Abstract
OBJECTIVES: The purpose of this study was to evaluate the association between job characteristics and musculoskeletal pain among shift workers employed at a 24-hour poultry processing plant in Southern Brazil. METHODS: This was a cross-sectional study of 1,103 production line workers aged 18-52 years. The job characteristics of interest were shift (day/night), shift duration, and plant sector ambient temperature. Musculoskeletal pain was defined as self-reported occupational-related pain in the upper or lower extremities and trunk, occurring often or always, during the last 12 months. RESULTS: The mean (SD) participant age was 30.8 (8.5) years, and 65.7% of participants were women. The prevalence of musculoskeletal pain was greater among female participants than male participants. After adjustment for job characteristics and potential confounders, the prevalence ratios (PR) of lower extremity musculoskeletal pain among female workers employed in extreme-temperature conditions those working the night shift, and those who had been working longer on the same shift were 1.75 (95% CI 1.12, 2.71), 1.69 (95% CI 1.05, 2.70), and 1.64 (95% CI 1.03, 2.62), respectively. In male workers, only extreme-temperature conditions showed a significant association with lower extremity musculoskeletal pain (PR=2.17; 95% CI 1.12, 4.22) after adjustment analysis. CONCLUSIONS: These findings suggest a need for implementation of measures to mitigate the damage caused by nighttime work and by working under extreme temperature conditions, especially among female shift workers, such as changing positions frequently during work and implementation of rest breaks and a workplace exercise program, so as to improve worker quality of life.