Conclusions and Recommendations
Based on a comprehensive review and analysis of the evidence, as described above, the panel has reached the following conclusions:
The panel concludes that there is a clear relationship between back disorders and physical load; that is, manual material handling, load moment, frequent bending and twisting, heavy physical work, and whole-body vibration. For disorders of the upper extremities,
1. Musculoskeletal disorders of the low back and upper extremities are an important national health problem, resulting in approximately 1 million people losing time from work each year. These disorders impose a substantial economic burden in compensation costs, lost wages, and productivity. Conservative cost estimates vary, but a reasonable figure is about $50 billion annually in work-related costs.
2. Estimates of incidence in the general population, as contrasted with the working population, are unreliable because more than 80 percent of the adult population in the United States is in the workforce.
3. Because workplace disorders and individual risk and outcomes are inextricably bound, musculoskeletal disorders should be approached in the context of the whole person rather than focusing on body regions in isolation.
4. The weight of the evidence justifies the identification of certain work-related risk factors for the occurrence of musculoskeletal disorders of the low back and upper extremities.
repetition, force, and vibration are particularly important work-related factors.
Work-related psychosocial factors recognized by the panel to be associated with low back disorders include rapid work pace, monotonous work, low job satisfaction, low decision latitude, and job stress. High job demands and high job stress are work-related psychosocial factors that are associated with the occurrence of upper extremity disorders.
5. A number of characteristics of the individual appear to affect vulnerability to work-related musculoskeletal disorders, including increasing age, gender, body mass index, and a number of individual psychosocial factors. These factors are important as contributing to and modifying influences in the development of pain and disability and in the transition from acute to chronic pain.
6. Modification of the various physical factors and psychosocial factors could reduce substantially the risk of symptoms for low back and upper extremity disorders.
7. The basic biology and biomechanics literatures provide evidence of plausible mechanisms for the association between musculoskeletal disorders and workplace physical exposures.
8. The weight of the evidence justifies the introduction of appropriate and selected interventions to reduce the risk of musculoskeletal disorders of the low back and upper extremities. These include, but are not confined to, the application of ergonomic principles to reduce physical as well as psychosocial stressors. To be effective, intervention programs should include employee involvement, employer commitment, and the development of integrated programs that address equipment design, work procedures, and organizational characteristics.
9. As the nature of work changes in the future, the central thematic alterations will revolve around the diversity of jobs and of workers. Although automation and the introduction of a wide variety of technologies will characterize work in the future, manual labor will remain important. As the workforce ages and as more women enter the workforce, particularly in material handling and computer jobs, evaluation of work tasks, especially lifting, lowering, carrying, prolonged static posture, and repetitive motion, will be required to guide the further design of appropriate interventions.
1. The consequences of musculoskeletal disorders to individuals and society and the evidence that these disorders are to some degree prevent-
able justify a broad, coherent effort to encourage the institution or extension of ergonomic and other preventive strategies. Such strategies should be science based and evaluated in an ongoing manner.
The injury or illness coding system designed by the Bureau of Labor Statistics should be revised to make comparisons possible with health survey data that are based on the widely accepted ICD-9 and ICD-10 coding systems.
The characterization of exposures associated with musculoskeletal disorders should be refined, including enhanced quantification of risk factors. Currently, exposure is based only on characterization of sources of injury (e.g., tools, instruments, equipment) and type of event (e.g., repetitive use of tools) derived from injury narratives.
Information collected from each employer should contribute to specificity in denominators for jobs including job-specific demographic features in the workplace, such as age, gender, race, time on the job and occupation.
Injury and illness information should include, in addition to the foregoing demographic variables, other critical variables, such as event, source, nature, body part involved, time on job, and rotation schedule. Combining these with the foregoing variables would, with appropriate denominator information, allow calculation of rates rather than merely counts or proportions, as is now the case for all lost-workday events.
Resources should be allocated to include details on non-lost-workday injuries or illnesses (as currently provided on lost-workday injuries) to permit tracking of these events in terms of the variables now collected only for lost-workday injuries (age, gender, race, occupation, event, source, nature, body part, time on job).
To upgrade and improve passive industry surveillance of musculoskeletal disorders and workplace exposures, the National Institute
2. To extend the current knowledge base relating both to risk and effective interventions, the Bureau of Labor Statistics should continue to revise its current data collection and reporting system to provide more comprehensive surveillance of work-related musculoskeletal disorders.
