Shoulder Girdle Muscles (cont)

Question 1

Deltoid (anterior, posterior, middle)

Answer 1

ORIGIN: clavicle and scapula

INSERTION: deltoid tuberosity of humerus

ACTION: abduction at shoulder (whole muscle)

INNERVATION: axillary nerve

Question 2

Pectoralis major

Answer 2

ORIGIN: ribs 2-6, body of sternum

INSERTION: greater tubercle of humerus

ACTION: flexion, adduction and medial rotation at shoulder

INNERVATION: pectoral nerves

Question 3

Supraspinatus (above spine of scapula)

Answer 3

ORIGIN: supraspinatus fossa of scapula

INSERTION: greater tubercle of humerus

ACTION: abduction at the shoulder

INNERVATION: suprascapular nerve

Question 4

Infraspinatus (below spine of scapula)

Answer 4

ORIGIN: infraspinatus fossa of scapula

INSERTION: greater tubercle of humerus

ACTION: lateral rotation at shoulder

INNERVATION: suprascapular nerve

Question 5

Teres Minor

Answer 5

ORIGIN: lateral border of scapula

INSERTION: greater tubercle of humerus

ACTION: lateral rotation at shoulder

INNERVATION: axillary nerve

Question 6

Teres Major (not part of rotator cuff)

Answer 6

ORIGIN: inferior angle of scapula

INSERTION: intertubercular groove of humerus

ACTION: extension, adduction, and medial rotation at shoulder

INNERVATION: lower subscapular nerve

Question 7

Subscapularis (along inner surface of scapula)

Answer 7

ORIGIN: subscapular fossa of scapula

INSERTION: lesser tubercle of humerus

ACTION: medial rotation at the shoulder

INNERVATION: subscapular nerves

Question 8

Latissimus Dorsi

Answer 8

ORIGIN: spinous process of inferior thoracic and lumbar vertebrae, ribs 8-12

INSERTION: intertubercular groove of humerus

ACTION: extension, adduction, and medial rotation at shoulder

INNERVATION: thoracodorsal nerve

Question 9

Coracobrachialis

Answer 9

ORIGIN: coracoid process of scapula

INSERTION: medial shaft of humerus

ACTION: Flexion and adduction at shoulder

INNERVATION: musculocutaneous nerve