Fundamental Study on Comprehensive Evaluation of Workload Based on Electromyography and Joint Angle

Abstract

Proposed here is a comprehensive evaluation of workload and a procedure for determining a recommended range for workplace design problems. The comprehensive workload evaluation was formulated as a multi-objective optimization problem. The proposed method was applied to the pushing task that applied a force perpendicularly to the frontal plane, and the validity of the proposed method was examined.The horizontal position (i.e. the left, middle, and right) and the vertical position (i.e. the hip height, elbow height, and shoulder height) were the design variables, and eight surface electromyograms (EMGs) and twelve joint angles were measured. The measurement result shows that there is a trade-off among the EMGs and joint angles. In addition, the optimum solution for all participants is determined. It is found that the optimum horizontal positions of the participants are gathered around a right position, while the optimum vertical positions of them have a wide distribution. Moreover, the comprehensive workload indicator for the participants was constructed, and the indicator shows that the range from the middle to the right and the hip to the elbow provides relatively low workloads.