不對稱坐姿對於久坐人員執行滑鼠作業時斜方肌和豎脊肌之影響

The effects of asymmetric sitting postures on the trapezius and erector spinae dur-ing a computer mouse task in sedentary people

背景和目的：直立坐姿是一般推薦辦公室工作人員的坐姿，是避免潛在肌肉骨骼疼痛發生的姿勢。但在日常生活中仍會採取多種不同的坐姿。少有研究探討不對稱坐姿的影響，如右盤腿坐姿和左盤腿坐姿等。本研究欲（1）確定個人特徵（包括性別、年齡和體重指數）如何影響久坐人員操作電腦滑鼠時的肌肉活動；（2）探討不對稱坐姿對頸部和背部肌肉活動的影響，並評估久坐人員在執行電腦滑鼠任務時左、右肌肉活動的差異。方法：3×3×2（靠背×下肢×肌肉的左右側）重複量測實驗設計。透過表面肌電圖採集四塊肌肉（兩側斜方肌和豎脊肌）的肌電訊號活動。共招募60位久坐人員，並隨機分配9種坐姿。結果：男性斜方肌活動顯著高於女性，體重過重組之斜方肌活動顯著高於健康組和體重偏低組。左盤腿坐姿的斜方肌活動顯著低於對稱坐姿的斜方肌活動。在左、右盤腿坐姿，右側豎脊肌活動均顯著高於左側。結論：不對稱坐姿之下軀幹和骨盆區域存在代償機制，不對稱坐姿不適合久坐人員。

 

Background: Although adopting a neutral sitting posture is recommended to avoid potentially painful positions, many sitting postures are still adopted in daily life. Few studies have examined the effects of sitting postures in daily life, such as the right cross-legged sitting posture and the left cross-legged sitting posture. Ob-jectives: (1) to determine how personal characteristics, including gender, age, and BMI, influenced muscle activity when operating a computer mouse in sedentary people.; (2) to investigate the effects of asymmetric sitting postures on neck and back muscular activity, and to evaluate the differences in the right and left muscular activities in the neck and back during a computer mouse task in sedentary people. Methods: A 3x3x2 (Backrest x Lower extremity x Right-left difference of examined muscles) repeated experiments design was used. The activities of four muscles (the trapezius and erector spinae on both sides) were collected by surface electromyog-raphy. Sixty sedentary people were recruited and randomly assigned sitting postures. Results: The trapezius activity was higher in males than in females, and higher in the overweight group than in the healthy and underweight groups. The trapezius ac-tivity was lower in the left cross-legged sitting posture than in the symmetric sitting posture. The erector spinae activity was higher in the right side than in the left side in both the left and the right cross-legged sitting postures. Conclusion: The com-pensation mechanism of lower trunk and pelvis regions was found in asymmetric sitting posture. Therefore, asymmetric sitting postures are not appropriate options for sedentary people.