Infraspinatus Anatomy

Infraspinatus Muscle

Origin: Infraspinous fossa of the scapula
Insertion: Middle facet of the greater tubercle of the humerus
Actions: External rotation of arm
Innervation: Suprascapular nerve (C5, C6)
Blood Supply: Suprascapular Artery and circumflex humeral artery from the axillary artery

Primary Actions of the Infraspinatus

1. Internal rotation of the arm at the shoulder

1. External rotation of the shoulder


  • Teres Minor
  • Deltoid (posterior fibers)


  • Subscapularis
  • Deltoid (anterior fibers)
  • Latissimus Dorsi
  • Pectoralis Major
  • Teres Major


Secondary Actions of the Infraspinatus

1. Assists with depression of the humeral head


  • Teres Minor
  • Subscapularis