<PRE>
[Federal Register: November 14, 2000 (Volume 65, Number 220)]
[Rules and Regulations]               
[<strong>Page</strong> <strong>68561</strong>-<strong>68610</strong>]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr14no00-20]                         
 
[[pp. <strong>68561</strong>-<strong>68610</strong>]] Ergonomics Program

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    Assuming that there is a three-fold higher risk of MSDs among 
higher-risk workers compared with lower-risk workers, the incidence of 
MSDs among higher-risk employees is estimated for

[[<strong>Page</strong> 68563]]

each industry sector by the following formula:
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where:

MSDInc<INF>tot</INF> is the MSD incidence among all workers in the 
industry sector;
Pct<INF>E</INF> is the percentage of workers in the industry sector who 
are considered to be regularly exposed to risk factors at levels that 
meet the final rule's screen; and
RR is the risk ratio of 3.

The derivation of this formula appears in Chapter 3 (Benefits) of 
OSHA's Final Economic Analysis.

     Table VI-9.--Summary of Risk Ratios in the Epidemiological Literature for MSDs Reviewed by OSHA, and Estimated Fraction of MSDs Attributable to
                                                                   Workplace Exposure
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                    Body part affected/disorder
                                         ---------------------------------------------------------------------------------------------------------------
                                             Neck or                                   Carpal
                                              neck/         Only          Elbow        tunnel      Hand/wrist     Hand/arm        Back          Lower
                                            shoulder      shoulder                    syndrome     tendinitis     vibration                   extremity
--------------------------------------------------------------------------------------------------------------------------------------------------------
Number of Studies Included..............          42            32            18            30            10            12           44              9
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                      Risk Ratios <SUP>a</SUP>
--------------------------------------------------------------------------------------------------------------------------------------------------------
Median..................................           2.7           3.3           2.8           3.2           3.7           6.6          1.85           2.2
Average.................................           4.5           5.2           5.5           4.4           6.5          12.6          2.66           2.4
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                          Estimated Percent of MSDs Attributable to Exposure to Risk Factors <SUP>b</SUP>
--------------------------------------------------------------------------------------------------------------------------------------------------------
Median..................................          63.0          69.5          63.6          68.5          72.6          84.8         45.9           53.5
Average.................................          77.6          80.6          81.9          77.5          84.6          92.1         62.4           58.9 
--------------------------------------------------------------------------------------------------------------------------------------------------------
<SUP>a</SUP> Risk ratios include odds ratios, prevalence rate ratios, and incidence ratios.
<SUP>b</SUP> Proportion of disorders among exposed workers that is attributable to their exposure at work; calculated as (RR-1)/RR, where RR is the median or
  average risk ratio derived from each group of epidemiological studies.
Source: Data presented in Tables V-1 through V-6 of the Health Effects section (Section V).

    The MSD incidence among lower-risk employees in each industry 
sector is estimated as the ratio of the number of MSDs that occurred in 
1996 among lower-risk employees to the estimated number of lower-risk 
employees in each industry sector (see formula in Table VI-8).
    The portion of the risk for higher-risk employees that can be 
attributed directly to workplace exposure to risk factors (i.e., that 
portion of the risk that is potentially preventable) lies between two 
extremes, the upper and the lower bound of the range of estimated 
risks. OSHA estimated the upper bound of the range to be equal to the 
MSD incidence among higher-risk employees; this bound assumes that the 
BLS data includes no cases reflecting background risk, since all of the 
MSD cases in the BLS data are work-related. The lower bound, on the 
other hand, assumes that the MSD incidence among lower-risk employees 
is entirely attributable to background, i.e., that work did not 
contribute in any of the MSD cases reported among lower-risk workers. 
To estimate the lower bound, OSHA estimated the excess risk among 
higher-risk workers from the general formula that the Agency has used 
in previous risk assessments to estimate excess risk. The general 
formula for estimating excess risk is
[GRAPHIC] [TIFF OMITTED] TR14NO00.012

where P<INF>d</INF> is the probability of injury or illness among 
workers exposed to a hazard and P<INF>0</INF> is the background risk 
that occurs among persons who are not exposed to the hazard. In this 
case, P<INF>0</INF> represents the estimated MSD incidence among 
workers who are either not exposed to risk factors at work or who are 
exposed to risk factors below the level meeting the final rule's 
screen.
    As with the first risk assessment approach discussed above, OSHA 
also estimated the lifetime risk of experiencing a LWD MSD to workers 
who work in jobs that meet the final rule's basic screening tool. 
Estimates representing the risk of experiencing at least one MSD and 
the average number of MSDs per worker (i.e., the expected value) were 
calculated assuming a 45-year working life. Table VI-10 presents OSHA's 
estimates of the lifetime risk of experiencing work-related MSDs, by 
industry sector; lifetime risks were calculated based on both the 
upper- and lower-bound estimates of the MSD incidence among higher-risk 
employees (i.e., those exposed to risk factors at levels meeting the 
final rule's screen). Based on the probability approach, the estimated 
probability that a higher-risk worker will experience at least one 
work-related MSD during a working lifetime ranges from 33 per 1,000 
workers to 926 per 1,000 workers, depending on the industry sector. 
Based on the expected value approach, the expected number of work-
related MSDs that will occur in a cohort of higher-risk workers all 
entering an industry at the same time ranges from 34 per 1,000 workers 
to 2,530 per 1,000 workers, since this approach recognizes that it is 
possible for a worker to experience more than one work-related MSD in a 
working lifetime.

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    Several rulemaking participants commented on the results of OSHA's 
preliminary risk assessment and the approaches taken by the Agency to 
estimate the magnitude of MSD risks to employees.

[[<strong>Page</strong> 68566]]

    In their post-hearing submissions (Exs. 500-221, 500-223), Keller & 
Heckman presented an alternative risk analysis that they believe could 
be used to compare work-related risks to the background risk of MSDs. 
Citing the work of Maizlish et al. (Ex. 26-1186), they stated that the 
background risk of carpal tunnel syndrome (CTS) is 1.05 cases per 1,000 
person-years; this estimate is based on an analysis of medical records 
in Rochester, Minnesota, between 1961 and 1980 (Stevens et al., Ex. 26-
1009). Using OSHA's estimates from the preliminary risk assessment of 
the total number of MSDs in U.S. industry for each of the six injury 
categories selected by OSHA, Keller & Heckman estimated a background 
incidence for each of the six injury types based on the ratio of the 
number of LWD cases for each injury type to the number of LWD CTS 
cases. For example, since OSHA's estimates of the number of LWD 
strains, sprains, and tears is 16.88 times higher than the number of 
LWD CTS cases, Keller & Heckman estimated that the background rate of 
LWD strain, sprain, and tear injuries in the U.S. population is 17.72 
cases per 1,000 people per year (i.e., 16.88  x  1.05). Across all six 
injury types, Keller & Heckman estimated the background rate for all 
LWD MSDs to be 22.83 cases per 1,000 persons per year for the U.S. 
population. They also estimated the MSD rate across the U.S. workforce 
to be 6.55 LWD MSD cases per person-year, by dividing the total 
estimated number of MSDs in 1996 (647,344) by private industry 
employment for 1996 (98,772,900 workers). From this analysis, Keller & 
Heckman concluded that there is no significant excess risk of MSDs in 
private industry, since the estimated background rate of MSDs in the 
general population is about 3.5 times higher than the rate that they 
estimated for the U.S. workforce. They presented similar estimates of 
MSD rates for selected industry sectors at the 3-digit SIC level and 
concluded that (1) only 10 of the hundreds of industry sectors covered 
by the ergonomics program rule have an MSD incidence that exceeds their 
estimated background rate of MSDs, and (2) that there is no excess risk 
of work-related MSDs in either SIC 204 (Grain Mill Products), SIC 206 
(Sugar and Confectionary Products), or SIC 331 (Steel Works, Blast 
Furnaces, and Rolling Mills).
    OSHA believes that the analysis conducted by Keller & Heckman is 
seriously flawed in a number of respects. First, Keller & Heckman make 
an improper comparison between estimated MSD rates in the working 
population, based on the BLS data, and estimated MSD rates in the 
general population, based on community medical records for the rate of 
CTS in Rochester, Minnesota. As explained in part B above, the BLS 
injury and illness survey is not designed to capture all injuries and 
illnesses that occur among workers; it is only designed to capture 
those that employers have determined to be work-related. In contrast, 
the Rochester study on which Keller & Heckman's analysis rests involved 
all cases of CTS that occurred in the community, regardless of whether 
those cases were work-related or not. These two statistics are not 
comparable in any meaningful way. To make a meaningful comparison, one 
would need to have data that permit estimates to be made of the total 
MSD rate in the U.S. workforce, not just the work-related component.
    Second, Keller & Heckman assume that the ratio between the number 
of one type of MSD to that of another will mirror the ratio of the 
incidence rates for the two types of MSDs in the general population. 
However, the ratio between the number of cases of two medical 
conditions can be equal to the ratio of the incidences of those 
conditions only if the cases of both medical conditions are drawn from 
the same population. Clearly, the population from which the BLS data 
are drawn differs from the general U.S. population in many ways. 
Consequently, OSHA believes that it is not possible to reliably 
estimate the background rate of any type of MSD in the general 
population from the ratio between two MSD types seen in the working 
population, and therefore the assumption made by Keller & Heckman in 
conducting their analysis is not supportable.
    Third, Keller & Heckman's analysis interprets the rate of CTS in 
the Rochester, Minnesota, population as the ``background'' rate of CTS. 
However, the study by Stevens et al. (Ex. 26-1009) made no effort to 
evaluate the work-relatedness of the CTS cases identified from the 
medical records, nor was there any mention of the investigators 
collecting work histories or assessing the work status of the cases 
identified. The Maizlish study (Ex. 26-1186) cited by Keller & Heckman 
was a study of a California surveillance system for work-related CTS, 
in which the Rochester CTS rate was used as a reference point for the 
purpose of identifying ``epidemic clusters'' of CTS (defined as a rate 
twice that of the Rochester CTS rate). Although the authors of this 
study refer to the Rochester CTS rate as a ``background'' rate, their 
rate is clearly not a background rate as that term is used in 
occupational epidemiology. It cannot represent the rate of CTS among 
persons without workplace exposure because the CTS cases in the 
Maizlish study were drawn from the entire Rochester population, which 
included both workers and non-workers.
    For these reasons, OSHA finds the analysis provided by Keller & 
Heckman both methodologically flawed and unconvincing. The Agency 
believes that its own risk analysis, which is based on estimates of the 
numbers of higher-risk and lower-risk workers and on the extensive 
epidemiological data presented in Section V of this preamble, 
appropriately takes account of that portion of the MSD rate among 
workers that is attributable to their workplace exposures.
    Keller & Heckman (Exs. 500-221, 500-223) also claim that the 
``aggregate risk (workplace and non-workplace risk combined)'' of a 
U.S. worker experiencing an LWD MSD due to anything that might be 
defined as a harmful physical agent would be no more than 0.7 per 1,000 
workers per year. They arrive at this rate by dividing the 1996 number 
of BLS MSD cases caused by repetition by total private industry 
employment. This estimate ignores the LWD cases attributed in the BLS 
data to overexertion or to awkward postures (i.e., ``bending, climbing, 
crawling, reaching, twisting''), both of which are exposure event codes 
that OSHA has determined to be highly relevant for assessing MSD risks 
to workers. Second, Keller & Heckman characterize their aggregate risk 
rate as reflecting both workplace and non-workplace contributions to 
MSD risk. Since the rate Keller & Heckman use is derived from BLS data, 
which reflects work-related cases exclusively, OSHA does not agree with 
this characterization.
    The National Coalition on Ergonomics (Ex. 32-368) and the American 
Iron and Steel Institute (Ex. 32-206) objected to the fact that OSHA 
did not modify its risk estimates from the BLS data by reducing them to 
account for MSDs that occurred in jobs that would not pass the 
screening criteria in Sec. 1920.902 of the proposal. In the final 
ergonomics program rule, OSHA has modified its screening criteria from 
the performance-oriented language contained in the proposal to be more 
specific in terms of the kinds and durations of exposures to risk 
factors that warrant further hazard analysis by the employer. Employers 
are not expected to conduct job hazard analysis or provide medical 
management of MSDs for employees in jobs where the exposures to risk 
factors are below those in the final rule's action

[[<strong>Page</strong> 68567]]

trigger. As described above, OSHA has now modified its risk assessment 
to estimate the number and incidence of MSDs that occur each year among 
workers who are in jobs in which exposures meet the action trigger. 
Thus, OSHA's final risk assessment reflects the excess MSD risks among 
the more highly exposed portion of the worker population covered by the 
standard.
    The Center for Office Technology (COT) (Ex. 30-2208) and the Puerto 
Rico Manufacturing Association (Ex. 30-3348) took issue with OSHA's 
statements in the preliminary risk assessment and significance of risk 
analysis for the proposed rule that the BLS data understate risk. For 
example, COT commented that

* * * BLS in their reports state that there is ``95% confidence that 
the `true' incidence rate falls within the confidence interval * * * 
and has an estimated relative standard error of about 0.9 percent.'' 
BLS does not state that their estimates of injury and illnesses 
reflect under reporting. Assistant Secretary Charles Jeffress is 
also on the record supporting the accuracy of the BLS data and is 
quoted * * * as saying ``90% of employers keep accurate records 95% 
of the time, or better.'' (Ex. 2208, p. 19)

    However, OSHA did not base its preliminary determination that work-
related MSDs are seriously underreported on the precision (or lack 
thereof) of the BLS survey. The BLS statement referred to in COT's 
comment simply reflects the fact that the BLS estimates of work-related 
injuries and illnesses in the United States are based on a sampling of 
OSHA 200 logs, not the logs of all employers. Consequently, the 
estimates generated from the sample of logs have some uncertainty 
associated with them, which is characterized by a 95% confidence 
interval around the estimate. The stated precision of the survey data 
provided by the BLS does not address issues related to the accuracy of 
the logs that are sampled, just the precision of the estimates 
generated from the sampled logs. OSHA's determination that MSDs are 
seriously underreported on OSHA logs is based on the findings of 
several scientific studies and other data that compared MSD rates from 
logs to those from medical insurance records, records of sick leave, or 
other sources of data independent from the OSHA logs; these studies 
were reviewed in Table VII-2 of the preamble to OSHA's proposed rule 
(64 FR 65982), and in Table VII-1 and OSHA's discussion of the 
Significance of Risk (Section VII) in this preamble.
    According to NIOSH (Ex. 32-450), OSHA's discussion of the 
limitations on the use of BLS data in the risk assessment section of 
the preamble is methodologically sound. These limitations include the 
following characteristics of reported cases:
    <bullet> The cases reported are only those that employers have 
agreed are work-related,
    <bullet> The cases reported are only those that were serious enough 
to involve at least one day away from work,
    <bullet> The cases reported do not include other types of work-
related MSD cases that rarely, if ever, come to the attention of the 
employer, and
    <bullet> The cases reported do not account for the extended or 
permanent disability that results in employee termination.

In addition, NIOSH points out that some workers with MSD episodes that 
may represent lost workday cases are reassigned to minimal work 
activities in order to avoid recording the case as one involving lost 
workdays. For these reasons, NIOSH agrees that there is a substantial 
likelihood of under-reporting in the BLS system and that the BLS 
estimates represent a lower bound of the true risks of work-related 
MSDs. NIOSH agrees with OSHA that the true incidence of work-related 
MSDs is greater than indicated by the BLS estimates.
    In its pre-hearing comments (Ex. 32-368), the National Coalition on 
Ergonomics objected to the use of BLS data in risk assessment on the 
grounds that the data reflect reports by workers to employers rather 
than medical diagnoses. The BLS data relied on by OSHA in this risk 
assessment is lost-work-day data, which employers provide to the BLS 
along with sufficient information about each injury or illness to 
permit detailed classification of each injury and illness. Thus, the 
data relied on by OSHA do not represent ``reports by workers to 
employers'' but cases that employers have determined to be work related 
and for which they provided detailed descriptions of the nature of the 
events associated with each case. Further, the Coalition's comment 
implies that MSD rates would be much lower if they were based on 
medical diagnoses rather than employer reports. However, evidence in 
the rulemaking record shows that the opposite result is more likely; 
several investigators have actually compared MSD rates from the OSHA 
logs with the rates reflected in other sources of data that report the 
results of medical evaluations of injuries and illnesses, such as 
medical insurance records, compensation claims, medical case records, 
and medical absence records (Exs. 26-28, 26-920, 26-1261, 26-1259, 26-
1260). These studies, reviewed in the Significance of Risk section of 
the preamble (Section VII), have consistently found the MSD rates 
reported on OSHA logs to be several-fold lower than those derived from 
medical records data. Thus, OSHA believes that a risk analysis based on 
accurate reports of the medical diagnoses of work-related MSDs would 
result in higher risk estimates than those in OSHA's analysis.
    The Edison Electric Institute (Ex. 32-300-1) and Southern 
California Edison (Ex. 30-3284) take OSHA's statement in the 
preliminary risk assessment that BLS data ``are not easy to use for 
risk assessment purposes'' to mean that these data are weak. This is 
not the case nor is it what OSHA meant by this statement. OSHA's 
statement that the BLS data are not easy to use for risk assessment 
referred to the fact that the BLS injury and illness classification 
system does not contain a single injury/illness category that contains 
data on all relevant MSDs. This fact required the Agency to select 
injury/illness categories and appropriate exposure event categories to 
represent the kinds of disorders addressed by the final rule. As 
discussed above, OSHA has determined both that the BLS data are the 
best available data for evaluating MSD risks to workers and that OSHA's 
reliance on these data is appropriate. In addition, these two 
stakeholders characterize the employment estimates from the U.S. Bureau 
of the Census as ``another questionable data source'' without providing 
any justification for this characterization. They also stated that 
combining these data to calculate MSD rates by occupation ``compounds 
the flaw.'' In fact, both the BLS and Bureau of Census population data 
have been used by the Agency to analyze the impact of its rules for 
several years, are used extensively by other researchers both within 
and outside the federal government, and represent state-of-the-art 
programs for conducting and analyzing nationwide surveys of working 
populations. OSHA knows of no other data sources that could provide 
more reliable information on occupations and workplace injuries and 
illness in the United States.
    Jesse McDaniel, a Certified Safety Professional from August Mack 
Inc. (Ex. 30-240), commented on OSHA's use of the BLS data and the 
preliminary risk assessment. First, Mr. McDaniel stated that injuries 
that do not involve lost workdays, restricted work, or medical 
treatment (or diagnosis in the case of an illness) are not recordable 
cases under OSHA's recordkeeping rules; he believes that OSHA was 
therefore incorrect in stating in the preliminary risk assessment that 
the BLS data understate the true MSD risk to workers

[[<strong>Page</strong> 68568]]

because it excludes cases that do not involve days away from work. In 
other words, Mr. McDaniel appears to believe that cases not counted as 
LWD MSDs in the BLS system are not recordable, and that OSHA's claim 
that the data understate the true risk is not warranted. OSHA does not 
agree it was incorrect in making this statement. The data relied on by 
OSHA for both its preliminary and final risk assessment comes from the 
detailed employer survey data, which requires employers to provide 
descriptions of work-related injuries and illnesses only for those 
cases involving days away from work, i.e., the employer is not required 
to provide detailed information on other kinds of recordable injuries 
and illness not involving days away from work. Therefore, OSHA's 
estimates of LWD MSD rates based on the BLS data do not include the 
other kinds of recordable MSDs referred to by Mr. McDaniel. He also 
believes that OSHA inflated its risk estimates by reporting MSD rates 
per 1,000 workers rather than on a per-100-worker basis, which is the 
convention used by BLS in reporting injury rates by industry sector and 
occupation. OSHA used the risk per 1,000 worker metric because OSHA's 
significant risk range is bounded by the Supreme Court's guidance in 
the Benzene decision, as explained in the preliminary risk assessment. 
Mr. McDaniel also provided examples that he believes suggest OSHA's 
estimated LWD MSD rates exceed the BLS-estimated total injury case 
rates for some industry sectors and occupations. However, since the BLS 
case rates are reported per 100 full-time-equivalent employees, and 
OSHA presents its risk estimates conventionally in terms of cases per 
1,000 employees, OSHA's rates, as they appear in this risk assessment, 
must first be divided by 10 to be comparable to the BLS injury case 
rates. When this adjustment is made, the comparisons made by Mr. 
McDaniel show that OSHA's estimated MSD rates are below the BLS's total 
injury case rates.

