[Association between occupational stress and musculoskeletal disorders in lower extremity]

To explore the relationship between occupational stress and musculoskeletal disorders in lower extremity.

The cross-sectional study was used to investigate 5338 workers in 13 factories and companies for prevalence of musculoskeletal disorders in lower extremity, working postures and occupational stress were investigated with questionnaires for past year. Perceived occupational stress was evaluated by the Chinese version of the Job Content Questionnaire (JCQ) and Effort-Reward Imbalance (ERI) Model Questionnaire. Logistic regression analyses were conducted to estimate the associations between occupational stress and prevalence of musculoskeletal disorders in lower extremity.

In the main dimensions of job strain and ERI model, physical demands and effort were risk factors of hip disorders, but job control was a protective factor of hip disorders. When job strain and ERI model scales were analyzed simultaneously, only physical demands were risk factor of hip disorders. When job strain and the effort-reward imbalance were computed by creating four independent categories, job strain was a risk factor of hip disorders, ERI was a risk factor of hip and knee disorders. The risk of imbalance between job strain and effort-reward the protective effect of job control increased with the disorder regions. According to continuous variable analysis, job strain by calculated with physical demands was risk factor of hip disorders, continuous ERI variable was risk factor of hip and knee disorders.

Occupational stress is associated significantly with musculoskeletal disorders in lower extremity. The control of occupational stress and increase of job control should be considered for preventing the musculoskeletal disorders in lower extremity.