Posterior Impingement Syndrome

This disorder is caused by anything that creates compression of the shoulder anatomy (e.g., muscles, tendons, nerves, or blood vessels). Other potential causes include imbalances between the muscles that permit shoulder motion and those that provide stability to the joint. These include the rotator cuff muscles, such as the infraspinatus and supraspinatus, which may cause friction against the posterior-superior part of the glenoid and glenoid labrum.

The wing bone (scapula) and collar bone (clavicle) create an arch at the tip of the shoulder, through ...