A pro football player attempts an arm tackle and hears a pop in his upper arm. A weightlifter doing curls suddenly feels his shoulder "bubble." A woman rearranging the living room furniture gets a sharp pain in her shoulder. Each of these individuals just ruptured their biceps tendon.
Tendons attach muscle to bone. The biceps muscle in the upper arm splits near the shoulder into a long head and a short head. Both attach to the shoulder in different places. At the other end of the muscle, the distal biceps tendon connects to the smaller bone (radius) in the lower arm. These connections help the muscle stabilize the shoulder, rotate the lower arm and accelerate or decelerate the arm during overhead motions such as pitching.
The long head of the biceps tendon is vulnerable to injury because it travels through the shoulder joint to its attachment point. If it tears, you may lose some strength in your arms and be unable to turn your arm from palm down to palm up. Because the torn tendon can no longer keep the muscle taut, you may also notice a bulge in the upper arm (Popeye muscle). If the distal tendon tears, you may be unable to lift items or bend your elbow.
Possible causes
Ruptures of the distal tendon near the elbow are rare. They usually occur when an unexpected force is applied to a bent arm. For example, a snowboarder can rupture the distal biceps tendon if he or she uses the arm to try to break a fall during a turn.
The proximal biceps tendons near the shoulder tear more easily. Tears can be either partial or complete. Often, these tendons are already frayed, particularly if you are over 40 years of age, have a history of shoulder pain, and participate in activities that involve overhead motions. Among the elderly, biceps tendon ruptures near the shoulder are often associated with rotator cuff tears.
Signs and symptoms
posted 11/1/2000
Your Orthopaedic Connection, Patient Education Web Site of the American Academy of Orthopaedic Surgeons, © 2002