composed of a nerve 
cell body (motor or sensory) and an axon, 
which extends to the periphery. An axon with 
its sheath constitutes a nerve fiber. 
Myelinated fibers are surrounded by single 
layers of Schwann cells arranged in a 
longitudinal manner along the nerve. Spaces 
on myelinated nerves created by adjacent 
Schwann cells are called nodes of Ranvier. 
Bundles of nerve fibers, called fascicles, 
are wrapped by perineurium and embedded with 
microvasculature in epineural tissue. The 
amount of epineural tissue and the presence 
or absence of myelination depends on the 
location and purpose of the nerve. The 
largest myelinated fibers (Group A) have the 
highest conduction velocity. Group B fibers 
are myelinated autonomic and preganglionic 
fibers. The thinnest, non-myelinated fibers 
have the lowest conduction velocity and

[[Page 65909]]

make up the visceral and somatic afferent 
pain Group C fibers.
   Substances required for membrane integrity 
are synthesized in the nerve cell body and 
transported to the periphery, while disposal 
of waste materials and transport of trophic 
and tropic factors both involve transport 
from the periphery to the nerve cell body 
(Lundborg and Dahlin, 1994, Ex. 26-561). Both 
propagation of impulses and transportation of 
materials require a sufficient energy supply 
and vasculature. Depending upon location, 
peripheral nerves are subject to variable 
amounts of gliding or excursion in response 
to muscle, tendon, and joint movement 
(Bozentka, 1998, Ex. 26-82; Chaffin and 
Andersson 1991, Ex. 26-420; Novak and 
Mackinnon, 1998, Ex. 26-1310; Rempel, Dahlin, 
and Lundborg, 1998, Ex. 26-444).
   There are several mechanisms by which 
peripheral nerves are either injured directly 
or contribute secondarily to pain and 
dysfunction. Nerve tissue plays a predominant 
role in transmitting information on the 
extent of tissue damage and in establishing 
the CNS link producing sensations of pain. 
Movement disorders and dystonias, which 
produce chaotic or uncontrolled patterns of 
hand movement or cramps, also involve 
patterns of abnormal nerve transmission, but 
here the problem has more to do with function 
and control than pain. Nerve tissue can also 
be directly injured, producing characteristic 
symptom patterns.
   The most widely recognized lesions of 
peripheral nerves associated with repetitive 
work and chronic overuse are the entrapment 
and compression neuropathies. Mechanical 
pressure on a peripheral nerve, if severe 
enough, causes a block or delay in the 
conduction of nerve impulses, a decline in 
sensory function, and paresthesias (``pins 
and needles''). Because defects in the 
conduction of nerve impulses can be assessed 
by electrophysiology (Wilbourn and Lederman, 
1984, Ex. 26-1409) or by shifts in thresholds 
of perception (Lundborg et al., 1987, Ex. 26-
645), nerve entrapments have traditionally 
been the most effectively studied MSDs. The 
notion of nerve entrapment implies that 
external pressure or resistance on a 
peripheral nerve restricts free nerve 
movement or impinges on nerve contents 
(Lundborg, 1988, Ex. 26-1145). This pressure 
or resistance can be caused by external 
compression through soft tissue swelling by a 
fracture or callus, or by swelling or 
scarring of the nerve tissues themselves. The 
necessity for peripheral nerves to move 
during musculoskeletal activity is often 
underappreciated, with ulnar nerve range at 
the elbow approaching 1.5 cm and median nerve 
mobility being 1.0 cm at the wrist (Millesi 
et al., 1990, Ex. 26-567). In the upper 
extremity, areas of potential nerve 
compression are most frequently situated in 
the vicinity of joints. The two most common 
upper-extremity disorders are CTS at the 
wrist and cubital tunnel syndrome at the 
elbow. In the low back, degenerative disease 
and bony compression of nerve roots is the 
most common cause of radicular pain patterns 
(Deyo et al., 1990, Ex. 26-106).
   The histopathology of human compressive 
neuropathy has not been well studied, because 
surgical management does not provide 
pathological specimens. However, findings 
from animal experiments appear to correlate 
with the limited findings from human 
specimens where nerve was resected or from an 
autopsy on an individual with compressive 
neuropathy (Novak and Mackinnon, 1994, Ex. 
26-1310; Mackinnon et al., 1986, Ex. 26-1321; 
Rempel, Dahlin, and Lundborg, 1998, Ex. 26-
444; Terzis and Noah, 1994, Ex. 26-587). 
After compression of nerve, changes in the 
blood-nerve barrier develop and are followed 
by subperineurial edema and thickening of 
both perineurial and epineural layers 
(Lundborg and Dahlin, 1994, Ex. 26-561 ; 
Novak and Mackinnon, 1998, Ex. 26-1310; 
Rempel, Dahlin, and Lundborg, 1999, Ex. 26-
444; Terzis and Noah, 1994, Ex. 26-587). 
After intraneural fibrosis, myelin thinning 
results, with fibers at the periphery of the 
nerve affected first. If compression 
continues, segmental demyelination progresses 
to more diffuse demyelination and, finally, 
axonal degeneration occurs (Mackinnon and 
Dellon, 1988, Ex. 26-296; Mackinnon et al., 
1984, 1985, Exs. 26-648 and 26-649).
   Histopathologic changes are dependent on 
the force and duration of compression, as 
well as the characteristics of the nerve. 
Changes can also vary among different 
fascicles within the nerve (Mackinnon, 1992, 
Ex. 26-646). Nerves composed of large amounts 
of connective tissue with relatively few 
fascicles may be less susceptible to injury 
(Dickson and Wright, 1984, Ex. 26-1298; 
Lundborg, 1988, Ex. 26-1145). The nearer 
nerve fascicles are to the site of 
compression, the sooner pathologic changes 
will occur.
   Laboratory observations appear to support 
these conclusions. In a study of canine 
extensor digitorum brevis muscle, Hargens et 
al. (1979, Ex. 26-135) created a compartment 
syndrome by infusing plasma. As pressure 
rose, the amplitude of the action potential 
declined until complete nerve block developed 
at 2 hours at pressures of 80 to 120 mm Hg. 
Histopathological evidence of axonal 
degeneration was noted after 3 weeks. Graded 
external compression of rabbit tibial nerve 
demonstrated complete interference with 
epineural venular, arteriolar, and 
intrafascicular capillary flow at pressures 
from 60 mm Hg to 80 mm Hg (Rydevik et al., 
1981, Ex. 26-321). The neural ischemia may 
then cause endoneurial edema, with further 
rises in intraneural pressure.
   As nerves are stretched over another 
anatomic structure, mechanical deformation 
can occur with microruptures, abnormal 
function (ischemia and decreased nerve 
conduction) and scarring (Armstrong, 1983, 
Ex. 26-927). In addition, there can be an 
incompatibility between the anatomic space 
available for the nerve and the volume and 
pressure of the space (Lundborg, 1988, Ex. 
26-1145). For example, in cubital tunnel 
syndrome, repeated flexion results in stretch 
and friction of the ulnar nerve (Harter, 
1989, Ex. 26-958). This can be compounded by 
elevations in the pressure in the cubital 
tunnel that have been observed with elbow 
flexion (Pechan and Julis, 1975, Ex. 26-575). 
Elbow flexion also places the ulnar nerve in 
a more superficial position, where it can be 
damaged by leaning the elbow on a work 
surface.
   Because it is the most common nerve 
entrapment disorder of the upper extremity 
and because it is easily studied, CTS has 
become the benchmark nerve compression 
disorder (Szabo and Gelberman, 1987, Ex. 26-
1013). In CTS, postural extremes can cause 
significant increases in mean intracarpal 
pressures from 2.5 to 30 mm Hg in normal 
subjects, and from 32 to 94 (flexion) or 110 
(extension) mm Hg in patients with CTS 
(Gelberman et al., 1981, Ex. 26-1127; Szabo 
and Chidley, 1989, Ex. 26-1168). Similarly, 
pressures can rise with exposure of flexor 
tendons to high forces (Smith, Sonstegard, 
and Anderson, 1977, Ex. 26-1006), or 
repetitive hand/wrist motions (Gelberman et 
al., 1981, Ex. 26-1127; Szabo and Gelberman, 
1987, Ex. 26-1013). Within 1 hour, elevated 
carpal tunnel pressures can result in 
impaired conduction and median nerve sensory 
function (Gelberman et al., 1981, Ex. 26-
1127; Lundborg, 1988, Ex. 26-1145). Even 
transient increases in intracarpal pressure 
can produce slowed nerve conduction and 
altered sensory function of the hand 
(Lundborg et al., 1982, Ex. 26-979). These 
types of

