[Co-occurrence of musculoskeletal disorders and influence factors among Chinese auto workers]

To analyze the prevalence and risk factors of multiple musculoskeletal disorders (MSDs) in auto workers and the associations between MSDs at different sites.

A cross-sectional survey was conducted in 3998 workers, who were selected from a Chinese auto corporation by cluster random sampling, using the revised Nordic MSDs standard questionnaire; 3800 completed questionnaires were returned. Multinomial logistic regression analysis was performed to assess the risk factors for multiple MSDs. The logbinomial model was used to calculate the prevalence ratios (PRs) of MSDs at different sites and evaluate the associations between MSDs at different sites.

Of the 3800 subjects, 2452 (64.5%) had MSDs at two or more sites, and 469 (12.3%) had MSDs at one site. The PRs varied from 1.5 to 6.7, with significant differences among different sites (P < 0.01). Relatively close associations were found between the MSDs at neck and shoulders, back and shoulders/waist, elbows and wrists/hands, waist and neck, wrists/hands and waist, hip and waist, knees and waist, and ankles/feet and elbows. The multinomial logistic regression analysis indicated that the highest risk factor for MSDs was poor posture, including often working in an uncomfortable posture, neck bending forward, and neck twisting (ORs = 3.39, 1.93, and 1.38), followed by labor organization, in which break between tasks could decrease the risk of MSDs at three or more sites to 31%, staff shortage, which could increase the risk of MSDs by 75%, and pushing and pulling heavy objects (> 20 kg) (OR = 1.76).

Most auto workers with MSDs have multiple sites affected, and there are high associations between the MSDs at different sites. The major risk factors for multiple MSDs in auto workers include poor posture, labor organization, and heavy physical labor.