Occupational physical activity and long-term risk of musculoskeletal symptoms: a national survey of post office pensioners.

The objective of this work was to address the relationship between physical activity in the workplace and subsequent musculoskeletal pain syndromes. We performed a survey of 5,042 men and women aged 70-75 years, selected from the retirement population of a large national employer (the post office). Subjects were sent a short postal questionnaire enquiring about all occupations held for at least 1 year, the physical activities performed in those jobs, and about recent rheumatic symptoms. The 1-month period prevalence of rheumatic symptoms ranged from 19.9% for hip pain or stiffness in men to 50% for knee pain or stiffness in women. Symptoms were more common in women than men at all sites and there were significant (P < 0.001) associations between symptoms at different sites. Obesity was significantly (P < 0.001) associated with the risk of pain or stiffness at the knee and hip. Prolonged occupational exposure (20+ years) to heavy lifting was associated with hip pain (RR = 1.5; 95% CI = 1.2-1.8); and prolonged exposure to working with arms elevated was associated with an increased risk of shoulder pain (RR = 1.4; 95% CI = 1.2-1.6). Tall stature (P = 0.003) and heavy lifting (P < 0.001) were both associated with increased risks of low back pain among men. This survey confirms the high prevalence of musculoskeletal symptoms observed in previous population-based studies. Associations between occupational activities and musculoskeletal symptoms were specific for activity type and skeletal site involved. Our results imply that the adverse effects of these occupational activities can be found many years after cessation of exposure.