One dislocation makes the next one easier

The shoulder joint is made of three bones: the collarbone, the **shoulder
blade**, and the upper arm bone, whose ball-shaped top sits in a cuplike
socket in the shoulder blade. A dislocation is the ball popping out of
that socket — partial, where it is only partly out, or full, where it
is completely out.

**Shoulders are the most movable joints in the body. They are also the most
commonly dislocated.** Those two facts are the same fact: the range of motion
that makes a shoulder useful is bought by giving up the deep socket that would
keep it in place.

How it happens

• Sports injuries
• Accidents, including traffic accidents
• Falling on the shoulder or an outstretched arm
• Seizures and electric shocks, which cause muscle contractions strong
  enough to pull the arm out of place

It can happen to anyone. It is more common in young men, more often
involved in sport and physical activity, and in **older adults, especially
women**, who are more likely to fall.

Symptoms

Severe shoulder pain · swelling and bruising of the shoulder or upper arm ·
numbness or weakness in the arm, neck, hand or fingers · trouble moving the
arm · the arm seems to be out of place · muscle spasms in the shoulder.

Get medical treatment right away.

Treatment, in three steps

1. Closed reduction — a provider puts the ball back into the socket. You
   may first be given medicine to relieve pain and relax the shoulder muscles.
   Once the joint is back in place, the severe pain should end.
2. A sling or other device to hold the shoulder in place, for **a few days
   to several weeks**.
3. Rehabilitation, once pain and swelling improve — exercises to restore
   range of motion and strengthen the muscles.

Diagnosis is a medical history and an examination, usually with an x-ray to
confirm.

Why it happens again

**A dislocation can make the shoulder unstable, and then it takes less force
to dislocate it again.** Each one raises the risk of the next.

That is why the third step matters after the pain has gone, and why your
provider may ask you to keep doing some exercises indefinitely. Surgery may
be needed if the surrounding tissues or nerves were injured, or if
dislocations keep happening.

Source: MedlinePlus, U.S. National Library of Medicine.