Scapular positioning in athlete's shoulder : particularities, clinical measurements and implications

Despite the essential role played by the scapula in shoulder function, current concepts in shoulder training and treatment regularly neglect its contribution. The 'scapular dyskinesis' is an alteration of the normal scapular kinematics as part of scapulohumeral rhythm, which has been shown to be a nonspecific response to a host of proximal and distal shoulder injuries. The dyskinesis can react in many ways with shoulder motion and function to increase the dysfunction. Thoracic kyphosis, acromio-clavicular joint disorders, subacromial or internal impingement, instability or labral pathology can alter scapular kinematics. Indeed, alteration of scapular stabilizing muscle activation, inflexibility of the muscles and capsule-ligamentous complex around the shoulder may affect the resting position and motion of the scapula. Given the interest in the scapular positioning and patterns of motion, this article aims to give a detailed overview of the literature focusing on the role of the scapula within the shoulder complex through the sports context. Such an examination of the role of the scapula requires the description of the normal pattern of scapula motion during shoulder movement; this also implies the study of possible scapular adaptations with sports practice and scapular dyskinesis concomitant to fatigue, impingement and instability. Different methods of scapular positioning evaluation are gathered from the literature in order to offer to the therapist the possibility of detecting scapular asymmetries through clinical examinations. Furthermore, current concepts of rehabilitation dealing with relieving symptoms associated with inflexibility, weakness or activation imbalance of the muscles are described. Repeating clinical assessments throughout the rehabilitation process highlights improvements and allows the therapist to actualize rationally his or her intervention. The return to the field must be accompanied by a transitory phase, which is conducive to integrating new instructions during sports gestures. On the basis of the possible scapular disturbance entailed in sports practice, a preventive approach that could be incorporated into training management is encouraged.