[[Page 65910]]

pressure can be induced by prolonged isotonic 
or isometric contractions of wrist and 
digital flexors (Werner, Elmquist, and Ohlin, 
1983, Ex. 26-1025). Studies of intracarpal 
pressure in these more exaggerated or non-
neutral positions have had consistent 
results, demonstrating large increases in 
pressure when the wrist is forcefully 
stressed, particularly in hyperextension 
(Rempel et al., 1994, Ex. 26-1151; Werner et 
al., 1994, Ex. 26-237). Relatively low 
fingertip loads (5 to 15 N) raise carpal 
tunnel pressures by 4 to 6.6 kPa (Rempel et 
al., 1997, Ex. 26-889). Classic studies in 
the meatpacking industry (Masear, Hayes, and 
Hyde, 1986, Ex. 26-983) and in the automobile 
industry (Silverstein, Fine, and Armstrong, 
1987, Ex. 26-34) have shown a consistent 
pattern of forceful wrist exertions and nerve 
compression syndromes. This same pattern of 
risks is evidenced in the so-called pinch 
grip, leading to innovations in tool handle 
design (Tichauer, 1978, Ex. 26-446). Use of 
modifications tend to involve the full palm 
rather than the fingers alone.
   Because of the strong association of CTS 
with repetitive and forceful work and awkward 
postures (Silverstein, Fine, and Armstrong, 
1987, Ex. 26-34), there has been particular 
attention to the process by which joint 
deviation and loading and repetitive muscle 
contraction can raise pressure at an anatomic 
canal. In the upper extremity, fibrotic 
changes in the radial and ulnar bursae and at 
the carpal tunnel have been located 
consistently. These changes potentially 
produce compressive stresses on the median, 
ulnar, and radial nerves from bone and 
retinaculum (Armstrong et al., 1984, Ex. 26-
1293).
   The transition from acute compression 
injury to a chronic nerve entrapment 
condition involves an extension of these 
pathophysiologic models. However, Mackinnon 
et al. (1984, Ex. 26-648) have presented a 
histologic model showing the gradual 
transition from a recoverable nerve 
compression injury, in which there is 
swelling and thickening of the connective 
tissue lining bundles of nerve fibers, to 
demyelination of the nerve and nerve 
fibrosis, in which there are often 
irreversible changes to the nerve. This has 
been extended to a model of CTS (Mackinnon 
and Novak, 1997, Ex. 26-1309).
   Novak and Mackinnon (1998, Ex. 26-1310) 
suggest that many patients with diffuse 
upper-extremity symptoms may experience 
problems from multiple levels or sites of 
nerve compression and concomitant muscle 
imbalance. These observations come from the 
often surprising clinical evidence that 
symptomatic patients often express signs at 
multiple sites of potential compression. This 
so-called ``double crush'' syndrome (Hurst et 
al., 1985, Ex. 26-965) can be a consequence 
of degenerative cervical spine disease or 
acquired postural torsion at the brachial 
plexus (Mackinnon and Novak, 1997, Ex. 26-
1309). In the ``double crush'' syndrome, 
there is compression at the carpal tunnel as 
well.
   The concept of ``double'' or ``multiple 
crush syndromes'' is a controversial subject. 
In 1973, Upton and McComas first proposed 
that a proximal site of nerve compression, 
such as a cervical disc herniation, could 
make a distal nerve more susceptible to 
injury. Other potential scenarios could 
include ulnar nerve entrapment at the 
brachial plexus and cubital tunnel, or at the 
cubital tunnel and Guyon's canal. Mackinnon 
(1992, Ex. 26-646) and Dellon and Mackinnon 
(1991, Ex. 26-616) have further describe the 
concept. These observations can be 
significant in situations where work postures 
place muscles in shortened positions. For 
example, workers who perform tasks requiring 
prolonged or resisted pronation may develop 
pronator muscle shortening that compresses 
the median nerve in the forearm when the 
forearm is placed in supination. 
Alternatively, prolonged and static work 
postures that result in pectoralis minor or 
scalene muscle tightness can compress the 
brachial plexus. Alterations in axoplasmic 
flow and transport of neutrophic substances 
has been proposed as the mechanism of this 
injury. Dellon and Mackinnon (1991, Ex. 26-
616) devised an experimental animal study to 
evaluate these phenomena. The authors banded 
either sciatic nerve, posterior tibial nerve, 
or both nerves in rat subjects. The group of 
rats with double banding demonstrated 
significantly worse mean amplitudes of the 
compound action potential than either group 
of single-banded rats. In theory, metabolic 
abnormalities (e.g., diabetes, alcoholic 
neuropathy, collagen vascular disease) could 
weaken a nerve and make it more susceptible 
to injury from less significant levels of 
compression. In the case of diabetes, a 
recent article by S.E. MacKinnon (1992, Ex. 
26-646) describes rodent and primate models 
of diabetes with superimposed nerve 
compression. With alcohol, it is biologically 
plausible, although not specifically 
documented, that a ``sick'' neuron resulting 
from alcoholism could similarly render a 
nerve metabolically damaged and therefore 
more susceptible to injury from compression 
at a distal site.
   A related observation is that persistent 
stretching of a nerve over an anatomic 
landmark, such as the ulnar nerve at the 
medial epicondyle of the elbow, can produce 
nerve trauma and inflammation (Harter, 1989, 
Ex. 26-958). The notion that micro-ruptures 
produce micro-anatomic injury and fibrosis of 
the epineurium (connective tissue lining the 
nerve) has been offered as a general model 
for CTS (Armstrong et al., 1993, Ex. 26-
1110). This model has its analogue in the 
epineural fibrosis that can be a consequence 
of nerve release surgery.
   It is important to recognize that CTS is 
not responsible for all cases of numbness and 
tingling in the fingers that occur in 
demanding work settings. Furthermore, there 
is no ``gold standard'' for diagnosis, and 
the presence of even classical symptoms does 
not necessarily mean that surgery is 
required. There is a high level of 
reversibility in CTS, and job modification 
can be enough to eliminate symptoms without 
aggressive individual therapy. Moreover, 
without job modification, surgery may only 
delay a recurrence. Even for this most 
accessible MSD, modest changes in diagnostic 
criteria--for example, whether symptoms and 
signs are weighted or full reliance is placed 
on the nerve conduction study--can alter the 
case rate by as much as 50% (Katz et al., 
1991, Ex. 26-151; Moore, 1991, Ex. 26-1335, 
Cherniack et al., 1996, Ex. 26-258).
   Other work-induced causes of peripheral 
nerve injury, such as hand-arm vibration, can 
induce small fiber nerve injury that is 
unrelated to entrapment or compression (see 
Section D.3). The result, however, is a 
similar pattern of symptoms. Even when the 
pattern of nerve injury distinctly implicates 
a focal site of compression, there is no 
automatic requirement for surgical 
decompression. It is also important to 
recognize that in the setting of low-back 
pain, even when symptoms radiate to the lower 
extremity along a nerve dermatome, fixed 
nerve root lesions and the correlated need 
for decompression are relatively rare 
(Andersson and McNeill, 1989, Ex. 26-413). 
The same is probably true for CTS, although 
the proportion of surgical cases for CTS 
remains comparatively high.
   Although most work-related peripheral 
entrapment disorders affect myelinated nerve 
fibers, there are other nerve tissue 
components that are at risk. Mechanoreceptors 
in the glabrous pads of the digits are 
intrinsic to touch and spatial discrimination 
(Vallbo and Johansson, 1984, Ex. 26-

