People with shoulder pain often assume they’ve injured their rotator cuff, but sometimes that is not the only culprit. Shoulder specialist and orthopedic surgeon Dr. Marc Kowalsky of ONS notes that an injury to the tendon of the biceps, the prominent muscle in the upper arm that made Popeye and spinach famous, can cause shoulder pain and other uncomfortable symptoms such as clicking or popping.
“The biceps tendon is an often-misunderstood structure of the shoulder and arm,” said Dr. Kowalsky. “We now know that damage to that tendon is often the primary cause of shoulder pain in active people.”
Anatomically, the biceps muscle has two tendons, called heads, that attach it from the elbow to the shoulder. The tendon of the short head attaches to a bone on the shoulder blade outside of the joint. The long head, usually the source of the pain, takes a circuitous path into the shoulder joint and attaches to the top of the socket and the glenoid labrum.
As with any other tendon in the shoulder, the biceps can develop tendonitis and tears as a result of repetitive, strenuous overhead activities. Pain from biceps tendonitis or partial tearing typically occurs over the front of the shoulder, and radiates toward the biceps muscle. If the biceps tendon fully tears or ruptures, patients may notice bruising and a cosmetic deformity as the muscle descends and becomes more prominent, in what is known as a “Popeye sign”. Lastly, the biceps tendon can be affected by instability, particularly in certain overhead athletes including swimmers. Biceps instability can also occur in association with a particular tear of the rotator cuff tendon in the front of the shoulder. When this happens, pain is caused because the biceps has slipped from its bony groove of the upper humerus (head of the arm bone).
Most patients with tendonitis, a partial, or complete rupture of the long head of biceps can be treated conservatively, with a combination of ice, anti-inflammatory medication, physical therapy, and corticosteroid injection, said Dr. Kowalsky. Although the cosmetic deformity from a complete rupture will persist, once the pain from the acute rupture improves, strength and overall function of the shoulder should return to normal. If conservative measures fail to relieve symptoms from biceps problems, surgery may be recommended. If you experience shoulder pain, consult with a fellowship-trained shoulder specialist at ONS.