DIAGRAM E2.1 Muscles Operating upon the Shoulder (Scapula) Diagram

pectoralis minor

action: depress, protract shoulder, elevate ribs (inhalation)

origin: ribs 3-5

insertion: scapula coracoid process

scapula coracoid process

insertion of pectoralis minor

depress, protract shoulder, elevate ribs (inhalation)

action of pectoralis minor

ribs 3-5

origin of pectoralis minor

serratus anterior

action: protract shoulder

origin: ribs 1-9

insertion: scapula medial border

trapezius

action: elevate or depress, retract shoulder, extend neck; unilateral: laterally flex neck

origin: vertebrae C7-T12; occipital

insertion: scapula spine, acromion; clavicle

levator scapulae

action: elevate shoulder, unilateral: laterally flex neck

origin: vertebrae C1-C4

insertion: scapula superior angle, medial border

rhomboid minor

action: retract shoulder

origin: vertebrae C7-T1

insertion: scapula medial border

rhomboid major

action: retract shoulder

origin: vertebrae T2-T5

insertion: scapula medial border