[[Page 65911]]

717). Their quantitative function has been 
effectively assessed through the testing of 
vibrotactile thresholds (Brammer et al., 
1987, Ex. 26-935; Verrillo and Capraro, 1975, 
Ex. 26-591). Individual mechanoreceptors, 
such as Pacinian corpuscles, which measure 
acceleration as a sensation of touch, respond 
to particular frequencies of vibration. This 
principle is useful in establishing 
thresholds of response and function for 
individual mechanoreceptor populations. 
Mechanoreceptor injury is a well-recognized 
consequence of exposure to hand-arm 
vibration, and dysfunction documented in 
objective tests has correlated with 
decrements in hand performance and 
sensitivity (Virokannas, 1992, Ex. 26-1355). 
Quantitative sensory dysfunction consistent 
with mechanoreceptor injury has also been 
observed in manual workers unexposed to 
vibration, but for whom energy transfer still 
occurs in the form of shock and impact 
(Flodmark and Lundborg, 1997, Ex. 26-370).
   There are several proposed mechanisms for 
the development of lumbar nerve root pain, 
including mechanical deformation, 
compression, ischemia, and inflammatory 
mediators. It appears that the spinal nerve 
root may be more susceptible to compression 
than peripheral nerves (Olmarker and Rydevik, 
1991, Ex. 26-190). In an in-vivo experiment 
compressing the porcine cauda equina 
(Olmarker, Holm, and Rydevik, 1990, Ex. 26-
518; Olmarker, Rydevik, and Holm, 1989, Ex. 
26-191; Olmarker et al., 1989, Ex. 26-311), 
venous flow was observed to cease at 
relatively low pressures (5 to 10 mm Hg), 
resulting in retrograde stasis of capillaries 
and impaired nutrient transport (Rydevik et 
al., 1990, Ex. 26-197). Changes in the 
permeability of the spinal nerve root 
endoneurial capillaries, intraneural edema, 
increased endoneurial fluid pressure, and 
impaired nutrition of the nerve roots have 
been described by others as resulting from 
compression (Low and Dyck, 1977, Ex. 26-482; 
Low, Dyck, and Schmeizer, 1982, Ex. 26-385; 
Lundborg, Myers, and Powell, 1983, Ex. 26-
162; Myers et al., 1982, Ex. 26-308; 
Olmarker, Rydevik, and Holm, 1989a, Ex. 26-
191; Rydevik, Myers, and Powell, 1989, Ex. 
26-198).
   Inflammatory mediators have also been 
implicated in the etiology for low-back pain, 
and histopathologic signs of inflammation 
have been observed in compressed nerve roots 
(Bobechko and Hirsch, 1965, Ex. 26-252; 
Diamant, Karlsson, and Nachemson, 1968, Ex. 
26-261; Marshall, Trethewie, and Curtain, 
1977, Ex. 26-483; Marshall and Trethewie, 
1973, Ex. 26-564; Nachemson, 1969, Ex. 26-
742). Proposed mediators include lactic acid, 
pH, substance P, bradykinin, cytokines, 
prostaglandins, and carrageenan, among 
others.
   In recent years there has been a growing 
recognition of pain syndromes maintained by 
the sympathetic nervous system. These 
sympathetically maintained pain syndromes 
(SMPSs), of which reflex sympathetic 
dystrophy (RSD) is the best known, are 
characterized by pain and swelling, usually 
of the hands or feet, and vascular 
dysfunction (Roberts, 1986, Ex. 26-402; 
Kozin, 1994, Ex. 26-556). Traumatic origins 
are common, particularly following fracture 
to the hand, but there is evidence of a more 
widespread occurrence, in the setting of CTS, 
for example. This broader definition of SMPS 
appears to have substantial relevance to 
chronic soft tissue injuries, such as MSDs, 
associated with the workplace.
   The evidence reviewed supports the 
conclusion that work conditions can be 
pathogenic for some nerve disorders. 
Mechanisms include external or internal nerve 
compression or mechanical deformation with 
subperineurial edema, altered metabolic nerve 
activity, demyelination, and axonal 
degeneration.
   d. Vasculature. The ability of muscles, 
tendons, ligaments and cartilage to perform 
work and permit repair is dependent upon 
adequate blood flow, tissue oxygenation, and 
transmission of nutrients and metabolic end 
products. Therefore, when the performance of 
work tasks results in exposure to external or 
internal factors that impair normal tissue 
blood flow, tissue damage can occur and 
result in the development of MSDs. Mechanisms 
of injury may include tissue hypoxia from 
elevations in intramuscular pressure 
associated with forceful work or postural 
task requirements (Armstrong et al., 1993, 
Ex. 26-1110; Herberts et al., 1984, Ex. 26-
51; Sjogaard and Sjogaard, 1998, Ex. 26-
1322), vascular occlusion from direct 
pressure to anatomic structures ( Duncan, 
1996, Ex. 26-366; Kleinert and Volianitis, 
1965, Ex. 26-380; Nilsson, Burstrom, and 
Hagberg, 1989, Ex. 26-693; Wheatley and Marx, 
1996, Ex. 26-693), and vibration-induced 
vasospasm or impairment of microcirculation 
from hand tool use or whole-body vibration 
(Hirano et al., 1988, Ex. 26-140; Kaji et 
al., 1993, Ex. 26-854; NIOSH, 1989, Ex. 26-
392). Thus it appears that vascular changes 
resulting from work exposures may contribute 
to the development or manifestation of MSDs.
   The circulatory system is a major target 
of acquired morbidity for general health. 
However, while conditions such as 
atherosclerosis and smoking-related 
endothelial dysfunction can compromise 
neuromuscular function, their etiology does 
not evolve out of the workplace. Ischemia due 
to arteriosclerosis is an important component 
of muscle pain and dysfunction, but it is not 
a primary acquired work-related disorder. 
Ischemia caused by static contraction and 
transmural pressure from muscles and bone 
across arteries is work-related, and is 
usually reversible. There are distinct vaso-
occlusive and vasospastic disorders of the 
hand that have a singular work-related 
etiology.
   Arterial occlusive disease, expressed as 
either Raynaud's phenomenon or digital pain, 
has been described in a variety of hand-
intensive tasks (Schatz, 1963, Ex. 26-200). 
Palmar and digital artery occlusion that is 
work-induced is usually due to traumatic 
ulnar artery occlusion, the so-called 
hypothenar syndrome or ulnar hammer syndrome 
(Wheatley and Marx, 1996, Ex. 26-693; Duncan, 
1996, Ex. 26-366). The general mechanism 
causing thrombotic emboli in the palm and 
fingers is blunt trauma, caused by using the 
hand as a percussive object or by 
aggressively twisting hard objects (Pineda et 
al., 1985, Ex. 26-493; Kreitner et al., 1996, 
Ex. 26-557). The disorder has also been 
associated, albeit uncommonly, with the use 
of hand-held pneumatic tools (Kaji et al., 
1993, Ex. 26-854). The usual mechanism is 
ascribed to trauma and abrupt injury of the 
endothelium (the blood vessel lining), with 
the ulnar artery being bludgeoned against the 
hook of the hamate (Benedict, Chang, and 
McCready, 1974, Ex. 26-352). Contractions 
around the ulnar artery due to an anatomic 
muscle sling or anomalous hypothenar muscle 
has also been described (Benedict, Chang, and 
McCready, 1974, Ex. 26-352). Physiologically, 
the lesion is the consequence of thrombi, or 
small clots, that lodge in smaller or more 
peripheral vessels. This can occur because of 
pressure, the blockage of blood flow, and 
stasis-related clot formation. It is also 
hypothesized that shear forces injure the 
endothelium and expose the underlying 
tissues, the vascular intima, to injury. The 
repair mechanism leads to clot formation.
   The most common vasospastic disorder 
associated with workplace exposure is 
occupational Raynaud's or vibration-induced 
white finger (VWF). In the field of hand-arm 
vibration, exposure measurement and 
specialized disease testing have produced 
highly evolved, methodologically

