肩膀前傾族群之胸小肌伸展位置與技術:肩胛運動學、肌肉柔軟度與肌肉運動表現

Abstract

肩膀前傾為一常見的姿勢變異，並且根據之前的研究指出，抱怨不適的最高頻率為肩膀。然而造成肩膀前傾的機制，有一假說認為胸小肌太緊，以致產生肩膀前傾，伴隨著肩胛運動學與肌肉運動表現的改變。因此本篇實驗目的有下列: (1) 測試肩胛運動學與胸小肌柔軟度(包括肌肉長度與鬆緊度)之間的關係; (2) 調查伸展介入對於姿勢、胸小肌柔軟度、肩胛運動學與肌肉運動表現的治療效果。(3) 確定何種伸展位置與技術可以獲得最佳的伸展治療效果。所有個案均接受下列的評估測量包括: (1) 肩胛距離 (第三胸椎棘突至肩峰下角); (2) 肩膀在肩胛面下前舉角度; (3) 胸小肌長度; (4) 肩胛面前舉時肩胛運動學; (5) 胸小肌緊度; (6) 肩部肌肉力量。完成一開始的評估後，個案會接受各自對於胸小肌的伸展治療，並再次接受以上的評估測量。各自的伸展治療持續兩個星期，並再次接受同樣的評估。本實驗第一個目的是測試肩胛運動學與胸小肌柔軟度之間的相關性，因此使用皮爾森積差相關係數來測試。二因子的變異數分析，包含組別與時間兩個因子，則用來檢驗伸展治療介入對於姿勢、胸小肌柔軟度、肩胛運動學與肩胛面下的運動表現是否有顯著差異。總共有28位受試者完成測試，實驗結果發現胸小肌與肩胛骨運動學前傾只有輕度相關(r = 0.261)。另外，伸展胸小肌後，可以觀察到肩胛距離、肩膀在肩胛面下前舉角度，肩部肌肉力量與肩胛運動學皆有時間效應(P < 0.05)。而組效應則只有肩胛距離與肩胛運動學有顯著差異(P < 0.05)。Self-30組在實驗中，表現出對於修正肩膀前傾不良姿勢的能力。Manual-30組則是可以在肩膀在肩胛面下前舉時，使得肩胛骨能降低前傾角度。總結來說，對於肩膀前傾的患者，在肩胛面下外展30度做兩種伸展胸小肌的治療，一者可以改善修正肩膀前傾，另者可以降低肩胛骨前傾角度，所以都是被建議施行在物理治療計劃中。

Forward shoulder posture commonly complaints in the shoulder area also showed the highest prevalence. One of the mechanisms inducing forward shoulder posture is pectoralis minor tightness. Therefore, causing shoulder is pulled forward and accompanying with changes of scapular kinematics and muscle performance. The purposes of this study are aimed: (1) to test the relationship between the scapular kinematics and pectoralis minor flexibility, including length and tightness; (2) to investigate stretch effect on posture, pectoralis minor flexibility, scapular kinematics and associated muscle performance and (3) to determine which stretching positions and techniques can obtain greatest stretch effect. The following measurements were collected: (1) total scapular distance (TSD: T3 spinous process to the inferior angle of the acromion); (2) shoulder elevation range of motion in scapular plane; (3) length of pectoralis minor; (4) three-dimensional scapular kinematics during shoulder scaption; (5) tightness of pectoralis minor; and (6) shoulder muscle strength. After the initial evaluation, the specific stretch protocol was applied to the subject. Then, the second evaluation was immediately performed to collect data again. Within the following two weeks, stretch protocol continues and subject returned to receive follow-up data collection after two weeks. For the first purpose to test the relationship between the scapular kinematics and pectoralis minor flexibility, including length and tightness, the Pearson product-moment coefficient of correlation was used. For the second and third purposes, 2-way mixed ANOVAs with group (4 levels: self-30, self-90, manual-30, manual-90) and time (3 levels: pre, post, follow-up) factors was used to investigate stretch effect on each outcome including posture, pectoralis minor muscle flexibility, scapular kinematics and scaption performance. Totally 28 subjects were included and data were analyzed. Only fair relationship between pectoralis minor length and scapular tipping (r = 0.261). TSD, ROM, STRE and TIP showed the simple effect of time (P < 0.05). TSD and TIP showed the simple effect of group (P < 0.05). The Self-30 subgroup corrected the forward shoulder posture significantly. And the Manual-30 subgroup increased the scapular posterior tipping during performing shoulder scaption. Overall, stretch at the 30 degrees of abduction in the scapular plane, both techniques should be included in the population with forward shoulder.