本體感覺受器包含關節、皮膚受器及肌肉受器，其功能在於接收關節及其附著之 軟組織受到外在刺激所產生的結構變形，再將此資訊傳至中樞神經來進行調控運動單位作用 ，調節肢體位置、角度及肌肉活動的協調性，以保護關節，以避免過度不正常的動作，造成 傷害。當肌肉疲勞產生而影響運動員或一般人的運動表現時，也可能會使本體感覺受器的精 準性下降，因而降低神經肌肉系統的動作控制及影響關節的穩定性，導致運動傷害的發生。 因此本研究之目的在於探討肩關節內外轉肌群肌肉疲勞前後，不同肩關節角度的本體感覺功 能差異的情形，以期能從神經肌肉系統來瞭解肌肉疲勞對動作控制的影響，以給予教練運動 訓練之參考。 本研究共 13 位受試者參與，本研究中使用 Kin-Com 等速肌力測量儀為進行 疲勞運動及量測本體感覺功能之儀器， 受試者坐上 Kin-Com 等速肌力測量儀，將肩關節姿 勢擺位在肩胛骨平面，並開始進行本體感覺前測，本體感覺測試分為兩部分：被動復位模式 及主動復位模式之測試，兩者測試方式以隨機選取的方式進行測試。本實驗之測試角度有三 個：起始角度、中間角度、及末端角度。之後再測量肩關節內外轉最大等速肌力，以角速度 90 ° /sec、 執行一回合、重複 5 次來測量肌力， 取這 5 次內轉肌肌力的平均值之 50% 做為肌肉疲勞的臨界值。 接著開始進行疲勞運動， 以角速度訂在 90 ° /sec 的 Kin-Com 等速肌力測量儀執行肩部內外轉的運動， 一直到受試者無法維持其內轉肌力在最大肌力的 50% 以上，連續三次，即馬上停止運動，並馬上進行本體感覺後測，研究者從電腦中得到的 角度減去原本計算的三個角度值，所得之數據再取其絕對值即為絕對誤差角度，本研究中本 體感覺功能以絕對誤差角度的多寡來表示其功能的優劣，絕對誤差角度愈小，本體感覺功能 愈好。以單因子變異數分析法及薛費氏事後多重比較法，分別考驗肌肉疲勞前後及三個關節 角度對絕對誤差角度之差異情形。本研究之結果發現：在主動復位及被動復位的三個關節角 度，肌肉疲勞前後均有顯著差異（ P<.05 ）。 肌肉疲勞前後，起始、中間、及末端角度對 絕對誤差角度，在主動復位模式，肌肉疲勞前，三個角度無顯著差異（ P>.05 ）， 而在肌 肉疲勞後，中間角度與末端角度有顯著差異（ P<.05 ）。 在被動復位模式，肌肉疲勞前， 中間角度與起始角度及末端角度均有顯著差異（ P<.05 ）； 肌肉疲勞後，只有中間角度與 起始角度有顯著差異（ P<.05 ）。 本研究建議加強負責穩定關節之肌肉的肌耐力，減少對 本體感覺的影響，間接影響肌肉正常的協調性及關節穩定性。未來研究重點將可針對肌肉疲 勞程度及疲勞後恢復時間長短對本體感覺功能之影響來進行探討。

　　　　　Proprioception has been referred to as a neuromuscular mechanism encompassing the sensations of joint position and movement. Its information probably plays an important role in shoulder joint stabilization. A proprioceptive deficit may lead to an alteration in joint stability and control of joint motion. Muscle fatigue produces neuromuscular deficiencies with the muscle that may alter proprioceptive ability, thus predisposing the joint to injury and decreasing in athletic performance. The purpose of this study was to determine the effects of shoulder internal and external rotators' fatigue on active and passive reposition function of shoulder proprioception at different joint angle. Thirteen healthy volunteers participated in this study. Each subject was seated on Kin-Com isokinetic dynamometer with selecting 3 joint angle: initial, middle, and terminal angle. Active and passive reposition test was randomly measured shoulder proprioception at 3 ° /sec of angular velocity. Three trial of active and passive reposition was recorded. Then the fatigue protocol was started. The fatigue protocol is one bout of maximal isokinetic shoulder internal/external rotator concentric contraction at 90 ° /sec until peak torque decreasing to 50% of the established maximal strength. Following the fatigue protocol, both active and passive reposition test were reassessed. The absolute error of angle of pre- and post-fatigue and three different joint angles were analyzed individually using one-way ANOVA. A significant difference was detected between pre- and post-fatigue test at all three angles. A significant difference was detected between middle and terminal angle at post-fatigue of active reposition. No significant difference was detected between initial, middle, and terminal angle at pre-fatigue test of active reposition. A significant difference was detected between initial and middle angle, middle and terminal angle at pre-fatigue test of passive reposition. It is concluded that shoulder proprioceptive function was declining after shoulder internal/external rotator' fatigue, suggesting the overhand athletes must emphasize increase muscle endurance of rotator cuff to increasing shoulder joint stabile ability and prevention of sports injury.