Influence of Brassiere Wearing on Shoulder Kinematics.

OBJECTIVE: Gender differences in scapular kinematics during arm elevation have been reported. Because women wear brassieres (bras) daily, their scapular motion may be restricted by the garment; however, the influence of bra wearing on this motion has not been reported. Therefore, using a three-dimensional electromagnetic tracking device, we investigated the influence of bra wearing on shoulder kinematics during arm elevation.
METHODS: The subjects were 19 healthy women, and the shoulder on the dominant side was evaluated. Subjects performed scapular plane arm elevation while wearing or not wearing bras. Kinematic data were recorded using an electromagnetic tracking device. The glenohumeral elevation angle, scapular upward and internal rotation angles, and the posterior tilt angle were determined from the recorded data. The angles were calculated at 20°-120° arm elevation, and the data were compared between the two conditions.
RESULTS: The scapular upward and internal rotation angles and the posterior tilt angle were significantly smaller with the subjects wearing bras than not wearing bras. In contrast, the glenohumeral elevation angle was significantly greater when bras were warn.
CONCLUSIONS: Bra wearing may influence shoulder kinematics. Consequently, great care should be taken to account for this factor during the evaluation of kinematics in female subjects. ©2018 The Japanese Association of Rehabilitation Medicine.