دانلود رایگان ترجمه مقاله عوامل استرس زای ارگونومیک و اختلالات عضلانی اسکلتی بالاتنه در تولید خودرو (نشریه BMJ 2004)

عوامل استرس زای ارگونومیک و اختلالات عضلانی اسکلتی بالاتنه در تولید خودرو: مطالعه ادامه دار یک ساله

Ergonomic stressors and upper extremity musculoskeletal disorders in automobile manufacturing: a one year follow up study

Aims: To estimate the one year cumulative incidence and persistence of upper extremity (UE) soft tissue disorders, in a fixed cohort of automotive manufacturing workers, and to quantify their associations with ergonomic exposures.

Methods: At baseline and at follow up, cases of UE musculoskeletal disorders were determined by interviewer administered questionnaire and standardised physical examination of the upper extremities. The interview obtained new data on psychosocial strain and updated the medical and work histories. An index of exposure to ergonomic stressors, obtained at baseline interview, was the primary independent variable. Cumulative incidence and persistence of UE disorders (defined both by symptoms and by physical examination plus symptoms) were analysed in relation to baseline ergonomic exposures, adjusting for other covariates. The incidence of new disorders was modelled using multivariate proportional hazards regression among workers who were not cases in the first year and the prevalence on both occasions was modelled by repeated measures analysis.

Results: A total of 820 workers (69% of eligible cohort members) was examined. Follow up varied slightly by department group but not by baseline exposure level or other characteristics. Among the non-cases at baseline, the cumulative incidence of UE disorders was 14% by symptoms and 12% by symptoms plus examination findings. These rates increased with index of physical exposures primarily among subjects who had the same jobs at follow up as at baseline. Increased exposure during follow up increased risk of incidence. The persistence of UE disorders from baseline to follow up examination was nearly 60% and somewhat associated with baseline exposure score.

Conclusions: These longitudinal results confirm the previous cross sectional associations of UE musculoskeletal disorders with exposure to combined ergonomic stressors. The exposure-response relation was similar for incident cases defined by symptoms alone and those confirmed by physical examination. View Full Text

T he epidemiological literature on musculoskeletal disorders (MSDs) in relation to occupational exposures consists primarily of cross sectional rather than prospective studies.1–3 Until recently there have been few longitudinal studies of occupational risk factors for upper extremity MSDs, and many of those addressed psychosocial stressors exclusively. The cross sectional literature documents numerous associations with physical exposures, but methodological concerns about these studies include the temporal relation of exposure to outcomes; information bias, especially when symptoms and exposures are collected simultaneously by self report (common instrument bias); over-representation of long duration cases (length biased sampling); and underestimation of effect due to potential selection bias (‘‘healthy worker effect’’).4 Further, knowledge remains sparse as to the factors that predict recovery or persistence among workers who continue in their jobs after onset of a musculoskeletal disorder.5

In a cross sectional study of ergonomic stressors and upper extremity musculoskeletal disorders (UE MSDs) in automotive manufacturing, 1314 workers had been surveyed in selected production areas of one engine plant and one stamping plant.6 Upper extremity, shoulder, and wrist/hand disorders were all associated with exposure to physical ergonomic stressors in the subjects’ usual jobs. A follow up survey was conducted about one year later. The primary objective was to examine whether the same occupational ergonomic exposures associated with UE disorders cross sectionally were also predictors of occurrence of UE disorders among previous non-cases and of MSD persistence among baseline cases, thus resolving the temporal direction of the previously reported associations.