Middle Deltoid

• O (origin)

  • Lateral margin of the acromion process via 4 tendinous slips

  A) Middle Deltoid

  
• R (direction)

  • Downwards

  A) Middle Deltoid

  
• I (insertion)

  • Deltoid tuberosity via a short thick tendon

  A) Middle Deltoid

  
• A (actions)

  • Abduction (in the line of the scapula and not the anatomical position) beyond the initial 20 °

  A) Middle Deltoid

  
• NS (nerve supply)

  • Axillary nerve (C5, C6)

  A) Middle Deltoid