Mechanical overstress in shoulders of subjects with or without congenital hyperlaxity may lead to pain and disfunction. The repetitive microtrauma applied on the structures of the joint may induce minimal lesions of the structure of the shoulder that will increase through the time. More commonly , the glenoid rim will present fraying or erosions . These structures are not detached from the glenoid or from the humeral head in Aios. Capsular thinning and stretching may be observed.
Ligaments often look thinner or ensheathed in the capsule .
Labrum may appear frayed and fragmented . The anterior , axillary and posterior pouchs are redundant and allow the humeral head to slide easily on the glenoid with rotation of the arm . Its anchor , involving the superior labrum , loose. Overhead and throwing activities may cause a limited lesion of the cuff due to repetitive microtrauma . This kind of lesions should be appreciated both from the anterior and posterior portals .