Posterior Deltoid

• R (direction)

  • Obliquely down and anteriorly

  A) Posterior Deltoid

  
• O (origin)

  • Lower lip of the spine of the scapula

  A) Posterior Deltoid

  
• I (insertion)

  • Deltoid tuberosity on the lateral surface of the humerus via a short thick tendon

  A) Posterior Deltoid

  
• A (actions)

  • Strong extensor and lateral rotator of the glenohumeral joint

  A) Posterior Deltoid

  
• NS (nerve supply)

  • Axillary nerve (C5, C6)

  A) Posterior Deltoid

  
• Function:

  Acts as antagonist to pectoralis major and latissimus dorsi during adduction of the arm to counteract medial rotation

  A) Posterior Deltoid