Infraspinatus - Muscle Physiology & Functional Anatomy


Infraspinatus Muscle




  • Infraspinous fossa of the (medial) scapula


  • Middle facet of greater tubercle of the (posterior) humerus

Major Arteries:

  • Suprascapular artery

  • Circumflex scapular artery


Neural Innervation:

  • Subscapular nerve


Trigger Points:





Concentric Functions:

  • External rotation, transverse abduction & transverse extension of the humerus


Eccentric Function:

  • Decelerates shoulder internal rotation


Isometric Function:

  • Assists in posterior stabilization of the shoulder joint


Related Muscles








More Images of the Infraspinatus Muscle



Infraspinatus Prone

More Information about the Infraspinatus Muscle

Infraspinatus is derived from the Latin words 'infra' meaning beneath and 'spina' meaning spine.  The infraspinatus muscle which is assisted by the teres minor is the second most commonly injured rotator cuff muscle.  behind the supraspinatus.

The infraspinatus works along with the other rotator cuff muscles to produce dynamic caudal glide in the glenoid fossa which helps prevent impingement.



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