Shoulder impingement is a common source of pain in the adult shoulder. Many athletes develop the condition—especially who use repetitive overhead movements such as swimmers, baseball players, or tennis players. Many people who perform repetitive lifting or overhead activities such as construction or painting also develop impingement. Trauma can also be a cause.
To provide an accurate description of impingement, we must first start with a brief look at the anatomy of the shoulder.
The rotator cuff is a tendon that links for muscles in your shoulder: the supraspinatus, the infraspinatus, the subscapularis, and the teres minor. The “ball” of the shoulder (or the head of the humerus) is covered by these four muscles, which work together to lift and rotate your shoulder. These four muscles also work together to keep the “ball” of your shoulder centered within the glenoid socket as your deltoid and other large shoulder muscles act to lift the arm overhead.
Impingement results from pressure on the rotator cuff from part of the shoulder blade (scapula) as the arm is lifted. Above the rotator cuff is a bony projection from the shoulder blade called the acromion. The acromion is positioned over and in front of the ball of your shoulder. When a person with impingement lifts their arm, the acromion rubs or “impinges” on the surface of the rotator cuff, causing pain and limited movement. The pain may be due to a “bursitis,” or inflammation, of the bursa overlying the rotator cuff or a “tendonitis” of the cuff itself. In some circumstances, a partial tear of the rotator cuff may cause impingement pain.
Between the rotator cuff tendons and the acromion is a protective fluid-filled sack called a “bursa”. When you lift your arm, there is some normal contact between the rotator cuff, the bursa, and the acromion – but if “bursitis” or inflammation exists, or if the cuff develops tendonitis, you may feel impingement pain. In some cases, the rotator cuff may have a partial tear, causing impingement pain.
Symptoms of Shoulder Impingement
People may experience mild symptoms to start. Common symptoms include pain that radiates from the front of the shoulder to the side of the arm – often present during activity as well as rest. Many people complain of sudden pain when lifting (or lowering) their arms or performing reaching movements. Additionally, athletes may experience pain when throwing or serving a tennis ball. The front of the shoulder area may be tender, and people may feel stiffness.
When shoulder impingement progresses, people may feel pain at night, and it may begin to become difficult to do activities that require strength or motion. In acute bursitis, the shoulder may become severely tender, all movement may be limited or painful.
Treatment of shoulder impingement is often first addressed non-surgically, and may include rest, avoidance of overhead activity, and nonsteroidal anti-inflammatory medication. Stretching as well as strength exercises may help, and we may recommend physical therapy. In addition, some patients will have success with cortisone injection therapy, which can relieve pain and allow patients to continue their stretching and strengthening exercises.
When non-surgical treatment does not relieve pain, your surgeon may recommend surgery to remove the impingement and create more space for the rotator cuff. Surgical treatment for shoulder impingement can be done using either arthroscopic or open techniques.
Orthopedic Specialists of Seattle provides specialized care of shoulder impingement, and performs hundreds of shoulder arthroscopies each year. In an arthroscopic procedure, the surgeon works from only two or three small incisions. A tiny fiberoptic scope connected to a large television screen allows the surgeon to examine the joint, and small instruments are used to remove bone and soft tissue. With shoulder arthroscopy, patients generally have much less postoperative pain.
If you have shoulder pain, we suggest calling to schedule an appointment with one of our orthopedic specialists.