What is the primary function of the supraspinatus muscle?

The supraspinatus muscle plays a crucial role in shoulder abduction, which is the movement of raising the arm away from the body. This muscle is one of the four rotator cuff muscles, and it is specifically tasked with initiating the first 15 degrees of shoulder abduction. It assists the deltoid muscle in this action, which takes over to lift the arm further after that initial degree of movement.

Understanding the role of the supraspinatus is essential for recognizing how shoulder mechanics function, particularly in activities that involve lifting or reaching. Its proper functioning is vital for maintaining shoulder stability and mobility, making it a key muscle in both athletic performance and daily activities. In contrast, the other functions listed such as shoulder flexion, extension, and rotation involve different muscle groups and movements not directly attributed to the supraspinatus.