Shoulder Dislocation

The shoulder

The shoulder is the most versatile joint in the body, moving in many different directions. A sudden force to the shoulder, as from a collision, for example, can cause the top of the upper arm bone (humerus) to pop out of the socket of the shoulder blade (scapula).

Shoulder dislocations are common for athletes in contact sports or sports that can involve lots of falling, such as gymnastics. Shoulder dislocations are also common to other accidents, such as car crashes and falls.

Once a shoulder is dislocated, it will be prone to further dislocations. Severe damage to the nerves, blood vessels, tendons, and/or ligaments may require surgical repair.

Here is the anatomy of the shoulder.

Parts of the shoulder

  • the ball on top of the upper arm bone (humerus)
  • the socket (glenoid) of the shoulder blade (scapula), in which the ball of the humerus fits
  • a rim of cartilage in the scapula (labrum) to make the glenoid a little deeper
  • surrounding ligaments (joint capsule)
  • surrounding muscles and tendons spanning from the scapula to the humerus (rotator cuff) to stabilize the upper arm bone and hold it tightly into the glenoid

What happens when a shoulder dislocates?

Most commonly, the ball of the humerus bone rolls out of the glenoid when the arms are struck while the elbows are held out (i.e. collisions in football).

Dislocation can also happen when:

  • the ball of the humerus is forced backward
  • landing on an outstretched hand to break a fall
  • direct blow to the front of the shoulder

Here is the anatomy of a healthy shoulder, how an anterior dislocation appears, and how a posterior dislocation appears.

Who is at risk for a shoulder dislocation?

  • athletes in contact sports, such as football or hockey
  • athletes in sports that involve frequent falling, such as gymnastics, skiing, or volleyball
  • active people between the ages of 18 and 25
  • older people with weaker ligaments or a greater tendency to fall down

What are the symptoms of a shoulder dislocation?

  • a visibly deformed shoulder
  • swelling or bruising
  • extreme pain
  • inability to move the arm
  • numbness, weakness, or tingling around the neck or down the arm
  • painful muscle spasms around the shoulder

How Boston Children's Hospital approaches shoulder dislocation

Because a dislocated shoulder is at risk for dislocating again, Boston Children's will help your child strengthen the muscles around the shoulder joint to help prevent future injuries. And if your child's shoulder is hurt too badly to be helped by conservative approaches, Boston Children's orthopedic team will help restore stability and range of motion to your child's shoulder.

You can have peace of mind knowing that the skilled experts in our Hand and Orthopedic Upper Extremity Program have treated thousands of babies and children with many arm conditions. We provide expert diagnosis, treatment and care, and we benefit from our advanced clinical and scientific research.