The labrum is a rim of strong, fibrous tissue that surrounds the outer edge of the shoulder socket (or glenoid) and acts as a “bumper” to the upper arm bone (or humerus). It helps to deepen the socket and stabilize the shoulder joint while allowing it a greater range of motion.

A SLAP (short for Superior Labrum Anterior and Posterior) tear or lesion is an injury to the top (superior) part of the labrum where the biceps tendon anchors to the labrum. The tear can occur both in front (anterior) and back (posterior) of the anchor point.

SLAP tears can cause damage to the biceps tendon and make using the biceps painful and difficult, even in small tasks such as using a screwdriver.

SLAP injuries are commonly caused by a fall on an outstretched arm, a forceful lifting maneuver, or repetitive overhead throwing.