[[Page 65912]]

detailed, and technically sophisticated 
approaches that have few equivalents in the 
occupational health literature, and none in 
the literature on soft tissue injury. Because 
vibration is a complex physical factor, 
lending itself to quantification and 
modeling, and because it produces distinct 
and reproducible effects on vessels and 
nerves, there are parallels to noise in the 
formality of measurement methodology. VWF is 
largely associated with hand-held oscillating 
pneumatic tools, such as metal grinders and 
pneumatic drills. It is also associated with 
chain saws and with powered tools causing 
repetitive impact, such as riveters and 
impact wrenches. The mechanisms producing 
Raynaud's in the setting of hand-arm 
vibration are not fully understood. However, 
there is evidence for a sympathetically 
mediated constriction of small arteries in 
the hand, interrupting cutaneous blood flow. 
There is also evidence of impaired dilatation 
of larger arteries. Section D.3.b presents a 
more complete discussion of hand-arm 
vibration.
   Vibration can also diminish the blood flow 
to the intervertebral disc. This has been 
demonstrated by Hirano et al. (1988, Ex. 26-
140) in the rabbit intervertebral disc 
exposed to in-vivo vibration. Unfortunately, 
the lumbar intervertebral disc is avascular, 
and its nutritional supply comes from 
diffusion through blood vessels surrounding 
the annulus fibrosus and under the hyaline 
end plate cartilage. Diminished blood flow to 
the cartilage end plate would limit the 
ability of the disc to maintain the degree of 
hydration necessary to provide support for 
the lumbar spine during loading. In the hand, 
direct pressure over the hypothenar eminence 
can also occlude the ulnar artery and result 
in hypothenar hammer syndrome (Conn, Bergan, 
and Bell, 1970, Ex. 26-821; Kleinert and 
Volianitis, 1965, Ex. 26-380; Nilsson, 
Burstrom, and Hagberg, 1989, Ex. 26-1148). 
Thus, it appears that vascular changes 
resulting from work exposures may contribute 
to the development or manifestation of MSDs.
   Extrinsic ischemic compression, while not 
an intrinsic disease of blood vessels, is 
also considered here to complete the 
discussion of vascular responses to work 
exposures. The ability of muscles, tendons, 
ligaments, and cartilage to perform work and 
permit repair depends on adequate blood flow, 
tissue oxygenation, and transmission of 
nutrients and metabolic end products. When 
external or internal factors impair normal 
tissue blood flow, tissue damage can occur 
and result in the development of MSDs. As 
discussed, elevations in intramuscular 
pressure with forceful exertion, confinement 
from bony structures, or tight fascial 
compartments can contribute to the onset of 
work-related MSDs as a result of tissue 
hypoxia (Armstrong et al., 1993, Ex. 26-1110; 
Sjogaard and Sogaard, 1998, Ex. 26-1322). For 
example, work tasks that require shoulder 
abduction and/or elevation to perform 
activities at or above shoulder height can 
decrease blood flow to the hypovascular 
portion of the supraspinatus tendon (Herberts 
et al., 1984, Ex. 26-51). A decrease in blood 
flow to the trapezius muscle has also been 
observed in assembly workers with localized 
chronic myalgia related to static loading 
(Larsson et al., 1990, Ex. 26-1332).
   e. Synovial Joints and Hyaline Cartilage. 
Work exposures may contribute to the 
development of joint disorders for many 
reasons. Joint cartilage matrix metabolism 
may be disturbed and inflammatory and 
chemical mediators stimulated by joint trauma 
or repetitive loading (Allan, 1998, Ex. 26-
1316; Howell, 1989, Ex. 26-1308; Radin et 
al., 1994, Ex. 26-578). Experimental animal 
studies have documented the loss of 
proteoglycans, fibroblast synthesis of 
inflammatory mediators, and the development 
of osteoarthritis from repetitive tissue 
loading (Allan, 1998, Ex. 26-1316; Farkas, 
1987, Ex. 26-463; Poole, 1986, Ex. 26-1316; 
Vasan, 1983, Ex. 26-590). With inadequate 
repair, cartilage thinning and hypertrophic 
remodeling may lead to osteoarthritis 
(Chaffin and Andersson, 1991, Ex. 26-420; 
Radin, 1976, Ex. 26-663; Radin et al., 1976, 
1994, Exs. 26-443 and 26-578). Repetitive or 
prolonged stair or ladder climbing, kneeling 
or squatting, standing, carrying heavy loads, 
and jumping are all work tasks that may be 
associated with lower-extremity joint 
loading. This is explored further in the 
sections on epidemiology and pathogenesis of 
lower-extremity disorders. Recurrent 
microtrauma associated with the pinching 
mechanism, highly intensive hand tasks 
requiring dexterity during assembly work or 
food preparation, and pneumatic tool use have 
all been observed to associated with upper-
extremity joint loading and the development 
of upper-extremity osteoarthritis (Bovenzi et 
al., 1987, Ex. 26-605; Fam and Kolin, 1986, 
Ex. 26-1123; Felson, 1994b, Ex. 26-543; 
Nakamura et al., 1993, Ex. 26-1314).
   A synovial joint consists of bone ends 
covered by hyaline articular cartilage and 
separated by a synovial-fluid-filled joint 
cavity. A synovial membrane and capsule cover 
the joint. The joint capsule contains dense 
connective tissue and is attached to the 
distal ends of the articulating structures. 
It is innervated by sensory nerves that 
provide proprioceptive feedback and the 
sensation of pain. The normal synovium 
consists of one to three layers of cells. 
Type A synoviocytes are derived from 
monocytes and behave as phagocytes for joint 
space debris. Type B synoviocytes produce 
glucosaminoglycans for joint lubrication and 
enzymes in response to inflammatory stimuli. 
Cytokines secreted by both cells help to 
regulate the structural repair process after 
injury or antigenic stimulation (Allan, 1998, 
Ex. 26-1316).
   Synovium has a rich vascular supply. It 
secretes synovial fluid and permits the 
transport of oxygen, carbon dioxide, 
nutrients, waste products, and immunologic 
cells to the joint. Trauma and inflammation 
impair the synovial microcirculation and 
transport of these substances across the 
joint.
   There are three zones or layers of the 
articular cartilage. In the superficial zone 
adjacent to the joint cavity, collagen fibers 
are parallel to the articular surface. This 
orientation becomes more random in the middle 
zone. At the deep zone adjacent to the 
subchondral bone, fibers are mostly 
perpendicular because they anchor to the 
underlying bone (Allan, 1998, Ex. 26-1316; 
Mow, Lai, and Rodler, 1974, Ex. 26-653).
   Collagen fibers are stable in the 
articular cartilage until degraded by age or 
disease, but proteoglycans are continuously 
synthesized by the chondrocytes (Allan, 1998, 
Ex. 26-1316). The proteoglycan matrix is 
hydrophilic, and osmotic pressure is resisted 
by tension in the collagen fibers in the 
unloaded joint. Once osmotic pressure is 
exceeded from external joint loading, water 
is squeezed out of the cartilage and the 
cartilage is flattened. Loaded, the articular 
cartilage undergoes elastic deformation 
followed by gradual creep. With unloading, 
the articular cartilage undergoes an initial 
elastic recoil followed by gradual recovery 
of its unloaded characteristics (Chaffin and 
Andersson, 1991, Ex. 26-420). Some joints, 
such as the knee, also contain fibrocartilage 
discs (menisci) to help protect the articular 
cartilage and distribute load forces.
   It is clear that significant joint trauma 
can initiate hypertrophic remodeling, usually 
at sites of synovial

