OIAs Muscles that move the Pectoral Girdle (4)

Question 1

Trapezius – upper back, most superficial

Answer 1

i. O: occipital bone & spines of thoraxic & cervical vertebrae
ii. I: clavicle, acromion process of scapula, & spine of scapula
iii. A: extends head, raises scapulae

Question 2

Serratus Anterior

Answer 2

i. O & I: 9th rib to medial scapula
ii. A: abducts and rotates scapula upward, pushes shoulders forward when pushing
something “boxers muscle”

Question 3

Pectoralis minor – under pectoralis major

Answer 3

i. A: abducts and rotates scapulae downward, raises ribs 3-5 for forced inspiration