D. Analysis of Ergonomic Program Effectiveness

    In the preliminary risk assessment, OSHA evaluated information and 
data that described the effectiveness of ergonomic interventions and 
programs similar to those of the proposed ergonomics program standard 
[64 FR 65943-65975]. These data were drawn from three sources. First, 
OSHA searched for and evaluated studies that investigated the effect of 
ergonomic interventions on reducing exposures to workplace risk 
factors. These included both field and laboratory studies. Second, OSHA 
compiled a large database of published and unpublished data from case 
studies that describe the effect of implementing ergonomic programs on 
workplace MSD injury rates. Finally, OSHA used the findings from the 
epidemiological studies contained in the NIOSH (1997, Ex. 26-1) review 
to estimate the potential effectiveness of ergonomics programs. Since 
publication of the proposal, a substantial number of additional 
scientific and ergonomic case studies were entered into the record; 
OSHA has relied on these to revise its effectiveness analysis. The 
additional information and data entered into the record confirm OSHA's 
preliminary determination in the proposal that ergonomic programs and 
interventions are effective both in reducing those forces on the 
musculoskeletal tissue that have been associated with the development 
of tissue pathology, and in reducing the incidence of MSDs. In this 
section, OSHA summarizes these studies and evidence and analyzes the 
data from these studies to estimate the overall reduction in MSD rates 
that is likely to occur when employers implement ergonomic programs 
like the program required by this standard.
    The record contains much testimony from scientific experts that 
ergonomic programs designed to reduce biomechanical load are effective 
in reducing MSD risk. In its pre-hearing testimony, NIOSH agreed with 
OSHA's preliminary conclusion that ergonomic programs are effective:

* * * [T]here are numerous companies which have reported success in 
using ergonomic programs as a cost-effective way to prevent or 
reduce work-related MSDs, and reduce lost time by workers with MSDs. 
Some of these companies also report increases in productivity and 
workplace morale. The studies--in part summarized in OSHA's 
preamble, reviewed by the NAS panel--illustrate that interventions, 
including redesign of tools, machines, and work stations, can reduce 
workplace hazards and the resulting MSDs. * * *
    The effectiveness of ergonomics programs was a resounding 
message echoed by labor, industry, business, universities, health 
care, and professional societies at two conferences co-organized by 
NIOSH and OSHA to stimulate an exchange of information about 
preventing work-related MSDs. * * * The conferences, attended by 
over 1,700 people, featured workshops and presentations by industry, 
labor, and government representatives sharing their successful 
ergonomics programs and how they have reduced lost work time and cut 
costs due to injuries and illnesses in a variety of industries and 
workplaces. * * *
    NIOSH believes that the evidence in the scientific literature 
showing the success of an ergonomics program approach to workplace 
hazards is strong. Likewise, NIOSH's experience in evaluating the 
risks of MSDs in a variety of workplaces and our review of 
information from a variety of sizes of industries has generally 
shown that using ergonomic programs is an effective way to prevent 
or reduce work-related MSDs.

(Ex. 32-450-1, pp. 8-10)

    Many expert witnesses also testified that, from their experience, 
ergonomic programs are effective in reducing MSD risks. For example, 
Dr. Snook testified on the effectiveness of ergonomic programs for 
reducing the disability from back pain:

    Now, this is what we know about ergonomics and low back 
disorders. First of all, we know that in heavy manual handling jobs, 
there is an increased disability from low back pain, as measured in 
lost work days and restricted duty.
    The second thing that we know is that there have been several 
guidelines developed to help identify the high risk manual handling 
jobs.
    Third, that when these jobs are designed according to the 
guidelines, the disability from low back pain decreases.
    And finally, employers who have used ergonomics programs to 
identify and control high-risk jobs have found them to be cost 
effective.
    I also believe it is important to acknowledge what we do not 
know. We simply do not know the * * * [etiology] or the cause of 
most low back pain.
    Some have suggested that this lack of knowledge must constitute 
a stopping point. Others, however, have demonstrated that this is 
not a stopping point, that implementing ergonomic intervention[s] 
and programs to reduce physical loads does reduce the disability 
from low back pain.

(Tr. 846-847)

Dr. Cherniak testified that the volume of published ergonomics 
literature itself is indicative of the success of ergonomics 
interventions:

    The extensive literature review included in this [OSHA's 
proposed] standard and explosion of the ergonomics literature in 
industrial countries are testaments to the seriousness of MSDs, but 
also to the effectiveness of responsive intervention. I would say 
that medical fields that lack components of prevention and 
therapeutics do not usually generate expanding literature. They 
generally lead to dead ends.

(Tr. 1134-1135)

    Many other rulemaking participants provided testimony that 
ergonomics programs reduce disease. Dr. Barbara Silverstein, Research 
Director for the Safety and Health Assessment and Research Team, 
Washington State Department of Labor and Industries, testified that 
``Reducing exposure to hazardous loads does reduce musculoskeletal 
disorder prevalence, incidence, and severity.'' (Tr. 17357) Both Drs. 
Bernacki and McCunney,

[[<strong>Page</strong> 68569]]

representing the American College of Occupational and Environmental 
Medicine, testified that ergonomics programs instituted at their 
respective universities were very effective in reducing MSD rates and 
severity. (Tr. 7690-7693) Sherri Gibson, representing the American 
Industrial Hygiene Association, testified that ``We know the controls 
and ergonomic programs work, we've seen it time and time again.'' (Tr. 
16466) Under questioning by OSHA, Mr. Fernandez, a practicing 
ergonomist, stated that, although some ergonomic interventions may 
require more than one attempt and some ``tweaking,'' in his experience 
he has never seen a case in which an ergonomic intervention or program 
was ultimately unsuccessful. (Tr. 5427)
    In the preliminary risk assessment that accompanied the proposed 
rule, OSHA relied, in part, on the large body of epidemiological data 
showing consistent associations between exposure to biomechanical 
factors at work and an increased prevalence or incidence of MSDs. 
Although these studies were not designed specifically to determine or 
measure the effectiveness of ergonomic interventions in working 
populations studied, OSHA finds that they nonetheless provide highly 
useful information on the potential for ergonomic interventions to 
reduce injuries and illnesses; these studies provide this information 
because they describe the relationship between exposure to the 
biomechanical risk factors addressed in this final ergonomics program 
rule and the risk to workers of developing MSDs. The Health Effects 
section (Section V of the preamble) summarizes the results of more than 
170 epidemiological studies overall, more than 60 of which demonstrate 
that increased MSD risk is related to increased duration and/or 
magnitude of exposure to biomechanical risk factors. Other 
biomechanical and biological data reviewed in the Health Effects 
section provide evidence that excessive force imposed on 
musculoskeletal tissue, absent sufficient repair and recovery time, is 
associated with tissue damage that is consistent with the kinds of 
disorders seen in the working populations studied; thus, this 
supporting evidence is consistent with the general model that excessive 
biomechanical loading increases the risk of developing MSDs. At the 
public hearings, OSHA presented much expert scientific testimony that 
this general model is supported by high-quality scientific evidence. 
Although there is evidence that other factors, including individual and 
non-biomechanical workplace factors (e.g., psychosocial factors), also 
influence risk, the evidence shows that work-related biomechanical 
factors act independently of these other factors in increasing MSD 
risk.
    Because of the independent relationship between biomechanical and 
other risk factors in the etiology of MSDs, a change in worker exposure 
to biomechanical risk factors would be expected to lead to a 
corresponding change in worker risk of MSDs. One of the basic 
principles of public health is that reducing exposure to a substance, 
agent, or force that has been demonstrated to be harmful to health will 
reduce the risk of harm; this principle has been the scientific 
rationale behind all of OSHA's substance-specific health standards. 
Accordingly, OSHA finds that the strong evidence in the scientific 
literature relating exposure to biomechanical risk factors to an 
increased risk of MSDs is, by itself, sufficient evidence for Agency 
action that will reduce the exposure of workers to biomechanical 
factors in the workplace. OSHA's determination is supported by the 
testimony of its witnesses. In his written testimony, Dr. Wells stated 
that the epidemiological studies involving biomechanical risk factors 
have found strong and consistent relationships between those risk 
factors and MSDs, and therefore that reducing exposures to these risk 
factors is a reasonable strategy for preventing MSDs (Ex. 37-18). 
Similarly, Dr. Frank commented that the epidemiological evidence and 
the results of other investigations on the biology of low back pain 
strongly suggest that reductions in forces exerted on the spine will 
substantially reduce disability (Ex. 37-27). During questioning at the 
public hearing, Dr. Frank explained:

* * * [A]cting on biomechanical risk factors will bring risk 
reductions according to our understanding of the multifactorial 
causal process even if we are unable, for example, at the present 
time to conclusively act to reduce psychosocial factors because we 
still understand them poorly.
    Q: So that given that as a conclusion, then in your opinion does 
that mean that an OSHA standard aimed at reducing exposure to 
biomechanical factors in the work place is likely to reduce lost 
time disability for low back pain?
    Dr. Frank: That is what every epidemiologist who understands 
these methods would say.

    Dr. Punnett also explained the importance of findings that 
biomechanical risk factors act independently from other factors and the 
implication of those findings on intervention strategies:

    Q: What is so important about this finding that the physical job 
factors causing MSD are independent of any of these other factors?
    Dr. Punnett: Well, that I think leads us fairly directly to the 
inference that reducing physical work load all other things being 
equal will reduce the magnitude and/or severity of musculoskeletal 
disorders. * * * That is that the effect is not confounded by those 
other factors. And therefore, we can anticipate a benefit 
proportional to the increase that has been identified with current 
exposures.
    Q: Does this mean that an OSHA standard aimed at reducing 
exposure to MSD hazards [i.e., biomechanical factors] is likely to 
prevent work-related MSDs?
    Dr. Punnett: I believe so, yes.

    Table VI-8 presented summary statistics from the epidemiological 
studies that OSHA selected for the Health Effects section; these 
studies include those contained in the 1997 NIOSH review (Ex. 26-1) as 
well as additional studies in the record. The statistics presented in 
Table VI-8 include the range in risk ratios reported in these studies, 
grouped by type of disorder studied, as well as the median and mean of 
the distribution of these risk ratios. The risk measures in the 
epidemiological studies include odds ratios, prevalence rate ratios, 
and (for a few studies) incidence ratios, and approximate the relative 
risk of musculoskeletal disorders in an exposed worker population 
compared with that in a referent group. Although the risk ratios 
reported in epidemiological studies cannot be used directly to measure 
the effectiveness of ergonomics programs, they do provide information 
on that part of the MSD incidence seen in workers that can be 
attributed directly to their exposure to biomechanical risk factors; 
this portion of the MSD incidence is termed the attributable, or 
etiologic fraction, and is also the fraction of the MSD incidence seen 
in worker populations that is potentially preventable.
    The concept of an attributable or etiologic fraction is standard in 
epidemiology, and the concept has been used previously to estimate the 
attributable fraction of several types of MSDs in working populations. 
Hagberg and Wegman (1987, Ex. 26-32) reviewed the epidemiological 
literature and selected 21 studies in which diagnoses of neck and 
shoulder disorders were made from physical or laboratory examinations. 
Odds ratio measures from studies describing similar disorders were 
pooled across studies for common occupations that involved exposures to 
workplace risk factors, and the authors computed the

[[<strong>Page</strong> 68570]]

overall odds ratio for each type of occupation and disorder. In 
addition, the authors assessed the effect of the exposure to workplace 
risk factors on MSD risk by computing the etiological fraction in the 
exposed population; the etiologic fraction was computed only from those 
odds ratios that were statistically significantly higher than 1. 
Hagberg and Wegman (1987, Ex. 26-32) found that the etiological 
fraction ranged from 40 to 99 percent, depending on the specific type 
of upper extremity disorder. This study thus provides evidence that the 
potential for ergonomic interventions to reduce MSD incidence among 
workers is quite high, provided that such interventions reduce worker 
exposures to biomechanical risk factors.
    OSHA's own summary of the risk ratios reported in the 
epidemiological database, both in the preliminary and final risk 
assessments, is consistent with the findings of Hagberg and Wegman (Ex. 
26-32). The distribution of risk ratios reported in the epidemiology 
studies relied on by OSHA in the Health Effects section of the preamble 
indicate that, based on the median of the distribution, between 46 
percent (back disorders) and 88 percent (hand-arm vibration syndrome 
(HAVS)) of the MSDs experienced by workers who have substantial 
exposure to biomechanical risk factors (i.e., those workers who 
comprised the exposed cohorts in these studies) can be attributed to 
their exposure to risk factors, and are therefore potentially 
preventable by reducing exposure to the biomechanical risk factors that 
caused them. For upper extremity disorders (excluding HAVS), neck 
disorders, and shoulder disorders, the attributable fractions based on 
the median of the risk ratios is between 55 and 65 percent. The mean of 
the distribution suggests a somewhat higher attributable fraction: 58 
percent for back disorders, 93 percent for HAVS, and between 70 and 80 
percent for all others.
    As discussed above, OSHA has determined that the strength of the 
epidemiological, biomechanical, and biological data reviewed in the 
Health Effects section is sufficient to justify the promulgation of an 
ergonomics program standard to reduce the significant risks of MSDs 
posed to workers who are exposed to biomechanical risk factors on the 
job. Nevertheless, the record contains a substantial body of scientific 
evidence and case reports that demonstrate directly that ergonomic 
programs designed to reduce exposures to biomechanical risk factors do 
reduce the incidence of MSDs in exposed workers. Some of this evidence 
was reviewed in the preliminary risk assessment for the proposed rule; 
however, since publication of the proposal, many additional studies and 
case reports have been made available in the record. The remainder of 
this part of OSHA's final risk assessment reviews these studies and 
reports.
    Intervention studies that employ formal scientific methods are 
particularly compelling and merit special attention. Unfortunately, 
intervention studies for ergonomics programs are infrequently conducted 
because they are complex and scientifically challenging because of the 
lack of control that investigators generally have over workplace 
conditions. Thirty-four reports of ergonomic interventions in 
workplaces were identified in the rulemaking record and are summarized 
in Table VI-11. Each of these 34 reports was characterized by:
    <bullet> A clearly described intervention,
    <bullet> Measurable exposure or health effects endpoints
    <bullet> Acceptable statistical methods, and
    <bullet> Characterization of exposure or health outcomes both prior 
to and after intervention.
    These 34 studies together represent the best available direct 
evidence that practical application of the principles and methods of 
ergonomics in the workplace results in reduced employee exposure to 
hazards and in a reduced incidence of work-related musculoskeletal 
disorders. These studies evaluated the effect of ergonomic 
interventions on risk factor exposure, health outcomes, or both. Of 
these studies, 22 reported that, after the ergonomic intervention, 
exposure was reduced, as measured by the magnitude of external 
stressors (i.e., reductions in repetitions or improved postures) or 
reduced tissue loading; 12 of these studies also documented reduced MSD 
rates as measured by injury records or employee symptom reports. OSHA 
believes that the 12 studies that measured both exposure and outcome 
effects are particularly strong, and their findings particularly 
significant, because they provide direct evidence of a relationship 
between reductions in exposure to biomechanical risk factors and 
reductions in the incidence of MSD cases or symptoms, findings that are 
consistent with the model derived from the epidemiological data, which 
posits that biomechanical risk factors are associated with an increased 
MSD risk independent of other contributing factors. Ten of the 
intervention studies documented outcome measures alone and found that 
injury rates or symptom reports declined following ergonomic 
interventions. Two studies (Bernacki, 1999, Ex. 38-34; Bohr, 1997, Ex. 
38-64) also reported improved recognition of potentially hazardous jobs 
among the participants in the ergonomics programs studied.

                       Table VI-11.--Summary of Scientific Studies Designed To Assess the Effectiveness of Ergonomic Interventions
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                       Health effects
               Study                       Population             Intervention          Analytic method        Exposure outcome           outcome
--------------------------------------------------------------------------------------------------------------------------------------------------------
Aaras (1994) Ex. 502-252; Westgaard  420 female              Reduce postural load:   Longitudinal survival  Decreased postural     Reduction in mean
 (1985) Ex. 26-787; Westgaard         telecommunication       individual adjustment   analysis (1967-        load intensity and     sick leave from 22
 (1984) Ex. 26-1026.                  assembly workers.       of workstation height   1984). Exposure        duration on            days to 1.8 days,
                                                              and angle, increased    evaluated by           trapezius, reduce      Reduced turnover
                                                              legroom, suspending     trapezius static       load in hand,          from 30.1% to 7.6%,
                                                              hand tools, arm         load via EMG,          reduced shoulder       Increased
                                                              supports, limit         postural angles        angles.                productivity.
                                                              vertical dimensions;    Outcome: signs &
                                                              Design work to reduce   symptoms, sick leave
                                                              postural fixity.        due to load-related
                                                                                      MSDs. Survival
                                                                                      analysis.

[[<strong>Page</strong> 68571]]

Aaras (1997) Ex. 26-63.............  20 VDU workers........  Forearm support,        Laboratory study       Trapezius load         .....................
                                                              screen sight angle      using open,            significantly lower
                                                              change.                 randomized Graeco-     with forearm support
                                                                                      Latin squared trial    (both duration and
                                                                                      with five test         intensity) with both
                                                                                      conditions using       sitting and
                                                                                      keyboard and then      standing. No
                                                                                      using mouse,           significant
                                                                                      measurements           differences with 15
                                                                                      included descending    versus 30 degrees
                                                                                      m. trapezius and       sightline.
                                                                                      erector spinae
                                                                                      lumbalis at L3 EMG
                                                                                      and inclinometer.
Aaras (1998) Ex. 26-597............  Male VDU workers, 50    1  new lighting.......  Serial interventions   Reduced trapezius      Reduced trapezius
                                      per group.             2  new workplace         in 2 intervention      load in intervention   pain, in
                                                              design to support       groups, 1 control      groups after forearm   intervention groups,
                                                              forearms.               group, Load measured   support and            no change in forearm
                                                             3  optical exams and     via EMG and            optometric             pain (appeared to be
                                                              corrections.            observation,           corrections, Reduced   associated with
                                                                                      controlled for         glare problems in      increased mouse use,
                                                                                      psychosocial factors   intervention groups.   no change in back
                                                                                      at work and home.                             pain). Headaches
                                                                                                                                    reduced after
                                                                                                                                    lighting change,
                                                                                                                                    borderline
                                                                                                                                    improvement with
                                                                                                                                    optometry, Visual
                                                                                                                                    discomfort improved
                                                                                                                                    with both lighting
                                                                                                                                    and optometry
Bernacki (1999) (Ex. 38-34)........  University employees,   Implementation of a     Longitudinal follow-   Ergonomic assessments  Incidence rate
                                      1992-1998.              program with early      up of employees        (2041), initially      decreased 80% (6.5
                                                              diagnosis and           reporting to the       with those with        in 1992 to 1.3/1000
                                                              treatment, ergonomic    medical department     UEMSDs for job         in 1998), surgery
                                                              assessment and          after policy to        modifications. By      trend also
                                                              correction: wrist       include medical        1994, significantly    decreased.
                                                              supports, document      workup and ergonomic   more assessments on
                                                              holders, foot rests,    assessments for        jobs believed to be
                                                              headsets, alternate     UEMSDs starting in     risky prior to
                                                              keyboards, glare        1992. OSHA 200 logs.   injury.
                                                              screens, chairs, etc.
Bohr (1997) Ex. 38-64..............  600 employees in three  Used participatory      One year longitudinal  14 problems            not assessed.
                                      departments in a        worker-management       evaluation of the      identified and
                                      large metropolitan      ergonomics teams to     ability of ergonomic   potential solutions
                                      medical center.         identify risks and      teams to identify      considered or
                                                              control strategies.     problems and design    identified.
                                                                                      solutions.
Brission 1999 Ex. 38-92............  627 university          Ergonomic training to   Six month              Greater decreases in   Greater decrease in
                                      employees working 5     identify postural       longitudinal           the prevalence of      the prevalence of
                                      or more hours per       stressors and make      comparison of          three postural         musculoskelatal
                                      week with a video       changes in equipment    postural stressors     stressors in the       disorders by both
                                      display unit.           and work activities.    and injury             experimental group     questionnaire and
                                                                                      statistics in          than the control       physical exam in
                                                                                      randomly assigned      group.                 experimental group
                                                                                      experimental (n=284)                          subjects under 40
                                                                                      and control (n=343)                           years of age than in
                                                                                      groups.                                       the control group.

