針對三角肌表面肌電圖生物回饋及神經肌肉電刺激反置式人工肩關節患者

Abstract

研究背景:反置式人工肩關節(Reverse Total Shoulder Arthroplasty, rTSA)為不可修 復性大範圍旋轉肌群撕裂(massive irreparable rotator cuff tears)及旋轉肌群破裂關節 病變(Cuff Tear Arthropathy) 的最佳治療方法。在 rTSA 族群的肩胛骨運動學 (Scapular kinematics)中會相較正常肩關節有更多肩胛骨向上旋轉、外轉及向後傾 斜，此外，肩胛肱骨節律(Scapulohumeral rhythm) 平均為 1.1~1.6，代表盂肱關節 (Glenohumeral joint) 動作較少而肩胛胸廓關節(Scapulothoracic joint)動作較多，因 過多的肩胛骨向上旋轉並無足夠的肱骨上抬可能導致肩胛鑿痕(scapular notching)，因此以降低肩胛骨動作或增加肱骨動作可能可以避免肩胛鑿痕。為了 代償旋轉肌群失能，三角肌扮演重要的角色，可以透過生物回饋或神經肌肉電刺 激以增強三角肌的功能，rTSA 術後病人之三角肌及肩胛骨周邊肌肉接受生物回 饋訓練或神經肌肉電刺激之效果不明。 研究目的:本次研究將(1)探討使用肌電圖生物回饋和神經肌肉電刺激於三角 肌在肌肉活化(上斜方肌、下斜方肌、前鋸肌及三角肌)及肩胛骨運動學(向上 旋轉/向下旋轉、外轉/內轉、向前傾斜/向後傾斜)的立即效果(2)評估使用肌電 圖生物回饋和神經肌肉電刺激於三角肌在肌肉平衡率(muscle balance ratio)及肩 胛肱骨節律的立即效果。

研究方法:本研究為交叉設計的研究，招收初次做rTSA術後的受試者，收入基本資料及術後肩關節活動度與肩關節功能量表，測試三個狀況為介入前、肌電圖生物回饋後及神經肌肉電刺激後，其中肌電圖生物回饋及神經肌肉電刺激為交叉設計，收取肌肉活化及肩胛骨運動學資料並計算肌肉平衡率及肩胛肱骨節律，本研究會使用肌電圖分析肌肉活化及使用三維電磁儀器分析肩胛骨運動學。

研究結果:本研究最終收取18位受試者，14位完成2次實驗，4位僅完成1次。於18位資料研究結果發現受試者使用肌電圖生物回饋於三角肌下，會使下斜方肌活化增加(平均數差異=10%, p=0.035)、肩胛骨外旋角度增加(平均數差異=2.0°~3.1°, p< 0.05)，使用神經肌肉電刺激於三角肌下，則會使下斜方肌肌肉活化減少(平均數差異=4%, p= 0.028)、肩胛骨外旋角度減少(平均數差異= 2.3°, p =0.031)。在肌電圖生物回饋組中，由於下斜方肌肌肉活化上升使三角肌/下斜方肌之肌肉平衡率下降(平均數差異=0.16, p =0.03)，反之，神經肌肉電刺 激組則升高(平均數差異=0.18~0.27, p < 0.05)，在肌電圖生物回饋組發現介入後 顯著性增加肩胛肱骨節律(平均數差異=0.2, p =0.041)。於14 位資料研究結果 發現加成效果顯示兩種介入方法順序不同會有不同的結果，在先使用肌電圖生物 回饋再使用神經肌肉電刺激的組中，下斜方肌(平均數差異=11%, p = 0.041)與前鋸肌(平均數差異=11%, p =0.041)的肌肉活化及肩胛骨外旋(平均數差異=1.9°~2.9°, p< 0.05)有顯著性增加，在先使用神經肌肉電刺激再使用肌電圖生物回饋的組別中，發現介入前後無顯著性差異。肩關節外展角度在介入前後無顯著性差異，但在肌電圖生物回饋組發現介入後角度減少而神經肌肉電刺激組則增加，在加成效果的結果也與單獨兩種介入的結果類似。

研究結論:肌電圖生物回饋及神經肌肉電刺激對三角肌介入產生相似的結果，但在下斜方肌肌肉活化與肩胛骨運動學的結果則截然不同，肌電圖生物回饋增加下 斜方肌肌肉活化與肩胛骨代償內縮，而神經肌肉電刺激則是能減少下斜方肌肌肉 活化與肩胛骨代償性內縮，研究結果顯示，神經肌肉電刺激在預防肩胛骨過度移 動相較於肌電圖生物回饋更有效，可降低肩胛骨鑿痕的風險。對於結合兩種介入 方式結果呈現有好有壞，雖然肌電圖生物回饋及神經肌肉電刺激都顯示出治療rTSA患者的前景，但此研究突顯出應用順序的重要性，因此，本研究節果顯示 使用神經肌肉電刺激於三角肌可顯著性增強rTSA患者的肌肉控制、肩胛肱骨間協調與關節活動度恢復。

