What is the primary action of the infraspinatus muscle?

The primary action of the infraspinatus muscle is external rotation of the shoulder. This muscle is one of the four rotator cuff muscles and is located on the posterior aspect of the shoulder. It originates from the infraspinous fossa of the scapula and inserts into the greater tubercle of the humerus. When the infraspinatus contracts, it pulls the humerus laterally, allowing for the external rotation movement at the shoulder joint.

Understanding the role of the infraspinatus is vital for athletes and individuals engaged in activities requiring shoulder mobility and stability. For example, in sports such as throwing or swimming, the proper functioning of this muscle helps to prevent injury and maintain shoulder health. This knowledge is essential in sports massage to aid recovery and enhance performance, as applying techniques to the muscles involved in external rotation can relieve tension and improve range of motion.

The other options pertain to actions performed by different muscles around the shoulder and elbow. Internal rotation is primarily the action of muscles like the subscapularis, while adduction and elbow flexion involve different muscle groups altogether. Understanding the specific actions of each muscle is crucial for effective treatment and rehabilitation strategies in sports massage.