Platysma

Origin:  fascia of chest

Insertion:  mandible, skin of chin & cheek

Action:  depresses lower lip, tenses skin of neck

Occipitofrontalis

Origin:  occipital bone

Insertion:  skin of eyebrow & bridge of nose

Action:  elevates eyebrow, wrinkles forehead, draws scalp anteriorly

Orbicularis oculi

Origin:  maxilla and frontal bones

Insertion:  encircles orbit of eye & inserts near origin

Action:  closes eyelids

Orbicularis oris

Origin:  maxilla and mandible

Insertion:  fascia and muscles of lips

Action:  closes lips

Buccinator

Origin:  mandible and maxilla

Insertion:  orbicularis at upper angle of mouth

Action:  flattens cheek

Zygomaticus major & minor

Origin:  zygomatic bone

Insertion:  orbicularis at upper angle of mouth

Action:  elevates & abducts upper lip

Depressor anguli oris

Origin:  mandible

Insertion:  skin at lower angle of mouth

Action:  depresses angle of mouth

Depressor labii inferioris

Origin:  mandible

Insertion:  skin of lower lip and orbicularis oris

Action:  depresses lower lip

Masseter

Origin:  zygomatic arch and maxilla

Insertion:  angle & ramus of mandible

Action:  elevates and protracts mandible

Temporalis

Origin:  squamous portion (temporal foss) on temporal bone

Insertion:  coronoid process and ramus of mandible

Action: elevates & retracts mandible (involved w/excursion)

Sternocleidomastoid

Origin:  sternum & clavicle

Insertion:  mastoid process of temporal bone

Action:  flexes neck (both sides contract); rotates head (if one side contracts) towards opposite side

Serratus anterior

(boxer's muscle)

Origin:  anterior margins of ribs 1-9

Insertion:  medial border of scapula

Action:  rotates scapula superiorly and laterally; protracts scapula; elevates ribs when scapula is fixed

Pectoralis minor

Origin:  anterior surfaces of ribs 3-5

Insertion:  coracoid proccess of scapula

Action:  depresses scapula; pulls scapula anteriorly; elevates ribs 3-5 when scapula is fixed

Rhomboideus minor & major

Origin:  spinous processes of C6 - T4

Insertion:  medial border of scapula

Action:  retracts scapula and slightly rotates it to tilt glenoid cavity downward

Trapezius

Origin:  external occipital protuberance; ligamentum nuchae; spinous processes of C7-T12

Insertion:  clavicle, acromion process and spine of scapula

Action:  middle portion retracts scapula, superior portion elevates scapula, inferior portion depresses scapula, extends head when scapula is fixed

Pectoralis major

Origin:  clavicle and sternum

Insertion:  crest of intertubercular groove of humerus

Action:  flexes shoulder, adducts and medially rotates arm

Latissimus dorsi

Origin:  spinous processes of T7-L5, posterior iliac crest, lumbodorsal fascia

Insertion:  crest of intertubercular groove of humerus

Action:  extends shoulder, adducts and medially rotates arm

Deltoid

Origin:  clavicle, acromion process and spine of scapula

Insertion:  deltoid tuberosity of humerus

Action:  flexes and extends shoulder; abducts, medially and laterally rotates arm

Supraspinatus

(rotator cuff)

Origin:  supraspinous fossa of scapula

Insertion:  greater tubercle of humerus

Action:  abducts arm

Infraspinatus

(rotator cuff)

Origin:  infraspinous fossa of scapula

Insertion:  greater tubercle of humerus

Action:  laterally rotates and adducts arm

Subscapularis

(rotator cuff)

Origin:  subscapular foss of scapula

Insertion:  lesser tubercle of humerus

Action:  medially rotates arm

Teres minor
(rotator cuff)

Origin:  lateral border of scapula

Insertion:  greater tubercle of humerus

Action:  adducts and laterally rotates arm

Teres major

Origin:  lateral border of scapula

Insertion:  crest of intertubercular groove of humerus

Action:  adducts and medially rotates arm; extends arm

Biceps brachii

Origin:  above glenoid foss, coracoid process of scapula

Insertion:  radial tuberosity

Action:  flexes forearm and arm; supinates forearm

Brachialis

Origin:  anterior surface of humerus

Insertion:  coronoid process of ulna

Action:  flexes forearm

Triceps brachii

Origin:  long head arises from lateral border of scapula; lateral head arises from lateral & posterior humerus; medial head arises from posterior humerus ("tri" = 3 heads)

Insertion: Olecranon process of ulna

Action:  extends forearm, extends and adducts arm 

Brachioradialis

Origin:  lateral border of distal end of humerus

Insertion:  styloid process of radius

Action:  flexes forearm

Flexor carpi radialis

Origin:  medial epicondyle of humerus

Insertion:  2nd & 3rd metacarpals

Action:  flexes & abducts wrist

Palmaris longus

Origin:  medial epicondyle of humerus

Insertion:  palmar aponeurosis (tendon is superficial to flexor retinaculum)

Action:  flexes wrist (tendon "bowstrings" due to position superficial to flexor retinaculum)

