Muscles that move the humerous

Question 1

Supraspinatus

Answer 1

Origin - supraspinous fossa of scapula

Insertion - superior greater tubercle of the humerus

Action - abduction of humerus at shoulder joint

*part of rotator cuff but doesn’t rotate
*not seen superficially

Question 2

Infraspinatus

Answer 2

Origin - infraspinous fossa of scapula

Insertion - posterior greater tubercle of humerus

Action - lat/extern. rotation of humerus at shoulder joint

• works with tires minor

Question 3

Teres minor

Answer 3

Origin - upper 2/3 of axillary boarder of scapula

Insertion - posterior greater tubercle of humerus

Action - lat/extern. rotation of humerus at shoulder joint

• works with infraspinatus

Question 4

Subscapularis

Answer 4

Origin - sub scapular fossa of the scapula

Insertion - lesser tubercle of the humerus

Action - medial/internal rotation of humerus at shoulder joint

Question 5

deltoid

Answer 5

Origin - lateral 1/3 of the clavicle; acromion and spine of the scapula

Insertion - deltoid tuberosity of the humerus

Action - abduction (all), flexion (anterior), extension (posterior) of the humerus at the shoulder joint

Question 6

pectoralis major

Answer 6

Origin - medial 1/2 of clavicle, anterior sternum, first 6 or 7 costal cartilage

Insertion - lateral edge of the inter tubercular sulcus of the humerus

Action - flexion, extension (not hyperextension), adduction, and medial/internal rotation of the humerus at the shoulder joint

Question 7

latissimus dorsi

Answer 7

Origin - SP’s of T6-L5, posterior crest of ilium

Insertion -medial edge of inter tubercular sulcus of humerus

Action -extension, adduction, and medial/internal rotation of the humerus at the shoulder joint

Question 8

Teres major

Answer 8

Origin - lower axillary border and inferior angle of the scapula

Insertion - medial edge of inter tubercular sulcus of the humerus

Action -extension, adduction, and medial/internal rotation of the humerus at the shoulder joint (SAME AS LATISSIMUS DORSI)