BACKGROUND Round shoulder posture (RSP) is one of the potential risks for shoulder impingement syndrome (SIS) due to alignment deviation of the scapula. Evidence on how the characteristics of a shoulder brace affecting the degree of RSP, shoulder kinematics, and associated muscle activity during movements is limited. RESEARCH QUESTION The purposes of this study were (1) to compare the effects of a shoulder brace on clinical RSP measurements, muscle activities and scapular kinematics during arm movements in subjects with shoulder impingement syndrome (SIS) and RSP; and (2) to compare the effects of two configurations (parallel and diagonal) and two tensions (comfortable and forced tension) of the brace straps on muscle activities and scapular kinematics during arm movements in subjects with SIS and RSP. METHODS Twenty-four participants (12 males; 12 females) with SIS and RSP were randomly assigned into 2 groups (comfortable then forced, and forced then comfortable) with 2 strap configurations in each tension condition. The pectoralis minor index (PMI), acromial distance (AD) and shoulder angle (SA) were used to assess the degree of RSP. Three-dimensional electromagnetic motion analysis and electromyography were used to record the scapular kinematics and muscle activity during arm movements. RESULTS All clinical measurements with the brace were significantly improved (p < 0.05). Under forced tension, muscle activities were higher with the diagonal configuration than with the parallel configuration in the lower trapezius (LT) (1.2-2.3% MVIC, p < 0.05) and serratus anterior (SA) (2.3% MVIC, p = 0.015). For upward rotation and posterior tilting of the scapula, the diagonal configuration was larger than the parallel configuration (1.5°, p = 0.038; 0.4°-0.5°, p < 0.05, respectively). SIGNIFICANCE Different characteristics of the straps of the shoulder brace could alter muscle activity and scapular kinematics at different angles during arm movement. Based on the clinical treatment preference, the application of a shoulder brace with a diagonal configuration and forced tension is suggested for SIS and RSP subjects.

中文翻译：

---

肩部撞击综合征和圆形肩部姿势的受试者中，肩膀支撑对肌肉活动和肩cap运动的直接影响：随机交叉设计。

背景技术由于肩the骨的对准偏差，圆肩姿势（RSP）是肩部撞击综合征（SIS）的潜在风险之一。关于运动中RSP程度，肩膀运动学和相关肌肉活动如何影响肩膀支撑特性的证据有限。研究问题本研究的目的是（1）比较肩部撞击综合征（SIS）和RSP患者在手臂运动过程中肩背支架对临床RSP测量，肌肉活动和肩cap运动的影响；（2）比较SIS和RSP受试者手臂移动过程中支撑带的两种配置（平行和对角线）和两种张力（舒适和强制张力）对肌肉活动和肩cap运动的影响。方法二十四名参与者（男十二名；女十名）。将12名具有SIS和RSP的女性随机分为两组（分别在舒适状态下用力，然后用力，再用压力再用舒适），每种状态下使用2条绑带。胸小肌指数（PMI），肩峰距离（AD）和肩角（SA）用于评估RSP程度。使用三维电磁运动分析和肌电图记录手臂运动过程中的肩cap运动学和肌肉活动。结果支架的所有临床测量均得到明显改善（p <0.05）。在强迫张力下，斜方肌（LT）（1.2-2.3％MVIC，p <0.05）和前锯肌（SA）（2.3％MVIC，p = 0.015）中，对角线构型的肌肉活动高于平行构型。 。为了使肩cap骨向上旋转并向后倾斜，对角线构型比平行构型大（分别为1.5°，p = 0.038； 0.4°-0.5°，p <0.05）。意义臂部运动期间，不同角度的肩部支撑带的不同特性可能会改变肌肉活动和肩k运动。根据临床治疗的偏爱，建议对SIS和RSP受试者使用对角线构型和强力拉紧的肩膀支撑。