[[<strong>Page</strong> 68572]]

Cook (1999) Ex. 38-205.............  20 meatpackers........  Clamp rather than hand  RMS EMG measurements   Left wrist and finger  .....................
                                                              to hold hog head        if biceps, extrinsic   flexor muscle effort
                                                              while chiseling.        finger and wrist       was significantly
                                                              Modified handle and     flexor muscles after   reduced in chiseling
                                                              tool balance for ham    calibration. Workers   operation (hand
                                                              trimming, Air knife     randomized order of    holding eliminated).
                                                              to cut casings rather   trials between old     Right wrist and
                                                              than pulling casings    and new method by      finger flexor muscle
                                                              by hand.                each worker for 30     effort significantly
                                                                                      minutes (multiple A-   reduced in ham
                                                                                      B-A-B research         trimming. Casing
                                                                                      design).               pulling task showed
                                                                                                             no significant
                                                                                                             reduction in muscle
                                                                                                             effort.
Drury & Wick (1984) Ex. 26-1244;     Shoe manufacturing      Ergonomics program      Pre-post study         Prototype              Body area discomfort
 Wick (1987) Ex. 26-1058.             workers.                including employee      design.                implementation         eliminated (except
                                                              training and            Observational          showed productivity    forearm). Two year
                                                              involvement in          analysis of posture,   increased or           follow-up of
                                                              developing controls,    force, frequency       remained unchanged,    ornament job (Wick)
                                                              systematic process of   every half hour for    awkward wrist          showed no additional
                                                              task analysis,          week pre and post      motions decreased,     injuries reported.
                                                              design, testing,        intervention,          postural stress
                                                              implementation and      postural discomfort    ratings decreased.
                                                              measurement. Tilted     survey, performance
                                                              work surfaces, arm &    measures Data for 5
                                                              foot rests,             jobs presented.
                                                              adjustable chair,
                                                              pneumatic pedal,
                                                              pallet leveller.
Evanoff (1999) Ex. 38-32...........  100-110 orderlies in a  Used a participatory    Two year longitudinal  Not reported.........  Decreased OSHA
                                      1,200 bed urban         worker-management       evaluation of pre                             recordable injury
                                      hospital.               ergonomics committee    and post                                      and lost workday
                                                              to design and           intervention injury                           rates (relative risk
                                                              implement changes in    rates and self                                = 0.64 for all
                                                              training and work       reports of symptoms.                          injuries and 0.4 for
                                                              practices for lifting.                                                lost time injuries
                                                                                                                                    among orderlies,
                                                                                                                                    adjusted for rates
                                                                                                                                    among other hospital
                                                                                                                                    staff. Statistically
                                                                                                                                    significant
                                                                                                                                    reductions in
                                                                                                                                    reports of various
                                                                                                                                    systems.
Garg (1999)........................  Seven nursing homes     Used Participatory      One year longitudinal  Not reported.........  For injuries from
                                      and one hospital,       employee-management     comparison of pre                             patient transfers:
                                      employing 57-136        advisory teams to       and post                                      62% decrease in the
                                      nursing personnel       implement ``zero-lift   intervention injury                           number of injuries,
                                      each.                   programs''.             statistics.                                   86% decrease in lost
                                                                                                                                    workdays, 64%
                                                                                                                                    decrease in
                                                                                                                                    restricted workdays,
                                                                                                                                    84% decrease in
                                                                                                                                    workers'
                                                                                                                                    compensation costs.

[[<strong>Page</strong> 68573]]

Garg & Owen (1992) Ex.-1093 (1994)   57 nursing assistants   Walking belts and       Pre-post study         Significant reduced    Back injury incidence
 Ex. 502-481; Owen & Garg (1994)      in 2 nursing home       mechanical hoists,      design: observed       perceived exertion     rate decreased from
 Ex. 26-1415.                         units.                  shower chairs.          transfer techniques,   with mechanical and    83 to 42 per 100
                                                                                      rate of perceived      belt transfers         FTEs, Severity rate
                                                                                      exertion, OSHA 200     compared to manual     decreased from 634
                                                                                      logs 4 years prior     transfers.             days to 0 days per
                                                                                      to intervention and    Mechanical lifts       100 FTEs [Note:
                                                                                      4 months post          with scales and        short follow-up time
                                                                                      intervention.          shower chairs          reduces strength of
                                                                                                             reduced the number     the study. There was
                                                                                                             of transfers           an increased in
                                                                                                             required per patient.  injury/severity rate
                                                                                                                                    in the first phase
                                                                                                                                    of the intervention
                                                                                                                                    on one unit, but
                                                                                                                                    none of thee
                                                                                                                                    injuries were
                                                                                                                                    related to resident
                                                                                                                                    transfers]
Harms-Ringdahl Ex. 26-630..........  71 Electronic circuit   Suspended arms support  Pre-post intervention  Not reported.........  31 subjects per-3
                                      board assembly          to reduce neck and      design. Symptoms                              months post shoulder
                                      workers.                shoulder muscle         (VAS) 12 months and                           symptoms decreased
                                                              static loading.         one week prior to                             from 62% to 45%, for
                                                                                      intervention, and 3                           neck decreased from
                                                                                      months (n=31) and                             57% to 55%. Mean end
                                                                                      monthly ratings for                           of shift VAS in 1.5
                                                                                      1.5 years post                                year follow-up
                                                                                      intervention (n=71).                          decreased from 46mm
                                                                                                                                    to 24mm, and for
                                                                                                                                    neck 41mm to 19mm.
                                                                                                                                    93% of subjects
                                                                                                                                    using the balancers
                                                                                                                                    after 1.5 years.
                                                                                                                                    [Note: paired
                                                                                                                                    analysis was not
                                                                                                                                    used at 1.5 years].
Jones (1997) Ex. 32-339-1-29.......  12,000 employees in 13  Comprehensive           Five year              Not reported.........  46% and 20% decrease
                                      poultry processing      corporate-wide          longitudinal                                  in UEMSD incidence
                                      plants.                 ergonomics program,     evaluation of                                 rate and severity
                                                              including management    workers'                                      rate, respectively.
                                                              commitment, ergonomic   compensation rates                            50% and 36% decrease
                                                              committees, risk        and costs and                                 in lifting claims
                                                              factor checklists,      overall program                               incidence rate and
                                                              job analysis, medical   assessment scores..                           severity rate
                                                              management, education                                                 respectively.
                                                              and training, and job
                                                              modification.
Kadefors (1996)....................  Auto assembly workers   Increase task           Comparsion of          Reduced time in        Not described; small
                                      in the assembly         variability, increase   factories with and     awkward postures in    sample size in pre-
                                      versus parallel         cycle time, increase    without parallel       each assembly step     full production
                                      assembly.               standing upright.       assembly and tilting   when using tilting     phase limits
                                                                                      car capacity using     device, lower muscle   conclusions.
                                                                                      observational          load with tilt
                                                                                      analysis and EMG.      assembly, reduced
                                                                                                             discomfort.
Loisel, (1997) Ex. 38-28...........  130 employees from      Either occupational     Population based       Not reported.........  The occupational and
                                      various workplaces,     (including ergonomic)   randomized clinical                           the combined
                                      absent from work for    or clinical             trail with three                              intervention groups
                                      more than four weeks    intervention,           intervention groups                           returned to regular
                                      with back pain.         separately and in       and one control                               work 1.5 and 2.4
                                                              combination.            group.                                        times faster than
                                                                                                                                    those in the usual
                                                                                                                                    care intervention
                                                                                                                                    group or the
                                                                                                                                    clinical
                                                                                                                                    intervention group.

[[<strong>Page</strong> 68574]]

Marklin & Wilzbacker (1999)........  Electric utility        (a) Raise location of   Pre-post intervention  Reduced lifting index  Not reported.
                                      warehouse workers.      heavy objects from      assessment of          (a&b), Increased
                                                              below knee to thigh     exposure in jobs       percentage of
                                                              height.                 with historically      population capable
                                                             (b) Replace heavy oak    high injury rates      (c & d), Reduction
                                                              gate with lighter       using NIOSH lifting    in probability of
                                                              pine gate.              equation, 3D Static    back injury reduced
                                                             (c) Modify tool with     Strength Prediction    (e & f), Reduction
                                                              extension and better    Program, Lumbar        in perceived
                                                              drill bit.              Motion Monitor and     exertion (g).
                                                             (d) Maintenance of       Perceived Exertion.
                                                              pulling system.
                                                             (e) Height adjustable
                                                              lift table for
                                                              handling meter
                                                              readers.
                                                             (f) Semiautomated
                                                              pallet wrap machine.
                                                             (g) Power tool for
                                                              opening line clamps.
McKenzie (1985)....................  6,600                   Ergonomics program      Pre-post program       Not reported.........  Dramatic decrease in
                                      Telecommunications      with taskforce,         design using OSHA                             number of cases,
                                      manufacturing workers.  training for            200 logs for                                  lost and restricted
                                                              engineers and           repetitive trauma                             days. Authors
                                                              supervisors, improved   disorder cases, lost                          attribute much of
                                                              workstation and         and restricted days.                          the improvement in
                                                              tools, medical          Program was                                   lost and restricted
                                                              management of           implemented in 1981.                          days to better
                                                              restricted workers.                                                   medical management.
Melhorn (1996) Ex. 38-19...........  212 rivet gun           Random assignment to    Longitudinal           Decreased risk         Not assessed.
                                      employees.              various combinations    evaluation of risk     associated with
                                                              of posture training,    factors among eight    ergonomic posture
                                                              exercise training and   exposure groups        training. Vibration
                                                              rivet gun types.        compared with          dampening rivet guns
                                                                                      controls.              associated with
                                                                                                             decreased risk among
                                                                                                             new hires and
                                                                                                             increased risk among
                                                                                                             previous hires.
Melhorn (1999) Ex. 38-131..........  3152 newly hired sheet  Comprehensive program   Prospective cohort     Not reported.........  Increased recordable
                                      metal mechanics.        of education, job       evaluation with pre                           case incident rate
                                                              placement,              and post                                      and hours worked per
                                                              modifications and       intervention                                  employee. Decreased
                                                              medical management      comparisons.                                  lost time case
                                                              designed for                                                          incident rate, lost
                                                              employees based on                                                    time severity rate,
                                                              individualized risk                                                   and workers'
                                                              assessments.                                                          compensation costs
                                                                                                                                    per employee.
                                                                                                                                    Benefit to cost
                                                                                                                                    ratio of 16.5/1.0.
Meyers et al.(1999)................  194 Wine grape harvest  Substitute smaller      Participatory          Reduced tub weight     Results not reported.
                                      workers in 3            tubs to lower weight    ergonomics             from 57 to 47 pounds.
                                      vineyards.              to below 50 pounds.     intervention study
                                                                                      addressing load
                                                                                      weight and hand
                                                                                      coupling. Used
                                                                                      checklist to
                                                                                      identify tasks and
                                                                                      lumbar motion
                                                                                      monitor and NIOSH
                                                                                      Lifting Equation to
                                                                                      assess physical
                                                                                      load, symptoms
                                                                                      questionnaires and
                                                                                      OSHA logs to assess
                                                                                      health.

[[<strong>Page</strong> 68575]]

Miller (1971) Ex. 26-1250..........  Surgeons and scrub      Added larger surface    Pre-post testing of    Reduced fatigue and    Not applicable.
                                      nurses.                 area to handle of       extensors and          required recovery
                                                              surgical forceps to     flexors with EMG       time.
                                                              increase stability      over 35 procedures
                                                              and decrease load on    by six surgeons.
                                                              fingers.
Moore (1994) Ex. 38-339-1-35.......  5 engine assembly       Participatory           Pre-post case study    Carrying tasks not     UECTD Incidence rate
                                      workers.                ergonomics approach:    of one job. OSHA 200   full eliminated,       decreased 78%, 82%
                                                              eliminate carrying      log incidence data     manual hammering       decrease in
                                                              11.6-14.7 kg parts,     (39 months pre, 30     eliminated Reduction   restricted or lost
                                                              eliminate high impact   months post), Borg     in RPE.                day rates.
                                                              use of brass head       scale, satisfaction,
                                                              hammers.                psychological
                                                                                      demands.
Moore & Garg, (1996) Ex. 38-24;      930 pork slaughtering   Two departmental        Quasi-experimental     Exertions per minute,  Not assessed.
 Moore & Garg, (1997) Ex. 26-21.      plant employees.        ergonomics teams used   design, using post     hand/wrist posture
                                                              to analyze jobs and     intervention           and strain index
                                                              develop ergonomics      comparisons of non-    scores improved for
                                                              interventions.          equivalent groups.     leaf lard pulling
                                                                                                             job. Biomechanical
                                                                                                             stresses to the low-
                                                                                                             back, shoulders and
                                                                                                             guts hand eliminated
                                                                                                             on gut snatch job.
                                                                                                             Percent exertion per
                                                                                                             cycle, exertions per
                                                                                                             minute, and hand/
                                                                                                             wrist postures
                                                                                                             improved on rib pull
                                                                                                             job.
Parenmark (1993)...................  Tool and Equipment      Engineering and         Pre-post design.       Not reported.........  Sick leave decreased
                                      manufacturing.          organizational          Follow-up 18 months                           5%.
                                                              improvements in         after production                             Turnover decreased
                                                              design of new           started in new                                25%.
                                                              factory: adjustable     factory, emg
                                                              work heights, work      biofeedback to keep
                                                              technique training,     load below 15-20%
                                                              job enlargement, work   MVC. Sick leave and
                                                              pace decrease 25%,      turnover rate were
                                                              work organization,      outcome measures.
                                                              flexible work hours,
                                                              wage system,
                                                              rehabilitation.
Rooney et al.(1992) Ex. 26-1056....  400 shoe and canvas     Total quality           Pre and post           373 job                Annual lost time
                                      luggage manufacturing   management program,     intervention job       modifications, 85 of   incident rate
                                      employees.              using an ergonomics     analysis.              which achieved more    reduced from 14.9 to
                                                              team ``to closely                              than 25% reduction     3.3 per 200,000
                                                              follow the proposed                            in force, repetition   hours during four-
                                                              OSHA ergonomics                                or postural stress.    year study period.
                                                              guidelines''.                                                         Not analyzed for
                                                                                                                                    specific
                                                                                                                                    associations with
                                                                                                                                    job modifications.
Rosecrance & Cook (2000) Ex. 38-253  455 Newspaper           Continuous improvement  Pre and post           At least one           Not assessed at 4-6
                                      employees.              process, using an       intervention           intervention           months post
                                                              ergonomics committee    questionnaires and     completed in eleven    intervention.
                                                              to manage a five step   non-structured         of twelve office and
                                                              problem solving         interviews.            production areas,
                                                              method.                                        including
                                                                                                             engineering and
                                                                                                             administrative
                                                                                                             changes to problem
                                                                                                             jobs with static
                                                                                                             postures, repetitive
                                                                                                             tasks and non-
                                                                                                             adjustable
                                                                                                             workstations.

[[<strong>Page</strong> 68576]]

St. Vincent (1998) Ex. 500-71-64...  2 electrical product    Participatory           Pre-post design.       78% of solutions       Not reported.
                                      manufacturing plants.   ergonomics process: 7   Video analysis of      reduced risk factors
                                                              jobs with 50            posture, force,        (postural load,
                                                              solutions               duration, frequency,   forces applied), 14%
                                                              implemented:            impacts.               had no observable
                                                              improving material                             effect, 8% could not
                                                              feed, repositioning                            be evaluated.
                                                              of materials, change
                                                              in work station
                                                              dimensions, change in
                                                              product jigs, tool
                                                              changes, job
                                                              enlargement, handling
                                                              aids.
Shi (1993) Ex. 26-1099.............  County government       One year Back injury    Pre-post randomized    Not reported.........  Nonsignificant
                                      workers.                prevention program:     intervention groups                           frequent back pain
                                                              Individual health       (n=4, 77%                                     prevalence decreased
                                                              risk assessment at      participation) and                            in intervention
                                                              year 1 and year 2 in    control groups (2)                            groups whereas
                                                              intervention group      with similar                                  overall prevalence
                                                              (fitness, job           demographics.                                 significantly
                                                              demands,                Measures:                                     decreased.
                                                              satisfaction,           Satisfaction, HRA                             Significant increase
                                                              demographics),          scores, symptoms                              in job satisfaction.
                                                              training, ergonomic     prevalence, workers                           Significant decrease
                                                              improvements (lifting   compensation rates.                           in HRA risk status
                                                              devices, gait belts,                                                  (not recorded for
                                                              improved seating,                                                     control groups). WC
                                                              minimizing transport).                                                costs per claim
                                                                                                                                    increased in control
                                                                                                                                    groups but decreased
                                                                                                                                    in all intervention
                                                                                                                                    groups. Return on
                                                                                                                                    investment =179%.
                                                                                                                                    Participants
                                                                                                                                    believed ergonomic
                                                                                                                                    interventions
                                                                                                                                    contributed the
                                                                                                                                    most. No attempt to
                                                                                                                                    separate effects of
                                                                                                                                    ergonomics
                                                                                                                                    improvements from
                                                                                                                                    individual health
                                                                                                                                    promotion behavior
                                                                                                                                    in design or
                                                                                                                                    analysis.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Three individual studies are particularly persuasive (Melhorn et 
al.1999, Loisel et al.1997, Brisson et al. 1999). Melhorn et al. (1999) 
reported the results of a 5-step MSD prevention program based on OSHA 
and NIOSH ergonomics guidelines and implemented in a large aircraft 
manufacturing facility. This comprehensive program included education, 
risk factor analysis, job placement (including transitional (or 
``restricted'') work), job modifications and medical management 
designed for employees based on individualized risk assessments. The 
authors followed a group of 3,152 newly hired sheet metal mechanics, 
using a prospective cohort design with pre-and post-intervention 
comparisons. Potential confounders considered included hours worked per 
employee, average number of employees and new hires, and rates in 
otherwise comparable plants without programs. The authors compared 
outcome data for several years pre- and post-program implementation. 
Although the recordable case incidence rate and the hours worked per 
employee increased moderately in the period studied, there was a 
substantial decrease in the lost time case incident rate, lost time 
severity rate, and workers' compensation costs per employee. Workers' 
compensation costs did not decrease in comparison facilities during the 
study. The authors reported a benefit to cost ratio of 16.5/1.0 for 
this program.
    Brisson et al. (1999) conducted a longitudinal comparison of 
postural stressors and injuries in randomly assigned experimental 
(n=284) and control (n=343) groups of university employees keying five 
or more hours per week at a video display unit. The experimental group 
received ergonomic training in the identification of postural stressors 
and in making changes in equipment and work activities. Measurements 
were taken two weeks prior and six months post intervention. Symptoms 
questionnaires and standardized physical examinations