Background: Reverse total shoulder arthroplasty (rTSA) has been the optimal treatment for massive irreparable rotator cuff tears and cuff tear arthropathy. Since scapular kinematics alteration was associated with shoulder disorders, scapular kinematics had been characterized in individuals post rTSA with more upward rotation, external rotation, and posterior tilt of the scapula. In addition, the average scapulohumeral rhythm ranged from 1.1 to 1.6, indicating lower glenohumeral joint movements and higher scapulothoracic movements. It supposed that more scapula upward rotation without adequate humeral elevation can result in the scapula notching. Therefore, strategy to decrease scapular movement or increase humeral movements during arm movements may prevent scapula notching. To compensate for rotator cuff deficiency, the deltoid muscle plays a crucial role post rTSA. Enhancing deltoid function can be accomplished through the use of biofeedback or neuromuscular electrical stimulation (NMES). However, the effect of NMES and surface electromyography (sEMG) biofeedback on the deltoid and associated scapular muscles in scapular kinematics, muscle activation, and muscle balance ratio in individual post rTSA remained unclear.

Objective: The objectives in this study would to (1) determine the immediate effects of NMES with EMG biofeedback to deltoid (D) on the muscle activation of upper trapezius (UT), lower Trapezius (LT) and serratus Anterior (SA) as well as the scapular kinematics (upward/downward rotation, external/internal rotation, anterior/posterior tilting) (2) evaluate the immediate effects of NMES with EMG biofeedback on the muscle balance ratios (D/UT, D/LT, D/SA) and the scapulohumeral rhythm (SHR) during arm elevation in the scapular plane at different range of motion.

Design: This was a crossover design. Subject with primary rTSA were recruited in this study with shoulder abduction in scapular plane above 90 degrees and more than 3 months following rTSA. By using surface electromyography and electromagnetic motion tracking sensors, the muscle activation and scapular kinematics were recorded during arm elevation in scapular plane. Arm elevation were conducted in three conditions including baseline, post- sEMG biofeedback, and post-NMES. The crossover two conditions were sEMG biofeedback and NMES.

Result: Eighteen subjects participated in the experiment. Fourteen of these subjects completed the experiment twice, while four completed it once. Compared to baseline, there were significantly higher LT muscle activity (mean difference = 10%, p = 0.035) and increased in scapular external rotation (mean difference =2.0°~3.1°, p < 0.05) in the sEMG group. In addition, a significant decrease in the LT muscle activity (mean difference = 4%, p = 0.028) and decreased in scapular external rotation (mean difference = 2.3°, p = 0.031) relative to baseline in NMES group. In muscle balance ratio of D/LT, the sEMG group showed a significant decrease (mean difference = 0.16, p = 0.03) between baseline and post-intervention. On the contrary, compared to the baseline, there was a significant decrease in D/LT (mean difference = 0.18 ~ 0.27, p < 0.05) in the NMES group. There was significant increase in scapulohumeral rhythm (mean difference = 0.2, p = 0.041) in sEMG group. The cumulative effect showed differences in the order of the two intervention methods. Group with sEMG first following NMES showed a significant increase in lower trapezius (mean difference = 11%, p = 0.041) and serratus anterior (mean difference = 11%, p = 0.041) of muscle activation and scapula external rotation (mean difference = 1.9°~ 2.9°,p < 0.05). There was no significant difference in the group with NMES first following sEMG. Additionally, although there was no statistically significant difference at abduction range, it was observed that the range of abduction decreased in the sEMG group, while it increased in the NMES group after the intervention.

Conclusion: Both sEMG biofeedback and NMES interventions produced similar effects on deltoid muscle activation. However, they yielded contrasting outcomes for LT activation and scapular movement. While sEMG biofeedback resulted in increased LT activation and compensatory scapular retraction, NMES application led to decreased LT activation and compensatory scapular retraction. These findings suggest that NMES may be more effective than sEMG biofeedback in preventing excessive scapular movement, potentially reducing the risk of scapula notching. Combining these two interventions produced mixed results. While both sEMG biofeedback and NMES have shown promise in treating rTSA, our study highlights the importance of considering the sequence of application. In conclusion, our study indicates that NMES, but not sEMG biofeedback, applied to the deltoid muscle can significantly enhance muscle control, scapulohumeral coordination, and range of motion recovery in rTSA patients.