Infraspinatus - Muscle Physiology & Functional Anatomy

 

Infraspinatus Muscle

Anatomy

 

Origin:

  • Infraspinous fossa of the (medial) scapula

Insertion:

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



Major Arteries:

  • Suprascapular artery

  • Circumflex scapular artery

 

Neural Innervation:

  • Subscapular nerve

 

Trigger Points:

 

 

Physiology

 

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

 

Antagonists:

 

Exercises:

 

 

 


More Images of the Infraspinatus Muscle

Infraspinatus

 

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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