[[<strong>Page</strong> 68577]]

were used to assess health effects, controlling for individual and 
lifestyle factors. Observational analysis was used to assess risk 
factor reductions. There were significantly greater decreases in the 
prevalence of three postural stressors (twisted neck, height of visual 
target, broken hand-wrist line) in the experimental group after the 
training than in the control group. There was also a greater decrease 
in the prevalence of musculoskeletal disorders as reported both in 
questionnaires and in physical examinations in the experimental group 
subjects under 40 years of age than in the control group. Symptom 
prevalence decreased from 29% to 13% in the experimental group for 
those less than 40 years of age. The prevalence of physical findings 
decreased from 18.8% to 2.9% for those under 40 in the experimental 
group compared to a decrease from 18.3 to 10.8% in the reference group. 
There were no significant differences between the experimental and 
control groups in hours of VDU use, psychosocial work factors, smoking, 
leisure time, or body mass index. The differences between the younger 
and older workers appeared to be related to the duration of symptoms 
with older workers having longer duration.
    Loisel et al. (1997) used a population-based, randomized clinical 
trial design to evaluate 4 return-to work (RTW) approaches for workers 
with acute back problems who were absent from work for more than 4 
weeks. These included occupational intervention (including ergonomics), 
clinical intervention, combined intervention or usual care. One hundred 
thirty employees from 40 different workplaces were followed for 1 year. 
Survival analysis was used to estimate return to work time. The 
occupational (ergonomics) intervention group and the combined 
intervention group returned to work 1.5 and 2.4 times faster, 
respectively, than the usual care group or the clinical intervention 
group.
    OSHA finds that this additional body of scientific intervention 
studies, taken together with the other data presented in the 
preliminary-final risk assessments, provides strong evidence that 
ergonomics programs are effective in reducing MSD risks to workers. 
These studies have documented that reductions in exposure to 
biomechanical risk factors, as well as reductions in the rates of MSD 
cases and symptoms, follow implementation of ergonomic interventions. 
These findings are consistent with the epidemiological and 
biomechanical evidence presented in the Health Effects section that 
demonstrate the role of biomechanical risk factors in the development 
of MSDs.
    OSHA also examined two recent reviews (Linton and Van Tulder, 2000, 
and Lincoln et al., 2000) that concluded that the intervention 
literature provides little or no evidence of the effectiveness of 
ergonomics programs. OSHA finds these reviews unconvincing for the 
following reasons:
    Linton and Van Tulder (2000, Attachment to Ex. 500-118) identified 
900 articles about the prevention of musculoskeletal problems. They 
then restricted their evaluation to 20 studies of randomized controlled 
trial design and 8 studies of non-randomized trial design, each of 
which was designed to study ways of preventing long-term neck or back 
problems in subjects not seeking treatment; the methods used in these 
studies included back school training, exercise programs, etc. None of 
the studies involved workstation modifications, changes in controls or 
work practices, or administrative controls. Not surprisingly, the 
authors concluded that there is no evidence of good quality on the 
effectiveness of ergonomics interventions. OSHA gives this study little 
weight because the authors made an arbitrary decision that studies have 
no validity unless they are ``controlled trials'' (the authors do not 
define the term). The authors also exclude from consideration any 
studies of upper or lower extremity problems and any studies involving 
subjects who sought treatment. Their sweeping conclusion goes far 
beyond what is supportable, based on the very small group of 28 studies 
that meet their inclusion criteria.
    Lincoln et al. 2000 [Ex. 500-118nn] assessed the intervention 
literature related to work-related carpal tunnel syndrome (CTS). 
Twenty-four studies met their inclusion criteria, which included having 
a comparison group; implementing engineering, administrative, personal 
or multiple component interventions; and describing outcome measures 
related to CTS or upper extremity MSDs. Although these authors found 
that multiple component programs were suggestive of positive effect, 
the authors concluded that lack of randomization and lack of control 
for confounding weakened the conclusions to be drawn from these 
studies. OSHA does not agree that this conclusion undermines the 
findings drawn from the many intervention studies reviewed by OSHA. As 
noted above, randomization of engineering controls in intervention 
studies is particularly problematic because very few employers are 
willing to permit investigators to dictate which employee groups 
receive different types of job interventions, or no intervention at 
all. Small sample sizes continue to limit research in this area as 
technology and markets change to more flexible niche market demands and 
as there is an increase in temporary workers limiting long-term follow-
up of outcomes. This real-world phenomenon is not unique to the study 
of work-related musculoskeletal disorders. Frank et al.1996 [Ex. 38-
207] pointed out that most of the study design factors that produce the 
most convincing evidence are outside the control of the researchers in 
occupational settings; such design factors include stable working 
populations and processes; randomization of intervention groups; and 
the need for long-term follow-up, which is made difficult during 
economic downturns, product or process changes, or during labor-
management problems. In most cases, quasi-experimental designs, such as 
those reviewed by OSHA in Table VI-10, which use either concurrent 
comparison groups or historical control groups, present the best 
available evidence of the effectiveness of engineering or 
administrative controls in reducing occupational risks (Zwerling et 
al., 1997, Ex. 500-71-65, Goldenhar & Shulte, 1994, Ex. 26-126). OSHA 
discusses the need for and use of randomized or controlled clinical 
trials in ergonomics research later in this section in response to 
comments that were made to the record.
    In addition to the scientific studies, the record contains a large 
number of case reports documenting the experiences of employers and 
occupational health professionals who have implemented ergonomics 
programs. OSHA reviewed several of these in its preliminary risk 
assessment; however, since publication of the proposal, many additional 
case reports have become available. Generally, these reports, which are 
listed in Appendix VI-B, involve case studies of individual companies 
that have instituted programs that include some or all of the elements 
of the ergonomics program required by the standard; these reports 
describe the results of ergonomic interventions in a wide variety of 
industry sectors, including manufacturing establishments, service 
establishments, health care facilities, as well as in other workplaces 
where jobs routinely involve manual handling. Overall, OSHA identified 
over 300 case studies that quantified the reduction in MSD incidence 
following implementation of ergonomic programs and interventions; of 
these, 262

[[<strong>Page</strong> 68578]]

provided data on the reduction in MSD numbers or rates. From these 
studies, OSHA's measure of intervention effectiveness is based on 226 
values for the reduction in total (i.e., lost workday and non-lost 
workday) injuries and illnesses, and 81 values for lost workday 
injuries and illnesses. These case studies do not reflect a ``quasi-
experimental'' study design because they do not use control groups and 
there is generally no evaluation of workplace exposures by an 
independent investigator; instead, a company's or establishment's MSD 
rate experience is evaluated before and after implementation of an 
ergonomics program or intervention. Thus, the outcome measure used in 
these studies reflects the measure that is probably most often used by 
employers who wish to evaluate whether their programs are effective. 
Documenting changes in MSD rates before and after implementation of an 
ergonomics program is, in fact, one of the methods listed in the final 
rule by which employers may evaluate the effectiveness of their 
ergonomics programs.
    To characterize the experiences of employers and safety and health 
professionals in implementing these programs, OSHA determined the 
range, median, and mean reduction in MSD case rates for the overall 
data set, using the same approach as was used in the preliminary risk 
assessment. From each of these case studies, OSHA calculated the 
effectiveness of the standard (e.g., employee involvement and training, 
implementation of engineering or work practice controls). These case 
studies of ergonomic interventions measure effectiveness as the percent 
reduction in either lost workday or total number of MSDs prior to and 
after implementation of the program. That is, effectiveness was 
calculated as the ratio
[GRAPHIC] [TIFF OMITTED] TR14NO00.015

where N<INF>B</INF> represents the number or incidence of MSD cases 
prior to implementation of the ergonomic intervention, and 
N<INF>A</INF> represents the number or incidence after the intervention 
\1\.
---------------------------------------------------------------------------

    \1\ Note that, by this definition, the presence of background 
MSD cases (non-work-related cases) will decrease the apparent 
effectiveness of ergonomic interventions since the interventions 
would presumably not have any effect on the background rate of MSDs 
in the working population (i.e., both N<INF>B</INF> and 
N<INF>A</INF> might contain background MSD cases).
---------------------------------------------------------------------------

    OSHA's estimate of the overall effectiveness of ergonomics programs 
is expressed as the median and mean reduction in MSD injury rates 
contained in this data set; Appendix VI-3 to this section tabulates 
OSHA's effectiveness measure for each of the case studies that provided 
quantitative data, and also shows the time interval over which the 
change in injury rate was measured. For all MSDs (i.e., lost workday 
and non-lost workday MSDs), these case studies reported a median 67-
percent reduction in injury rates (mean effectiveness was 64 percent). 
The median and mean reductions for lost workday MSDs only were somewhat 
higher, at 75 percent and 71 percent, respectively. Although the 
effectiveness of individual ergonomics programs varied widely among the 
establishments described in these case studies, most interventions 
(about 87 percent of the case studies) achieved at least a 30 percent 
reduction in MSD injury rates, 61 percent of the case studies reduced 
MSD rates by half or more, and several achieved the total elimination 
of lost workday MSDs (see Appendix VI-B).

E. OSHA's Response to Comments on the Program Effectiveness Evidence

    Gibson, Dunn & Crutcher (Exs. 32-241-4, 500-197) raised several 
issues regarding OSHA's analysis in the proposed rule of the 
effectiveness of ergonomics programs. These issues were
    <bullet> The lack of evidence that ergonomic interventions will 
reduce low back pain, as evidenced by a comprehensive literature 
evaluation conducted to develop the Agency for Health Care Policy and 
Research (AHCPR) medical guidelines for acute low back pain;
    <bullet> The necessity of conducting randomized controlled trials 
to determine whether ergonomics programs will, in fact, be effective;
    <bullet> OSHA's reliance on the epidemiological data in making 
inferences about the effectiveness of ergonomics programs; and
    <bullet> Criticisms of individual case studies relied upon by OSHA 
to demonstrate program effectiveness.
    In their post-hearing comments, from Gibson, Dunn & Crutcher (Ex. 
500-118) stated that ``After conducting an exhaustive study, Dr. Bigos' 
panel, under the auspices of the AHCPR, `failed to find evidentiary 
support for the use of ergonomic interventions to treat back pain 
injury complaints.' '' However, in the Executive Summary for the AHCPR 
low back pain guidelines, the purpose of the effort was clarified as 
follows: ``The Agency for Health Care Policy and Research (AHCPR) 
convened a 23-member, multidisciplinary, private-sector panel to 
develop a guideline for the evaluation and treatment of acute low back 
problems in adults.'' (Emphasis added)
    Under the section entitled Scope and Organization, the following 
statement occurs: ``This Clinical Practice Guideline is intended to 
provide primary care clinicians with information and recommended 
strategies for the assessment and treatment of acute low back problems 
in adults.'' The word ``ergonomic'' appears four times. Twice, this 
term is used to describe back school programs included in the analysis. 
One citation simply points to a review of safe lifting. The final 
citation notes: ``Several ergonomic guidelines on lifting and 
materials-handling tasks are available to help the clinician provide 
ranges of activity alterations at work.'' Thus even the AHCPR panel 
felt it beneficial to employ ergonomic guidelines on lifting and 
materials handling in establishing safe levels of work activity for 
patients with acute low back pain. The section on prevention consists 
of a total of two paragraphs and 195 words, including a just three 
citations, two of which are opinion papers rather than research 
studies. Therefore, the published AHCPR low back pain guidelines do 
not, and do not purport to, have a focus on non-acute low back pain, 
work-related low back pain, ergonomics or prevention of low back pain. 
Citing the AHCPR guidlines as evidence that ergonomics interventions 
are not effective in reducing the risk of low back disorders is 
inconsistent with the cited purpose and scope of the document itself. 
Therefore, OSHA is not persuaded by this argument that the guidelines 
``failed to find evidentiary support for the use of ergomonic 
intervention to treat back pain injury complaints;'' indeed, they would 
hardly have done so because they did not look for such evidence.
    Regarding the second issue, Gibson, Dunn & Crutcher (Exs. 32-241-4, 
500-197) asserted that randomized controlled trials (RCT) and 
controlled clinical trials (CCT) are the only study designs that can 
demonstrate whether ergonomics interventions are effective. They stated 
that:

    The fact that there is no RCT supporting the proposed standard 
is a major weakness in OSHA's position * * *. [W]ithout RCT, OSHA 
cannot show that the alleged risks at issue will be alleviated by 
particular solutions contained in its proposed rule. [Ex. 500-197, 
pp. I-104 to I-105]

They also quote the statements of two of their witnesses, Dr. Bigos and 
Dr. Fisher. Dr. Stanley Bigos, Orthopedic Surgeon and Professor in the 
University of Washington Department of Orthopaedics, called prospective 
RCTs:

[[<strong>Page</strong> 68579]]

* * * the gold standard for evaluating the efficacy of interventions 
in medicine. * * * This is a widely accepted standard across 
medicine, and across science. * * * The strength of the RCT is that 
both known and unknown risk factors are balanced across treatment 
groups, so that any differences in outcomes are more likely to be 
attributable to specific interventions (Ex. 500-197, pg. I-104).

    Dr. Lloyd Fisher, Professor Emeritus in the Department of 
Biostatistics, University of Washington, likewise claimed that because 
there have been no RCTs on interventions in ergonomics, ``We have no 
evidence that these rules are going to work. They might work. They 
might be harmful.'' (Fisher Tr. 6740). A third witness, Dr. Shekelle, 
stated:

    To my knowledge there is not a single well conducted randomized 
clinical trial of any intervention designed to modify any of the 
ergonomic factors proposed in the OSHA document that has proven to 
have a beneficial effect on disability due to back pain. (Ex. 500-
197, pg. I-104).

    Controlled clinical trials are used principally in medicine to test 
the efficacy of alternative treatments on patients. In a typical 
design, one group of patients that has been diagnosed with a specific 
disease or disorder is given the usual medical care and one or more 
other groups of patients with the same disease or disorder are given 
alternative treatments. The response of the test group(s) to the new 
treatment is compared with the response in the control group to 
determine whether the new treatment(s) were more or less effective than 
the standard for treatment. In a randomized trial design, the patients 
are randomly assigned to the various test or control groups; in a 
controlled, non-randomized clinical trial, assignment of patients to 
the various groups is not made using a purely randomized procedure. The 
randomized trial is considered overall to be the superior design since 
it has the greatest likelihood of controlling for both known and 
unknown confounders, increasing the ability to attribute any observed 
differences in treatment responses between the groups to the treatments 
themselves.
    OSHA has carefully considered these comments that RCT studies in 
ergonomics are necessary to determine the effectiveness of 
interventions in reducing risk (and the related argument that such a 
high standard of scientific evidence is necessary before prevention 
procedures should be required). Although the Agency agrees with Dr. 
Bigos that RCT and CCT are the appropriate statistical designs for 
trials on the safety and efficacy of pharmaceuticals, or for a 
comparison of the effectiveness of different treatments for diseases 
and medical conditions, the study of interventions in ergonomics covers 
many more and different factors. Thus, any ergonomics RCT or CCT would 
require far more complex statistical designsand require many more 
subjects. Another major difference is that intervention studies, unlike 
typical medical or pharmaceutical efficacy studies, would start with 
healthy groups and then test for differences in subsequent risk or 
incidence of MSD. A pharmaceutical study equivalent, for example, would 
be a trial to test a drug that would prevent a specific cancer or 
chronic disease, not just treat it. Such medical RCT prevention trials 
would require a less complex statistical design than a good ergonomic 
intervention, i.e., prevention, study; yet even are such a trial would 
be prohibitively expensive when the disease incidence is fairly low, 
(because many subjects would be required), and this expense would 
increase as the required follow-up time and effort increased.
    As an example of the expense of an RCT ergonomic study, Dr. Frank, 
considering a simpler prospective design than required would be 
required for an ergonomic intervention study, in his testimony related 
his attempt to study physical loads on the back as an independent risk 
factor for workplace lower back pain, controlling for several 
individual characteristics of the worker:

    And in a nutshell, we decided that the key thing was, and it is 
very expensive to do this, to actually measure the physical loads on 
the back. * * * It costs us about $2,000 U.S. dollars per subject. 
And we did well over 300 subjects to simply use a case-control 
design (emphasis added). * * * you cannot afford to do those 
measurements on the 5,000 workers, give or take a few thousand that 
you need to follow if you are going to use a cohort or prospective 
design to see who subsequently develops back pain (Tr. 1341).

    In addition to the expense of RCT intervention studies, conducting 
such studies over a period of time sufficient to make valid 
conclusions, often means that unforeseen changes in conditions occur, 
invalidating the original study design. This is especially true when 
dealing which are often characterized by workplaces with changing 
conditions and workers who can self select on job or life style 
condition changes. For these reasons, and also because the number of 
industry sectors and variety of work conditions is so large, the 
results from the few carefully designed ergonomic RCTs that could be 
conducted over the next 5 to 10 years would be difficult to generalize 
to U.S. industry as a whole.
    For all of these reasons, OSHA believes that sufficient RCT 
intervention studies could not be practically conducted within a 
reasonable time frame to justify delaying regulatory action. Therefore, 
OSHA disagrees with the arguments of the Coalition and its witnesses 
that OSHA should wait to issue its final rule until RCT studies can be 
conducted.
    In estimating risk and risk reduction in this section, OSHA, as it 
has in all of its past rulemaking efforts, relies on the well-founded 
public health concept that, if risk factors can be identified that 
contribute to the etiology of disease, it is reasonable to act to 
reduce exposure to those risk factors to reduce the risk of disease. 
OSHA's logic and rationale in this rulemaking are similar to the 
position taken by Dr. John Frank, Professor, Public Health Sciences, 
University of Toronto (Ex. 500-64). Under the heading ``Standard Public 
Health Practice Regarding Hazard Control'', Dr. Frank poisted three 
conditions as the basis for deciding whether to implement ergonomic 
abatement policies:
    <bullet> ``Is there `reasonable cause' * * * to believe that 
exposure to the putative hazard truly does lead to measurable adverse 
health effects?'';
    <bullet> ``Is there reasonable cause to believe that feasible 
hazard abatement/control intervention * * * e.g. ergonomic job 
modification/design * * * actually reduce exposure to the hazard?'' and
    <bullet> ``Is there reasonable cause to believe that no significant 
harmful consequences of implementing such an intervention will occur * 
* *?'' (Ex. 500-64)
    Regarding the first question, whether the evidence supports causal 
association between exposure to the hazard and workplace MSDs, OSHA has 
concluded in its Health Effects section (Section V) that there is 
substantial evidence that exposure to biomechanical risk factors at 
work--repetitive motion, forceful exertion such as heavy lifting, non-
neutral body postures, contact stress, and segmental vibration--all 
contribute to the risk of MSDs. OSHA has followed the weight-of-
evidence approach for evaluating the best available body of scientific 
evidence on ergonomics, especially the large amount of epidemiologic 
data, and finds that the evidence, as judged by the (Sir Austin 
Bradford) Hill criteria, used by the scientific community for over 
forty years, is convincing. Like Dr. Frank, OSHA especially notes the 
consistency in findings across epidemiologic studies and the 
consistency between the epidemiological studies and the accumulated 
scientific knowledge on

[[<strong>Page</strong> 68580]]

biomechanics and tissue pathology that provide mechanistic explanations 
of the etiology of work-related MSDs. This body of evidence is also 
coherent in terms respect to temporality, i.e., to the cause and effect 
timing and to the populations in which the effects are most frequent or 
severe. The Health Effects section (Section V) also contains sufficient 
evidence on exposure-response to further confirm these findings.
    Dr. Laura Punnett, an epidemiologist and ergonomist, and member of 
the panel that reviewed the epidemiologic evidence on work-related MSD 
for the National Academy of Sciences, agrees with OSHA's findings:

    In summary, the epidemiologic evidence that links physical and 
ergonomic exposures at work with the risk of MSD is extensive and 
includes a sufficient number of methodologically strong studies to 
[implement] primary prevention activities. In the light of the 
experimental literature, the epidemiology is certainly most 
plausibly interpreted [as] showing a causal effect of occupational 
physical stressors on MSD among people with exposures on the job 
(Punnett, Tr. 874).

