Muscles Of The Shoulder And Upper Extremity

Question 1

Trapezius (upper, middle, lower)

Answer 1

Origin: Occipital bone, spinous process of T1-12
Insertion: Lateral clavicle, acromion, and scapular spine of scapula
Action: rotation, retraction, elevation, depression of scapula; extends neck and stabilizes shoulder
Innervation: accessory nerve (cranial nerve 11)

Question 2

Levator scapulae

Answer 2

Origin: transverse process of C1-4
Insertion: medial border of scapula
Action: retraction of scapula
Innervation: dorsal scapular nerve

Question 3

Rhomboids (major,minor)

Answer 3

Origin: spinous process (minor: C7-T1)(major:T2-5)
Insertion: medial border of scapula
Action: retraction of scapula
Innervation: dorsal scapular nerve

Question 4

Pectoralis minor

Answer 4

Origin: ribs 3-5
Insertion: Coracoid process of scapula
Action: elevates ribs, draws scapula down and medially
Innervation: medial pectoral nerve

Question 5

Serratus Anterior

Answer 5

Origin: Upper 8-9 ribs
Insertion: medial border of scapula
Action: protraction of scapula
Innervation: long thoracic nerve