Shoulder motion during tennis serve: dynamic and radiological evaluation based on motion capture and magnetic resonance imaging.

Purpose: Rotator cuff and labral lesions in tennis players could be related to posterosuperior internal impingement or subacromial impingement during tennis serve. However, it is unknown which of these impingements are responsible for the lesions found in the tennis player's shoulder. Moreover, there is a lack of validated noninvasive methods and dynamic studies to ascertain impingement during motion.

Methods: Ten intermediate or ex-professional tennis players were motion captured with an optical tracking system while performing tennis serves. The resulting computed motions were applied to patient-specific shoulder joints' 3D models based on magnetic resonance imaging (MRI) data. During motion simulation, impingements were detected and located using computer-assisted techniques. An MRI examination was also performed to evaluate the prevalence of shoulder lesions and to determine their relevance with the simulation findings.

Results: Simulation showed that internal impingement was frequently observed compared to subacromial impingement when serving. The computed zones of internal impingement were mainly located in the posterosuperior or superior region of the glenoid. These findings were relevant with respect to radiologically diagnosed damaged zones in the rotator cuff and glenoid labrum.

Conclusions: Tennis players presented frequent radiographic signs of structural lesions that seem to be mainly related to posterosuperior internal impingement due to repetitive abnormal motion contacts. The present study indicates that the practice of tennis serve could lead with time to cartilage/tendon hyper compression, which could be damageable for the glenohumeral joint.