Flexor digitorum superficialis

Origin:  medial epicondyle of humerus and radius

Insertion:  middle phalanges of digits 2-5

Action:  flexes wrists and fingers

Flexor carpi ulnaris

Origin:  medial epicondyle of humerus and ulna

Insertion:  pisiform, hamate, and 5th metacarpal

Action:  flexes and adducts hand

Extensor carpi radialis longus

Origin:  lateral epicondyle of humerus

Insertion:  2nd metacarpal

Action:  extends and abducts hand

Extensor carpi radialis brevis

Origin:  lateral epicondyle of humerus

Insertion:  3rd metacarpal

Action:  extnds and abducts hand

Extensor digitorum

Origin:  lateral epicondyle of humerus

Insertion:  2nd - 5th middle and distal phalanges

Action:  extends phalanges and wrist

Extensor carpi ulnaris

Origin:  lateral epicondyle of humerus and ulna

Insertion:  5th metacarpal

Action:  extends and adducts hand

Rectus femoris

(quadriceps)

Origin:  anterior inferior iliac spine

Insertion:  tibia tuberosity via patellar ligament

Action:  extends leg, flexes thigh

Vastus lateralis

(quadriceps)

Origin:  greater trochanter and linea aspera of femur

Insertion:  tibia tuberosity via patellar ligament

Action:  extends leg

Vastus medialis

(quadriceps)

Origin:  linea aspera of femur

Insertion:  tibia tuberosity via patellar ligament

Action:  extends leg

Vastus intermedius

(quadriceps)

Origin:  body of femur

Insertion:  tibia tuberosity via patellar ligament

Action:  extends leg

Sartorius

("tailor's muscle")

Origin:  anterior superior iliace spine

Insertion:  medial surface of tibia near tibia tuberosity

Action:  flexes thigh and leg; laterally rotates thigh; medially rotates leg

Pectineus

Origin:  pubis crest

Insertion:  inferior to lesser trochanger of posterior aspect of femur

Action:  adducts, extends, and laterally rotates thigh

Adductor longus

Origin:  inferior ramus of pubis

Insertion:  linea aspera of femur

Action:  adducts, extends, and laterally rotates thigh

Adductor magnus

Origin:  inferior ramus of pubis to ischial tuberosity

Insertion:  linea aspera and medial epicondyle of femur

Action:  adducts, extends and laterally rotates thigh

Gracilis

Origin:  inferior ramus

Insertion:  medial surface of tibia inferior to medial condyle

Action:  adducts thigh, flexes and medially rotates leg

Tensor fasciae latae

Origin:  lilac crest

Insertion:  lateral condyle of tibia via iliotibial tract

Action:  flexes, abducts and medially rotates thigh

Gluteus maximus

Origin:  iliac crest, sacrum, coccyx

Insertion:  gluteal tuberosity of femur

Action:  extends abducts and laterally rotates thigh

Gluteus medius

Origin:  iliac crest

Insertion:  greater trochanger of femur

Action:  abducts and medially rotates thigh

Gluteus minimus

Origin:  posterior ilium

Isertion:  greater trochanter of femur

Action:  abducts and medially rotates thigh

Biceps femoris

(hamstrings)

Origin:  long head arises from ischial tuberosity, short head arises from linea aspera

Insertion:  lateral condyle of tibia and head of fibula

Action:  flexes leg and extends thigh

Semitendinosus

(hamstrings)

Origin:  ischial tuberosity

Insertion:  medial surface of proximal tibia

Action:  flexes and medially rotates leg; extends thigh

Semimembranosus

(hamstrings)

Origin:  ischial tuberosity

Insertion:  medial condyle of tibia

Action:  flexes and medially rotates leg; extends thigh

Tibialis anterior

Origin:  lateral condyle of tibia

Insertion:  1st metatarsal, medial cuneiform

Action:  dorsiflexion, inverts foot

Extensor digitorum longus

Origin:  lateral condyle of tibia and fibula

Insertion:  2nd - 5th middle and distal phalanges

Action:  dorsiflexion, eversion, extends 2nd - 5th toes

Fibularis (peroneus) longus

Origin:  lateral fibula

Insertion:  1st metatarsal, medial cuneiform

Action:  plantar flexion, everts foot

Gastrocnemius

Origin:  lateral & medial condyle of femur

Insertion:  calcaneus via Achilles tendon

Action:  plantar flexion, flexes leg

Soleus

Origin:  head of fibula and tibia

Insertion:  calcaneus via Achilles tendon

Action:  plantar flexion

External abdominal oblique

Origin:  5th to 12th ribs

Insertion:  linea alba and iliac crest

Action:  compresses abdomen, depresses thorax, flexes spine, contraction of one side alone rotates spine

Internal abdominal oblique

Origin:  iliac crest

Insertion:  10th - 12th ribs

Action:  compresses abdomen, depresses thorax, flexes spine, contraction of one side alone rotates spine

Transversus abdominus

Origin:  7th - 12th ribs

Insertion:  linea alba

Action:  compresses abdomen

Rectus abdominis

Origin:  pubic crest

Insertion:  xiphoid process & costal cartilage of 5th - 7th ribs

Action:  compresses abdomen, flexes vertebral column

Erector spinae

(group of 7 paired muscles)

Origin:  sacrum, ilium, vertebral spines

Insertion:  vertebrae, ribs, and mastoid process

Action:  extends vertebral column

Diaphragm

Origin:  xiphoid process, sternum and lumbar vertebrae

Insertion:  central tendon

Action: inspiration; increases size of thoraci cavity for breathing

External intercostalis

Origin:  inferior border of each rib

Insertion:  superior border of next rib

Action:  inspiration; elevate ribs

Internal intercostalis

Origin:  superior border of each rib

Insertion:  inferior border of the previous rib

Action:  expiration; depresses ribs