musculoskeletal disorders, including factors that can contribute to such disorders, and strategies for intervention to ameliorate or prevent them. Approximately 110 leading scientists were invited by the steering committee to participate in the workshop, and 66 were able to attend. The attendees represented the fields of orthopedic surgery, occupational medicine, public health, epidemiology, risk analysis and decision making, ergonomics, and human factors (see Appendix A). Several attendees presented prepared papers; many others presented oral and written responses to the papers or comments on the field of inquiry. Two criteria guided the selection of invitees: that they are involved in active research in the area and that the group, overall, represent a wide range of scientific disciplines and perspectives on the topic.
In designing the workshop, the steering committee considered several approaches to framing the topics. After careful consideration, we chose not to have the presentations focus on specific parts of the body and associated musculoskeletal disorders. Rather, we organized our examination of the evidence—and the workshop discussions (see agenda, Appendix B)—to elucidate the following sets of relationships between factors that potentially contribute to musculoskeletal disorders: (1) biological responses of tissues (muscles, tendons, and nerves) to biomechanical stressors; (2) biomechanics of work stressors, considering both work and individual factors, as well as internal loads; (3) epidemiological perspectives on the contributions of physical factors; (4) non-biomechanical (e.g., psychological, organizational, social) factors; and (5) interventions to prevent or mitigate musculoskeletal disorders, considering the range of potentially influential factors. Our belief was that this approach would provide a framework for reviewing the science base for each set of relationships, as well as the wider interactions among the sets. This approach allowed us to take advantage of both basic and applied science and a variety of methodologies, ranging from tightly controlled laboratory studies to field observations. As a result, we considered sources of evidence that extend well beyond those provided by the epidemiological literature on which the public discussion has focused.
Discussions in each of five of the topic areas (all but topic 4) revolved around a paper commissioned for the workshop and comments of invited discussants; a panel format was used to address the epidemiology of physical factors (topic 4), given the availability of recent reviews of literature on this topic.
The next section presents a conceptual framework integrating the factors thought to be related to the occurrence of musculoskeletal disorders. We used this framework to select and organize topics covered in the workshop.
Figure 1 outlines a broad conceptual framework, indicating the roles that various work and other factors may play in the development of musculoskeletal disorders. This framework serves as a useful heuristic to examine the diverse literatures associated with musculoskeletal disorders, reflecting the role that various factors—work procedures, equipment, and environment; organizational factors; physical and psychological factors of individuals; non-work-related activities; organizational factors; and social factors—can play in their development. Its overall structure suggests the physiological pathways by which musculoskeletal disorders can occur or, conversely, can be avoided.