GH Muscles

Question 1

Middle deltoid

Answer 1

Origin: acromion
Insertion: deltoid tuberosity of GH
Action: abduct GH
Innervation: axillary nerve

Question 2

Posterior deltoid

Answer 2

Origin: scapular spine
Insertion: deltoid tuberosity GH
Action: add GH 60 degrees, extend GH, ER GH, horizontally Abd
Innervation: axillary nerve

Question 3

Teres major

Answer 3

Origin: inferior angle scapula
Insertion: medial border bicipital groove
Action: IR GH, extend GH, add GH, horizontally abd GH
Innervation: lower subscapular nerve

Question 4

Anterior deltoid

Answer 4

Origin: lateral 1/3 clavicle
Insertion: deltoid tuberosity of humerus
Action: add GH 60 degrees, flex GH, IR, horizontally add
Innervation: axillary nerve

Question 5

Latissimus dorsi

Answer 5

Origin: Lower thoracic T7-T12 SP, thoracolumbar fascia, posterior iliac crest, Ribis 9-12, Inferior angle scapula
Insertion: medial border bicipital groove
Action: add GH, ext GH, IR GH, horiz. abd GH, retract scapula, down rotate scapula, depress scapula
Innervation: thoracodorsal nerve

Question 6

Pectoralis major (clavicular)

Answer 6

Origin: 1/3 medial border clavicle
Insertion: Lat border bicipital groove
Action: IR GH, Flex GH, horizontally add, add GH if 90˚
Innervation: Medial and lateral pectoral nerves

Question 7

Pectoralis major (sternal)

Answer 7

Origin: sternum, costal cartilages 2-6
Insertion: lateral border bicipital groove
Action: extend GH if >30˚ flex, flex GH if hyperextend, add GH, IR GH, horizontally add GH, downward rot scap, protract scap
Innervation: medial and lateral pectoral nerves

Question 8

Coracobrachialis

Answer 8

Origin: coracoid process of scap
Insertion: medial humerus
Action: flex GH, add GH, (IR GH), horizontal add
Innervation: musculocutaneous nerve