Hawaii Massage License Practice Exam

What is the primary function of the infraspinatus muscle?

1. Abduction of the shoulder

2. Adduction of the shoulder

3. External rotation of the shoulder

4. Internal rotation of the shoulder

The correct answer is: External rotation of the shoulder

The infraspinatus muscle plays a crucial role in the movement and stabilization of the shoulder joint, particularly by enabling external rotation of the arm. This muscle is one of the four rotator cuff muscles and is located on the back of the shoulder blade. When the infraspinatus contracts, it helps to rotate the humerus (the upper arm bone) away from the body, which is essential for performing various upper body movements that require external rotation, such as throwing or reaching behind. Understanding this muscle's function is important not only for those studying anatomy and physiology but also for professionals in fields such as physical therapy, sports medicine, and massage therapy, as they may work with clients who require rehabilitation for shoulder injuries or conditions affecting shoulder mobility. Proper functioning of the infraspinatus is essential for overall shoulder stability and function, as it works in conjunction with the other muscles of the rotator cuff to maintain the integrity of the shoulder joint during movement.