The shoulder joint is considered a ball and socket joint. The
ball is the head of your humerus (upper arm bone) and the socket is called the
glenoid. Think of a golf ball sitting on a tee, where the ball is the humerus
and the tee is the glenoid. A dislocation is when the head of the humerus slips
out of the glenoid.
The shoulder is the most commonly dislocated joint in the body. Dislocations
are typically caused by falls or if the arm is forced into an awkward position
by another force such as a tackle in football. Most dislocations occur anteriorly
(to the front), but can also happen posteriorly (to the back) or inferiorly
(downward into the arm pit)
Signs and symptoms may include pain, an obvious deformity, and the inability
to move the arm. Immediate attention is necessary.