muscle details

trapezius orgin

superior nuchal line, EOP, nuchal ligament, C7-T12 spinal process

trapezius insertion

lateral third of clavicle, acromion, and spine of scapula

trapezius nerve

spinal accessory nerve

trapezius action

elevate, retract, and depress scapular (upper, middle, and lower respectively) together they can superiorly rotate scapular to enable full arm abduction

latissimus dorsi orgin

thoracolumbar fascia, spines of T7-12 and L1-5, iliac crest, inferior 3-4 ribs

latissimus dorsi insertion

floor of the inertubercular groove of the humerus

latissimus dorsi nerve

thoracodorsal nerve

latissimus dorsi action

extends, adducts, and medially rotates the humerus, think of swimming

levator scapulae orgin

transverse process of C1-C4

levator scapulae insertion

superior angle of the scapula

levator scapulae nerve

dorsal scapular nerve (not rhomboid)

levator scapulae action

retract(adduct) and inferiorly rotate scapula

Rhomboid minor orgin

C7-T1

Rhomboid minor and major insertion

medial boarder of the scapula

Rhomboid major and minor nerve

dorsal scapular nerve (not LS)

Rhomboid major and minor action

retract(adduct) and inferiorly rotate the scapula (working together)

Rhomboid major orgin

T2-T5

Serratus posterior superior orgin

nuchal ligament, C7-T3 spinous process

serratus posterior superior insertion

ribs 2-5(lateral to angle)

serratus posterior superior nerve

intercostal nerves 2-5

serratus posterior superior action

elevates ribs to aid in inspiration

serratus posterior inferior orgin

T11-L3 spinous processser

serratus posterior inferior insertion

Ribs 9-11(below angles)

serratus posterior inferior nerve

intercostal nerves 9-11

serratus posterior inferior action

depresses ribs, counteracts pull of diaphram, which aids in forceful expiration

splenius capitis orgin

nuchal lingament and spinous process of C7-T4

splenius capitis insertion

mastoid process and lateral portion of superior nuchal line

splenius cervicis orgin

spinous process of T3-T6

splenius cervicis insertion

posterior tubercle of transverse process of C1-C3

Splenius capitis and cervicis nerve

dorsal rami of middle cervical spinal nerves

splenius capitis and cervicis actions

bilateral contraction(extend head and cervical spine), unilateral contraction(lateral flexion and ispilateral rotation)

Erector spinae muscles orgin

broad aponeurosis from throacolumbar fascia, iliac crest, sacrum, and lower lumbar spine

erector spinae nerve

dorsal rami of spinal nerve at corresponding levels

erector spinae actions

bilaterally it extends vertebral column and head, the major postural muscles, unilaterally it laterally flexes to the same side

Rotatores, multifidi, and semispinalis nerve

dorsal rami of spinal nerve (multi)

Rotatores, multifidi, and semispinalis actions

bilaterally extend vertebral column and unilaterally rotates vertebral column contralaterally

rectus capitis posterior minor orgin

posterior tubercle of atlas

rectus capitis posterior minor insertion

medial part of inferior nuchal line of occipital bone

rectus capitis posterior minor action

extends and stabilizes the head, ispilateral rotation

rectus capitis posterior major orgin

spinous process of axis

rectus capitis posterior major insertion

lateral part of inferior nuchal line of occipital bone

rectus capitis posterior major action

extends head, ispilateral roation(forms medial wall of suboccipital triangle)

rectus capitis posterior major and minor nerve

suboccipital

Obliquus capitis superior orgin

transverse process of C1

Obliquus capitis superior insertion

occipital bone (btw superior and inferior nuchal lines)

Obliquus capitis superior action

laterally flexes head and assists extension(forms superior wall of the triangle)

Obliquus capitis inferior orgin

spinous process of C2

Obliquus capitis inferior insertion

transverse process of C1(not the head)

Obliquus capitis inferior action

rotates atlas and head ispilaterally and forms inferior wall of triangle

Obliquus capitis inferior and superior nerve

suboccipital nerve (the trick one)

pectoralis major orgin

medial clavicle, manubrium and body of sternum, costal cartilage of 2-6 ribs, and aponeurosis of external oblique muscle

pectoralis major insertion

lateral part of the intertubercular groove of humerus

pectoralis major nerve

lateral AND medial pectoral nerves

pectoralis major action

adducts and medially rotates the humerus, clavicular head alone can flex humerus from this position the sternocostal head helps extend the humerus

pectoralis minor orgin

upper margin of ribs 3-5

pectoralis minor insertion

coracoid process of scapula

pectoralis minor merve

medial pectoral nerve

pectoralis minor action

downward(inferior) rotation of the scapula, spa

serratus anterior insertion

medial boarder of scapular on costal side

serratus anterior nerve

long thoracic nerve

serratus anterior action

can raise the ribs for respiration, also protracts the scapula and superiorly rotates the glenoid cavity of scapula to enable full abduction of arm

subclavius orgin

1st rib cartilage

subclavius insertion

inferior surface of midclavicle

subclavius nerve

branches of C5-6

subclavius action

depresses lateral end of clavicle, stabilizes clavicle and also serves as protection of axillary stuff if clavicle breaks

deltoid orgin

lateral clavicle, spine of scapular, and acromion

deltoid insertion

deltoid tuberosity of humerus

deltoid nerve

axillary nerve

deltoid action

abducts arm also flexes and extends arm

teres major orgin

inferior angle of scapula

teres major nerve

lower subscapular

teres major action

adducts and medial

suprasinatus orgin

supraspinous fossa of scapula

suprasinatus insertion

superior part of greater tubercle of humerus

suprasinatus

infraspinatus orgin

infr

infraspinatus insertion

medial facet of greater tubercle of humerus

infraspinatus nerve

suprascapular nerve (not supra)

infraspinatus action

laterally rotates humerus

teres minor orgin

posterolateral boarder of scapula

teres minor insertion

lower part of greater tubercle

teres minor nerve

axillary (small muscle)

teres minor action

adducts and laterally rotates humerus

subscapularis orgin

subscapular fossa

subscapularis insertion

lesser tubercle of humerus and capsule of shoulder joint

subscapularis nerve

upper AND lower subscapular nerve

subscapularis action

medially rotates humerus

coracobrachialis orgin

coracoid process of scapula

coracobrachialis insertion

mid-humerus

coracobrachialis, biceps, brachialis nerve

musculocutaneous

coracobrachialis action

flexes and adducts arm

biceps brachii orgin

short head=coracoid process of scapula, long head=supraglenoid region of scapula

biceps brachii insertion

radial tuberosity

biceps brachii action

flexes elbow, supinates forearm, flexes arm

brachialis orgin

distal anterior humerus

brachialis insertion

ulnar tuberosity

brachialis action

flexes elbow