    Having found that MSDs are causally related to multiple 
biomechanical risk factors, OSHA rejects the arguments of the 
commenters that OSHA should conduct RCTs in order to determine whether 
or which specific interventions will reduce MSD risk. OSHA believes 
that other types of approaches can be used; in particular, OSHA 
believes that the analogy between ergonomice interventions to address 
the multifactoral nature of ergonomic risk factors and interventions 
for the multiple risk factors associated with the development of 
coronary heart disease (CHD, e.g., blood pressure, weight, smoking, and 
cholesterol) is appropriate. For CHD, risks and risk reductions were 
estimated for these factors long before there were any results from 
controlled prospective trials (Frank, Tr. 1340). OSHA notes the post-
hearing comments of Anheuser-Busch Inc. and United Parcel Service Inc. 
comparison which included Dr. Michael Vender's and Dr. Arthur Barsky's 
objections to Dr. Frank's of CHD and back pain. Dr. Vender states that, 
unlike coronary heart disease, back pain is ``a subjective experience 
and can originate from many sources that are not readily identified or 
measurable, including muscle, ligament, joint and disc.'' (Ex. 500-118, 
Tab Kn pg. 21). OSHA finds Dr. Vender's argument irrelevant, however, 
since the relevant connection in Dr. Frank's analogy is that in the 
case of CHD the medical and public health communities implemented 
interventions to lower CHD risk factors that had been identified 
through study designs that were not RCT, rather than waiting to 
intervene until RCT studies had been conducted.
    OSHA next considers the second question posed by Dr. Frank, whether 
there is reasonable cause to believe that feasible hazard abatement and 
control interventions (e.g., ergonomic job modification/design) will 
actually reduce exposure to the hazard. As with its other rules, OSHA 
finds that, having identified specific biomechanical risk factors that 
contribute to the etiology of MSDs, procedures to reduce exposure to 
those factors will reduce risks. This is the underlying principle that 
has goverened all of OSHA's prior health rulemakings, and it is also 
the principle providing the foundation for public health interventions. 
Moreover, as the discussion earlier in this part of the Risk Assessment 
demonstrates, OSHA has accumulated substantial evidence, both 
scientific in nature and less formal, reflecting employers experiences 
with ergonomic programs, and showing that ergonomic interventions do 
reduce exposures to biomechanical risk factors and do reduce the 
prevalence and incidence of MSDs.
    With respect to the types of studies needed to estimate risk and 
risk reduction, OSHA notes that potential risk reduction is estimated 
in many of the Agency's past rules by extrapolation of study results 
using mathematical dose-response models. None of these risk and risk 
reduction estimations relied on RCT. Several of these estimates were 
derived from modeling studies with retrospective cohort designs. In 
these studies, it was common in the course of the cohort's time frame 
that ``interventions'' occurred, in the industrial hygiene sense, to 
reduce exposures to the putative chemical agent. However, in these 
studies information about the exact interventions or exactly which 
cohort members these interventions affected is usually very limited, 
and the studies could hardly be considered ``controlled.'' Furthermore, 
all estimates for risk reduction required extrapolation beyond the 
range of observation, for which there were no ``interventions.'' This 
methodology is based on the logical rationale that if causes or risk 
factors for adverse health effects are established, a reduction in 
exposures to these factors will lead to a reduction in the adverse 
effects.
    With regard to Dr. Frank's third question, whether there is 
reasonable cause to believe that no significant harmful consequences of 
implementing such an intervention will occur, OSHA has found no 
evidence in the record that implementation of ergonomic programs will 
harm employees; several of the scientific witnesses testifying on 
behalf of the UPS and others raised this possibility (Exs. 32-241-3-4), 
claiming that ergonomic interventions will result in deconditioning of 
the workforce and a resulting increase in the risk of MSDs. OSHA 
discussed this issue in detail in the Health Effects section (Section V 
of the preamble) and rejected this argument. In brief, OSHA finds that 
its final ergonomics program standard is consistent with current 
medical practice and guidelines, will not encourage an unhealthy level 
of inactivity in lieu of returning to a safe level of work following an 
injury, and is therefore unlikely to harm workers by discouraging 
conditioning.
    Finally, several commenters presented arguments that it would be 
unethical to withhold interventions. The ethical arguments was 
summarized by Dr. Frank:

    There is also the moral impropriety of randomizing [for RCT 
studies] a set of communities or set of workplaces to not have a 
putative hazard abated (Ex. 500-64).

Dr. Punnett also testified that controlled trials are inappropriate in 
the context of protecting the public from exposures to hazardous 
agents. When asked whether controlled trials are the only 
scientifically rigorous method for determining causal relationships 
between exposure to risk factors and the risk of MSDs, she replied:

    You know, I really find that quite an extraordinary concept. * * 
* I could hardly imagine that OSHA would have ever been held to 
putting subjects in an exposure chamber and exposing them to coke 
emissions or benzene vapors or cotton dust to see whether they 
developed cancer or lung disease. And the whole idea that this would 
be the kind of evidence that would need to be provided in order for 
OSHA to take preventive action, truly it is astounding to me. And 
there are lots of examples. I mean, I showed international criteria 
documents, the European Union taking action on physical ergonomic 
exposures without ever a mention of such a thing as a randomized 
clinical trial in this area. [Tr. 1001-1002]

    OSHA considers this ethical argument to be valid in that the Agency 
does not desire to delay hazard abatement in order to conduct an RCT, 
the result of which may or may not be generalized to worker populations 
overall. This is especially the case because the Agency already has a 
sound methodology for measuring the extent of current risk and the 
potential that reduction in risk associated with implementation of the 
standard.

[[<strong>Page</strong> 68581]]

    Gibson, Dunn & Crutcher in their post hearing comments criticized 
OSHA for using epidemiology studies to assess the work-relatedness of 
MSDs and as a source of information and data to estimate the 
effectiveness of ergonomics programs (Ex. 500-118, pp. II-25 to II-36). 
Part of Gibson, Dunn & Crutcher's criticism relates to their claim that 
``a statistical level of `risk association' from an epidemiologic study 
cannot translate into a measure of effectiveness for OSHA's proposed 
program.'' (Ex. 500-118, p. II-27). They provided three reasons to 
support this claim. First, they claim, even assuming that OSHA's risk 
ratio estimates for the work-related MSDs are correct (which they do 
not concede), that by changing the job conditions:

there will still be some level of force or repetition, some movement 
from completely neutral posture * * * that presumably could cause 
`contact stress.' * * * In changing a job to address one `risk 
factor,' moreover, an entirely different concern might be created. * 
* * Yet OSHA's approach would measure the effect as if it were the 
difference between the ``risk'' from the old job and zero. That 
assumption is simply wrong. (id. II-29).

    Second, they claim that `` `deconditioning' from a reduction in 
physical activity may play a very significant role in increasing the 
risk of MSDs. * * * An epidemiologic study that focuses solely on 
alleged `risk factors' in the existing job, however, provides no 
mechanism for taking this into account, or any other change in the 
nature of a job as altered after an intervention.'' (Ex. 500-118, p. 
II-29). The third reason is that ``the `risk ratios' yielded by 
epidemiologic studies control only for factors that each author was 
able to identify and analyze. * * * In the real world, * * * [with many 
other factors to be considered] the `risk ratios' attributable to job 
factors, after fully accounting for all these other variables, would be 
far lower than those reflected in the epidemiologic evidence.'' (Ex. 
500-118, p. II-30). OSHA notes that all of the ``real world'' 
complications pointed to by these commenters are also pertinent to RCF.
    OSHA disagrees with all three of Gibson, Crutcher & Dunn's 
arguments that ergonomic risk factor epidemiology studies may not be 
used for risk reduction estimates. Gibson, Crutcher & Dunn argue that 
reducing one stress factor will either lead to increased risk due to 
exposure to another stress factor (reason one), or, contradictorily, 
lead to increased risk because the body is ``deconditioned'' and, 
therefore, more susceptible to injury (reason two). OSHA's approach for 
estimating the potential effectiveness of ergonomics programs, in both 
the Preliminary and Final Risk Assessments, is to estimate the 
proportion of disease occurring among workers exposed to risk factors 
that can actually be attributed to their exposure. This approach does 
not reflect a risk of ``zero,'' as Gibson, Dunn & Crutcher suggest. 
Instead, this approach explicitly recognizes that only some portion of 
the disease prevalence observed in a population of exposed workers will 
be affected by intervening to reduce the hazardous exposure. The risk 
ratios from epidemiological studies are precisely the kind of data that 
are used to estimate the attributable fraction of disease in an exposed 
population (e.g., see Hagberg and Wegman Ex. 26-32). For example, if an 
epidemiological study reports that the rate of disease in an exposed 
population is twice as high as that seen in an unexposed population, 
(e.g., an OR of 4), then the attributable fraction can be estimated to 
be 0.75, or 75 percent. This means that the rate of disease in the 
exposed population can be reduced by up to 75 percent in response to an 
intervention. The actual result achieved in an intervention may be 
less, depending on the effectiveness of the specific intervention 
employed. These commenters' third reason is that, because the 
epidemiology studies are limited and cannot control for enough risk 
factors, the risk ratio estimates from these studies overstate the risk 
due to the studied risk factor and cannot be generally applied to 
intervention risk reduction estimates. However, it is not always the 
case that study biases lead to an overestimate of the risk. Risk ratio 
estimates may overestimate or underestimate the true risk, depending on 
the study design, the interrelationship of the risk factors involved, 
and the comparison of the exposed and control groups. For example, 
errors in exposure assessment that arise because of the use of 
imprecise measures to characterize exposure (such as job title) leads 
to exposure misclassification, which usually results in an 
underestimate of risk, or even the observed absence of an association 
where one actually exists.
    Gibson, Crutcher & Dunn further argue that, ``even if the 
epidemiologic evidence has some application, OSHA's review of it for 
benefit purposes was fatally flawed.'' (id., pg. II-31). They offer 
several reasons for this opinion; their primary reason is that OSHA 
took an unweighted median or mean risk of ``every `risk ratio' it could 
find in a NIOSH table, even in situations where the majority of study 
ratios--all but eight in one case--did not even satisfy measures of 
statistical significance.''(Ex. 500-118, p. II-33). In short, according 
to Gibson, Dunn & Crutcher, OSHA agglomerated studies of all qualities 
and all significance levels, studies measuring different risk factors, 
using different levels of exposure, and different types of control 
groups. ``The result, in the end, is a mathematically meaningless 
number whose content dependes primarily on happenstance.'' (Ex. 500-
118, pg. II-33).
    OSHA believes that there is a good rationale for applying this 
methodology to estimate median or mean risk ratios from the 
epidemiological data base by weighing each risk ratio equally (64 FR 
65950-65951, see Table VI-9). OSHA believes that the use of 
epidemiological data and such unweighted median and mean risk ratio 
estimates, separately for each body part, using the epidemiological 
data is fair and appropriate, for several reasons. First, the 
epidemiological data, which is drawn largely from the 1997 NIOSH review 
(Ex. 26-1), is an unbiased screened review of the published literature, 
with the result that only higher quality studies are selected. Second, 
estimating risk ratios by body part agglomerates studies that reflect 
similar background rates; this should provide a more even distribution 
of risk ratio estimates than would be the case if all of the studies 
were grouped together.
    Third, including all risk ratios by body part is reasonable, even 
though some studies estimated risks for more than one body part and may 
therefore be included in analyses of more than one body part. Often 
when more than one body part is included in the same study, the risk 
estimates are based on different subgroups of workers. In OSHA's final 
risk assessment any one study is included for each body part only once.
    Finally, OSHA addresses the criticism of combining unweighted odds 
ratios from many different high-quality studies, even though NIOSH may 
have ranked studies according to their quality criteria. OSHA believes 
that, in this case, unweighted or equal-weighted means and unweighted 
medians are appropriate and fair. Most important, this methodology 
gives the same weight to high-quality studies that show no association 
as to those that do, instead of focusing on the highest risk estimate. 
OSHA believes this is fair because the large variety of study designs, 
work situations, and specific disorders addressed in these studies will 
be more representative of the varied nature of working conditions 
across the country. On the other hand, if OSHA were to weight risk 
ratios by some quality

[[<strong>Page</strong> 68582]]

criteria, where the best designed studies are rated the highest, the 
resulting composite risk estimates would be more reflective of a small 
number of specific exposure conditions, and thus less representative of 
the broad mix of workplaces covered in the final rule. Consequently, 
given OSHA's objective to quantitatively characterize the work-related 
risk of MSDs and the potential effectiveness of ergonomic 
interventions, using the best available data, OSHA finds that its 
approach that makes use of all of the epidemiological data judged by 
the Agency to be of reasonable quality is preferable to relying only on 
a small subset of those data.
    In both their pre- and post-hearing submissions (Exs. 32-241-4, 
500-197), Gibson, Dunn & Crutcher raised several criticisms of some of 
the specific case studies relied on by OSHA in the preliminary risk 
assessment (these case studies were summarized in Appendix VI-B of the 
preamble to the proposed standard, 64 FR 65965-65975). In addressing 
each of these specific comments below, OSHA first identifies the case 
study or studies being addressed in the comment, quotes or summarizes 
the comment, and follows that with a response to the comment.

Group of 24 Case Studies From M. Oxenburgh, Increasing Productivity and 
Profit Through Health & Safety (Ex. 26-1041).

    Comment: Methodology that Dr. Oxenburgh used is biased because he 
only obtained claims of reported success. ``Oxenburgh confirmed that he 
was looking to write a book * * * to demonstrate `the effectiveness * * 
* from an injury reduction perspective' of ergonomic interventions 
[citing Tr. 2646]. Having `made known what [he] was looking for,' 
[citing Tr. 2647] he obtained only reports of success.'' (Ex. 500-197, 
p II-10) ``* * * [T]reatise * * * unabashedly describes itself as an 
assemblage of ergonomic `success stories' designed `to make believers' 
out of management [citing p. 2 of Ex. 26-1041].'' (Ex. 32-241-4, p. 
215).
    OSHA's Response: The introduction to Dr. Oxenburgh's book was 
written by Dr. Stover Snook, who used the quoted phrases ``success 
stories'' and ``to make believers.'' Dr. Oxenburgh actually objected to 
terms such as ``making believers'' and ``success stories,'' because, as 
he stated at the hearings, he compiled ``a series of case studies which 
illustrate the concept of health and safety and productivity running 
together'' (Tr. 2643, ln. 11-13). Gibson, Dunn & Crutcher criticize Dr. 
Oxenburgh's publication as part of their argument that the case studies 
relied on by OSHA (which included some of Dr. Oxenburgh's case studies) 
are not scientific studies (see Ex. 32-241-4, pp. 10-214). However, in 
its preamble to the proposed rule, OSHA did not claim that the case 
studies it relied on represented ``scientific'' studies, but instead 
simply characterized them as sources of ``* * * data on the success of 
ergonomics programs and workplace interventions, * * * [which are in 
turn] supported by data from [other] scientific studies [i.e., 
epidemiological studies and experimental laboratory studies in the 
record] indicating the potential for successful ergonomics programs'' 
(Ex. 28-1, p. IV-4). The 24 case studies from Dr. Oxenburgh's book that 
OSHA used as a source of effectiveness data provide precisely this kind 
of information, and OSHA does not find that the absence of a formal 
study design diminishes the utility of these data in describing the 
beneficial effects that ergonomic interventions have had on MSD rates 
in actual workplaces. In fact, real-world effectiveness studies, almost 
by definition, describe what happens in a particular workplace 
environment when interventions of the kind required by the standard are 
put into effect. OSHA did not in the proposal and does not in the final 
rule claim that these studies do more than report what employers have 
done and the results they have.
    Comment: In his testimony, Dr. Oxenburgh stated that he relied as 
little as possible on written data (citing Tr. 2648), and preferred to 
accept what he was told on site by the people involved in implementing 
and working with the intervention (Exs. 500-197, p. II-11, 32-241-4, p. 
215). Dr. Oxenburgh did not use a methodology that involved to 
verification of his claims (Ex. 500-197, pp. II-11). Oxenburgh was 
willing to accept employer accounts without independent verification 
(Ex. 32-241-4, p. 231). Dr. Oxenburgh's sources were health and safety 
professionals who had much to gain and nothing to lose by making 
exaggerated claims of benefits (Exs. 32-241-4, p. 231; 500-197, p. II-
12).
    OSHA's Response: To obtain information from establishments, Dr. 
Oxenburgh visited facilities to conduct personal interviews and perform 
inspections of the interventions firsthand (Tr. 2648). Although Dr. 
Oxenburgh did inspect some documents on the site visits, he sometimes 
obtained written documentation after the visit ``* * * by which time 
[plant contacts] would have looked up their information.'' (Tr. 2649) 
At the informal hearing, Dr. Oxenburgh testified that the information 
and data he received were reliable:

    I cannot see any reason why they should have told me any lies. 
They were very open with me. When I was going around a workplace, 
there were no restrictions placed on me to say, ``Oh, don't talk to 
the workers,'' or anything like that * * * I have no reason to 
believe that people were not telling me just the facts that were 
there. [Tr. 2714-2715]

    The approach taken by Dr. Oxenburgh is often relied on by 
regulatory agencies (e.g., OSHA and the EPA), academic researchers, and 
other investigators; it involves having individuals with professional 
expertise (in Dr. Oxenburgh's case, in ergonomics and productivity 
measurement) talk to involved individuals, take notes, inspect 
equipment and facilities, and evaluate what has been observed. For 
example, in conducting research to obtain data for the economic and 
technological feasibility analyses to support its standards, OSHA 
conducts many site visits to gather data on control technologies and 
work practices, worker exposures, costs of exposure controls, and 
economic data. In more than 20 years of experience, the Agency has 
never had reason to conclude that the information collected in this way 
is not reliable. In fact, site visits and onsite interviews generally 
provide much more detailed and accurate information than can be 
obtained in written form alone. OSHA believes that this is why Dr. 
Oxenburgh ``relied as little as possible on people's * * * written 
data'' (Tr. 2648): he understands that the answers to specific 
questions and to follow-up questions are far more revealing than the 
information in paper records. OSHA finds that the information and data 
collected by Dr. Oxenburgh and contained in his book are fair and 
accurate reports on the effectiveness of ergonomic interventions, and 
the Agency does not agree with Gibson, Dunn & Crutcher's insinuation 
that the data are unreliable. Further, Gibson, Dunn & Crutcher provide 
no evidence that the information in Dr. Oxenburgh's book is exaggerated 
or was misrepresented by safety and health professionals intent on 
promoting their reputations and careers. OSHA therefore rejects this 
argument as specious.
    Comment: Each case study in Dr. Oxenburgh's book describes 
``health, safety and productivity gains'' in broad generalities and 
rarely provides any quantitative statistics (Ex. 32-241-4, p. 215)
    OSHA's Response: OSHA relied only on the 24 case studies from Dr. 
Oxenburgh's book that did in fact report quantitative changes in the 
number or rate of MSDs; these quantitative data are

[[<strong>Page</strong> 68583]]

reflected in Appendix VI-B in both the preliminary and final risk 
assessments.
    Comment: ``Oxenburgh holds a doctorate in biochemistry but, after 
15 years in this field, saw a career opportunity during the early 
stages of the infamous Australian repetitive strain injury epidemic of 
the early 1980's and switched disciplines with no further academic 
training.'' (Ex. 32-241-4, p. 214) ``Primarily * * * Oxenburgh 
described his expertise as being based on various consulting activities 
he undertook after becoming ``interested in ergonomics'' and 
``join[ing] the Ergonomics Society of Australia [citing Tr. 2700].'' 
(Ex. 500-197, p. II-12)
    OSHA's Response: Gibson, Dunn, & Crutcher impugn Dr. Oxenburgh's 
professional experience and training but fail to acknowledge that Dr. 
Oxenburgh has in fact worked in the field of occupational health and 
safety since 1976 (Tr. 2700) and has practiced in the field of 
ergonomics for 20 years, since he joined the Ergonomics Society of 
Australia and became a committee member of the New South Wales division 
(Ex. 37-24, Tr. 2700). Dr. Oxenburgh also served for several years as a 
founder and co-ordinator of the Economics and Ergonomics specialist 
group of the International Ergonomics Association. Over the past 12 
years, Dr. Oxenburgh has been an expert witness in more than 700 common 
law injury claims, in which capacity he has appeared about half the 
time on behalf of the employer and half the time in support of the 
plaintiff. Dr. Oxenburgh has also been the principal author on a number 
of research studies, including several seminal works on the 
quantifiable effects of early reporting and medical management (see, 
for example, Exs. 38-188, 26-1405, Winkle and Oxenburgh (1990) cited in 
Ex. 37-24, Oxenburgh (1997) cited in Ex. 37-24, Oxenburgh (1994) cited 
in Ex. 37-24). OSHA made Dr. Oxenburgh available to testify at the 
informal public hearing because of the importance of his work on 
ergonomics and productivity, and finds Gibson, Dunn, & Crutcher's 
characterization of Dr. Oxenburgh's qualifications both inaccurate and 
unjustified.
    Comment: Regarding the robot case study contained in Dr. 
Oxenburgh's book, Dr. Oxenburgh admitted that this is a very unusual 
case (Tr. 2655) and that the workers are no longer performing that job 
at all (Tr. 2653). Consequently, there is no ``compelling justification 
for including it in a case study compilation to broadly represent ways 
in which employers purportedly can achieve `100%' effectiveness through 
ergonomic interventions.'' (Exs. 500-197, p. II-13, 32-241-4, p. 226).
    OSHA's Response: Although the ``robot'' case study is an unusual 
case (because employers generally mechanize jobs but only rarely 
automate them), it is an example of an engineering approach that 
eliminated a job that had previously caused musculoskeletal injuries 
among an extraordinary high percentage of workers (60 to 80 percent of 
the workforce that performed these functions) (Tr. 2654). The 
engineering control (i.e., the robot) was implemented after facility 
personnel determined that other options (e.g., job rotation, increased 
rest breaks, and complete workstation redesign) would not prevent the 
injuries (Tr. 2654-2655, Ex. 26-1041, pp. 156-158). In his testimony, 
Mr. Caple also discussed situations in which robots are used in 
chocolate making and in the automotive industry (Tr. 2624-2625). 
However, both Dr. Oxenburgh's and Mr. Caple's testimony confirm that 
robotics are used rarely to control MSD risks. However, because of the 
unusual nature of the control approach in this case study (i.e., 
robotics), OSHA has deleted it from the case study data set and is not 
relying on it in its effectiveness analysis.
    Comment: ``It is surely no coincidence that 9 of the 24 Oxenburgh 
case studies invoked by OSHA cite General Motors as the source of 
information. At the time * * * General Motors was facing a major 
5(a)(1) ergonomics citation, backed up by considerable pressure from 
its union on the subject of ergonomics * * * [GM] had every incentive 
to look for outlets to publicize that it was committed to ergonomics 
and was achieving results.'' (Ex. 32-241-4, p. 231)
    OSHA's Response: Gibson, Dunn & Crutcher imply that the information 
and data taken from these 9 case studies are unreliable because GM was 
willing to fabricate or distort information to promote its ergonomics 
activities. OSHA does not believe that General Motors operates in this 
way, and the Agency notes that Gibson, Dunn & Crutcher provide no 
evidence of any kind to support their allegations that these 9 case 
studies are anything other than factual accounts of ergonomic 
interventions. Accordingly, OSHA is not persuaded by this comment.