3. The National Center for Health Statistics and the National Institute for Occupational Safety and Health should include measures of work exposures and musculoskeletal disorder outcomes in ongoing federal surveys (e.g., the National Health Interview Surveys, the National Health and Nutritional Examinations), and NIOSH should repeat, at least decennially, the National Occupational Exposure Survey.
To provide more active surveillance opportunity, the National Institute for Occupational Safety and Health should develop a model surveillance program that provides ongoing and advanced technical assistance with timely, confidential feedback to participating industries.
for Occupational Safety and Health should develop adaptable surveillance packages with associated training and disseminate these to interested industries.
4. The National Institute for Occupational Safety and Health should take the lead in developing uniform definitions of musculoskeletal disorders for use in clinical diagnosis, epidemiologic research, and data collection for surveillance systems. These definitions should (1) include clear and consistent endpoint measures, (2) agree with consensus codification of clinically relevant classification systems, and (3) have a biological and clinical basis.
5. In addition to these recommendations, the panel recommends a research agenda that includes developing (1) improved tools for exposure assessment, (2) improved measures of outcomes and case definitions for use in epidemiologic and intervention studies, and (3) further quantification of the relationship between exposures and outcomes. Also included are suggestions for studies in each topic area: tissue mechanobiology, biomechanics, psychosocial stressors, epidemiology, and workplace interventions. The research agenda is presented in Chapter 12.
Because of the importance of continued data collection and research to further elucidate the causes and prevention of musculoskeletal disorders of the low back and upper extremities, the panel believes it would be useful for relevant government agencies, including the National Institute for Occupational Safety and Health, the Occupational Safety and Health Administration, and the National Institute of Arthritis and Musculoskeletal and Skin Diseases to consider the following program initiatives.
Developing new mechanisms and linkages among funding agencies (e.g., the National Institute for Occupational Safety and Health,
1. Expanding research support and mechanisms to study musculoskeletal disorders in terms of risk factors at work, early detection, and effective methods of prevention and their cost effectiveness. Some examples include:
Creating mechanisms to stimulate collaboration and cross-training of researchers in the basic and applied sciences directly relevant to work-related musculoskeletal disorders.
Developing mechanisms to promote research jointly conducted by industry and the relevant academic disciplines on work-related musculoskeletal disorders.
the National Institute of Arthritis and Musculoskeletal and Skin Diseases) to expand ongoing basic research on relevant tissues (e.g., skeletal muscle, tendon, peripheral nerve) to promote study of those parameters that are directly relevant to work-related musculoskeletal disorders.
Establishing a database of and mechanism for communicating “best practices.”
Providing incentives for industry and union cooperation with due regard for proprietary considerations and administrative barriers.
Encouraging funding for such studies from industry, labor, academia, and government sources.
2. Expanding considerably research training relevant to musculoskeletal disorders, particularly with relation to graduate programs in epidemiology, occupational health, occupational psychology, and ergonomics, to produce additional individuals with research training.
3. Expanding education and training programs to assist workers and employers (particularly small employers) in understanding and utilizing the range of possible workplace interventions designed to reduce musculoskeletal disorders. In addition, consideration should be given to expanding continuing education (e.g., NIOSH Education and Research and Training Projects) for a broad range of professionals concerning risk factors that contribute to musculoskeletal disorders inside and outside the workplace.
4. Developing mechanisms for cooperative studies among industry, labor unions, and academia, including:
5. Revising administrative procedures to promote joint research funding among agencies.
6. Encouraging the exchange of scientific information among researchers interested in intervention research through a variety of mechanisms. Areas that could benefit include the development of (1) research methodologies, especially improved measurement of outcomes and exposures, covariates, and costs and (2) uniform approaches, allowing findings to be compared across studies. In addition, periodic meetings
should be considered to bring together individuals with scientific and “best practices” experience.
In order to implement these suggestions, the scope of research and training activities of the National Institute for Occupational Safety and Health would have to be expanded and funding significantly increased. In addition, other federal agencies (e.g., the National Institute of Arthritis and Musculoskeletal and Skin Diseases, the National Institute of Mental Health) would have to broaden their support of research programs examining musculoskeletal disorders and the workplace. In the panel's view these steps deserve serious consideration.