Shoulder instability

Shoulder instability occurs when the ball (humeral head) of the upper arm bone slips out of the shoulder socket (glenoid). This can happen due to injury, overuse, or looseness of the supporting soft tissues like ligaments and muscles. It may cause repeated dislocations or a feeling that the shoulder is loose or slipping. Symptoms often include pain, weakness, and reduced shoulder function. Treatment ranges from physical therapy to strengthen supporting muscles, to surgery in more severe cases, to restore stability and prevent future dislocations.