The supraspinatus muscle is a small muscle that helps make up the rotator cuff. It is responsible for shoulder stability as well as lateral rotation of the arm, and help initiate abduction of the shoulder. This muscle can become injured from overhead movements of the shoulder such as painting a ceiling or throwing movements. When this happens trigger points will form producing pain felt in the shoulder, and down the arm. These points will also cause weakness and stiffness. Trigger points must be released for the area to heal.