Abstract

BACKGROUND:

Shoulder external rotation in the throwing motion involves movement of the scapulothoracic and glenohumeral joints, thoracic spine, and the thorax. Restriction of thoracic expansion may decrease scapulothoracic joint motion and compensate by excessive glenohumeral joint motion. However, it is unclear how restricting the expansion of the thorax alters shoulder motion.

OBJECTIVE:

To elucidate changes in scapulothoracic and glenohumeral joint movements caused by restricted thoracic expansion.

METHODS:

Kinematic data were obtained using an electromagnetic tracking device (Liberty; Polhemus), from 18 male participants, during shoulder external rotation in the sitting position with and without restriction of thoracic expansion. The displacements from the start position to the maximum external rotation position were compared, and Pearson’s correlation coefficient was calculated.

RESULTS:

A significant difference was observed in the scapulothoracic posterior tilt angle (P< 0.01) and glenohumeral external rotation angle (P< 0.01). A significant positive correlation existed between scapulothoracic posterior tilt and glenohumeral external rotation (P< 0.05) with and without restriction.

CONCLUSIONS:

Restriction of thoracic expansion decreased scapulothoracic motion and increased glenohumeral motion. Thus, a decrease in thoracic expansion may change scapulothoracic and glenohumeral movements, which may be a risk factor for throwing injuries.

中文翻译：

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胸廓扩张限制对肩关节外旋过程中肩胛胸关节和盂肱关节运动的影响

摘要

背景：

投掷动作中的肩部外旋涉及肩胸关节和盂肱关节、胸椎和胸部的运动。胸廓扩张的限制可能会减少肩胛胸关节的运动，并通过过度的盂肱关节运动来代偿。然而，目前尚不清楚限制胸部扩张如何改变肩部运动。

客观的：

阐明由胸廓扩张受限引起的肩胸关节和盂肱关节运动的变化。

方法：

运动学数据是使用电磁跟踪装置 (Liberty; Polhemus) 从 18 名男性参与者那里获得的，在坐位肩部外旋期间有和没有限制胸部扩张。比较起始位置到最大外旋位置的位移，计算皮尔逊相关系数。

结果：

肩胛胸后倾角观察到显着差异（P<0.01)和盂肱外旋角(P<0.01）。肩胛胸后倾与盂肱外旋之间存在显着正相关（P<0.05) 有和没有限制。

结论：

胸廓扩张的限制减少了肩胛胸廓运动并增加了盂肱运动。因此，胸廓扩张的减少可能会改变肩胛胸廓和盂肱关节的运动，这可能是投掷损伤的危险因素。