[[Page 65913]]

membrane and ligament attachment. The result 
is secondary cartilage breakdown (Howell, 
1989, Ex. 26-1308). Unfortunately, cartilage 
has a limited vascular supply and ability to 
heal itself. With damage to subchondral 
tissues, there is reactive ossification and 
secondary cartilage thinning (Radin et al., 
1976, 1994, Exs. 26-443 and 26-578). After 
cartilage deteriorates, bone becomes subject 
to increased stress from loading, and 
reactive bone deposition occurs, resulting in 
sclerosis, spurring, or bone cysts noted in 
osteoarthritis. As the joint spaces narrow, 
the joint becomes more susceptible to further 
mechanical damage, inflammation, and scarring
   Mechanical stresses associated with 
certain tasks that exceed the limits of 
tissue tolerance can either cause 
degenerative joint disease and/or accelerate 
the normal degenerative process that occurs 
with aging. They can also interact to hasten 
other forms of secondary osteoarthritis, 
including cases that occur after trauma or 
infection, and congenital, developmental, or 
anatomic abnormalities. For example, 
repetitive joint loading can impair cartilage 
matrix metabolism and disturb the repair 
processes (Allan, 1998, Ex. 26-1316; Radin et 
al., 1994, Ex. 26-578). Studies of repetitive 
loading in dogs after 8 months of treadmill 
exercise have demonstrated a loss in 
proteoglycan similar to findings in models of 
osteoarthritis (Poole, 1986, Ex.26-1316; 
Vasan, 1983, Ex. 26-590). Rabbits subjected 
to 8 weeks of repetitive loading on the tibia 
show severe osteoarthritis after 24 weeks 
(Farkas et al., 1987, Ex. 26-463). In-vitro 
fibroblast studies have also shown that 
repetitive motion can stimulate the synthesis 
of inflammatory mediators, including 
prostaglandins (Allan, 1998, Ex. 26-1316).
   Degenerative joint disease can occur even 
after relatively low loads on joints if the 
forces are applied impulsively and 
repetitively (Radin and Paul, 1971, Ex. 26-
496). This may occur because loads that are 
applied too rapidly to permit normal 
cartilage fluid movement could result in 
microscopic injury to the matrix (Radin et 
al., 1994, Ex. 26-578). Loss of proteoglycans 
and cartilage fibrillation is also noted in 
this setting (Radin et al., 1976, Ex. 26-
443). Allan (1998, Ex. 26-1316) suggests that 
several joint interactions involved with 
repetitive loading may contribute to 
pathology. Since joints involve many 
structures, including tendon, muscle, nerve, 
and bone, damage to one structure may occur 
although the recovery cycle of another 
structure was not exceeded. Pain from one 
structure may also alter feedback from other 
structures. In the absence of cartilage pain 
receptors, excessive force may be applied to 
damaged cartilage without the ability to 
promote adequate protective responses.
   Aging itself is associated with gradual 
physiologic changes in cartilage matrix, loss 
of repair activity of chondrocytes, and 
eventual development of degenerative joint 
disease. This is most commonly noted in 
people over 40, and affects mostly large 
joints like the hip or knee that are exposed 
to repeated loading (Felson, 1994, Ex. 26-
544). Felson (1988, Ex. 26-114) postulated 
the following reasons for age-induced 
degenerative joint disease: metabolic changes 
in cartilage increase susceptibility to 
fatigue fracture, bone adjacent to damaged 
cartilage becomes increasingly stiff from 
microfractures, and declining muscle mass and 
tendon strength decrease protective shock 
absorbency.
   At times, it can be difficult to 
distinguish degenerative changes caused by 
age from those caused by work, although many 
studies have demonstrated increased rates of 
osteoarthritis in certain working populations 
(see Appendix I, Ex. 27-1), and there are 
consistent pathogenic explanations to link 
work conditions to some degenerative joint 
diseases. Potential mechanisms include damage 
to subchondral tissue from excessive, 
impulsive, or repetitive joint loading; 
impaired cartilage matrix metabolism; 
reactive ossification and cartilage thinning; 
reactive bone deposition; and disturbed 
repair processes.