Harley-Davidson Case Study (McGlothlin and Baron, Ex. 26-1080)

    Comment: The case study documents a general upward trend in MSDs 
during the study period. ``The only way a decrease in injury rates 
could be claimed was to pick an aberrational year two to four years 
prior to program implementation and draw comparisons from that single 
statistical quirk'' (Exs. 500-197, p. II-14, 32-241-4, p. 227).
    OSHA's Response: NIOSH initiated this Health Hazard Evaluation in 
1990 and followed up in 1993; the purpose of the evaluation was to 
identify jobs associated with upper-extremity and back MSDs in the 
flywheel milling department, and to make recommendations to reduce MSDs 
in that department. The MSD incidence rates per 100 workers for the 
study period, as presented in Table 8 of the report (Ex. 26-1080), were 
27.6 (1989), 11.5 (1990), 18.7 (1991), 13.4 (1992), and 12.5 (1993) 
(Ex. 26-1080). These data do not appear to support Gibson, Dunn & 
Crutcher's claim of a ``general upward trend in MSDs during the study 
period.'' Gibson, Dunn & Crutcher described the incidence rate of 27.6 
for 1989 as a ``statistical quirk'' because it is substantially higher 
than the incidence rates for 1987 (11.8), 1988 (8.9), and 1990 (11.5) 
(Ex. 32-241-4, p. 227). The case study indicates, however, that this 
increased rate was associated with hiring a nurse between 1988 and 1989 
who ``brought new vigilance to the reporting of musculoskeletal 
disorders'' (Ex. 26-1080, p. 12), suggesting that the lower rates 
reported for 1987 and 1988 reflect the underreporting, rather than low 
incidence, of MSDs. Further, the case study suggested that the MSD 
incidence for 1990, which was substantially lower than that for 1989 or 
1991, may have decreased because of a sudden 20-percent increase in the 
department's workforce: new workers may have under-reported 
musculoskeletal problems, or it is possible that the disorders did not 
become symptomatic until the following year (Ex, 26-1080, pp. 12-13). 
For these reasons, OSHA does not agree that the MSD rate for 1989, 
which is taken as the base year for comparison with post-intervention 
years, is necessarily a statistical aberration, but rather that the 
lower MSD rates for the surrounding years may reflect underreporting of 
MSDs and abrupt increases in the workforce of the establishment. 
However, because of the concern raised about the representativeness of 
the injury rate for 1989, OSHA is basing its estimate of program 
effectiveness from this study on the injury rate for 1991, which 
represents the first year in which interventions were planned and 
implemented.

[[<strong>Page</strong> 68584]]

Telecommunications (Video Display Terminal (VDT) operator) Case Study 
(Tadano, Ex. 26-1337)

    Comment: ``OSHA attributed significance to a `40.8' percent 
reduction in `Total MSDs' allegedly achieved by an ergonomics program * 
* * [T]his reduction took place after a very substantial increase in 
MSD reports during the preceding period. The article suggests that this 
claimed reduction may have arisen from `a certain operator hysteria 
about * * * catching [repetitive motion sickness], * * * possibly 
connected to sentiments, fueled by union activities, that `management 
was * * * not doing enough * * * to curb this epidemic'' ' (citing Ex. 
30-1337, p. 69). The reported reduction, therefore, might have nothing 
to do with the effectiveness of the ergonomics program and more to do 
with the statistical effect of ``regression to the mean'' (Ex. 500-197, 
pp. II-17-18).
    OSHA's Response: This case study describes an ergonomic 
intervention implemented by a telecommunications establishment to 
address an increase in the rate of upper-extremity MSDs among VDT 
operators. There is nothing in the case study that supports Gibson, 
Dunn & Crutcher's contention that the observed decline in the number of 
upper extremity MSD cases and their associated medical costs was due to 
``regression to the mean'' following an unusual increase in MSD rates, 
nor is there any suggestion by the author that ``operator hysteria'' 
was solely or even primarily responsible for the increase in the MSD 
rate prior to instituting the intervention. When reports of MSDs began 
to increase, the article stated that the ``* * * medical department 
staff was especially concerned, as they were aware that a similar 
department of a company branch in an adjacent state had been faced with 
[repetitive motion syndrome] in `epidemic proportions'.'' (Ex. 26-1337, 
p. 69) The article also stated that ``* * * the job was considered 
stressful and monotonous by many operators,'' and that ``* * * [the] 
labor management relationship had previously been good.'' (Ex. 32-1337, 
p. 69) The author clearly attributed the decline in MSD cases following 
the ergonomic intervention to the intervention itself, and reported 
that ``* * * these results indicate the value of a positive approach to 
prevention of this occupational group [of disorders].'' (Ex. 26-1337, 
p. 70) Therefore, OSHA finds that it is appropriate to rely on this 
case study as part of its data set of ergonomic interventions.
    Comment: ``Tadano also explains at length that CTDs `have a 
multifactorial etiology' and that it is often not possible to attribute 
trends to any single intervention. She concludes:

    In the current study, so many factors were changed * * * that 
success or improvement cannot be attributed to any single factor. 
Also the data were limited, in that the sample size was small and 
the duration of time measured was limited.'' [Citing Ex. 26-1377, p. 
70]

    Yet, OSHA does exactly what Tadano warns it no[t] to do ``it 
attributes the entire * * * success or improvement * * * described in 
the article to the * * * single factor * * * of ergonomic interventions 
in the workplace'' (Ex. 32-241-4, p. 218-219).
    OSHA's Response: Gibson, Dunn & Crutcher omitted an important part 
of the excerpt they quote from the Tadano study. The excerpt should 
read that ``* * * so many factors were changed (i.e., worker methods, 
work-station design, addition of exercises, and mini-breaks) that 
success or improvement cannot be attributed to any single factor.'' The 
factors mentioned by Tadano all relate to the ergonomic interventions 
described in the study, and all would be considered appropriate 
engineering, administrative, and medical management interventions under 
the final rule. Thus, OSHA did not attribute the reduction in the MSD 
rate inappropriately, Gibson, Dunn & Crutcher imply; instead, OSHA, as 
well as the author of the study, attribute the post-intervention 
reduction in MSD rate to the collective effect of all of the components 
of the ergonomic intervention.

Leiyu Shi Study (Ex. 26-1099)

    Comment: Although this study is a randomized study, there are 
serious flaws including small size and lack of sufficient study period 
to eliminate Hawthorne effect or other variables as potential 
explanations (Tr. 6823; Ex. 32-241-3-7, p.15). The author admits that 
``* * * his analysis `contains a number of limitations,' including the 
need for further examination and empirical testing to establish `the 
reliability and validity' of the methodology he used and the very real 
possibility of `a Hawthorne effect among the participating units' 
because employees knowing they are being studied react unusually and 
their reported behavior change may be more a result of their enthusiasm 
rather than that of an injury prevention program.'' [citing Ex. 26-
1099, p. 210] (Ex. 32-241-4, p. 219).
    OSHA's Response: The Leigu Shi study is a randomized trial of a 
back injury prevention program implemented among county employees; the 
program consisted of a combination of education, training, physical 
fitness activities, and ergonomic improvements. The author acknowledged 
that it was not possible rule out a Hawthorne effect bias in the 
results. However, although the author was aware of the potential for 
some confounding, he made several observations about the effectiveness 
of the back injury intervention program studied:

    The results of the study lend support to the widely held belief 
that health promotion in the workplace can significantly reduce 
employee health risks. * * * [T]he study offers suggestive evidence 
for the initial benefits of a back injury prevention program. 
Whether such interventions will continue to reap benefits in future 
years depends, to a large extent, on a favorable work environment 
and the maintenance and continuation of positive behavioral changes 
(emphasis added) (Ex. 26-1099, pp. 209-210).

    I response to general comments in the record that the case studies 
OSHA used to indicate program effectiveness are seriously biased, OSHA 
does not dispute that these case studies, like all such reports and 
investigations, may reflect some bias; no study can eliminate all 
biases or potential confounders. However, the large number of case 
studies accumulated by the Agency makes it highly unlikely that any 
single unaccounted for confounder, such as the Hawthorne effect, could 
explain the consistent results reported in these studies as well as the 
effect OSHA postulates: that ergonomic interventions work.

Malcolm Pope Case Study of Telecommunications Workers (Ex. 26-1073)

    Comment: As an example of an ``emphatic disclaimer'' OSHA's critics 
claim the authors of the technical articles made and OSHA ignored Pope 
explains in his article [which was used by OSHA in its effectiveness 
analysis] that ``there are other factors involved * * * [in low back 
pain] such as abnormal anatomy, the physical fitness of the individual, 
changes related to age and previous injury.'' (Ex. 32-241-4, p. 219, 
citing Ex. 26-1073, p. 450).
    OSHA's Response: The Pope paper discusses the etiology of work-
related low back pain and approaches for reducing back injury rates. 
Part of this report presents a case study of an ergonomic intervention 
in a telecommunications manufacturing facility. In discussing the 
etiology of low back pain, Pope stated, almost as an aside, that other 
factors may be involved; however, in discussing the etiology of low 
back pain, Pope

[[<strong>Page</strong> 68585]]

emphasizes the importance of repeated biomechanical load on tissues. 
For example, the article stated that ``all connective and structural 
tissues [i.e., even in those individuals who do not have abnormal 
anatomy, poor physical fitness, or advanced age] will fail if subjected 
to loads that are too high for too long a period of time without an 
opportunity for repair to occur'' (Ex. 26-1073, p. 450). In addition, 
he notes that ``[l]ow back pain has, in most cases [of over-exertion 
injuries reported], occurred due to a mechanical overload to one of the 
tissues of the back'' (i.e., lifting to much, too far, too long, etc.) 
(Ex. 26-1073, p. 450). Dr. Pope concluded the section of his paper on 
etiology by stating that ``The key issue for those involved in the 
prevention of occupational injuries is to use epidemiologic information 
so that the relationships between load, repetition rate and exposure 
can be identified.'' (Ex. 26-1073, p. 450)
    Dr. Pope then described the case study that exemplifies his 
approach (Ex. 26-1073, p. 453, abstract). The results of the case study 
showed that, within one year of implementing an ergonomics program that 
included engineering changes, the incidence rate of significant 
repetitive trauma disorders decreased from 1.1 cases per 100,000 
working hours to 0.26 cases/100,000 working hours and lost work days 
decreased from 1,000 to 129 (i.e., an almost eightfold decrease in lost 
work days). Dr. Pope concluded his paper as follows:

    An ergonomic approach, soundly based on biomechanical 
principles, will be effective in reducing such injuries if the 
correct management approach is taken. [Ex. 26-1073, p. 454]

    Based on Dr. Pope's discussion of the etiology of low back pain and 
the conclusions that accompany the case study, OSHA does not agree that 
the reference to ``other factors'' cited by Gibson, Dunn & Crutcher 
represent an ``emphatic disclaimer'' of the case study's findings.

Westgaard and Aaras Study of a Telecommunications Manufacturer (Ex. 26-
1026)

    Comment: The authors note in this paper that ``musculo-skeletal 
illness may also develop as a result of other factors than work load, 
for instance as a complication because of other illnesses, due to 
general defects of the musculo-skeletal system, due to muscle spasms as 
a consequence of problems of a psychological nature, or to strenuous 
leisure time activities [;t]hus, one should not conclude that the work 
station is the major causal factor for any individual case of musculo-
skeletal disorders' (Ex. 32-241-4, p.219, citing Ex. 26-1026, pp. 173-
174). This statement represents another ``disclaimer'' that weakens the 
case study.
    OSHA's Response: This study was a formal investigation of sick 
leave and medical records to evaluate the effectiveness of ergonomic 
improvements made in 1975 in a telecommunications parts manufacturing 
plant. Although the authors stated that ``* * * one should not conclude 
that the work station is the major causal factor for any individual 
case of [MSD]'' (emphasis added), there is no question that the 
investigators believed that reducing exposures to biomechanical load 
was responsible for reducing the sick leave associated with MSDs:

    There is no doubt that there has been an unusually high rate of 
musculoskeletal illness among the workers * * * in general. * * * It 
is also clear that the work situations have been strenuous, with the 
strain mainly affecting a limited number of muscles in the shoulder 
and neck region * * *. [I]t is very unlikely that those employed at 
the [work station] * * * have a sufficiently different life 
situation to other women of the same age to explain the group 
differences in sick leave due to musculo-skeletal disorders. The 
work load and, specifically, the strain on shoulder and neck 
muscles, must therefore be considered a major causal factor in the 
development of musculo-skeletal disorders among [the] workers 
[Emphasis added]. [Ex.26-1026, p. 174]

    Thus, based on the specific conclusions reached by the authors of 
this study, OSHA finds that it appropriate to include this study among 
the data base of case studies that describe the effectiveness of 
ergonomics programs.

Meatpacking Case Study (Ex. 26-1043)

    Comment: Group is too small to support statistically valid 
conclusions. Baseline of four reported injuries at meatpacking 
operation (Ex. 32-241-4, p. 220, see footnote 805).
    OSHA's Response: This article describes the comprehensive 
ergonomics program implemented by a major meatpacking company. Although 
the program was implemented for ``all plant locations'' of the company, 
the article reports quantitative results only for the bacon department. 
Although the number of MSD cases is small, Gibson, Dunn & Crutcher fail 
to mention that the reduction experienced by the department was a 
decrease from four CTDs in one month to none in the six months 
following the implementation of the program (Ex. 26-1043, pp.138 & 
140), a change that the author clearly attributed to the use of 
employee rotation in the department.

Ice Cream Manufacturer Case Study (Ex. 26-1100)

    Comment: The group is too small to support statistically valid 
conclusions. Baseline of four compensation claims, not necessarily 
attributable to MSDs (Ex. 32-241-4, p. 220, see footnote 805).
    OSHA's Response: This case study of a mid-sized ice cream 
manufacturer (230 workers in summer, 60 in winter) clearly identifies 
the four workers' compensation cases as involving ``soft tissue'' (Ex. 
26-1100, p. 52). All of these claims occurred after the installation of 
six new workstations, whereas in the preceding seven years (before the 
workstations were installed) there had been no such claims. In addition 
to the decrease in the number of claims after the intervention, the 
implementation of ergonomic changes resulted in a decrease in 
absenteeism from ten to four percent, an increase in productivity of as 
much as 55 percent, and an overall increase in morale (Ex. 26-1100). 
Thus OSHA finds it appropriate to include this study in its database.

Cattle Feed Processing Case Study (Ex. 26-1046)

    Comment: Group is too small to support statistically valid 
conclusions. Purportedly scientific article making claims based solely 
on the experience of two cattle feed processing employees without any 
attempt to explore the etiology of the reports (ex. 32-241-4, p. 220, 
see footnote 805).
    OSHA's Response: This study describes a case in which a processing 
plant began producing experimental cattle feed in a manual operation. 
According to the article, the operation ``was apparently initiated 
without either pre-run trials or consideration of occupational health 
and safety issues'' (Ex. 26-1046, p. 27). The injuries sustained by the 
two employees were shown to have been a direct result of these specific 
workplace activities; between two and four weeks after beginning these 
specific workplace activities, both of the workers sustained 
irreversible back injuries. After engineering controls were 
implemented, there were no incidents of reported back pain during three 
subsequent trials of the redesigned process. The author reported that 
``* * * [h]ad such countermeasures been implemented immediately, the 
irreversible injury would have been prevented'' (Ex. 26-1046, p. 28). 
Again, OHSA finds this study is appropriately included.

[[<strong>Page</strong> 68586]]

Hand Tool Operations Case Study (Ex. 26-1070)

    Comment: Group is too small to support statistically valid 
conclusions: ``the data are inadequate for rigorous statistical 
evaluation'' (Ex. 32-241-4, p. 220, see footnote 805, citing Ex. 26-
1070, p. 678).
    OSHA's Response: This was a formal study of OSHA log and medical 
records at a telecommunications manufacturing facility during the 
implementation of a program to introduce redesigned hand tools and 
provide employee training on ergonomics; one of OSHA's expert 
witnesses, Dr. Thomas Armstrong, was a co-author of this study. The 
plant-wide incidence rate of OSHA reportable repetitive trauma 
disorders prior to the implementation of engineering and administrative 
ergonomic controls was 2.2 cases per 200,000 workhours and 1,000 lost 
workdays. In addition, incidence rates were as high as 4.6 percent in 
some areas of the facility and work restrictions were impeding the 
balance of production lines. Four departments accounted for 68 percent 
of all repetitive trauma injuries, and 48 percent of all repetitive 
trauma injuries occurred among assemblers (Ex. 26-1070, pp. 674, 676-
677).
    After the implementation of controls, repetitive trauma disorders 
decreased to 0.53 per 200,000 workhours and only 129 lost workdays. The 
authors stated that the contribution of the control program to the 
reduction in MSDs seen in the facility ``cannot be statistically tested 
using the available medical data,'' but emphasized that they believe 
the control program was ``an important factor in this reduction'' (Ex. 
26-1070, p. 677) and stated that the program ``appears very promising'' 
(Ex. 26-1070, p. 678). Based on the authors own conclusions, OSHA finds 
that the reported reduction in MSDs in this plant are apprpriately 
attributed to the ergonomic interventions described.

