FEATURE: SWIMMER’S SHOULDER Freestyle high elbow ‘catch’ Butterfly streamline arm position, characterised by bilateral end of range shoulder elevation 7. Kinetic chain: shoulder-hip and pelvis is essential to allow ‘hip INJURY CAUSATION connection rotation’ to drive propulsion. From an injury perspective, if the hips (pelvis) The theories for development Swim coaches highlight the importance over-rotate, the opposite shoulder of swimmer’s shoulder include of maintaining ‘connection’ between theis inefficient during the catch. Duringimpingement, glenohumeral joint pulling shoulder and the hip, via latissimusbutterfly and breaststroke, the abdominalhyperlaxity and more recently, primary dorsi and abdominal muscle engagement.muscles are recruited to avoid excessiverotator cuff tendinopathy. These potential This connection is underpinned by spinal extension and shoulder hyper- causative factors may interact as part precise control of scapula upward elevation during the catch. Improving of an injury continuum (Diagram 1). rotation, which allows optimal shoulder core strength for all strokes can position to generate power. Correct reduce work at the shoulder. For example, rotator cuff tendinopathy timing of long axis rotation of the thorax may be primary in origin, however, the associated increased tendon thickness DIAGRAM 1 may increase the likelihood of impingement, which, in turn, may Proposed shoulder injusry continuum: inter-relationship between causative factors exacerbate the tendinopathy via compression. Subsequent rotator Repetition of extreme shoulder elevation and rotational motions during swim training cuff dysfunction may reduce dynamic shoulder stability. Swim-stroke shoulder positions may contribute to primary impingement and rotator cuff Potential for intrinsic RC Potential for primary Potential for attenuation tendinopathy development. Acquired tendon over-use and sub-acromial and of GHJ mechanical retraints GHJ hyperlaxity, may alter sensorimotor primary tendinopathy internal impingement and acquired hyperlaxity control, contribute to dynamic stabiliser fatigue, altered antero-superior humeral head translation and RC fatigue dysfunction Abnormal humeral head Altered sensorimotor secondary impingement. and dynamic instability translation and potential for control secondary impingement The location and type of neural receptors in the shoulder is important when VOLUME 36 • ISSUE 3 2018 9