The biceps muscle attaches to bone by their tendons at the shoulder and at the elbow. The long head of the biceps tendon runs in a groove on the front of the shoulder before entering the shoulder joint. The biceps groove is bordered on three sides by bone and covered by the transverse humeral ligament. The biceps muscle is important for bending the elbow and rotating the forearm. It also plays a role in shoulder function. The tendon may move in and out of the groove known as biceps tendon subluxation or instability. This rarely occurs without other shoulder problems. It is most often associated with a partial or complete tear of the subscapularis or supraspinatus rotator cuff.
Unstable proximal biceps tendon with fraying
Frequent Signs and Symptoms
- Clunk felt as the arm is rotated outwardly passively or inwardly against resistance
- Pain and occasionally tenderness or swelling over the front of the shoulder
- Pain and clunking that are worse with shoulder and elbow motion (bending the elbow and turning the palm up against resistance while turning the arm outward)
- Crepitation (a crackling sound) when the shoulder is moved