Muscles Of The Shoulder Girdle

Front 1

Pectoralis minor
Origin
Insertion
Action
Innervation

Back 1

Pectoralis minor
Origin: anterior surfaces of 3rd-5th ribs
Insertion: coracoid process of scapula
Action: abduction, downward rotation, depression
Innervation: medial pectoral nerve (C8 &T1)

Front 2

Serratus anterior
Origin
Insertion
Action
Innervation

Back 2

Serratus anterior
Origin: surface of the upper 9 ribs at the side of the chest
Insertion: anterior aspect of the whole length of the medial border of the scapula
Action: abduction, upward rotation
Innervation: long thoracic nerve (C5-C7)

Front 3

Trapezius I
Origin
Insertion
Action
Innervation

Back 3

Trapezius I
Origin: skull occipital protuberance, superior nuchal lines, & C1-3
Insertion: lateral one-third of clavicle's superior surfaces
Action: elevation
Innervation: C3, C4, & accessory CN IX

Front 4

Trapezius II
Origin
Insertion
Action
Innervation

Back 4

Trapezius II
Origin: transverse processes of C1-C7
Insertion: superior surface of scapula's acromion process
Action: elevation, (assist) adduction, upward rotation
Innervation: C3, C4, & accessory CN IX

Front 5

Trapezius III
Origin
Insertion
Action
Innervation

Back 5

Trapezius III
Origin: transverse processes of T1-T5
Insertion: superior surface of scapula's spine
Action: adduction
Innervation: C3, C4, & accessory CN IX

Front 6

Trapezius IV
Origin
Insertion
Action
Innervation

Back 6

Trapezius IV
Origin: transverse processes of T6-T12
Insertion: scapular spine root
Action: depression, adduction (assist), upward rotation
Innervation: C3, C4, & accessory CN IX

Front 7

Levator scapulae
Origin
Insertion
Action
Innervation

Back 7

Levator scapulae
Origin: transverse process of C1-C4
Insertion: medial border of scapula between spine and superior angle
Action: elevation, downward rotation (assist)
Innervation: dorsal scapular nerve C5 and ventral primary rami of C3 & C4

Front 8

Rhomboid
Origin
Insertion
Action
Innervation

Back 8

Rhomboid
Origin: spinous processes of C8-T5
Insertion: medial border of scapula inferior to scapular spine
Action: elevation, adduction, downward rotation
Innervation: dorsal scapular nerve C5

Front 9

Latissimus dorsi
Origin
Insertion
Action
Innervation

Back 9

Latissimus dorsi
Origin: posterior crest of the ilium, back of the sacrum and spinous processes of the lumbar and T6-T12; slips from the lower three ribs
Insertion: medial lip of the intertubercular groove of the humerus, just anterior to the insertion of the teres major
Action: depression (assist)
Innervation: thoracodorsal nerve C6-C8