Loose shoulder (multidirectional instability) is a condition that occurs when the tissue that forms a capsule around the shoulder joint stretches and can no longer keep the ball of the humerus (the top of the arm bone) within the shoulder joint or socket. Patients will experience dislocations of the shoulder. Typically, this condition is caused by repetitive stress through sports like baseball, volleyball or even swimming. Patients with loose shoulder may experience frequent shoulder dislocations.

Cause

Loose shoulder occurs when the head of the upper arm bone is forced out of the shoulder socket. This can happen as a result of a sudden injury or from overuse. Prior instances of shoulder dislocation, where the ball of the humerus slips out of the shoulder socket, can stretch or tear the soft tissue that forms the capsule. Loose shoulder can also occur as a result of a sudden injury.

Symptoms

The main symptom is a looseness or feeling of instability in the shoulder, as if it could fall off at any moment. This is called apprehension. Other symptoms include:

  • Pain caused by shoulder injury
  • Repeated shoulder dislocations
  • Repeated instances of the shoulder giving out
  • A persistent sensation of the shoulder feeling loose, slipping in and out of the joint, or just “hanging there”