Material Handling at Grocery (OSHA Site Visit) (Ex. 26-1176)

    Comment: Group is too small to support statistically valid 
conclusions. ``From these data, it is not certain that costs associated 
with CTDs, the severity of CTDs (as represented by cost per claim), or 
the impact of CTDs on total medical claims have changed significantly 
for the long term'' (Ex. 32-241-4, p. 220, see footnote 805, citing Ex. 
26-1176).
    OSHA's Response: This case study resulted from an OSHA-sponsored 
site visit to a retail grocery establishment. Although the site visit 
report acknowledges its limitations in predicting long-term effects 
from the employer's newly implemented ergonomics program, it also 
stated the following:

    [I]t appears that [worker CTD compensation] claims have declined 
somewhat, but the program has not really been in place long enough 
to be able to verify a trend * * * It does look promising, however, 
particularly in terms of the number of CTD claims, which have fallen 
even while total employment has risen, and perhaps the average cost 
per claim.
    On a division-wide basis, members of the company CTD committee 
think that, as a result of the CTD strategy implementation, the 
numbers of CTD-related injuries and illnesses have decreased, the 
associated costs of claims (workers' compensation and medical) have 
decreased, employee complaints have been reduced, and employee 
morale has improved (Ex. 26-1176, pp. 12-13).

    Thus, it is clear that this employer representative attributed the 
observed decline in MSDs directly to implementation of the program, and 
OSHA therefore finds it appropriate to include it in the data set being 
relied on by the Agency to evaluate the effectiveness of ergonomic 
interventions.

Garg and Owen Study of Ergonomic Interventions in a Nursing Home (Ex. 
26-1093)

    Comment: Group is too small to support statistically valid 
conclusions. ``[L]arge-scale studies in different nursing homes are 
necessary to confirm the * * * findings'' in the article (Ex. 32-241-4, 
p. 220, see footnote 805, citing Ex. 26-1093).
    OSHA's Response: The study was conducted in two units of a nursing 
home which employed 57 nursing assistants. As a result of the controls 
implemented, the incidence rate for back injury decreased from 83 per 
2,000,000 work-hours to 47 per 2,000,000 work-hours. The authors 
concluded that ``an appropriate ergonomic intervention program offers 
great promise in reducing physical stress and risk of low-back pain to 
nursing personnel.'' OSHA agrees that, as the authors stated in their 
article, the specific findings of this one study may not reflect the 
results achieved in other establishments that implement similar 
ergonomic measures. Garg and Owen explain that implementing such 
measures requires consideration of staffing levels, training, workload, 
and administrative support (Ex. 26-1093). However, the study by Garg 
and Owen is only one of several case studies used by OSHA to examine 
the effectiveness of ergonomics programs in nursing homes and other 
health care industry sectors (see Appendix VI-2 in this section of the 
preamble). These other studies also report reduced MSD rates that are 
attributed to ergonomic interventions, many of them similar to those 
investigated by Garg and Owen (i.e., use of mechanical devices for 
patient lifting, modifying showers and toilets for easier access). 
Therefore, OSHA does not agree that it is inappropriate to include the 
Garg and Owen case study in the database, despite the authors' caution.

Couch, Summary of Six Case Studies (Ex. 26-1086)

    Comment: The importance of non-work factors such as gender and age 
are mentioned as potential contributors. ``The above examples of the 
cost benefits of ergonomics are quite positive and indicate that 
ergonomics does seem to reap monetary rewards as well as improve worker 
well being. However, there are many factors that have not been 
accounted for or controlled in these reports; these factors, such as 
changes in the economy that reduce job turnover or changes in 
production technology and product lines that may eliminate high risk 
jobs or leave only the survivors in remaining jobs, may also contribute 
to the apparent payback. Because ergonomic case studies such as these 
are done `in the field,' it is very difficult to hold these independent 
or external variables constant'' (Ex. 32-241-4, p. 220, see footnote 
805, citing Ex. 26-1086).
    OSHA's Response: OSHA recognizes that the case studies contained in 
Appendix VI-2 are, because of their real-world rather than laboratory 
nature, unable to control for a number of factors that could affect 
injury and illness outcomes; some of these factors are mentioned in the 
Couch article (Ex. 26-1086) and in Gibson, Dunn & Crutcher's comment. 
However, OSHA is not basing its finding that ergonomic interventions 
are effective on any single study or a few case studies. Instead, OSHA 
has identified more than 200 case studies from the record, all of which 
document reductions in MSD numbers or rates following implementation of 
ergonomic interventions. These case studies reflect a wide variety of 
industry sectors, workplace conditions, labor market conditions, and 
technologies. Nevertheless, despite the presence of confounding or 
modifying factors such as those mentioned in the Couch article, all of 
these studies attributed the observed reductions in MSD rates primarily 
to the ergonomic interventions described. Because such a large number 
of case studies yields such

[[<strong>Page</strong> 68587]]

consistent results, OSHA finds it unlikely that the kinds of factors 
identified by Couch, rather than ergonomic interventions, were 
primarily responsible for the reductions in MSD rates reported in this 
large group of studies.

Automobile Cable Manufacturer (OSHA Site Visit) (Ex. 26-1181)

    Comment: OSHA's estimate of the reduction in the number of MSDs 
pre-and post-intervention are based on numbers of illness cases, lost 
workday cases, and lost work days in 1991 and 1993. However, the 
statistics for 1993 represent only the first 9 months of the year. 
Further, the establishment reported an increase in the total number of 
injuries, which must include some MSDs, from 46 in 1991 to 65 in the 
first 9 months of 1993. OSHA cannot base its effectiveness estimate 
solely on the reduction in illness cases reported (Ex. 32-241-4, p. 
222).
    OSHA's Response: The site visit report clearly states in a footnote 
to the ``1993'' column which of the data ``covers [the] period from 
January to September 1993'' (Ex. 26-1181, p. 10). If the statistics for 
1993 are extrapolated to cover a full year, based on the experience of 
the first 9 months, declines in lost workday cases and illnesses are 
still apparent: lost workday cases decline from 48 (1991) to 36 (1993) 
(a 25-percent reduction); the number of lost workdays decline from 
1,287 (1991) to 367 (1993); and the number of illnesses decline from 47 
(1991) to 23 (1993) (a 51-percent reduction). Although the report 
clearly indicates that the number of total injuries increased from 1991 
to 1993, the report also states that ``[t]he facility believes that 
their ergonomics program has contributed to decreases in the following: 
number of overall illnesses, number and costs of worker's compensation 
claims, number of work days and lost workday cases, medical (i.e., non-
compensated disability) cost, and turnover'' (Ex. 26-1181, p. 9). These 
claims are supported by the data presented in the report. No reason was 
given for the increase in the total number of injuries from 1991 to 
1993, nor was there any evidence in the report to suggest that the rise 
in total number of injuries was attributed to an increase in the number 
of MSDs. It is apparent, however, from the report that the employer 
would have been likely to classify some MSDs as injuries rather than 
illnesses. Therefore, OSHA has revised its analysis for the final rule 
to reflect that lost workday cases declined by 25 percent, and is not 
relying on the illness statistics presented in the report for its 
effectiveness analysis.

Luopajarvi et al.Study of a Food Packing Establishment (Exs. 26-1042, 
26-1090)

    Comment: OSHA attributed to an ergonomics program the elimination 
of hand MSDs from a pre-intervention level of 51 MSDs in 1976. ``The 
claim is false: the exhibit makes no reference to elimination of hand 
MSDs, and the underlying data tables confirm the existence of 
continuing injury reports. Moreover, ergonomic interventions were not 
even proposed at the plant until 1977, a year in which MSDs dropped to 
a level (20) more consistent with the lower rates existent prior to 
this year.'' (Ex. 32-241-4, p. 220).
    OSHA's Response: Tables 3 and 4 of Ex. 26-1090 (p. 430) provide 
data on the numbers of hand MSDs from 1972 to 1984 in this food 
packaging facility. The incidence of hand MSDs increased steadily from 
1972 to a high of 51 cases in 1976 and 20 in 1977; between 1979 and 
1984, the table reported between 0 to 1 MSDs occurring annually, 
indicating that the problem had been virtually eliminated. OSHA has 
revised the entry for this case study in Appendix VI-2 to report the 
study's findings more precisely. With reference to the second part of 
Gibson, Dunn & Crutcher's comment, OSHA did not rely on the hand MSD 
statistics for its overall measure of program effectiveness, but on 
data presented in Table 5 of the article, which reported the number of 
MSDs of the neck and upper extremity in 1977 and 1981 and reflect an 
overall reduction in the number of MSD of 47 percent. Thus, OSHA is 
using 1977 as the baseline year, the year in which ergonomics 
interventions were being proposed.

Footwear Assembly Case Study (Ex. 26-1059)

    Comment: OSHA attributes a 62-percent decline in MSDs over a 2-year 
period to an ergonomics training program. However, the article explains 
that ergonomic remedies were unsuccessful and the ergonomics training 
program ``* * * was actually a `behavioral management' program designed 
to improve worker attitudes and morale'' (Ex. 32-241-4, p. 225). This 
case study is consistent with evidence that ``reports of pain are 
rooted in psychosocial factors rather than workplace `hazards,' [and 
that] the attitude adjustment strategy apparently achieved what 
ergonomics could not.'' [Ex. 32-224-4, pp. 225-226]
    OSHA's Response: This article describes a training program 
implemented at a footwear manufacturing facility that had 700 workers, 
84 percent of whom were involved in repetitive tasks. The company 
experienced a rise in serious and lost-time upper-extremity MSDs 
throughout the early 1980's. The article does not claim, as the comment 
contends, that ``ergonomic remedies were unsuccessful.'' Instead, the 
article stated that several attempts were made to develop a ``safety 
program'' that was not further described (Ex. 26-1059, p. 52). If 
engineering solutions to address MSDs were implemented, they were not 
discussed in the article; instead, the article reported that ``because 
of the expense of workstation redesign in this very old facility, 
almost all human-factors engineering measures were also deemed to be 
impractical'' (Ex. 26-1059, p. 52). Therefore, no claim can be made as 
to the success of an ergonomic intervention based on engineering at 
this facility. The comment states that the program implemented was 
actually `` `a behavioral management program' designed to improve 
worker attitudes and morale.'' Behavior management is defined in the 
article as ``simply the management of people in the work place in such 
a way that they interact with the environment in the most safe and 
efficient manner'' (Ex. 26-1059, pp. 51-52). The training ``attempted 
to educate employees on the causes and effects of [cumulative trauma 
disorders] * * * and the state workers' compensation system.'' (Ex. 26-
1059, p. 53) The final rule requires employers to provide similar 
information to all employees on the causes and characteristics of MSDs. 
The program at the facility also encouraged employee participation, 
another important component of the final rule. OSHA does not agree with 
the comment that the case study demonstrates that psychosocial factors 
are more important that biomechanical factors; OSHA's review of the 
scientific evidence on the role of psychosocial factors is presented in 
the Health Effects section (Section V of the preamble), where the 
Agency finds that, although psychosocial factors play a role in the 
etiology of work-related MSDs, they do not outweigh the significance of 
exposure to biomechanical factors in the workplace and are independent 
of biomechanical efferts.

Sewing and Cutting Operations Case Study (Ex. 26-1060)

    Comment: This is an article written by an OSHA area office employee 
about an inspection of a sewing facility. ``The article actually 
reports, however, that there was a steady decline in reported CTD rates 
beginning long before any ergonomic interventions: 26% in 1987,

[[<strong>Page</strong> 68588]]

18% in 1988, and 15% in 1989'' [citing Ex. 26-1060, p. 1]. The article 
does not identify exactly when ergonomic controls were implemented, but 
it does state that rates continued to decline to 14.6% in 1990 and 6.8% 
in 1991, but increased to 11% in 1992. The article also noted that 
``there was an increase initially reported'' after ergonomics controls 
were implemented, which could only refer to the jump from 6.8% to 11%. 
Since no statistics are given for years after 1992, these data would 
suggest, if anything, that ergonomic controls reversed a previous trend 
of declining injury reports at this plant, prompting a 62% increase 
from 6.8% to 11%.'' (emphasis in original) [Ex. 32-241-4, p. 223]
    OSHA's Response: This article reports on an OSHA inspection 
conducted at a sewing facility in October of 1989. Since the 
inspection, at least through 1992, the company had been working under 
an abatement plan that required the facility to develop and implement a 
comprehensive ergonomics program ``from the ground up'' (Ex. 26-1060, 
p. 3). In 1992, the year in which the MSD rate increased over that of 
1991, the report stated that there were ``fewer incidents reported 
[overall],'' which suggests that employment in the plant had fallen 
since 1991 (there had previously been about 100 workers at this plant). 
There were also no surgeries reported in 1992, compared to 13 reported 
between 1987 and 1989 (Ex. 26-1060, p. 2). The report concludes that 
the ``lost workday injury rate has been effectively reduced,'' and 
noted that the number of employee complaints of MSD symptoms had fallen 
from 34 in 1991 to 14 in 1992 (Ex. 26-1060, p. 6). Therefore, OSHA does 
not agree with the analysis of this report by Gibson, Dunn & Crutcher, 
which suggests that the ergonomics program led to an increase in the 
rate of MSDs.

Poultry Processing Case Study (Ex. 26-1174)

    Comment: ``OSHA claims that `ergonomic solutions' at a poultry 
plant decreased recordable injuries and illnesses * * * from 10-14/100 
workers (1988-89) to 7/100 workers (1991). * * * [T]he only two notable 
dips in recordable injury rate--which includes all injuries and not 
just MSDs--occurred between 1987 and 1988, when the rate declined from 
14.0 to 10.5, and between 1989 and 1990, when there was a further drop 
from 10.5 to 7.5. The first occurrence took place before ergonomics 
began, and the second occurrence took place before the majority of the 
program was rolled out.'' (Ex. 32-241-4, p. 224) OSHA's attribution of 
the reduction in MSDs to the ergonomics program, when the reduction 
occurred prior to program implementation, and its use of total injury 
rates as if they were MSDs are ``blatant distortions of the truth.'' 
(Ex. 32-241-4, p. 224)
    OSHA's Response: This case study is a site visit report of a 
poultry slaughtering and processing plant. The injury rate history of 
this plant was as follows: 14.0 in 1987, 10.5 in 1988, 10.5 in 1989, 
7.5 in 1990, and 7.0 in 1991 (Ex. 26-1174, p. 17). The comment by 
Gibson, Dunn & Crutcher suggests that the reduction in injury rate that 
occurred in 1990 occurred prior to implemetation of most of the 
ergonomics program. However, the site visit report states clearly that 
$410,000 in capital cost was incurred for engineering controls in 1990, 
compared to $242,500 in 1991, indicating that most engineering 
improvements to address MSDs were made in 1990 (Ex. 26-1174, pp. 9-10). 
Therefore, OSHA does not agree that the 1990 injury rate reflects a 
time when most of the program had not yet been implemented. Further, 
the first drop in injury rate, which occurred in 1988, can be at least 
partly attributed to the large increase in employment in 1988 (from 950 
workers in 1987 to 1,350 workers in 1988) (Ex. 26-1174, p. 17). Because 
of the change in employment in 1988, OSHA used the injury rates from 
both 1987 and 1988 as baseline years to calculate the percent reduction 
in injury rate pre- and post-implementation (i.e., OSHA used an average 
baseline rate of 12 injuries per year). Additional evidence that the 
drop in injury rate in 1990-1991 can be attributed to the ergonomics 
program comes from other statistics provided by the facility that show 
drops in both worker absenteeism and turnover in 1990-1991 compared 
with earlier years; in contrast, there was no drop in absenteeism or 
turnover rates to accompany the drop in injury rate seen from 1987 to 
1988 (Ex. 26-1174, p 17). Therefore, OSHA finds that the decline in 
injury rate seen in the 1990-1991 time period is most likely to have 
been the result of the ergonomic improvements made in 1990 and 1991 at 
this factility.

Packaging Sugar Cubes Case Study (Ex. 26-1041, Case 41)

    Comment: OSHA attributes a 100-percent reduction of MSDs at a sugar 
cube packing operation, where the author of the study, Dr. Oxenburgh, 
stated that ``the risk of serious strain injuries to the hands and 
upper limbs has been virtually eliminated'' (citing Ex. 26-1041, p. 
230, emphasis added). ``The statement only reflects the subjective 
judgement of Dr. Oxenburgh about `risk'; he provides no actual data 
concerning actual injury experience after the change.'' (Ex. 32-241-4, 
p. 225) Further, the numbers are too small for statistical analysis, 
and ``Oxenburgh's unverified hunch about risk has no place in a 
statistical analysis.'' (Ex. 32-241-4, p. 225)
    OSHA's Response: This case study describes a sugar cube packing 
operation in which 5 employees used a tool to pack cubes tightly into 
boxes. Because of the hand posture and pressure required to operate the 
tool, injuries to the hand and upper limbs occurred in about 1 out of 4 
operators (i.e., 25 percent of workers). After implementing an 
engineering and marketing solution that allowed the cubed sugar to be 
packed loosely into bags, productivity increased to the point where 
only 2 workers were required for the packing operation. The complete 
quote partially cited by Gibson, Dunn & Crutcher from the case study 
reads as follows: ``The risk of serious strain injuries to the hands 
and upper limbs has virtually been eliminated and has led to 
considerable savings in sickness absence and workers compensation.'' 
Although no statistics are presented, this is significant because it 
demonstrates a clear benefit from the change to the process. Rather 
than representing an ``unverifiable hunch,'' as Gibson, Dunn & Crutcher 
suggest, OSHA finds it logical to conclude from Dr. Oxenburgh's 
statement that no serious injuries occurred among the two remaining 
operators because the change eliminated the forceful repetitive motion 
(i.e., pressing the sugar cubes together) responsible for the prior 
injuries.

Computer Manufacturer Case Study (Ex. 26-1068)

    Comment: OSHA attributes a 41-percent reduction in upper-extremity 
disorders in 1994-1995 and a further 50-percent reduction in 1995-1996 
to an ergonomics program. However, the program was implemented in 1991, 
after a year (1990) in which the company's upper-limb disorder rate was 
0.5 per 100 workers. This rate increased to a high of 2.5 cases per 100 
workers in 1994, after which they drop in 1995 and 1996. ``Thus, the 
reported declines in 1995 and 1996 brought the company down to 
approximately a 0.7 rate--a 40-percent increase over the experience it 
had during the last year before ergonomic interventions were 
introduced.'' (Ex. 32-241-4, p. 226, emphasis in original)

[[<strong>Page</strong> 68589]]

    OSHA's Response: Although this computer manufacturer did implement 
an ergonomics program in the early 1990s, according to the case study, 
the program began ``with a reactive approach, addressing individuals.'' 
This isolated approach could be a reason why an immediate reduction in 
upper-limb disorders was not realized. In addition, ``[p]art of the 
increase in the number of CDT cases per year [from 1990 through 1994] 
can be attributed to the company's rapid growth, which more than 
doubled during that period.'' The trend was not reversed until the 
company, beginning in 1993, ``spent at least two days a week performing 
evaluations, held mandatory ergonomic training classes for high risk 
groups including technical publications, order[ed] administration and 
customer technical phone support, and created and distributed a 16-<strong>page</strong> 
ergonomics brochure.'' Additionally, with the growth in 1994 and 1995, 
the company purchased new furniture ``allowing employees a greater 
range of postures and flexibility.'' It was this expanded and 
comprehensive approach that led to the 41 percent drop in reportable 
upper-limb disorders from 1994 to 1995 and the further decrease of 50 
percent in reportable CDT cases from 1995 to 1996 (Ex. 1068, pp. 7-8). 
Therefore, OSHA finds that the decline experienced in MSD rates 
beginning in 1995 is consistent with the company's implementation of 
ergonomic improvements that consisted of appropriate education and 
training of its workers, as well as workstation modifications.

