Bilateral scapular kinematics in competitive adolescent swimmers: an age- and gender-matched comparison with healthy non-athletes scapular kinematics in competitive adolescent swimmers

Since swimming is a bilateral sport, it has been wondered whether scapular kinematics are symmetrical.

The aim of our study was to (a) compare the scapular kinematics of asymptomatic young swimmers with those of healthy non-athletes and (b) to compare the scapular kinematics between the dominant and non-dominant shoulders in asymptomatic young swimmers and healthy non-athletes.

This cross-sectional study included 27 asymptomatic young swimmers (age: 12.7 years) with at least 3 years of experience in a professional swimming club and 22 healthy non-athletes (age: 11.5 years). 3D scapular kinematics were evaluated at 0°, 30°, 60°, 90°, and 120° with the electromagnetic tracking system during bilateral arm elevation and lowering on the scapular plane. The differences in the scapular kinematics of the dominant and the non-dominant side were analyzed with 2 by 8 mixed-model ANOVA.

Scapular internal/external rotation (p = 0.35, 0.38), upward/downward rotation (p = 0.20, 0.29), and posterior/anterior tilt (p = 0.20, 0.25) were not statistically different between swimmers and the control group. In addition, internal/external rotation, upward/downward rotation, and posterior/anterior tilt were not statistically different at all angles measured between dominant and non-dominant shoulders in both the groups (respectively, for swimmers p = 0.25/0.26, p = 0.68/0.67, p = 0.31/.32; for non-athletes p = 0.16/0.14, p = 0.10/0.9, p = 0.65/0.64).

These results showed adaptations in scapular kinematics in swimmers, like the healthy control group. In addition, it showed that swimming preserves the symmetrical posture in scapular kinematics with bilateral loading.