앉은 자세에서 글쓰기 작업 시 구부정한 자세와 곧게 세운 자세에 따른 목과 체간 신전근의 근활성도 변화 비교

Comparison of Postural Changes between Slump and Upright Sitting Posture on Neck and Trunk Motion and Erector Spinae Muscles Activity during Writing Task

Objective: The purpose of this study was to investigate whether slump and upright posture affect on the neck and trunk range of motion, and these erector muscle activity during writing task. Method: All participants performed a writing task at the same desk and chair in the upright and slump sitting posture. Motion analysis system and surface electromyogram (EMG) were used to analyzing the neck and trunk motion and spine erector muscles activity. Paired t-tests were used to compare neck and trunk angles and both muscles activity. Results: There are significant differences in neck flexion-extension, lateral flexion, and rotation (p<.05). Trunk flexion, rotation was significantly greater in slump posture. In both cervical and lumbar erector muscles, there are significant differences in slump and upright posture (p<.05). Lumbar muscle symmetry ratio was significantly higher in slump than upright sitting posture (p<.05). Conclusion: Slump sitting posture may lead to more joint motion and muscle activity in neck and trunk joints and spine erector muscles. These findings suggest that maintain the upright posture would be more effectiveness to joints and muscles for prevent musculoskeletal disorders.