action muscles

raises eyebrows (as in surprise); wrinkles forehead skin horizontally

pulls scalp posteriorly

draws eyebrows together and inferiorly;wrinkles skin of forehead vertically (as in frowning)

protects eyes from intense light and injury; blinking, squinting & draws eyebrows inferiorly

raises lateral corners of mouth upward (smiling muscle)

draws corner of lips laterally, tenses lips (synergist of zygomaticus)

opens lips; raises and furrows upper lip

draws lower lip inferiorly (as in a pout)

draws corners of mouth downward and laterally (as in "tragedy mask" grimace)**antagonist of zygomaticus**

closes lips; purses and protrudes lips; kissing and whistling muscle

protrudes lower lip; wrinkles chin

helps depress mandible; pulls lower lip back and down, tenses skin of neck

Prime mover of jaw closure; elevates mandible

closes jaw; elevates and retracts mandible; side-to-side movements(synergist of pterygoids); maintains position of mandible at rest

synergist of temporalis and masseter muscles in elevation of mandible; side-to-side (grinding movements)

protrudes mandible (pulls it anteriorly); provides forward sliding and side-to-side grinding movements of lower teeth

elevate hyoid bone and steady it during swallowing and speech; from behind, they open mouth and depress mandible

elevates and retracts hyoid, elongating floor of mouth during swallowing

elevates hyoid bone and floor of mouth; enables ongue to exert backward & upward pressure that forces food bolus into pharynx

depresses larynx and hyoid bone (may also flex skull)

pulls thyroid cartilage (plus larynx and hyoid bone inferiorly)

depresses hyoid bone and elevates larynx if hyoid is fixed

constrict pharynx during swallowing, which propels a food bolus to esophagus(peristalsis)

Prime mover of head flexion; rotates head toward shoulder and tilts or laterally flexes head to its own side(knodding head to say yes)

elevate first two ribs (aid in inspiration); flex and rotate neck

act as a group to extend of hyperextend head; head is rotated and bent laterally toward same side ***also involves trapezius***

bending forward at the waist

extend vertebral column, maintain erect posture, bend vertebral column to same side

extend vertebral column, bend it laterally, extends head and turns the face toward the same side

Extends vertebral column

flexes vertebral column laterally, maintains upright posture, assist in forced inspiration (allows you to elevate hip)

elevate rib cage during inspiration; relax during quiet expiration; synergist to diaphragm

draw ribs together and depress rib cage; forced expiration antagonists to external intercostals

Prime mover of inspiration; flattens on contraction: moves down during inspiration: relax: moves up during expiration

(see diaphram)

forced deep inspiration; lift ribs

forced expiration; pulls ribs inferiorly

forced inspiration

push diaphragm superiorly

Flex and rotate lumbar region of vertebral column; fix and depress ribs, stabilize pelvis during walking, increase intra-abdominal pressure

aid rectus abdominis in flexing vertebral column and in compressing abdominal walls and increasing intra-abdominal pressure; aid muscles of back in trunk rotation and lateral flexion

see external oblique

compresses abdominal contents

supports and maintains position of pelvic viscera;resists downward thrusts that accompany rises in intrapelvic pressure during coughing,vomiting

supports pelvic viscera;supports coccyx and pulls it forward after it has been reflected posteriorly by defecation and childbirth

with ribs fixed, draws scapula forward and downward; with scapula fixed, draws rib cage superiorly

Prime mover to protect and hold scapula against chest wall; rotates scapula so that its inferior angle moves laterally and upward;important role in abduction and raising of arm and in horizontal arm movements (pushing,punching)"boxer's muscle

stabilizes,raises,retracts, and rotates scapula; middle fibers retract (adduct) scapula; superior fibers elevate scapula or can help extend head with scapula fixed; inferior fibers depress scapula and shoulder

elevates/adducts scapula in concert w/superior fibers of trapezius;tilts glenoid cavity downward when scapula is fixed,flexes neck to same side

acts w/trapezius fibers to retract scapula,"squaring shoulders";rotate glenoid cavity of scapula downward as when arm is lowered;paddling a canoe…stabilize scapula

Prime mover of arm flexion; rotates arm medially; aducts arm against resistance;pulls rib cage upward, helps in climbing,throwing,pushing and in forced inspiration

Prime mover of arm extension;powerful arm adductor;medially rotates arm at shoulder;depresses scapula;important role in power stroke(striking a blow,hammering,swimming,rowing) if arms fixed overhead,pulls rest of body upward and forward

Prime mover of arm abduction;antagonist of pectoralis major and latissimus dorsi;active during rhythmic arm movements during walking

chief medial rotator of humerus;helps to hold head of humerus in glenoid cavity;stabilizes shoulder joint

stabilizes shoulder joint;helps to prevent dislocation of humerus;assists in abduction

helps to holdhead of humerus in glenoid cavity,stabilizing shoulder joint;rotates humerus laterally

same action as infraspinatus muscle;adducts arm

posteromedially extends,medially rotates, and adducts humerus,synergist of latissimus dorsi

Powerful forearm extensor (prime mover, particularly medial head)antagonist of forearm flexors;may help stabilize shoulder joint and assist in arm adduction

flexes elbow joint and supinates forearm(open a bottle of wine, it turns corkscrew and pulls the cork)

A major forearm flexor (lifts ulna as biceps lift the radius)

Synergist in forearm flexion; during rapid flexion and extension, stabilizes the elbow

Pronates forearm; weak flexor of elbow

Iliopsoas is the prime mover for flexing thigh or for flexing trunk on thigh during bow

same as iliacus;also effects lateral flexion of vertebral column; important postural muscle

Flexes, abducts, and laterally rotates thigh;flexes knee (weak);"tailors muscle"

used in all movements that press thighs together,also important in pelvic tilting movements that occur during walking and in fixing the hip when the knee is flexed and the foot is off the ground

anterior part adducts and medially rotates and flexes thigh; posterior part is a synergist of hamstrings in thigh extension

adducts, flexes, and medially rotates thigh

adducts, flexes and medially rotates thigh

adducts, flexed and medially rotates thigh

adducts thigh, flexes and medially rotates thigh, especially during walking; flexes knee

powerful knee extensor used in climbing, jumping, running and rising from seated position, tone of quads plays important role in strenghthening knee joint

extends knee and flexes thigh at hip

extends and stabilizes knee

extends knee; inferiro fibers stabilize patella

extends knee

flexes and abducts thigh;rotates thigh medially;steadies the knee on trunk,synergist of iliopsoas and gluteus medius and minimus

Major extensor of thigh; complex,powerful and most effective when thigh is flexed..climbing stairs,running, inactive during standing, and walking;laterally rotates and abducts thigh

abducts and medially rotates thigh;steadies pelvis;important in walking

abducts and medially rotates thigh;steadies pelvis;important in walking

prime movers of thigh extension and knee flexion***sites for common sports injuries….

extends thigh and flexes knee; laterally rotates leg, especially when knee is flexed

extends thigh at hip;flexes knee; with semimembranosus, medially rotates leg

extends thigh and flexes knee; medially rotates leg

Prime mover of dorsiflexion; inverts foot; assists in supporting medial longitudinal arch of foot

Plantar flexes and everts foot; may help keep foot flat on ground

Plantar flexes and everts foot

Plantar flexes foot when knee is extended; since it also crosses knee joint, it can flex knee when foot is dorsiflexed

Plantar flexes foot; important locomotor and postural muscle during walking, running, and dancing