Which movement is primarily performed by the supraspinatus muscle?

The supraspinatus muscle plays a critical role in shoulder movements, specifically shoulder abduction. This muscle is part of the rotator cuff group and is situated above the spine of the scapula. Its primary function is to initiate the abduction of the arm at the shoulder joint, particularly during the first 15 to 30 degrees of motion.

When the arm is raised, the supraspinatus works in conjunction with the deltoid muscle to lift the arm laterally away from the body. While the deltoid becomes more influential in shoulder abduction as the arm is raised further, the supraspinatus is essential for the initial phase of this movement. Understanding the anatomical positioning and function of the supraspinatus helps clarify its predominant role in shoulder abduction compared to other movements.