有無電刺激之神經肌肉控制訓練對於全身性關節 過度鬆弛且伴有多方向性肩關節不穩定患者的影響

Abstract

研究背景：肩關節不穩定常見於青少年與年輕女性，表現型態從無症狀的多方向性不穩定到有症狀的情況不等。多方向性肩關節不穩定(MDI)通常與關節過度活動症候群與高活動型埃勒斯-當洛氏症候群相關，這些族群皆具有關節鬆弛與反覆性脫位特徵，嚴重影響日常生活與運動表現。然而，現有文獻對於這類患者在動作中肱骨頭位移與肌肉活化特性的實證仍不清楚。此外，針對特定肩部肌肉進行電刺激是否能改善肱骨頭位移，亦尚待證實。實驗目的：本次實驗將：(1) 檢驗患有多方向性肩關節不穩定的患者，在三種等長收縮過程中，是否相比健康對照組具有較大的肱骨頭移位；(2) 探討肱骨頭移位與相關肌肉活動之間的關聯性；(3) 檢驗神經肌肉肌肉控制訓練及神經肌肉電刺激對多方向性肩關節不穩定患者肱骨肌肉的影響，並評估其對肱骨頭移位的影響。實驗設計：本研究為橫斷式觀察設計合併單組前後測設計，使用超音波與表面肌電圖比較 30 位 MDI 病患與 30 位健康受試者在執行三種等長收縮任務期間的肱骨頭位移與肩部肌肉活化。在 MDI 組中，亦進一步比較介入前、接受神經肌肉控制訓練與合併神經肌肉電刺激 介入後的肱骨頭位移變化。實驗結果：與健康組相比，MDI 病患在三個動作中皆出現顯著更大的肱骨頭位移，包括肩屈曲時前向位移為 2.57 ± 1.06 mm，相較於健康組的 0.41 ± 0.27 mm，效果量為 2.79；水平內收時後向位移為 2.15 ± 1.20 mm，相較於健康組的 0.40 ± 0.15 mm，效果量為 2.06；手肘伸直負重時下向位移為 3.03 ± 1.83 mm，相較於健康組的 0.28 ± 0.16 mm，效果量為 2.12，三項皆達統計顯著差異（p < 0.05）。相關性分析結果顯示，前向位移與肱二頭肌長頭活化呈顯著負相關（r = –0.58），後向位移與前鋸肌活化呈負相關（r = –0.72），而三角肌中束的活化與前後向位移皆呈正相關（r = 0.65–0.86）。在介入效果方面，針對特定方向進行的神經肌肉控制與神經肌肉電刺激介入均能有效減少肱骨頭位移，呈現出由無介入、神經肌肉控制至神經肌肉控制合併電刺激的階段性改善趨勢 (前向: 3.1 → 1.6 → 0.71 mm; 後向 3.3 →1.6 →0.58 mm; 下向: 4.4 →1.4 →0.69 mm; p < 0.05, 效果量 = 0.98–1.9)。實驗結論：本研究證實多方向肩關節不穩定患者在不同動作中展現出方向性與任務特異性的肱骨頭位移現象，並可透過針對性神經肌肉訓練策略，特別是強化肱二頭肌長頭、棘下肌或三角肌中束的活化，根據不穩定的方向不同，皆與肱骨頭位移的減少相關。值得注意的是，肱二頭肌長頭與前鋸肌分別在前向與後向不穩定中展現出顯著的穩定作用；而在適當穩定條件下，中束三角肌的參與則可能有助於改善下向不穩定。促進穩定肌群活化，進而有效降低位移程度，支持方向導向的復健模式應用於多方向性肩關節不穩定患者。

Background: Shoulder instability, particularly multidirectional instability (MDI), is a common issue in adolescents and young females. It can range from asymptomatic cases to symptomatic ones that significantly impact daily life and athletic activities. MDI is often associated with conditions like hypermobility spectrum disorder (HSD) and hypermobile Ehlers-Danlos syndrome (hEDS), both characterized by joint laxity and recurrent dislocations. However, there's been a lack of clear evidence on how humeral head displacement and muscle activity are affected during movement in these populations. Additionally, the impact of muscle-specific electrical stimulation on humeral head translation in MDI patients hasn't been well understood. Objective: This study aimed to address these gaps by: (1) examining whether patients with MDI exhibit increased humeral head translation compared to healthy controls during three isometric contractions; (2) investigating the relationship between humeral head translation and associated muscle activity during these isometric contractions; (3) examining the effect of neuromuscular control training (NMCT) and combined with neuromuscular electrical stimulation (NMES) on humeral head translations in MDI patients. Study design: This cross-sectional observational combined with pretest-posttest experimental design study compared humeral head translation and shoulder muscle activity during isometric tasks between 30 patients with MDI and 30 healthy controls, using ultrasound and surface EMG. In MDI patients, measurements were repeated during NMCT and NMES targeting key stabilizing muscles. Results: Compared to controls, patients with MDI showed significantly greater humeral head translation across all conditions: anterior during flexion (FLEX) (2.57 ± 1.06 vs 0.41 ± 0.27 mm, ES = 2.79, p <0.05), posterior during horizontal adduction (HADD) (2.15 ± 1.20 vs 0.40 ± 0.15 mm, ES = 2.06, p <0.05), and inferior during extension holding weight (EHW) (3.03 ± 1.83 vs 0.28 ± 0.16 mm, ES = 2.12, p <0.05). In subgroup analysis, anterior translation was negatively correlated with biceps long head activity (r = –0.58) in anterior instability group, and posterior translation with serratus anterior (r = –0.72) in posterior instability group; middle deltoid activity was positively correlated in both directions (r = 0.65–0.86) in anterior and posterior instability group. Direction-specific interventions produced reductions in translation from resting to NMCT and further with NMES (anterior: 3.1 → 1.6 → 0.71 mm; posterior: 3.3 → 1.6 → 0.58 mm; inferior: 4.4 → 1.4 → 0.69 mm; p < 0.05, ES = 0.98–1.9). Conclusion: Our findings demonstrated that patients with MDI exhibit direction- and task-specific humeral head translation, which can be mitigated through targeted neuromuscular strategies. Interventions such as NMCT and NMES effectively reduced translation by enhancing the activation of key muscles like the biceps long head, infraspinatus, and middle deltoid for anterior, posterior and inferior instability respectively. These results supported a direction-specific rehabilitation approach to improve dynamic joint stability in individuals with MDI.