A study on posture analysis of assembly line workers in a manufacturing industry

Abstract

Objective: In order to reveal and analyze the feature of surface electromyography (sEMG) signal and assembler’s posture of repetitive work, assembler’s posture and electrical manifestations of localized muscles was collected by using the inertial motion capture technology and sEMG during the work. Methods: Six male workers were chosen in laser lettering workshop of a medical equipment manufacturing industry. They performed repetitive pull-and-push operation, meanwhile, sEMG and posture signal in 10 min period was collected at the beginning and end of work. Results: The MFs of LST, LBB and LFCR were significantly lower at the beginning than at the end of work, while the RMSs of LST, LBB and LFCR were significantly higher at the beginning than at the end of work. And the differences of LST between the beginning and the end of work was most distinct. Keeping fixed joint angle for a long time had a greater effect on muscle fatigue, and the result was statistically significant (P < 0.05). Conclusions: The fatigue strength of muscle increased significantly with repetitive push-and-pull operation of workers for a long time, especially of the shoulder; And fatigue was easily caused by keeping fixed joint angle for a long time.