The term SLAP stands for Superior Labrum Anterior and Posterior. In a SLAP injury, the top (superior) part of the labrum is injured.
This top area is also where the biceps tendon attaches to the labrum. A SLAP tear occurs both in front (anterior) and back (posterior) of this attachment point. The biceps tendon can be involved in the injury, as well.
A SLAP tear is an injury to the labrum of the shoulder, which is the ring of cartilage that surrounds the socket of the shoulder joint. Shoulder is a ball-and-socket joint made up of three bones: your upper arm bone (humerus), your shoulder blade (scapula), and your collarbone (clavicle).
The head of your upper arm bone fits into a rounded socket in your shoulder blade. This socket is called the glenoid. Surrounding the outside edge of the glenoid is a rim of strong, fibrous tissue called the labrum.
The labrum helps to deepen the socket and stabilize the shoulder joint. It also serves as an attachment point for many of the ligaments of the shoulder, as well as one of the tendons from the biceps muscle in the arm.