muscle primary actions

frontalis

raises eyebrows

temporalis

closes jaw

masseter

closes jaw

orbicularis oculi

blinks and closes eye

orbicularis oris

closes and protrudes lips

buccinator

compresses cheek, holds food between teeth

sternocleidomastoid

flexes neck, laterally rotates head

platysma

tenses skin of neck

digastric

opening the jaw, elevating the hyoid bone

pectoralis major

adducts and flexes humerus

serratus anterior

pulling the shoulder blade forward

rectus abdominis

flexes vertebral column

external oblique

flexes and rotates vertebral column

biceps brachii

flexes elbow and supinates forarm

brachialis

flexes elbow

deltoid

abducts arm

brachioradialis

flexing the forearm

flexor carpi radialis

flexes wrist and abducts hand

flexor carpi ulnaris

flexes wrist and adducts hand

flexor digitorum

flexes wrist and fingers

rectus femoris

extending the leg at the knee, flexing the thigh at the hip

iliopsoas

flexes hip

adductor muscles

adduct and medially rotate the thigh

vastus lateralis

knee extension

vastus medialis

knee extension

fibularis

plantarflexion and foot eversion

tibialis anterior

dorsiflexes and foot inversion

extensor digitorum longs

extends toes

sartorius

sitting cross-legged (hip and knee movements)

occipitalis

pulls scalp posteriorly

trapezius

shrug shoulders, raises/retracts/rotates scapula

latissimus dorsi

extends and adducts humerus

erector spinae

extends and laterally flexes spine

triceps brachii

extends elbow

extensor carpi radialis

extends wrist and abducts hand

extensor digitorum

extends fingers

gluteus medius

abducts thigh, steadies pelvis

gluteus maximus

extends hip

hamstring muscles (biceps femoris, semitendinosus, and semimembranosus)

flex knee and extend hip (less forceful)

gastrocnemius

plantarflexion and knee flexion

soleus

plantarflexion