Abstract
BACKGROUND: Many people work in a sitting position where they have to use their upper extremities and hands. Muscle activity in sitting position is affected by the chair height of, the height of the worktable, and the distance to the working target. OBJECTIVE: The purpose of this study is to investigate differences in muscle activity between men and wemen at different chair heghts and working distances. METHODS: Surface electromyography (EMG) was employed to determine the muscle activity of the upper limbs and the trunk, while an arm-stretching task was performed in a sitting position. RESULTS: Women's muscle activity was higher than that of men in most muscles as the chair height and working distance changed. CONCLUSIONS: As the height of the chair or the working distance was changed, muscle activity was greater in women than in men for most of the muscles analyzed. Under the same conditions, women may feel more muscle fatigue than men, so it is necessary to consider gender in the working environment.