Purpose: To examine acromio-humeral distance (AHD) and shoulder isometric strength for external rotation (ER) and internal rotation (IR) in national elite badminton players. Methods: Seven elite badminton players with asymptomatic shoulders aged 24 ± 4 (mean ± SD) from the Danish national badminton team were investigated. Shoulder AHD, isometric strength in ER and IR were bilaterally assessed with ultrasonography and a hand-held dynamometer (HHD). Results: AHD was greater on the dominant vs. the nondominant side (p = 0.018). Moreover, IR strength was greater on the dominant side vs. the nondominant side (p = 0.041). Furthermore, AHD and ER strength were highly correlated on the dominant side (p = 0.007, r = 0.900). A correlation was also shown between AHD and the ER/IR strength ratio on the dominant side (p = 0.033, r = 0.793). Conclusion: This preliminary study demonstrates that shoulder ER strength is strongly associated with AHD size, largely reflecting supraspinatus tendon-muscle hypertrophy as a result of sport-specific adaptation in national elite badminton players with asymptomatic shoulders. These novel data also suggest that habitual loading of the shoulder improves the supraspinatus tendon size, which may lower the mechanical stress and potentially reduce the risk of injury. This warrants strengthening the shoulder external rotators as a potential strategy to reduce the risk of future shoulder injury.

中文翻译：

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急性肱骨距离与国家优秀羽毛球运动员的肩膀外力相关—初步研究

目的：研究国家羽毛球精英运动员的肩肱距离（AHD）和肩部等距力量的外旋度（ER）和内旋度（IR）。方法：调查了丹麦国家羽毛球队7名无症状肩部，年龄为24±4（平均±SD）的精英羽毛球运动员。通过超声检查和手持测功机（HHD）双向评估了肩部AHD，ER和IR的等距强度。结果：AHD在显性一侧比非显性一侧更大（p = 0.018）。此外，IR强度在显性一侧比非显性一侧更大（p = 0.041）。此外，AHD和ER强度在显性方面高度相关（p = 0.007，r= 0.900）。还显示了AHD与占主导地位的ER / IR强度比之间存在相关性（p = 0.033，r = 0.793）。结论：这项初步研究表明，肩部ER强度与AHD大小密切相关，在很大程度上反映了无症状肩部国家羽毛球运动员运动特异性适应的结果是棘上肌腱-肌肉肥大。这些新颖的数据还表明，肩部的惯常负荷可改善脊柱上肌腱的大小，这可能会降低机械应力并潜在地降低受伤的风险。这有必要加强肩膀的外部旋转肌，作为减少未来肩膀受伤风险的潜在策略。