Shoulder Biomechanics Part 3: The Supraspinatus Muscle

The final rotator cuff muscle in this series on shoulder biomechanics is the supraspinatus. This muscle originates in a trough-like area above the scapular spine, hence its name supra, which means “above.” The supraspinatus then inserts onto the greater tuberosity just behind where the long head of the biceps enters the shoulder (figure 1).

(We’ve covered the subscapularis, infraspinatus and teres minor muscles  along with some key biomechanical points about each muscle—click to review.)

Contracting the supraspinatus abducts the humerus at the glenoid socket (takes the arm out to the side) for the first 15 degrees. After that, it becomes a synergist of the deltoid for abduction. As with the other muscles of the cuff, the supraspinatus also stabilizes the humeral head in the socket. Figure 2 illustrates this in Warrior II. 

The supraspinatus is the rotator cuff muscle that is most frequently torn. Tears start to become common beyond the age of forty, with an increased incidence in each decade of life. Figure 3 illustrates a supraspinatus rotator cuff tear.

For more information on shoulder anatomy, visit these links:

Shoulder Anatomy 101: A Beginner’s Guide to the Shoulder Girdle

Shoulder Anatomy 102: A Beginner’s Guide to the Major Muscles of the Shoulder Girdle

Learn more about yoga and shoulder anatomy with YogaUOnline and Julie Gudmestad – Yoga Anatomy: Keeping the Rotator Cuff Healthy in Yoga.

Reprinted with permission from Daily Bandha.

3d Graphic Designer / Illustrator Chris Macivor has been involved in the field of digital content creation for well over ten years. He is a graduate of Etobicoke School of the Arts, Sheridan College and Seneca College. Chris considers himself to be equally artistic and technical in nature. As such his work has spanned many genres from film and television to video games and underwater imagery.