Muscle Origin & Insertion

Front 1

TRAPEZIUS

Back 1

ORIGIN - occipital bone, ligament nuchae, and spinous processes of C7-T12

INSERTION - a continuous insertion along the acromion and spine of the scapula, and the lateral third of the clavicle

ACTIONS - upward rotation , elevation , retraction and depression of the scapula

Front 2

STERNOCLEIDOMASTOID

Back 2

ORIGIN - (2 heads) manubrium of sternum, and medial portion of clavicle

INSERTION - mastoid process of the temporal bone

ACTIONS - flexion, rotation of the head

Front 3

LEVATOR SCAPULAE

Back 3

ORIGIN - transverse processes of C1-C4

INSERTION - medial border of the scapula

ACTIONS - prime mover in elevation, aids in downward rotation of the scapula

Front 4

RHOMBOID MINOR

Back 4

ORIGIN - spinous process of C7-T1

INSERTION - medial border of the scapula

ACTIONS - retracts scapula, acts with trapezius

Front 5

RHOMBOID MAJOR

Back 5

ORIGIN - spinous process of T2-T5

INSERTION - medial border of scapula

ACTIONS - retracts scapula, acts with middle fibres of trapezius

Front 6

SERRATUS ANTERIOR

Back 6

ORIGIN - finger like projections from the upper 8-9 ribs

INSERTION - entire anterior surface of medial border of scapula

ACTIONS - protects scapula, holds scapula against chest wall, works with upper fibres of trapezius in upward rotation of the scapula

Front 7

PECTORALIS MINOR

Back 7

ORIGIN - anterior surfaces of ribs 3-5

INSERTION - coracoid process of scapula

ACTIONS - scapula is fixed, fixator, aids protraction of the shoulder