Rotator cuff injuries and labral tears are the most common shoulder injuries.
Rotator Cuff Injury
The muscles that help hold the upper arm in the shoulder joint (the rotator cuff muscles) can get pinched (shoulder impingement syndrome), become inflamed (tendinitis), or can tear partially or completely.
Rotator cuff pinching (impingement) and tendinitis often occur in sports that require the arms to be moved over the head repeatedly, such as pitching in baseball, lifting heavy weights over the shoulder, serving the ball in racket sports, and swimming freestyle, butterfly, or backstroke. Repeatedly moving the arm over the head causes the top of the arm bone to pinch the rotator cuff muscles against the top part of the shoulder blade and results in inflammation and swelling of the muscles. If the movement is continued despite the inflammation, the tendon can weaken and tear.
Symptoms and Diagnosis
Shoulder pain is the main symptom. At first, the pain occurs only during activities that require lifting the arm over the head (impingement syndrome). Pain is worse when lifting the arm between 60 and 120 degrees away from the side. Unless effectively treated, the shoulder may later become painful at rest (tendinitis), often particularly at night, disrupting sleep. If the tendon tears, normal outward turning of the arm at the shoulder is weak or impossible.
Doctors make the diagnosis based on the person's symptoms and examination findings. Magnetic resonance imaging (MRI) sometimes is needed to rule out a tear of the rotator cuff muscles.
The shoulder can be rested in a sling for a couple of days if pain is moderate or severe. Exercises that involve raising the arm above the level of the shoulder, especially against resistance, should be avoided. Once the shoulder can be moved through its range of motion without pain, the rotator cuff muscles are strengthened. Exercises to strengthen some of the muscles restore balance to the rotator cuff and decrease impingement during activities that involve reaching overhead. If the pain is severe, doctors sometimes inject a corticosteroid into the space above the rotator cuff (bursa).
Surgery is sometimes needed when the rotator cuff is torn or tendinitis does not resolve with other treatments. Surgery removes excess bone from the shoulder, creating a larger space for the rotator cuff and thus preventing pinching of the rotator cuff when the arm moves above the head. If the rotator cuff is torn, surgical repair is usually recommended.
The glenoid labrum, which cushions the shoulder joint, can tear as a result of injury.
The shoulders are ball and socket joints that allow the arms to have inward and outward rotation as well as forward, backward, and sideways movement. The shoulder tends to be unstable. It has been likened to a golf ball sitting on a tee because the socket (glenoid bone) is very shallow and small compared to the size of the ball (humeral head). To enhance stability, the socket is deepened by the labrum, a rubbery material attached around the lip of the glenoid bone. The labrum can tear during athletic activities, especially during throwing sports, or as a result of falling and landing on an outstretched arm.
When the labrum tears, the athlete feels pain deep in the shoulder during movement, for example, when pitching a baseball. This discomfort may be accompanied by a painful clicking or clunking sensation and a feeling of catching in the shoulder.
MRI may be necessary to make the diagnosis. Physical therapy is the usual initial treatment. If symptoms do not resolve, surgical repair is usually needed.
Last full review/revision February 2009 by Paul L. Liebert, MD