Rotator Cuff Muscle Anatomy: Supraspinatus, Infraspinatus,
Teres Minor, and Subscapularis

This page has a brief description of the rotator cuff anatomy.

There are 4 muscles that form the cuff. They have individual actions, but they all work together to dynamically stabilize the shoulder.

The 4 muscles are the Supraspinatus, Infraspinatus, Teres Minor, and Subscapularis.

The tendons and muscles are all vulerable to overuse injuries such as tendonitis, and tendonitis is a very common shoulder injury for people who do a lot of upper body and arm exercises.

Note: If you have shoulder pain, you should seek the counsel of a licensed health professional. The information on this site is only for informational purposes and is not intended as medical advice.

4 Rotator Cuff Muscles

Supraspinatus: The supraspinatus gets its name from it's position on the scapula. It is above the spine of the scapula (shoulder blade).

If you pat yourself on the back, you should feel a the bony ridge of the scapula-- that is the spine of the scapula. The supraspinatus starts just above that ridge and it's underneath the trapezius muscle.

It pulls the arm out to the side and works with the other muscles to stabilize the shoulder.

Infraspinatus: The infraspinatus also gets its name from it's position. It is below the spine of the scapula.

This muscles rotates the shoulder out to the side (external rotation). External rotation exercises are among the most popular shoulder rehab exercises.

Teres Minor: The teres minor is a small muscle that starts on the outside of the shoulder blade just below the infraspinatus. It helps the infraspinatus to turn the shoulder out to the side and helps to keep the shoulder stable.

Subscapularis: The subscapularis is a unique muscle because it is the only one of the 4 that is located on the front of the shoulder.

Since it is on the front of the shoulder blade it rotates the shoulder inwards (internal rotation). Internal rotation exercises are just as important as external rotation exercises.


All 4 muscles are important, so it is important to exercise all 4 muscles. External rotation tends to be weaker than internal rotation so your workout may include slightly more emphasis on the external rotation motion.

Yours in Health,
Dr. Charles PT/PT

Return to the Main Arm Muscle Anatomy Page

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