MSA1 Shoulder Muscles

  1. Origin and insertion of Corachobrachialis
    • Origin- Coracoid process of the scapula
    • Insertion- Medial surface of the middle shaft of the humerus
  2. Action, R/N, and D/S of corachobrachialis
    • Flexes the shoulder (GH joint)
    • Adducts shoulder
    • NR
    • B (mostly superficial, but deep at the origin)
  3. Origin and insertion of Pectoralis Major
    • Origin- medial half of clavicle, sternum, cartilage of ribs 1 through 6
    • Insertion- crest of greater tubercle of humerus
  4. Actions of all fibers of Pectoralis Major
    • Adducts shoulder
    • Medially rotates shoulder
    • Assists in elevating thorax in forced inspiration (sudden inhalation)
  5. Actions of the upper fibers of Pectoralis Major
    Flexes and horizontally adducts the shoulder
  6. Action of the lower fibers of Pec Major
  7. Pec Major- R/N, D/S
    • Nonropy
    • Superficial
  8. Origin and insertion of Teres Major
    • (Lats' little helper)
    • Origin- Inferior angle and lower 1/3 of lateral border of the scapula
    • Insertion-Crest of the lesser tubercle of the humerus
  9. Action, R/N, and D/S of Teres Major
    • Extends the shoulder
    • Adducts shoulder
    • Medially rotates the humerus
    • Nonropy
    • Superficial
  10. Latissimus Dorsi is the ____ muscle of the back
    broadest muscle of the back
  11. Origin and insertion of Latissimus Dorsi
    • Origin- Inferior angle of scapula, SPs of last 6 lumbar vertebrae, last 3-4 ribs, thoracolumbar aponeurosis, posterior iliac crest
    • Insertion- Intertubercular groove of the humerus
  12. Action, R/N, and D/S of Latissimus Dorsi
    • Extends shoulder
    • Adducts shoulder
    • Medially rotates the humerus
    • Nonropy
    • Superficial
  13. Origin and insertion of Deltoid
    • Origin- Lateral 1/3 of clavicle, acromion and spine of scapula (fan-shaped origin)
    • Insertion- Deltoid tuberosity
  14. Action of all fibers of the Deltoid
    Abduct shoulder joint
  15. Action of posterior fibers of Deltoid
    • Extend and laterally rotate the shoulder joint
    • Horizontally abduct GH
  16. Actions of anterior fibers of Deltoid
    • Flex & medially rotate the shoulder joint
    • Horizontally adduct GH
  17. R/N, and D/S of Deltoid
    • Nonropy
    • Superficial
  18. Which muscles adduct the shoulder?
    • Corachobrachialis
    • Pectoralis major
    • Teres major
    • Latissimus dorsi
  19. Which muscle abducts the shoulder joint?
Card Set
MSA1 Shoulder Muscles
Muscles that move the shoulder- lesson plans 15 & 16