Serratus Anterior

• O (origin)

  • Via fleshy digitations to the outer surfaces of the upper 8/9 ribs and the intercostal fascia

  A) Serratus anterior

  
• R (direction)

  • Backwards

  A) Serratus anterior

  
• I (insertions)

  • Costal surface of the medial border of the scapula

  A) Serratus anterior

  
• A (actions)

  • Protraction and lateral rotation of scapula

  A) Serratus anterior

  
• NS (nerve supply)

  • Long thoracic nerve (C5 - C7)

  A) Serratus anterior

  
• Function:

  • Movements which drive the scapula forwards e.g. pushing, punching
  • Major stabiliser of scapula during upper limb movements, holding medial border against the thoracic wall

  A) Serratus anterior

  
• Winged Scapula:

  • Paralysis of serratus anterior e.g. severed long thoracic nerve
  • ‘Winging’ scapula in which medial border of scapular stands away from chest wall
  • Lateral rotation of scapula limited so arm cannot be abducted more than 90 °

  A) Serratus anterior