A SLAP tear is an injury to a part of the shoulder joint called the labrum. The shoulder joint is a ball and socket joint, similar to the hip; however, the socket of the shoulder joint is extremely shallow, and thus inherently unstable. To compensate for the shallow socket, the shoulder joint has a cuff of cartilage called a labrum that forms a cup for the end of the arm bone (humerus) to move within.
A specific type of labral tear is called a SLAP tear; this stands for Superior Labrum fromAnterior to Posterior. The SLAP tear occurs at the point where the tendon of the biceps muscle inserts on the labrum.