Medical Device Manufacturer Case Study (Ex. 26-1183)

    Comment: OSHA apparently attributes a 29-percent reduction in MSD 
rates from 1990 (2.1 cases per 100 workers) to 1992 (1.5 cases per 100 
workers) to an ergonomics program (Ex. 32-241-4, p.228, footnote 857). 
However, ``the corporation did not begin to address ergonomic issues 
until 1991, did not formalize the program until 1993, and did not 
conduct training or implement the vast majority of its workplace 
modifications until 1992 or 1993. The result was a very substantial 
increase in `ergonomics incidence rate' to 2.8 [per 100 workers] in the 
first three months of 1993 from * * * pre-intervention levels.'' (Ex. 
32-241-4, p. 228)
    OSHA's Response: This case study is a site visit report to a 
manufacturer that produced suction canisters used to collect blood 
during surgical procedures. The company began to address ergonomic 
issues in 1989 (a year in which their MSD rate was 5.2 cases per 100 
workers), and first began to implement controls in 1991 (Ex. 26-1183, 
p. 2). OSHA used 1990, the first year prior to implementation of 
ergonomic controls, as the base year in its effectiveness analysis. The 
company continued to implement controls in 1992 and 1993. Since injury 
statistics were only available for the first 3 months of 1993, OSHA 
believed that a reliable injury rate could not be determined for that 
year. OSHA does not agree that the statistics available for the first 
quarter of 1993 show that the MSD rate was increasing because it 
reflected too short a period. Consequently, there are no data available 
in the report to permit an assessment of the effect of ergonomic 
interventions implemented in 1992 or 1993 at this facility. OSHA 
attributed the decline in MSD rates from 1990 to 1992 to the 
improvements made in 1991, based on the report's finding that ``[t]he 
facility believes that their ergonomics program has contributed to a 
general decrease in the plant's annual incidence rate for ergonomic-
related injuries and illnesses.'' OSHA believes that this is an 
appropriate interpretation of this study. (Ex. 26-1183, p. 10)

Vehicle Seat Assembly Case Study (Ex. 26-1076)

    Comment: This case study reported that the number of tendinitis and 
carpal tunnel syndrome cases had dropped 93 and 96 percent, 
respectively, but OSHA ignored information that the broader category of 
``strains and sprains'' increased over the same period.
    OSHA's Response: This is a case study of an automobile seat 
manufacturer that began experiencing problems with MSDs shortly after 
beginning full production. The ``slight'' increase in sprains and 
strains reported by the case study occurred during a time when the 
numbers of tendinitis and carpal tunnel syndrome cases dropped 
dramatically. According to the manufacturing manager, the increase in 
strains and sprains ``reflected the employees reporting the discomfort 
and pain [of MSDs] earlier.'' (Ex. 26-1076, p. 66) Because the increase 
in strain and sprain reports was described as ``slight'' by the 
manufacturing manager (Ex. 26-1076, p. 66), OSHA finds that the much 
larger decreases in the numbers of tendinitis and CTS cases fairly 
reflect the results achieved by the company's ergonomics program.

Aircraft Parts Manufacturer Case Study (Ex. 26-1179)

    Comment: OSHA attributes a reduction of 96.2 percent in total MSD 
cases at an aircraft parts manufacturer ``based solely on data 
referring to specific diagnosis of CTS, ignoring information * * * 
clearly stating that the total `number of reportable ergonomic injuries 
and illnesses [not just CTS] has actually increased since the 
ergonomics program began.' '' (Ex. 32-241-4, p. 232, citing Ex. 26-
1179, p. 15, emphasis in original)
    OSHA's Response: This case study is a report of a site visit 
conducted at an aircraft parts manufacturing facility. A formal 
ergonomics program was initiated in 1988, but did not have ``solid 
commitment from upper management and * * * [was] not readily accepted 
by the workforce.'' (Ex. 26-1179, p. 1) In 1991, the facility 
implemented a redesigned program following an OSHA citation, ``which 
[the program] proved to be very successful since it had the support of 
upper management and relied on hourly employees working together to 
identify and implement solutions to ergonomic problems.'' (Ex. 26-1179, 
p. 1) The facility reported that the percentage of total recordable 
injuries represented by ergonomics cases rose from 13.5 percent in 1991 
to 20 percent in 1992 (i.e., MSDs represented a larger proportion of 
all injuries and illnesses in 1992 than in 1991). This does not 
necessarily mean that the number or rate of MSDs increased during this 
period, as Gibson, Dunn & Crutcher claim. In fact, facility 
representatives stated that ``the actual number of [MSD] cases is at 
least holding steady.'' (Ex. 26-1179, p. 15) However, because the site 
visit report makes clear that there were MSD cases that occurred in the 
facility in addition to the CTS cases used by OSHA to calculate program 
effectivness, and because the report provides no statistics or other 
details on the number or rate of these cases, OSHA is no longer relying 
on this case study in its effectiveness analysis for the final rule.

Office Furniture Manufacturing Case Study (Ex. 26-1102)

    Comment: OSHA claimed a 67-percent reduction in MSD rate, 
apparently from a ``passing reference to a claimed reduction in 
``incidence rate'* * * (``incidence of what is not specificed)'' (Ex. 
32-241-4, p. 232). However, the information presented in OSHA's 
Appendix VI-2 shows a reduction only from 21 per 100 workers in 1989 to 
19 per 100 workers in 1991-1992, a change of only 9 percent ``that is 
of dubious statistical significance'' (Ex. 32-241-4, p. 232).
    OSHA's Response: In OSHA's final analysis of the effectiveness of 
ergonomics programs, OSHA is basing

[[<strong>Page</strong> 68590]]

its measure of effectiveness for this case study on the reported 9-
percent decline in MSD rate. Regarding the comment on statistical 
significance, it was not OSHA's intent to limit its analysis of case 
studies only to those studies where the reported change in MSD rate 
could be shown to be statistically significant, primarily because most 
of the case studies lacked information to perform tests of statistical 
significance. OSHA believes it important to base its analysis on all of 
the experiences reported in the set of case studies, however large or 
small the result attributed to ergonomics interventions, and not to 
limit its analysis to the small group of case studies for which tests 
of significance could be performed.

Freight Truck Terminal Operations Case Study (Ex. 26-1177)

    Comment: OSHA assumes a 46-percent decline based on a table that 
shows 13 MSDs occurred in 1989 and 7 in 1991, ``but it overlooks 
further information in adjacent sections of the report indicating that 
there have been ``no changes'' in overall * * * [MSD] incidence'' and 
that there has been no decrease in MSD-related disabilities (Ex. 32-
241-4, p. 233)
    OSHA's Response: This case study is a site visit report for a truck 
terminal operation. The site visit report was prepared in July, 1992 
and contained a table that reported numbers of MSDs occurring in 1989 
through 1991. OSHA's analysis of ergonomics intervention effectiveness 
was based on these numbers. Although the report stated that no decline 
in MSD-related disabilities had been seen, it also stated that the 
program had been recently implemented (in 1990) and ``its effectiveness 
may not yet be apparent'' (Ex. 26-1177). A follow-up telephone 
interview was conducted in January, 1994, at which time the employer 
indicated subjectively that there were no changes in MSD incidence. 
However, the employer also reported that the company ``had no hard data 
to back that up,'' and that no information was available to track 
changes in workers' compensation claims related to the ergonomics 
program (Ex. 26-1177, pp. 5-7 & 5-8). Therefore, it is clear that the 
employer had not been evaluating the performance of their program after 
1991, and therefore no conclusions can be reached regarding the 
effectiveness of the program after 1991, the last year in which OSHA 
was able to obtain data on MSD injuries. OSHA finds that the quotes 
cited by Gibson, Dunn & Crutcher are not convincing in establishing 
that the ergonomics program was ineffective in the 1989-1991 period.

Materials Handling, Electrical Utility (Ex. 26-1085)

    Comment: OSHA attributes 100-percent effectiveness to an ergonomics 
program based on a ``passing reference'' in the case study to 
eliminating 9 injuries just by getting in and out of vehicles. The 
article explains elsewhere that the total program is in its `infancy 
stage' and the overall asserted effect so far has been to reduce lost-
time injuries from more than one per 100 employees to 0.42, only part 
of which is allegedly attributable to ergonomics.'' (Ex. 32-241-4, pp. 
233-234)
    OSHA's Response: This case study is a published article describing 
the ergonomics program at a major utility company. OSHA based its 
measure of intervention effectiveness on the results of two specific 
interventions discussed in the article. These are not ``passing 
references'' but are examples of the earliest interventions implemented 
by the company:

    ``Downsizing water and ice kegs from 10 to five gallons and 
lowering their placement on trucks is one way we profited from 
ergonomic thinking right away * * * Since making the change, we've 
had no injuries associated with lifting water kegs' (Ex. 26-1085, p. 
25).
    ``[t]hrough the use of ergonomics, `we have reduced sprain 
injuries in several of our operations areas.['] For example, he 
says, `we went from nine injuries last year from just getting in and 
out of trucks and vehicles, to zero this year'' (Ex. 26-1085, p. 25)

    The article also makes clear that the ergonomics program is in its 
`infancy stage' on the corporate-wide level, i.e., that not all 
problems have been addressed at the time the article was published. For 
example, the article makes reference to workers who work at bill 
processing machines for extended periods of time and are at risk of 
developing carpal tunnel syndrome. Because the program had not yet been 
fully implemented, OSHA did not base its effectiveness measure on 
corporate-wide injury statistics (the company reported that total lost-
time injuries declined from more than 1 per 100 workers to 0.42 per 100 
workers) (Ex. 26-1085, p. 27), but instead based it on the proven 
effectiveness of the specific interventions discussed in the case 
study. After considering this comment and reviewing the case study, 
OSHA finds that this is still a reasonable approach and therefore has 
continued to include this study in its database.

Auto Air Conditioner Manufacturer Case Study (Ex. 26-1078)

    Comment: ``[OSHA] * * * recites two examples from self-interested 
company officials claiming `50%' and `100%' reductions in `total MSDs', 
while ignoring a lengthy description in the same article of 
scientifically documented experience at a different company showing 
that `job improvements' cannot be expected to translate to any 
reduction in `the number of back injury claims filed'.'' (Ex. 32-241-4, 
p. 234, citing Ex. 26-1078, p. 30)
    OSHA's Response: The ``scientifically documented experience'' 
referred to by Gibson, Dunn & Crutcher is a short article by Dr. 
Stanley Bigos, University of Washington Department of Orthopaedics, 
describing his results from the Boeing study and the role of 
psychosocial factors in low back disability. OSHA discusses both the 
Boeing study and psychosocial factors at length in the Health Effects 
section (Section V) of this preamble.

UPS Case Study (Ex. 26-1084)

    Comment: Steven Thompson, who co-authored a UPS report, ``does not 
believe that it would be legitimate to cite the article as evidence 
that ergonomic interventions pursuant to OSHA's proposal would have the 
effect that OSHA claims'' because, among other things, the article did 
not attempt to link the observed reduction in reported MSD cases to any 
particular cause or to account for the Hawthorne effect (Ex. 32-241-4, 
p. 217).
    OSHA's Response: This case study is a published report of the 
results of an ergonomics program that provided adjustable sit-stand 
workstations to UPS employees using computer stations to perform a 
variety of tasks. Benchmark data collected prior to introducing the 
sit-stand workstations included production levels, absenteeism, survey 
results on operator comfort, and injury and illness rates. The study 
reported that injury and illness rates declined by more than 50 percent 
in the year after introducing the new workstations, and that there were 
no costs associated with the remaining injuries. In addition, the study 
reported an average reduction of 62 percent in symptoms of discomfort. 
There was no change in production level or absenteeism, which the 
authors believed may be partly explained by poor weather at the 
beginning [winter] of the follow-up year. In an attachment to Gibson, 
Dunn & Crutcher's submission, Mr. Thompson of the UPS, one of the co-
authors of the study, stated that the article in question ``did not

[[<strong>Page</strong> 68591]]

engage in the type of individual cause-and-effect analysis that would 
be necessary to link the observed reduction in reported MSD cases to 
the sit-stand workstation as opposed to other non-ergonomic factors.'' 
Mr. Thompson identifies several factors relating to the moving of the 
office location to a new building from an ``old crowded building.'' 
``The new building had better lighting, ventilation, temperature 
control, windows, modular doors, and an overall open environment.'' 
According to Mr. Thompson's statement, the authors of the report ``did 
not account for the Hawthorne effect in light of these factors'' and 
other factors, some of which are often, in fact, considered engineering 
and administrative ergonomic changes.
    In the original article, published as part of the Proceedings of 
the Human Factors and Ergonomics Society 38th Annual Meeting, the 
authors, Nerhood and Thompson, do discuss moving employees to a new 
building to provide a better working environment and providing 
adjustable sit-stand workstations for those employees ``with the 
heaviest risk of discomfort'' (Ex. 26-1084, p. 668). The authors also 
acknowledge the possibility of a Hawthorne effect being a 
``contributing factor to any production changes'' (Ex. 26-1084, p. 671, 
emphasis added) because ``the study cycle was too short to hypothesize 
long term results [on production]'' (Ex. 26-1084, p. 668); however, 
nowhere in the article do the authors indicate that the Hawthorne 
effect was or could have been responsible for the observed drop in 
injury rate or operator discomfort. Despite the non-ergonomic changes 
in the work environment associated with the new building, the authors 
concluded that ``[t]he commitment from all groups involved was the key 
to the successful implementation of the ergonomics program and 
installation of the new adjustable sit-stand workstations'' (Ex. 26-
1084, p. 671, emphasis added). Thus, in the original study, the authors 
attribute the reduction in operator discomfort and injury rate to the 
ergonomic intervention. Because of the strong conclusion made in the 
original study, OSHA finds it appropriate to retain this study in its 
data set.
    In their post-hearing brief, Gibson, Dunn & Crutcher describe the 
testimony of several witnesses as examples of ergonomic interventions 
that failed (Ex. 500-197, pp. II-20 to II-23). The following summarizes 
these examples and OSHA's response to Gibson, Dunn & Crutcher's 
interpretation of the testimony.

Carl Zipfel, Seton Company

    Comment: ``Carl Zipfel, Director of Environmental Compliance and 
Safety for Seton Company, a supplier of automotive interior leather, 
testified about his company's efforts to help employees who were 
stretching leather hides over a table and began to complain about 
shoulder problems. Seton Company tried every measure that OSHA could 
expect. * * * After all of these efforts no improvements were 
observed.'' (Ex. 500-197, p. II-20)
    OSHA's Response: In his testimony at the informal hearing, Mr. 
Zipfel provided the following information, which explains why no 
improvements were observed:
    <bullet> Under questioning, Mr. Zipfel agreed that Seton had no 
ergonomics program that would either meet the definition of an existing 
program under the grandfather clause or that would meet the 
requirements for an ergonomics program in the standard as proposed (Tr. 
3051-3052).
    <bullet> Although Seton has investigated incidents of MSD symptoms, 
the company has no one trained to do a job hazard analysis (Tr. 3066).
    <bullet> Mr. Zipfel stated that Liberty Mutual and Penn State 
analyzed jobs and prepared reports for Seton regarding the leather 
stretching problem, but he never discussed what remedies were 
recommended in those reports or whether Seton tried to implement any of 
the suggested remedies (Tr. 3059).
    There is no evidence in Mr. Zipfel's testimony that indicates that 
Seton had implemented engineering or administrative controls to address 
the problem at the leather stretching station; thus, OSHA does not 
agree that Seton ``tried every measure that OSHA could expect,'' and 
finds Mr. Zipfel's testimony unpersuasive evidence for the failure of 
ergonomics interventions.

Robert Willoughby, Boral Bricks

    Comment: After implementing Boral's insurance company's suggestion 
of automating certain jobs in some of his facilities, the ``injury 
rates are not significantly better than [at] the plants that [have ] 
more manual [jobs]'' (Ex. 500-197, pp. II-20 to II-21, citing Tr. 
7776).
    OSHA's Response: Mr. Willoughby stated that Boral's insurance 
company recommended the automation of two jobs: setting green, unfired 
brick on kiln cars and hand packaging the finished product (Tr. 7745-
7746). It is clear from Mr. Willoughby's description that the automated 
equipment has contributed significantly to reduction in exposure to 
risk factors. For example, one automated piece of equipment that 
removes brick from the kiln required employees to stand on top of the 
cars and bend below knee level to lift bricks and place them into 
trays. Employees suggested and implemented an approach that prevented 
the need to bend below knee level but still required workers to lift 
bricks at waist height using an extended reach (Tr. 7787-7788). In this 
example, Mr. Willoughby commented without providing evidence, that 
``what we have accomplished [from eliminating the deep bend] is going 
to be offset by the fact of extending the arms'' (Tr. 7788). On the 
other hand, Mr. Willoughby provided two examples of job fixes that he 
believed were worthwhile: one involved using pallets to package brick 
in smaller increments for easier handling, and the other used metal 
strapping bands and magnetic lifts to reduce the need for manual 
handling (Tr. 7790-7791). Regarding Boral's overall ergonomics program, 
Mr. Willoughby testified that he developed a written program a few 
years ago, but it has not been fully implemented; as part of their 
overall safety and health program, Boral currently provides information 
on MSDs, trains employees in recognizing potential hazards, and has 
safety and health committees at its facilities, some of which actively 
inspect the workplace and propose improvements (Tr. 7785-7786). Because 
of the continued exposure of employees to risk factors in jobs that had 
been automated, and Mr. Willoughby's testimony about the value of some 
of the interventions implemented by Boral, OSHA does not agree that the 
experience of Boral Bricks represents a failed ergonomics effort.

Mary Banks, Social Security Administration

    Comment: Ms. Banks, a key operator who was diagnosed with 
DeQuervain's syndrome in 1998, testified that her symptoms have not 
improved at all and have gotten progressively worse in the year since 
she was provided with a new workstation. (Ex. 500-197, pp. II-21 citing 
Tr. 10664).
    OSHA's Response: Ms. Banks described the new furniture as ``too 
little, too late'' for her (Tr. 10690). Her testimony indicated that 
her condition was quite severe:

    This impairment is devastating at times. I feel pain most of the 
time. It is difficult for me to pick up anything that weighs more 
than three pounds. It is hard to reach in back of me, to clap my 
hands even in church. It is difficult to open an envelope. I cannot 
pick up my grandbaby without fear of dropping him. (Tr. 10666-10667)

[[<strong>Page</strong> 68592]]

    In addition, Ms. Banks was also diagnosed with tendinitis (Tr. 
10667), and used only able to use her right hand to key at the time of 
the hearing (Tr. 10695). She concluded her testimony by stating that, 
if the ergonomics program had been in place, she would not have 
developed her condition (Tr. 10667). OSHA does not find that the lack 
of improvement in Ms. Banks serious upper-extremity disorder after she 
was issued a new workstation (details of which were not described 
during her testimony) constitutes adequate evidence that properly 
designed computer and VDT workstations are ineffective in reducing the 
risk of developing MSDs among healthy workers.

Dr. Charles Roadman for American Health Care Association

    Comment: ``Dr. Roadman testified, however, that `everything that we 
have tried has not decreased the incidents of [carpal tunnel 
syndrome]''' (Ex. 500-197, p. II-21 citing Tr. 4448).
    OSHA's Response: Dr. Roadman was not discussing programs that 
members of the American Health Care Association (AHCA) had instituted 
to handle carpal tunnel syndrome, but was referring to an Air Force 
program he had instituted years before when he had been Surgeon General 
of the Air Force (Tr. at 4448). Although he felt that the interventions 
he had seen tried with computer users did not seem qualitatively to 
reduce the incidence of CTS, he also stated that ``that doesn't mean we 
should not keep trying to do that'' (Tr. 4448). In general, Dr. Roadman 
has positive things to say about ergonomic programs. He discusses 
favorably programs that the AHCA created with the assistance of OSHA 
(Tr. 4355-6). He also stated that ergonomic programs ``can be very 
positive if all the factors are in place and you have good cooperation 
* * * between labor and management and the assessment process. Yes, 
they can be very successful'' (Tr. 4436).
    From the examples above, OSHA is not convinced that the testimony 
cited by Gibson, Dunn & Crutcher demonstrate that ergonomic 
interventions are ineffective, as a general matter.
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</PRE>