The Shoulder

The normal shoulder joint can be thought of as a golf ball balancing on a tee. If a large enough force in the right direction is applied to the arm, the ball will dislocate from the socket, resulting in a dislocated shoulder.

The rotator cuff is the group of four muscles and tendons that surround the shoulder joint, providing strength and stability. Above the rotator cuff there is a bursa, or sac of tissue, that covers and protects the rotator cuff as it comes into close contact with bones around the shoulder. When the rotator cuff is injured or damaged, it can lead to inflammation of the bursa, called bursitis, which causes pain and loss of motion.

Osteoarthritis is the most common type of shoulder arthritis. This is also known as degenerative joint disease. Less common types of shoulder arthritis are rheumatoid arthritis (inflammatory) and traumatic arthritis.

A shoulder fracture can result from a fall on the shoulder, a motor vehicle accident, contact sports, etc. The type of shoulder fracture varies by age. Most fractures in children occur in the clavicle bone (collarbone). In adults, the most common fracture is of the top part of the humerus (upper arm bone).

The shoulder is a ball and socket joint that allows a wide range of movement. Injury or degradation of the joint structures, from the muscles and soft tissues to the bones, can result in shoulder pain.