Estimated costs associated with lost days and compensation claims related to musculoskeletal disorders - including back pains and repetitive motion injuries - range from $13 billion to $20 billion annually. This is a serious national problem that has spurred considerable debate about the causal links between such disorders and risk factors in the workplace. This book presents a preliminary assessment of what is known about the relationship between musculoskeletal disorders and what may cause them. It includes papers and a workshop summary of findings from orthopedic surgery, public health, occupational medicine, epidemiology, risk analysis, ergonomics, and human factors. Topics covered include the biological responses of tissues to stress, the biomechanics of work stressors, the epidemiology of physical work factors, and the contributions of individual, recreational, and social factors to such disorders. The book also considers the relative success of various workplace interventions for prevention and rehabilitation.