Shoulder Dislocation

The shoulder joint is your body's most mobile joint. Its ability to turn in many directions is both an advantage and a weakness because it makes your shoulder joint easy to dislocate. A partial dislocation (subluxation) means the head of the upper arm bone (humerus) is partially out of the socket (glenoid). A complete dislocation means it's all the way out.

Your shoulder joint can dislocate forward, backward or downward. A common type of shoulder dislocation is when your shoulder slips forward (anterior instability). This means your upper arm bone moved forward and down out of its joint. It may happen when you put your arm in a throwing position.


Symptoms of a dislocated shoulder include pain, swelling, numbness or bruising in the shoulder, which usually forces the patient to hold their arm at their side, slightly away from their body with their forearm turned outward. The normal rounded shape of the deltoid muscle is also usually affected. Sometimes a dislocation will tear ligaments or tendons in the shoulder or damage nerves. Muscle spasms can also occur after a dislocation, which can cause further pain.

Causes and Risk Factors

Usually a fall or sports-related injury causes a shoulder to dislocate. In about 95 percent of cases the top of the humerus sits in front of the shoulder blade, which is called an anterior dislocation. In 5 percent of cases, the top of the humerus is behind the shoulder blade, which is called a posterior dislocation. Such dislocations are usually caused by a seizure or electrocution.


An examination and talking with a patient is usually enough to diagnose a dislocated shoulder. A doctor will examine the patient to determine if there is any nerve or blood vessel damage before the shoulder is repositioned. An X-ray is usually taken to check for any fractures, and to determine the pattern of the dislocation.


The physician will put the ball of the upper arm bone (humerus) back into the joint socket. This process is called closed reduction. Your severe pain stops almost immediately once your shoulder joint is back in place. Your physician will place the ball of the upper arm bone (humerus) back into the joint socket, which usually stops the severe pain immediately.

After securing the shoulder, a sling may be used to keep your shoulder from moving and give it rest after the injury. After the pain and swelling go down, your doctor will prescribe physical therapy. This helps restore your shoulder's range of motion and strengthens your muscles. In addition, physical therapy may also help prevent future dislocations.

If your shoulder dislocation recurs often, a brace can sometimes help. However, if physical therapy and a brace do not work, then you may need surgery to repair or tighten torn or stretched ligaments. This will help keep the joints in place.