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Abstract
Muscle pain (myalgia) represents a large portion of work-related musculoskeletal disorders (WRMSD). The purpose of this study was to further examine the effects of cycle time, duty cycle, and load on the amount of rest taken by the muscles during a highly repetitive task. Ten female participants performed a simulated repetitive screw driving task with a T-handle grip against a vertical surface. Three torque levels (1, 1.75 & 2.5 Nm), 3 duty cycles (25, 50 & 75%) and 3 rest times per cycle (1, 2.5 & 5s) were tested in a full factorial design. The electromyographic signal (EMG) from 4 upper limb muscles of the right side were collected using standard electrode placements (flexor digitorum superficialis, extensor carpi radialis brevis, biceps brachii and trapezius). The results suggest that rest must be given in a large enough block to be optimally utilized for the load and duty cycle requirements of a task. (Abstract shortened by UMI.)