3. Vibration

   Vibration is traditionally divided into 
whole-body vibration, particularly pertinent 
for seat design and transportation, and 
segmental vibration, affecting the hand and 
arm. In the latter case, health effects are 
usually related to energy transfer to the 
upper extremity from either powered tools or 
from stationary sources producing oscillatory 
vibration, such as mounted drills and 
pedestal grinders. Because vibration is a 
complex physical factor, lending itself to 
quantitation and modeling, and because it 
produces distinct and reproducible effects on 
blood vessels and nerves, there are parallels 
to noise in the formality of measurement 
methodology.
   a. Whole-Body Vibration. Whole-body 
vibration can affect skeletal muscle and 
predispose an individual to work-related low-
back pain. Etiologies for this can include 
bursts of cyclic muscle contraction, muscle 
fatigue, decreased ability of fatigued 
muscles to protect spinal structures from 
loads, continuous compression and stretch of 
structures, decreased blood flow, and altered 
neuropeptides (Brinckmann, Wilder, and Pope, 
1996, Ex. 26-418; Friden and Lieber, 1994, 
Ex. 26-546; Hansson and Holm, 1991, Ex. 26-
134; Seidel, 1988, Ex. 26-1003). Whole-body 
vibration, especially seated vibration, has 
been associated with the development of low-
back disorders (Damkot et al., 1984, Ex. 26-
1121; Frymoyer et al., 1983, Ex. 26-950; 
Kelsey and Hardy, 1975, Ex. 26-855; Bernard 
and Fine, 1997, Ex. 26-1; Troup, 1988, Ex. 
26-1021). Several mechanisms have been 
postulated. These include microfractures at 
vertebral endplates, vasospasm and decreased 
blood flow, tissue fatigue from mechanical 
overload and stretching of spinal structures, 
and ultrastructural changes in the spinal 
nerve root dorsal ganglion with biochemical 
alterations involving pain-inducing 
neuropeptides (Hansson, Kefler, and Holm, 
1987, Ex. 26-134; Hirano et al., 1988, Ex. 
26-140; Kazarian, 1975, Ex. 26-379; Keller, 
Spengler, and Hansson, 1987, Ex. 26-290; 
McLain and Weinstein, 1994, Ex. 26-1347; Pope 
et al., 1984, Ex. 26-440; Seidel and Heide, 
1986, Ex. 26-672; Seroussi, Wilder, and Pope, 
1989, Ex. 26-205).
   Radiographic and pathologic changes have 
been noted in human subjects exposed to 
whole-body vibration (Frymoyer et al., 1980, 
1983, Exs. 26-707 and 26-950; Kelsey, 1975, 
Ex. 26-1134; Pope et al., 1991, Ex. 26-1305; 
Wilder et al., 1982, Ex. 26-694). Christ and 
Dupuis (1966, Ex. 26-134) evaluated 
radiographic lumbar spine findings for 
tractor operators. As the annual number of 
hours of operation increased, so did the 
prevalence of x-ray changes. Changes were 
observed in 61% of operators who drove for 
less than 700 hours per year, 68% in those 
who drove for 700 to 1,200 hours per year, 
and 94% in those who drove for over 1,200 
hours per year. The small number of subjects 
weakened the study. Other studies, though, 
have reported similar associations of driving 
time, symptoms of low-back disorder, and 
radiographic abnormalities of the lumbar 
spine (Fishbein and Salter, 1950, Ex. 26-267; 
Seidel and Heide, 1986, Ex. 26-672). Findings 
reported with increased frequency include 
reduced disc height, facet arthrosis, 
spondylosis, Schmorl's nodules, and 
spondylolisthesis. It has been pointed out 
that these studies have been retrospective, 
and some lack adequate controls (Hansson and 
Holm, 1991, Ex. 26-134). Unfortunately, many 
heavy-equipment operators and fork truck 
drivers are exposed to

[[Page 65914]]

