Resting scapular posture in healthy overhead throwing athletes

Introduction: On shoulder examination, asymmetric scapular posture is often associated to abnormalities of the shoulder complex joint. However, shoulder asymmetries may also be related to adaptations to sports practice. The overhead throwing motion is a highly repetitive skilled motion performed at high velocities. Due to overuse of the dominant overhead-throwing shoulder, athletes may develop some kind of overhead throwing shoulder adaptation pattern that possibly includes scapular asymmetry at the resting position.

Purpose: To quantify the asymmetry between dominant and non-dominant resting scapular posture in 3 groups of healthy subjects (volleyball players, team-handball players and a control group).

Methods: Bilateral 3D scapular kinematics with the arm at rest was measured using a 6 degrees-of-freedom electromagnetic tracking device.

Results: In handball athletes, the dominant scapula was more in internal rotation and anteriorly tilted than in volleyball players. Between athletes and non-athletes groups, the dominant scapula was more anteriorly tilted in the athletes.

Conclusions: Clinicians should be aware that some degree of scapular asymmetry may be normal in some athletes. It should not be considered automatically as a pathological sign but rather an adaptation to sports practice and extensive use of upper limb.