Muscles of the back

  1. Trapezius M. function
    • Elevation, retraction, and rotation of scapula.
    • Helps in adduction and slight elevation of arm.
  2. Trapezius M. innervation
    Accessory N. (CNXI) and C3-C4 (propioception and pain)
  3. Rhomboid Minor/Major M. function
    • Press the scapula to the thoracic wall.
    • Retraction of scapula medially.
  4. Rhomboid Minor/Major M. innervation
    Dorsal scapular N. (C4-C5)
  5. Leavtor Scapulae M. function
    Elevates the scapula.
  6. Levator Scapulae M. innervation
    Dorsal scapular N. (C4-C5)
  7. Latissimus dorsi M. function
    • Adduction and lowering the arm.
    • Medial rotation and extension of the arm.
    • Raises the body toward the arm when climbing.
  8. Latissimus dorsi M. innervation
    Thoracodorsal (C6, C7, C8)
  9. Serratus posterior inferior/superior M. function
    • Rib elevation
    • *May function as accessory muscles of respiration (in COPD).
  10. Serratus posterior inferior/superior M. innervation
    Intercoastal N. (T9-T12)
  11. Erector Spinae lateral M. function
    • Erect posture of the body.
    • Splenii rotate the head.
    • Extensors when both sides contract.
    • Flexion when one side contracts.
  12. Erector Spinae lateral M. innervation
    Primary spinal dorsal rami.
  13. Erector Spinae medial M. function
    • Extensors when both sides contract.
    • Flexors when one side contracts.
    • Some stabilize and some rotate the vertebral column.
  14. Erector Spinae medial M. innervation
    Primary dorsal rami.
  15. Suboccipital triangle function
    Turning the head backward or laterally.
  16. Suboccipital triangle innervation
    • Sensory: Greater occipital N (C2)
    • Suboccipital N (C1) innervates all 3 muscles
  17. Suboccipital triangle contents
    • Third part of vertebral artery.
    • Suboccipital N (C1) innervating all 3 muscles.
    • Suboccipital plexus of veins.
Card Set
Muscles of the back
Muscle innervation and function of the back.