IMPINGEMENT SYNDROME

Impingement syndrome is a common shoulder condition seen in adults. This condition is closely related to shoulder bursitis and rotator cuff tendinitis. These conditions may occur alone or in combination.

In most parts of the body, muscles surround bones. In the shoulder, however, the muscle is surrounded by bone. If you were to tap on your shoulder, you would feel bone. This bone is called the acromion. Under that bone lies your rotator cuff muscles that control rotational shoulder movements. Under the rotator cuff muscles is your upper arm bone (or proximal humerus). In other words, the rotator cuff muscles are sandwiched between the acromion shoulder bone and the upper arm bone. This arrangement of bone/muscle/bone at the shoulder joint leads to the condition of impingement syndrome (shoulder bursitis, rotator cuff tendinitis).

When an injury to the rotator cuff muscle occurs, the muscle responds by swelling much the way an ankle does when it is sprained. However, because the rotator cuff muscle is surrounded by bone, its swelling causes a number of events to occur. The pressure within the muscle increases, resulting in compression and loss of blood flow in the small blood vessels called capillaries. When the blood flow is diminished, the muscle tissue begins to fray much like a rope. As the muscle tissue swells, it results in the classic features of a pain characterized like a toothache. Pain is aggravated by actions such as reaching up behind the back and reaching up overhead. Night pain may also result from this shoulder condition and results in sleep interruption. Initial treatment of impingement syndrome consists of resting the shoulder muscles and reducing inflammation.

Early symptoms include dull pain during activity and rest, severe pain with lifting, reaching up behind the back and reaching up overhead. As the condition progresses, you may experience pain at night which can result in sleep interruption. Additionally, range of motion and strength can be limited.

The goal of treatment is to reduce pain and inflammation and to restore function of the shoulder. The healing process can take up to months for full function without pain. Initial treatment of impingement syndrome consists of resting the shoulder muscles and reducing inflammation. Anti-inflammatory medicine may also be prescribed to reduce swelling. Physical therapy can help restore the normal range of motion and down the road, strengthen the muscles to avoid reoccurrence. If these methods do not work, steroid injections may be administered for the same purpose. Surgery may be recommended if nothing else works.