Investigation of upper limb muscle activity during repetitive light task using surface electromyography (SEMG)

A study was conducted to investigate the effect of upper limb muscles during repetitive task consisted of three hand-arm directions: 30°, 90°, and 150°. The aims of this study were to investigate muscle activity during repetitive task, to compare muscle activity between genders and to determine the correlation between muscles and time. Biceps brachii, anterior deltoid, and upper trapezius muscles were identified as a significant muscle in the repetitive light task experiment. Surface electromyography (SEMG) measurements for each muscle mentioned above were taken from ten subjects in the duration of one hour experiment. The results indicated that anterior deltoid is the highest affected muscle by the tasks. There was a significantly increase of root mean square (RMS) between the beginning and the end of the experiment, that indicated muscle fatigue. However there were no significant differences of RMS between male and female subjects, and between 30°, 90°, and 150° hand-arm directions.