The biceps brachii is a muscle located on the front of the upper arm. It has two attachments at the shoulder. The short head attaches to the corocoid process of the scapula or shoulder blade and the long head attaches to the top of the glenoid or shoulder socket of the scapula. Its function is to flex the elbow and supinate the forearm or turn the palm up (like turning a doorknob). This injury is usually found in middle-aged patients. There often is some degree of pre-existing degenerative changes within the tendon, that predisposes it to fail. The rupture can occur from an injury to the shoulder caused by falling on an outstretched arm or a direct force to the upper arm.
Diagnosis:
Patients usually complain of anterior shoulder pain prior to its rupture. There is a sudden pain associated with an audible snap when the tendon finally fails. Some patients may experience pain relief with the rupture. Following the failure, the tendon retracts altering the shape of the biceps in the upper arm (this is referred to as a “Popeye muscle”). The retracted muscle sags, giving it the appearance of a very prominent bulging biceps muscle. One must consider the possibility of a combined injury to the rotator cuff tendons with the biceps injury. An evaluation by your sports medicine expert will determine the extent of the injury. An MRI scan may be necessary to further define the tendon involvement.
