OIA Pectoral Girdle

Serratus anterior action

rotates scapula so that its inferior angle moves laterally and upward

Trapezius insertion

A continuous insertion along acromion and spine of scapula and lateral third of clavicle

Subclavius insertion

Groove on inferior surface of clavicle

Trapezius origin

Occipital bone; ligamentum nuchae; spines of C7 and all thoracic vertebrae

Pectoralis minor origin

anterior surface of ribs 3-5

Serratus anterior origin

by a series of muscle slips from ribs 1-8 (or 9)

Pectoralis minor insertion

coracoid process of scapula

Subclavius origin

costal cartilage of rib 1

Levator scapulae action

elevates and adducts scapula

Serratus anterior insertion

entire anterior surface of vertebral border of scapula

Subclavius action

helps stabilize and depress pectoral girdle

Rhomboids insertion

medial border of scapula

Levator scapulae insertion

medial border of scapula superior to spine

Rhomboids origin

spinous processes of C7 and T1 (minor) and spinous processes of T2-T5 (major)

Rhomboids action

stabilizes scapula

Trapezius action

stabilizes, raises, retracts, and rotates scapula

Levator scapulae origin

transverse processes of C1-C4

Pectoralis minor action

with ribs fixed, draws scapula forward and downward