Module 30: Muscles of the Pectoral Girdle

trapezius superior fibers

action: elevate & superiorly rotate scapula

trapezius middle fibers

action: retract scapula

trapezius inferior fibers

action: depress scapula

trapezius

origin: occipital bone

trapezius & subclavius

insertion: clavicle

trapezius

innervation: accessory nerve (CN XI)

levator scapulae

action: elevates & inferiorly rotates scapula

levator scapulae

origin: cervical transverse processes

levator scapulae & rhomboid minor

insertion: superior medial border of scapula

levator scapulae, rhomboid major, rhomboid minor

innervation: dorsal scapular nerve

rhomboid major & minor

action: elevates, retracts, and inferiorly rotates scapula

rhomboid major & minor

origin: vertebrae

rhomboid major

insertion: medial border of scapula

pectoralis minor

action: protracts and depresses scapula

pectoralis minor

origin: ribs 3-5

pectoralis minor

insertion: coracoid process of scapula

pectoralis minor

innervation: medial pectoral nerve

serratus anterior

action: protracts & superiorly rotates scapula; stabilizes scapula

serratus anterior

origin: ribs 1-8

serratus anterior

insertion: anterior medial border of scapula

serratus anterior

innervation: long thoracic nerve

subclavius

action: stabilizes and depresses clavicle

subclavius

origin: rib 1

trapezius & subclavius

insertion: clavicle

subclavius

innervation: nerve to subclavius