Upper extremity musculoskeletal symptoms and disorders among a cohort of women employed in poultry processing

We evaluated musculoskeletal problems among women employed in poultry processing in rural northeastern North Carolina. Poultry processing is the largest single employer of women in this economically depressed region with a black majority population.

Data were collected from a cohort of 291 women through interviews and physical exams conducted at 6-month intervals over 3 years. An index of cumulative exposure, based on departmental rankings and work history, was the primary exposure variable. Other variables of interest included work organization factors, other medical conditions, depressive symptoms, children in the home, and hand intensive home activities. Poisson regression with generalized estimating equations was used to evaluate factors associated with occurrences of upper extremity symptoms and incidence of disorders at follow-up.

Symptoms making it difficult to maintain work speed or quality and depressive symptoms at baseline were associated with symptoms at follow-up; age, being overweight, and job insecurity at baseline were associated with incident disorders. After considering these factors, the exposure response pattern was J-shaped with risk decreasing in the second quartile of cumulative exposure and then going steadily up; the effect was stronger for disorders.

The pattern of risk is consistent with onset of early musculoskeletal problems among women new to the industry followed by a later increase with continued exposure. Among this highly exposed population, the effects of depressive symptoms and work organization factors were diminished when cumulative exposure was considered, illustrating the contextual nature of the complex relationships between physical work exposures and psychosocial factors.