a number of additional factors that increase 
disc stress, including seated postures, 
kyphotic postures, twisting, and whole-body 
vibration (Dupuis, 1994, Ex. 26-847). These 
probably accounts for the premature onset of 
degenerative disc disease in these workers.
   The natural resonance frequency of the 
human lumbar spine in the seated position is 
in the range of 4 to 6.5 Hz (Magnusson et 
al., 1990, Ex. 26-166; Wilder, Pope, and 
Frymoyer, 1982, Ex. 26-694). This is similar 
to the vibration characteristic of many motor 
vehicles. Whole-body vibration imposes 
several motions on the body and the spine, 
including impact, translation, and rotation. 
Within the natural frequency range, one 
animal in-vivo study demonstrated that disc 
pressure and axial and shear strain from 
vibration can increase 2 to 3 times (Hansson 
et al., 1987, Ex. 26-134). The significant 
increase of spinal loading from vibration in 
the natural frequency has the consequence of 
exacerbating the amount of disc shrinkage 
noted after simple sitting. This has been 
demonstrated in human subjects using 
continuous measurement of the spine 
(Kazarian, 1975, Ex. 26-379; Magnusson et 
al., 1990, Ex. 26-166). As frequency 
increases within the range of 0 to 15 Hz, 
stiffening of the spinal structure is noted 
in normal human subjects (Wilder, Pope, and 
Frymoyer, 1982, Ex. 26-694). Shifting to 
positions of mild lateral spinal flexion 
transiently decreases stiffness, but this 
posture imposes other mechanical 
disadvantages, such as paraspinal and 
abdominal muscle fatigue (Wilder, Pope, and 
Frymoyer, 1982, Ex. 26-694). Brinckmann et 
al. (1987, 1988, Exs. 26-84 and 26-1318) 
performed in-vitro experiments and noted that 
repeated cyclic loading of vertebral bone, as 
opposed to single loading events, reduced the 
strength of the material. They suggested that 
the resulting endplate fractures were a 
possible mechanism of later disc injury and 
low-back pain.
   Vibration has additional effects on the 
erector spinae muscles, with observations of 
greater myoelectric activity and fatigue 
(Seidel and Heide, 1986, Ex. 26-672; 
Seroussi, Wilder, and Pope, 1989, Ex. 26-205; 
Wilder, Pope, and Frymoyer, 1982, Ex. 26-
694). Johanning (1991, Ex. 26-1228) observed 
that subway operators experienced trunk 
muscle fatigue after being exposed to whole-
body vibration for 1 hour. Pope et al. (1984, 
Ex. 26-440) also believe that the fatigue of 
paraspinal muscles, ligaments, and discs 
contributes to low-back pain associated with 
exposure to whole-body vibration. Progressive 
muscle fatigue limits the ability of skeletal 
muscle to protect spinal structures. 
Additional spinal loading can also result 
when the muscle response diverges out of 
phase with the vibration input (Seroussi, 
Wilder, and Pope, 1989, Ex. 26-205).
   The physiologic result of vibration in the 
natural resonance frequency is structural 
failure. This occurs first in the vertebral 
end plate, adjacent spongy bone of the 
vertebral body, and the intervertebral disc 
(Keller, Spengler, and Hansson, 1987, Ex. 26-
290). Hirano et al. (1988, Ex. 26-140) 
demonstrated that blood flow decreased in the 
rabbit intervertebral disc exposed in vivo to 
vibration. Porcine intervertebral disc 
experiments have shown that solute transport 
is also disrupted (Holm and Nachemson, 1985, 
Ex. 26-1374). Both of these effects are 
likely to precipitate disc degeneration 
because of disturbed metabolic activity, as 
discussed earlier. McLain and Weinstein 
(1994, Ex. 26-1347) studied ultrastructural 
and neuropeptide changes in the rabbit lumbar 
spine dorsal ganglion exposed to whole-body 
vibration at amplitudes and frequencies 
similar to those of motor vehicles. On 
electron microscopy, the group exposed to 
vibration had more significant findings of 
nuclear clefting, mitochondrial, rough 
endoplasmic reticulum, and ribosomal changes 
relative to controls. The authors suggested 
that this may provide an anatomic link 
between the clinical observation of increased 
back pain and the biochemical alterations 
involving pain-related neuropeptides.
   b. Hand-Arm Vibration. Disorders resulting 
from hand-arm vibration are the sole subject 
of the cited epidemiologic studies on 
vibration. Outcomes involving measurable 
neurological and arterial dysfunction have 
taken precedence over pain and function, in 
marked distinction to more clinically 
appreciated musculoskeletal diseases. In 
1986, the International Standards 
Organization published methods for measuring 
vibration and controlling its exposure--ISO 
5349 (1986, Ex. 26-1301). The approach was 
adopted by the American National Standards 
Institute in ANSI S3.34 (1986, Ex. 26-1402). 
This accepted approach to measurement 
reflects the technical feasibility of 
characterizing the vibratory qualities of 
hand tools. Vibration is measured in terms of 
the frequency distribution of oscillations; 
the direction, velocity, and acceleration of 
those oscillations; and the impulsiveness, or 
force range (amplitude), expressed in each 
impact cycle (Starck and Pyykko, 1986, Ex. 
26-678; Maeda et al., 1996, Ex. 26-562). Each 
of these physical characteristics has a 
bearing on symptoms and tissue injuries that 
may occur, particularly in the palms and 
digits, but also more proximally in the 
shoulder and neck.
   In the field of hand-arm vibration, 
exposure measurement and specialized disease 
testing have produced highly evolved, 
methodologically detailed, and technically 
sophisticated approaches. These have few 
equivalents in the general occupational 
health literature, and none in the area of 
soft tissue injury. The industrial control of 
hand-arm vibration is based on the reduction 
of the most prominent sign and symptom 
complex, cold-related finger blanching or 
Raynaud's phenomenon. The pioneering 
occupational medicine physician Alice 
Hamilton first described this phenomenon in 
the United States, among Indiana quarry 
workers using air-powered tools (Hamilton, 
1918, Ex. 26-1401). By 1960, more than 40 
studies had been published (Cherniack, 1999, 
Ex. 26-1354). NIOSH reviewed the available 
epidemiology in 1989 and 1997 (NIOSH, 1989, 
Ex. 26-392; Bernard and Fine, 1997, Ex. 26-1) 
and found overwhelming evidence of a strong 
dose effect between duration and intensity of 
vibration exposure and the onset of acquired 
Raynaud's, known as VWF. Arterial hyper-
responsiveness and impaired vasodilation 
following cold challenge are also 
characteristics of vibration white-finger 
(VWF). In some studies, more than 70% of an 
exposed workforce evinced signs and symptoms 
of local vasospasm in the digits of the upper 
extremity, most often measured by recording 
finger systolic blood pressure and digital 
temperature stability in the setting of cold 
challenge (Bovenzi, 1993, Ex. 26-1280). 
Although a major mechanism of vibration-
induced vasospasm seems attributable to local 
autonomic dysfunction (Gemne, 1994, Ex. 26-
1320; Ekenvall and Lindblad, 1986, Ex. 26-
462), a more generalized co-morbid vascular 
pathology may also contribute to hand 
symptoms and impaired function. Finger 
biopsies of workers heavily exposed to local 
vibration have shown signs of significant 
endothelial injury (Takeuchi et al., 1986, 
Ex. 26-681). Increased free radical formation 
and elevated leukotriene B4 levels, both 
indicators of atheromatous injury, are 
observed concomitants of vibration exposure 
(Lau, O'Dowd, and Belch, 1992, Ex. 26-480). 
Overall, a satisfactory pathophysiologic 
model for occupational Raynaud's has been 
elusive.

[[Page 65915]]

