Musculoskeletal Disorder Risk Associated with Auto Rotation Angle during an Assembly Task

Abstract

The purpose of this study was to quantify how musculoskeletal disorder exposure risk changes in an auto assembly task as a function of car body rotation. Twelve subjects participated in the study. There were three car body angles including 1) zero or standard, 2) forty-five degrees and 3) ninety degrees from horizontal. Musculoskeletal exposure included spine loads, spine posture, shoulder posture, neck posture and wrist posture, as well as normalized electromyography of the shoulder and neck. The results showed that musculoskeletal disorder exposure risk decreased as the car was rotated to forty-five degrees and further decreased as the car was rotated to ninety degrees. Thus, rotating the car body reduces musculoskeletal exposure which in turn may reduce the risk of musculoskeletal disorders. It should be noted that the results may vary with other assembly tasks.