Infraspinatus

The infraspinatus muscle is vital for shoulder function as it allows for lateral rotation of the humerus, which is crucial for various activities such as lifting objects overhead and throwing motion in sports. It helps stabilize the head of the humerus in the glenoid cavity of the scapula, thereby preventing dislocation during arm movement. This muscle works in conjunction with the other rotator cuff muscles, allowing for coordinated movement and control of the shoulder joint. Its role in stabilizing the shoulder during dynamic activities underscores its importance not only for athletes but also for everyday functions that require reaching or lifting.

The infraspinatus is located on the posterior aspect of the shoulder. It originates from the infraspinous fossa, a concave surface on the scapula below the spine of the scapula. The muscle fibers extend laterally and insert into the greater tubercle of the humerus, situated just below the acromion process of the scapula. This positioning allows the infraspinatus to play a key role in connecting the scapula to the humerus while contributing to the overall structure and movement of the shoulder joint.

• The infraspinatus is one of the most commonly injured rotator cuff muscles, particularly in athletes who frequently perform overhead motions.
• Infraspinatus injuries can lead to pain, weakness, and reduced range of motion in the shoulder.
• This muscle is extensively used in activities like swimming, tennis, and baseball, where shoulder mobility is essential.