目的：電腦操作者約有30~80%時間使用電腦滑鼠；主要是因現今的軟體大多改為視窗化，不像
以前利用鍵盤式的文字輸入指令，改由圖像化的界面，並藉由滑鼠點選來執行。使用電腦滑鼠，
可能會需要上肢長時間維持在不自然的姿勢和肌肉的持續性活化，造成肩頸和手臂等部位疼痛。
另外，許多電腦遊戲玩家，常會為了提升表現，犧牲前臂支撐，保持在所謂機動姿勢下，也可
能更易造成肩頸和手臂等處肌肉的持續性活化。本研究之目的為比較不同姿勢下操作電腦滑鼠，
對於肩頸和手臂等特定肌群之肌電活化情形。方法：本研究以8位過去無嚴重上肢骨骼神經肌肉
疾病病史的受試者為研究對象，年齡介於18至28歲間，平均年齡為21.63歲。實驗中利用表面肌
電圖儀（Electromyography, EMG）來量測肩頸和手臂等處肌肉，包含上斜方肌、前三角肌、中三角肌、肱橈肌及屈指肌，並紀錄其最大自主收縮下肌肉活化情形（Maximum Voluntary Contraction,MVC%）。受試者在標準坐姿下，以機動姿勢（前臂沒有支撐）與一般姿勢（前臂有支撐），執行相同的電腦遊戲20秒鐘。並利用配對樣本t檢定，分析於機動姿勢與一般姿勢下其肌肉活化情形是否有顯著差異。結果：機動姿勢下平均肌肉活化值分別為10.82、5.38、4.76、9.36及8.45（MVC%），一般姿勢下其平均肌肉活化值分別為5.93、4.79、3.99、7.85、8.01（MVC%）；而最大肌肉活化值也有相似的情形。顯示機動姿勢下上斜方肌、前三角肌、中三角肌、肱橈肌及屈指肌的平均肌肉活化值，都較一般姿勢下大。上斜方肌，不管是平均肌肉活化值與最大肌肉活化值於不同姿勢下，皆達到顯著性差異（p<0.05），機動姿勢下其活化值在平均及最大值高於一般姿勢分別為4.89和7.57（MVC%）。結論：由分析之結果可得知在機動姿勢容易造成肩頸肌肉持續活化，所以長時間下來可能造成肌肉疲乏和酸痛等問題。臨床意義：本研究結果可以提供臨床人員，對於電腦遊戲玩家較正確姿勢的建議，以降低肩頸疼痛等問題。

Purposes: Mouse operation may account for 30-80% of working time spent at the computer.The computer mouse became an important tool for the operation of computers, as operating systems and software applications have evolved to graphics based windowed environments. Sustained improper postures and muscle activities are primary risk factors to contribute to the musculoskeletal injuries of upper extremity. Many online players may use maneuver posture that may lead to more loads on shoulder and neck to improve their performance. This study aimed to evaluate the effect on the shoulder-neck muscle activation at different mouse operation
positions.Methods: Eight healthy volunteers (aged 18~28 years old and mean age is 21.63) participated in this experiment. We used surface EMG (EMG-MA300, Motion Lab System, Inc., LA,USA) to measure shoulder-neck muscles activities in two tasks and muscles activation. Surface electrodes were placed on top of the anterior deltoid, the medial deltoid, the upper trapeziums,brachioradialis and flexor digitorum muscle bellies. While subjects used the maneuver posture (i.e. forearm non-support) and general posture (i.e. forearm support) toconduct computer games twenty seconds. The paired t-tests were then used to compare muscle activities values between the different tasks. Results: Higher level of mean and maximum muscle activity in maneuver posture was found compared to that of general posture. The upper trapeziums, anterior deltoid,
medial deltoid, brachioradialis and the flexor digitorum mean muscle activities in maneuver posture were 10.82, 5.38, 4.76, 9.36 and 8.45 (MVC%), respectively. In general posture, the upper trapeziums, anterior deltoid, medial deltoid, brachioradialis and the flexor digitorum mean
muscle activities were 5.93, 4.79, 3.99, 7.85, 8.01 (MVC%), respectively. The upper trapeziums maximum (4.89 MVC%) and mean muscle activities and (7.57 MVC%) in maneuver posture were significantly difference (p<0.05) compared to in general posture. Conclusion: The maneuver posture may easily lead to shoulder-neck muscle continuous activity; and that causesthe muscle fatigue, pain, and so on for the long time. Clinical Relevance: The findings in this study provided useful information for clinical persons to suggest the correct posture to reduce the upper
extremity problem.