Understanding the Causes of Shoulder Dislocation and Instability

xray of a dislocated shoulder boneA partial or total shoulder dislocation is an extremely painful condition where the head of the humerus (the upper arm bone) disconnects from the shoulder socket, and they can be caused by several different factors. Unfortunately, experiencing one dislocation or subluxation (partial dislocation) can make it more likely to reoccur, as the connective tissue that attaches the arm to the shoulder bone can stretch or even tear with each event. A person who experiences multiple shoulder dislocations likely has shoulder instability.


The primary cause of a shoulder subluxation or dislocation is traumatic injury. These injuries are commonly caused by falling, over-extension, or sports injuries. A shoulder dislocation caused by a traumatic injury may cause more extreme damage to the shoulder’s ligaments and cartilage.

Strain and Repetitive Motion

A person may also experience a dislocation by straining the shoulder muscles and connective tissues. This sort of dislocation tends to be associated with repetitive motion from sports like swimming and tennis or from work injuries at physically demanding jobs. It also may be caused by a daily or weekly routine that puts pressure on the shoulder area.


Some people are more susceptible to shoulder dislocations because they naturally have loose ligaments or their arm doesn’t perfectly fit in their shoulder joint. Some of these patients may be “double-jointed” and have loose ligaments all over their body, but some people predisposed to dislocations only experience the issue in one or both shoulders.


Patients experiencing shoulder instability and multiple subluxations or dislocations have both surgical and nonsurgical treatment options. Depending on the cause and severity, patients may be able to simply avoid the activities and motions that tend to lead to dislocations. Physical therapy may help strengthen the surrounding muscles, making it less likely to dislocate in the future. Patients who experience frequent dislocations, particularly from everyday motions, may need surgery to repair the damaged cartilage and ligaments.

If you’ve experienced a subluxated or dislocated shoulder multiple times, a specialist can help diagnose the cause and recommend treatment options. For those in the Houston area, contact orthopedic surgeon K. Mathew Warnock, MD. He and his team provide compassionate care to help treat shoulder injuries, including dislocations. Schedule an appointment today by calling 281-807-4380.

Image by Hellerhoff

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