   Over the past two decades, numerous 
investigators have noted that neurological 
symptoms, including paresthesias, 
dysesthesias, and loss of fine motor skills 
among workers using air-powered tools, are 
even more common than vascular effects 
(Pyykko, 1986, Ex. 26-662; Ekenvall and 
Lindblad, 1986, Ex. 26-462; Futatsuka, 
Inaoka, Ueno, 1990, Ex. 26-547; Letz et al., 
1992, Ex. 26-384). It has often proven 
difficult to localize clinical 
neuropathologic symptoms to a precise 
anatomic locus. Accordingly, there has been 
considerable attention in the vibration 
literature to differentiating more proximal 
entrapment neuropathies such as CTS from 
distal small fiber nerve injuries in the 
digits (Pelmear and Taylor, 1994, Ex. 26-880; 
Wieslander et al., 1989, Ex. 26-1027), and 
from more diffuse axonopathies (Farkkila et 
al., 1988, Ex. 26-947). In the past 15 years, 
most investigators have recognized that small 
fiber injury to fingertip nocioceptors is 
distinctly more common than CTS in vibration-
exposed workers, that electrodiagnostic 
studies are insensitive measures of this type 
of injury, and that quantitative sensory 
testing is essential if unnecessary carpal 
tunnel surgery is to be avoided (Miller et 
al., 1994, Ex. 26-303; Pelmear and Taylor, 
1994, Ex. 26-880). These tests, particularly 
measurement of vibrotactile thresholds, have 
consistently demonstrated deficits in 
perception in symptomatic and asymptomatic 
patients exposed to vibration (Flodmark and 
Lundborg, 1997, Ex. 26-370; Virokannas, 1992, 
Ex. 26-1355; Cherniack et al., 1990, Ex. 26-
1116). They also have shown that subjective 
deficits in hand functions correlate well 
with raised sensory thresholds (Virokannas, 
1995, Ex. 26-891). The contribution of small 
fiber injury to deficits in touch and 
temperature recognition is consistent with 
the observation that the tissues of the digit 
and palm absorb well over 90% of transmitted 
energy from a conventional vibrating tool. 
The importance of small fiber nerve injury is 
reflected in current use of terms to 
characterize the health effects of vibratory 
hand tool exposure. The historical term 
``vibration-induced white finger'' reflects 
the traditional focus on vasospastic 
symptoms. In 1987, a consensus panel meeting 
in Stockholm coined the term hand-arm 
vibration syndrome (HAVS) to give separate 
and equal weighting to neurological symptoms 
(Gemne et al., 1987, Ex. 26-624).
   The prominence of digital vasospasm and 
small fiber nerve injury in HAVS, as an 
outcome of vibration exposure, does not 
preclude other potentially important 
vibration-related health effects in tissues 
of the upper extremity. The CTS, in 
particular, has been recognized for its 
prevalence and severity in workers using 
pneumatic tools (Koskimies et al., 1990, Ex. 
26-973; Chatterjee, 1992, Ex. 26-942). 
Uncertainty exists, however, over the 
relative contributions of direct energy 
transfer to nerve tissue from the vibrating 
tool and secondary pathophysiologic or 
biomechanical responses to vibration that 
might provoke myelinated nerve injury. For 
example, EMG determined that muscle activity 
in the finger flexors, but also in the 
trapezii, has been affected by different 
qualities of vibration as well as by arm 
position. This is amplified in the setting of 
powered tools, such as nutrunners and 
fasteners, that create predominant 
biomechanical exposures other than vibration 
(Freivalds and Eklund, 1993, Ex. 26-116; 
Radwin, VanBergeijk, and Armstrong, 1989, Ex. 
26-519). In these settings, more traditional 
ergonomic considerations, such as grip force, 
posture related to work surface, and duration 
of the torquing phase, have played a role in 
reported discomfort and EMG activity (Rohmert 
et al., 1989, Ex. 26-999).
   For the purpose of recognizing work-
related health effects associated with 
vibration, it is useful to consider several 
pertinent features of vibratory exposure:
    Vibration is a physical factor, 
expressible in precise units: frequency in 
Hz, acceleration in m/sec\2\ or G's, and 
cycles in milliseconds. This offers highly 
accessible measurement with available 
instrumentation, principally accelerometry 
and frequency spectrum analysis.
    Vibratory characteristics are 
highly tool-specific. Chainsaws and drills, 
for example, are primarily oscillatory and 
continuous; impact wrenches and rivet guns 
have large physical displacements and are 
highly impulsive; tools such as nutrunners 
have major non-vibratory biomechanical 
components. Thus, simple generic measurements 
(weighted acceleration, for example) may not 
capture the extent of a potential tool-
specific hazard.
    Vibration can be quite well 
characterized as an extrinsic exposure, but 
health effects are the direct result of 
altered physiology that occurs entirely on 
the other side of the hand-tool interface.
   Appreciation of these properties is 
essential for hazard identification and 
medical management, because significant 
patterns of disease have occurred in 
exceptional settings or tool applications 
that are not necessarily predictable from 
published standards and advisory documents. 
Frequency, direction of vibration, and arm 
and hand position all have an effect on 
impedance to and absorption of vibration 
energy (Burstrom, 1997, Ex. 26-609; Kihlberg 
et al., 1995, Ex. 26-755). Push and pull, as 
well as grip force, affect transmission, and 
are in turn altered by the characteristics of 
vibration, including its impulsiveness and 
frequencies (Keith and Brammer, 1994, Ex. 26-
1324; Griffin, 1997, Ex. 26-373).
   Perhaps the most problematic area involves 
high-impulse acceleration. The ISO-and ANSI-
weighted curves treat all vibration as 
harmonic, ignoring impact forces and 
instantaneous peak accelerations that can 
exceed 105 m/sec\2\. Starck (1984, Ex. 26-
677) noted that the dramatic reduction in 
vascular symptoms occurring with the 
introduction of anti-vibration chainsaws in 
the 1970s was better explained by the 
flattening of high transient accelerations 
than by a reduction in root mean square 
(RMS). In addition, the consistent 
underestimation of vascular symptoms by ISO 
5349 for pedestal grinding and stone cutting 
was better accounted for when high-peak 
impulsivity was factored into the exposure 
model (Starck and Pyykko, 1986, Ex. 26-678). 
This is consistent with, but does not fully 
explain, the high prevalence of Raynaud's in 
platers and riveters, who use high-impulse 
tools only a few minutes per day (Dandanell 
and Engstrom, 1986, Ex. 26-614; Engstrom and 
Dandanell, 1986, Ex. 26-620; Burdorf and 
Monster, 1991, Ex. 26-454).
   A similar problem arises in the setting of 
tools that oscillate at very high 
frequencies, such as small precision drills 
and saws. Most measurement protocols exclude 
frequencies that exceed 1500 Hz. 
Nevertheless, neurologic (Hjortsberg et al., 
1989, Ex. 26-1131) and vascular symptoms 
(Cherniack and Mohr, 1994, Ex. 26-1341) have 
been highly concentrated in select 
populations that use these types of tools.
   Another area of importance is the 
occurrence of neck and shoulder pathology in 
workers using highly impulsive tools 
(Viikari-Juntura et al., 1994, Ex. 26-873; 
Kihlberg et al., 1995, Ex. 26-755). This is a 
complex area, particularly since the most 
common shoulder diagnoses--impingement and 
rotator cuff tendinitis--are clinically 
useful but without very specific 
pathophysiologic meaning. In the following 
epidemiologic review (Appendix I, Ex. 27-1), 
the neck, but not the shoulder, is shown to 
be associated with a vibration-

[[Page 65916]]

related pathology. The separation of 
biomechanical, physiologically adaptive, and 
vibration-specific factors is especially 
difficult for the neck and shoulder. Scapular 
stability and posture are the heart of large-
muscle activation sequences involving 
efficient distal muscle group movement 
(Mackinnon and Novak, 1997, Ex. 26-1309). 
Moreover, static shoulder posture, important 
for tool stabilization, is an important 
contributor to early arm fatigue (Sjogaard et 
al., 1996, Ex. 26-213). Finally, the quality 
of a vibratory stimulus (continuous or 
discrete) has significant impacts on efferent 
recruitment and firing (Maeda et al., 1996, 
Ex. 26-562). The combined effects of this 
complexity are not easily modeled. This is 
all the more reason why neck/shoulder 
symptoms should be carefully scrutinized when 
a power tool is part of the exposure 
background. It may prove difficult in 
practice to distinguish neck/shoulder 
symptoms that have their origins in strictly 
biomechanical processes from vibration-
induced injuries. However, there is 
sufficient evidence in support of an etiology 
to merit intervention.
   The consequent injuries to blood vessels 
and nerve fibers from vibration are well 
known. When biomechanical and other ergonomic 
factors complicate exposures, particular 
attention should be paid to the tools in use, 
patterns of use, and specific symptom 
presentations.


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