The labrum is a collagenous cuff that encapsulates the ball-and-socket shoulder joint. The shoulder joint inherently has less stability due to incredible range of motion. The labium provides additional stability and support by increasing the depth of the shoulder socket (the glenoid).

Labral tears can occur causing general shoulder pain, discomfort during specific activities, and a catching sensation during certain movements.

A SLAP injury, which stands for Superior Labrum from Anterior to Posterior, is a tear to the labrum at the top of the glenoid where the biceps attach to the shoulder.

SLAP injuries are most commonly seen with repetitive overhead actions such as throwing a baseball, falling on an outstretched hand, and lifting heavy objects.

Further Reading:

American Academy of Orthopaedic Surgeons: Shoulder Joint Tear (Glenoid Labrum Tear)

BioMet: Arthroscopic Surgery / Labral Tears