The supraspinatus muscle is a small, triangular muscle located in the posterior (back) region of the shoulder. It originates at the supraspinatus fossa of the scapula (shoulder blade), and inserts into the greater tubercle of the humerus (upper arm bone). The supraspinatus muscle is one of the muscles that make up the rotator cuff, and is located deep to the trapezius and deltoid muscles.

The main function of the supraspinatus muscle is to abduct (move away from the midline) the arm at the shoulder joint. This movement is essential for activities such as lifting the arm to the side, and helps to provide stability and support for the shoulder joint. The supraspinatus muscle also helps to stabilize the shoulder joint, and assist in lateral rotation (rotation outward) of the arm.

In everyday life, the supraspinatus muscle is used in many activities that involve abduction of the arm, such as reaching for something on a high shelf or waving to someone. It is also used in activities that require stability and support for the shoulder joint, such as carrying a heavy bag or pushing a door open.