BACKGROUND: Scapular dyskinesis has been associated with shoulder dysfunctions, and changes in electromyographic (EMG) activity have been reported during the execution of some exercises. OBJECTIVE: To compare upper limb muscles EMG of asymptomatic subjects with and without scapular dyskinesis during bench-press and dumbbell fly exercise performed on different surface stability conditions. METHODS: Twenty-eight physically active men were allocated into two groups: Control group (n= 14) and Dyskinesis group (n= 14). The participants performed six repetitions lasting three seconds of the bench press and dumbbell fly exercises with 50% of one-repetition maximum (1RM) on a bench and a Swiss ball. The EMG activity of the pectoralis major, serratus anterior, upper and lower trapezius, anterior deltoid, biceps and triceps muscles were recorded. RESULTS: No differences were found between groups, regardless of exercise or surface type. Inserting the unstable surface in the supine exercise promoted a slight increase in upper trapezius EMG activity for the control [4.32 (95% CI: 1.04 to 7.60)] and dyskinesis [3.30 (95% CI: 0.34 to 6.27)] groups. CONCLUSIONS: There is no difference in upper limb muscle EMG activity between subjects with and without scapular dyskinesis. In addition, inserting unstable surfaces did not modify EMG activity.

中文翻译：

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在稳定和不稳定表面上进行卧推和哑铃飞鸟时肩胛骨运动障碍患者上肢肌肉的激活

背景：肩胛骨运动障碍与肩部功能障碍有关，并且在执行某些练习期间已报告肌电图 (EMG) 活动发生变化。目的：比较有无肩胛骨运动障碍的无症状受试者在不同表面稳定性条件下进行卧推和哑铃飞鸟运动时的上肢肌肉肌电图。方法：将 28 名身体活跃的男性分为两组：对照组 (n= 14) 和运动障碍组 (n= 14)。参与者进行了六次重复，持续三秒的卧推和哑铃飞鸟练习，在长凳和瑞士球上进行了一次重复最大值 (1RM) 的 50%。记录胸大肌、前锯肌、上斜方肌和下斜方肌、前三角肌、二头肌和三头肌的肌电图活动。结果：无论运动或表面类型如何，各组之间均未发现差异。在仰卧运动中插入不稳定表面促进了对照组 [4.32（95% CI：1.04 至 7.60）] 和运动障碍 [3.30（95% CI：0.34 至 6.27）] 组的上斜方肌 EMG 活动略有增加。结论：有和没有肩胛骨运动障碍的受试者的上肢肌肉肌电图活动没有差异。此外，插入不稳定的表面不会改变 EMG 活动。有和没有肩胛骨运动障碍的受试者的上肢肌肉 EMG 活动没有差异。此外，插入不稳定的表面不会改变 EMG 活动。有和没有肩胛骨运动障碍的受试者的上肢肌肉 EMG 活动没有差异。此外，插入不稳定的表面不会改变 EMG 活动。