The shoulder is a ball-and-socket joint that allows for an abundance of varied types of movements. Unlike the hip joint, which is a very stable joint, the shoulder is more closely similar to a bowling ball on a dinner plate. This means that while shoulder has excellent movement, it also can become unstable and susceptible to injury.

The shoulder joint is surrounded by a capsule of tough fibers. If the shoulder is pushed too far in any direction, it can dislocate, which means that the upper arm bone has stretched or torn through the capsule. In addition to tearing the capsule, dislocations can cause fractures to the shoulder socket or tears to the labrum or ligaments. The labrum is a fibrous ring of cartilage (similar to rubber) that helps make the socket deeper. Ligaments are strong fibers that help to hold the shoulder together.

The bursa is a fluid-filled sac in the shoulder that helps reduce friction and protect the muscles from rubbing against the bones. Excessive overuse or improper conditioning can cause irritation the bursa.

Tendonitis/Impingement Syndrome

Tendons attach muscle to the bone. Overuse or improper conditioning can irritate the tendons, causing tendonitis. If the situation becomes chronic, the body begins to deposit calcium in the tendon. Eventually the tendon becomes pasty and will break. This is called calcific tendonitis.

There are four major muscles that attach to the shoulder joint. They are referred to together as the rotator cuff. Injury or excessive overuse can cause a tear in one or several of these muscles.

Another result of wear and tear is arthritis, which is the breakdown or softening of the bone in the shoulder. This generally occurs on the ball and socket and sometimes at the AC joint, which is the "tip" or "point" of the shoulder.

Adhesive capsulitis or "frozen shoulder" is a condition that comes on slowly. The exact cause is not known at this time. The shoulder becomes painful, leading to reduced motion. The joint capsule becomes adhered to other tissues in the shoulder joint, which leads to less range, and the cycle continues until there is no motion left in the shoulder.

Fractures usually occur with trauma or a fall, but as noted earlier, can happen with dislocations as well.

Modalities such as ultrasound, electrical stimulation, heat and cold can enhance healing and provide pain relief for conditions of bursitis, tendonitis, and minor rotator-cuff tears. Therapeutic exercise is initiated for range-of-motion recovery, strengthening, conditioning and endurance. Exercise is also helpful for regaining stability in the dislocated shoulder. Manual therapy or hands-on treatment may be necessary for frozen shoulder or situations in which range is limited. With proper care and perseverance with therapy, many shoulder dysfunctions can be resolved. If inflammation persists, your physician may elect to inject an anti-inflammatory drug into the shoulder joint.

If a rotator cuff tear, fractures, labral tear or arthritic damage is severe enough, the shoulder may require surgery.