Lecture Notes on Muscle Groups and Scapular Movement

Scapular Elevation

• Key Muscles:
  • Levator Scapula
    • Origin: Spine
    • Insertion: Superior angle of the scapula
    • Function: Lifts the scapula when it contracts
  • Upper Trapezius
    • Origin: Spine
    • Insertion: Scapula
    • Function: Elevates the scapula when it contracts

Scapular Depression

• Key Muscles:
  • Lower Trapezius
    • Function: Pulls the scapula down
  • Latissimus Dorsi (indirectly)
    • Function: Assists in scapular depression through GH joint adduction
  • Pectoralis Major
    • Function: Contributes to scapular depression through adduction of the GH joint
• Additional Notes:
  • Scapular depression often works with gravity
  • Against gravity examples:
    • Walking with crutches
    • Sliding board transfer (patients push their body up to slide)

Scapular Upward Rotation

• Key Muscles:
  • Upper Trapezius
    • Function: Pulls the scapula upward
  • Lower Trapezius
    • Function: Pulls the scapula downward
  • Serratus Anterior
    • Function: Pulls the scapula laterally
• Combined Action: These three muscles work together to produce upward rotation of the scapula

Scapular Downward Rotation

• Key Muscles:
  • Rhomboid Minor
    • Origin and Insertion: Located above the spine of the scapula
    • Function: Pulls the scapula downward
  • Rhomboid Major
    • Origin and Insertion: Located below the spine of the scapula
    • Function: Pulls the scapula downward
  • Pectoralis Minor
    • Origin and Insertion: Attaches to the coracoid process
    • Function: Pulls the scapula downward
• Additional Notes:
  • The mnemonic to remember the rhomboids: Minor is above the spine, Major is below the spine

Scapular Protraction

• Key Muscle: Serratus Anterior
  • Origin: Rib
  • Insertion: Medial border of the scapula
  • Function: Moves the scapula laterally and forward, causing a winging motion
• Clinical Note: Excessive winging indicates a weak serratus anterior or a long thoracic nerve injury

Scapular Retraction

• Key Muscles:
  • Rhomboid Minor and Major
  • Middle Trapezius
    • Function: Pulls the scapula toward the midline

Summary

• Muscle groups involved in scapular movement include:
  • Elevation
  • Depression
  • Protraction
  • Retraction
  • Downward rotation
  • Upward rotation