Lesson 2: Shoulder Muscles

Question 1

Origin & Insertion

Deltoid

p. 67

Hint: deltoid helps you carry SACS

Answer 1

origin: lateral third of clavicle, acromion, and spine of scapula
insertion: deltoid tuberosity

Question 2

Actions

deltoid

p. 67

Answer 2

all fibers: shoulder abduction
anterior: shoulder flexion, internal/medial rotation, horizontal adduction
posterior: shoulder extension, external/lateral rotation, horizontal abduction

Question 3

Origin & Insertion

latissimus dorsi

p. 71

Answer 3

origin: inferior angle scapula, T7-T12 spinous processes, 9th/10th-12th ribs, thoracolumbar fascia, posterior iliac crest
insertion: intertubercular groove of humerus

Question 4

Actions:

latissimus dorsi

p. 71

Answer 4

shoulder extension
shoulder adduction
internal/medial rotation

Question 5

Origin & Insertion

teres major

p. 71

Answer 5

origin: posterior margin of the inferior angle of the scapula
insertion: crest of less tubercle of humerus

Question 6

Actions

teres major

p. 71

Hint: same as lats

Answer 6

shoulder adduction
shoulder extension
internal/medial rotation

Question 7

Origin & Insertion

supraspinatus

p. 75

Answer 7

origin: supraspinatous fossa of scapula
insertion: greater tubercle of humerus

Question 8

Actions

supraspinatus

p. 75

What group of muscles is this a part of? (SITS)

Answer 8

shoulder abduction

rotator cuff

Question 9

Origin & Insertion

infraspinatus

p. 75

Answer 9

origin: infraspinous fossa of scapula
insertion: greatur tubercle of humerus

Question 10

Actions

infraspinatus

p. 75

What group of muscles is this a part of?

Answer 10

shoulder adduction
external/lateral rotation

Question 11

Origin & Insertion

teres minor

p. 75

Answer 11

origin: upper 2/3 of lateral border of scapula
insertion: greater tubercle of humerus

Question 12

Actions

teres minor

p. 75

What group of muscles is this a part of? (SITS)

Answer 12

shoulder adduction
shoulder external/lateral rotation

same as infraspinatus

Question 13

Origin & Insertion

subscapularis

p. 75

Answer 13

origin: subscapular fossa of scapula
insertion: lesser tubercle of humerus

Question 14

Actions

subscapularis

p. 75

What group of muscles is this a part of? (SITS)

Answer 14

internal/medial rotation

rotator cuff

Question 15

Origin & Insertion

pectoralis major

p. 89

Answer 15

origin: medial half of clavicle, sternum, ribs 1-6
insertion: greater tubercle of humerus

Question 16

Actions

pectoralis major

p. 89

Answer 16

all fibers: shoulder adduction, internal/medial rotation
upper: shoulder flexion, horizontal adduction
lower: shoulder extension

Question 17

Origin & Insertion

coracobrachialis

p. 99

Answer 17

origin: coracoid process of the scapula
insertion: medial surface of the mid-humeral shaft

Question 18

Actions

coracobrachialis

p. 99

Answer 18

shoulder flexion
shoulder adduction

Question 19

Origin & Insertion

biceps brachii

p. 95

Answer 19

origin:
* short head: coracoid process of the scapula
* long head: supraglenoid tubercle of the scapula
insertion: tuberosity of the radius

Question 20

Actions

biceps brachii

p. 95

Answer 20

elbow flexion
shoulder flexion
forearm supination

Question 21

Origin & Insertion

triceps brachii

p. 97

Answer 21

origin:
* long head: infraglenoid tubercle of scapula
* lateral head: posterior surface of proximal half of humerus
* medial head: posterior suface of distal half of humerus
insertion: olecranon process of the ulna

Question 22

Actions

triceps brachii

p. 97

Answer 22

all heads: elbow extension
long head: shoulder extension, shoulder adduction