A SLAP (superior labral anterior posterior) shoulder injury is not the same as a rotator cuff tear. Both affect the shoulder. Different parts are injured. In the rotator cuff tear, one of four tendons around the shoulder is torn.

The SLAP lesion is a tear of the fibrous rim along the upper portion of the glenoid cavity (shoulder socket). The upper (superior) part of the labrum anchors one of the two tendons of the biceps muscle.

A SLAP injury occurs if the arm is bent inward at the shoulder enough times or with enough force. The upper arm (humerus) acts as a lever and tears the biceps tendon and labrum cartilage from the glenoid cavity. The tear occurs in a front-to-back (anterior-posterior) direction. That's why it's called a superior labrum anterior-posterior tear. In simpler terms it's an upper rim front-to-back injury.

The SLAP lesion can occur as a result of overuse or trauma. It's most common among overhead throwing athletes. When the force of injury is great enough the rotator cuff can be torn along with the labrum.