Muscle Anatomy: Musculature

Trapezius

Origin: occipital bone, c7 and all T vertebrae

insertion: scapula, clavicle

action: extends, elevates, rotates and retracts scapula; secondary: extends head

Latissimus dorsi

Origin : Lower vertebrae, ilium

insertion: humerus

action: : extends, adducts and medially rotates arm

Serratus anterior

origin: upper 8 ribs

insertion: scapula

action: protracts and rotates scapula superiorly and laterally

rhomoboideus

origin: C7-T5

insertion: scapula

action: stabilize scapula

pectoralis

origin: clavicle, sternum, costal cartilages

insertion: humerus

action: flexes, adducts and medially rotates arm

pectoralis minor

origin: ribs 3,4,5

insertion: scapula

action: draws scapula anteriorly and inferiorly

deltoids

origin: clavicle, acromion and scapular spine

insertion: humerus

action: abducts arm

supraspinatus

origin: scapula

insertion: humerus

action: abducts arm

infraspinatus

origin: infraspinous fossa

insertion: humerus

action: lateral rotation of humerus

triceps brachii

origin: scapula, humerus

insertion: ulna

action: extends forearm

biceps brachii

origin: scapula

insertion: radius

action: flexes elbow, supinates forearm

brachialis

origin: humerus

insertion: ulna

action: flexes forearm

flexor carpi ulnaris

origin: humerus, ulna

insertion: 5th metacarpal, pisiform and hamate

action: flexes wrist, adducts hand

palmaris longus

origin: humerus

insertion: palmar aponeurosis

action: tenses skin and fascia of palm weak flexor of wrist

flexor carpi radialis

origin: humerus

insertion: 2nd and 3d metacarpals

action: flexes wrist, abducts hand

pronator teres

origin: humerus

insertion: radius

action: pronates and flexes forearm

Brachioradialis

origin: humerus

insertion: radius

action: flexes forearm

extensor carpi radialis

origin: humerus

insertion: metacarpals II and III

action: extends and abducts wrist

extensor digitorum communis

origin: humerus

insertion: phalanges of digits 2-5

action: extends fingers and wrist, abducts fingers

extensor digitorum minimi

origin: N/A

insertion: N/A

action: extends 5th digit

extensor carpi ulnaris

origin: humerus

insertion: metacarpal V

action: extends and adducts wrist

Masseter

origin: zygomatic arch

insertion: angle and ramus of mandible

action: elevates mandible

Mylohyoid

origin: mandible

insertion: hyoid bone

action: elevates hyoid

Digastricus

origin: mandible and mastoid process

insertion: hyoid bone

action: open mouth and depress mandible

Sternohyoid

origin: manubrium and clavicle

insertion: hyoid

action: depresses hyoid and larynx

Sternomastoideus

origin: manubrium, clavicle

insertion: mastoid process

action: singly, rotates head to opposite shoulder; together, flexes head

external abdominal oblique

origin: lower 8 ribs

insertion: ilium and linea alba

action: flexion and rotation at waist

internal abdominal oblique

origin: lumber fascia;

insertion: lower 4 ribs

action: flexion and rotation of trunk; lateral flexion

transverse abdominis

origin: ilium

insertion: linea alba and pubic crest

action: compresses abdominal wall

rectus abdominis

origin: pubic bone

insertion: ribs 5-7 and xiphoid process

action: flexion at wrist

tensor fasciae latae

origin: ilium

insertion: iliotibial tract

action: steadies trunk on thigh

gluteus medius

origin: ilium

insertion: femur

action: abduction and medial rotation of thigh

gluteus maximus

origin: ilium, sacrum, coccyx, coccyx

insertion: femur

action: major extensor of thigh

Sartorius

origin: ilium

insertion: tibia

action: flexes, abducts and laterally rotates thigh; flexes knee

Gracilis

origin: pubis

insertion: tibia

action: adducts thigh, flexes and medially rotates leg

adductor magnus

origin: ischium and pubis

insertion: femur

action: adducts, flexes and medially rotates thigh

long head of biceps femoris

origin: ischium and femur

insertion: tibia and fibula

action: extends thigh, flexes knee

Semitendinosus

origin: ischium

insertion: tibia

action: extends thigh, flexes knee

Semimembranosus

origin: ischium

insertion: tibia

action: extends thigh, flexes knee

vastus lateralis

origin: femur

insertion: patella and tibia

action: extends knee, stabilizes knee

vastus medialis

origin: femur

insertion: patella and tibia

action: extends knee

vastus intermedius

origin: femur

insertion: patella and tibia

action: extends knee

rectus femoris

origin: ilium

insertion: patella and tibia

action: extends knee, flexes thigh at hip

Gastrocnemius

origin: femur

insertion: calcanea tendon onto calcaneus

action: flexes lower leg, plantar flexes foot

tibialis anterior

origin: tibia

insertion: first cuneiform and first metatarsals

action: dorsiflexes and inverts foot

Soleus

origin: fibula and tibia

insertion: calcanea tendon onto calcaneus

action: plantar flexes foot

fibulas longus

origin: fibula

insertion: first metatarsal and medial cuneiform

action: plantar flexion and foot eversion

extensor digitorum longus

origin: tibia

insertion: phalanges of toes 2-5

action: extend toes 2-5 and dorsiflexes ankle

teres major

origin: scapula

insertion: humerus

action: extends , adducts and medially rotates arm lateral rotation of humerus

teres minor

origin: scapula

insertion: humerus

action: lateral rotation of humerus

Subscapularis

origin: scapula

insertion : humerus

action: medial rotation of humerus, stabilizes shoulder joint

pectineus

origin: pubis

insertion : femur

action: adducts, flexes and medially rotates thigh

psoas major

origin: lumbar vertebrae

insertion : femur

action: prime mover in thigh flexion and in flexing trunk

extensor pollicis

origin: N/A

insertion : N/A

action:extends digit 1

extensor retinaculatum

origin: N/A

insertion : N/A

action: tendon sheath for extensor tendons

flexor retinaculatum

origin: N/A

insertion :N/A

action: tendons sheath for flexor tendons

orbicularis oris

origin: N/A

insertion : N/A

action: puckers lips; tightens lip closure

orbicularis oculi

origin: N/A

insertion: N/A

action: closed eye

frontalis (epicranium)

origin: N/A

insertion: N/A

action: raises eyebrrows

Temporalis

origin: N/A

insertion: N/A

action: elevates and reacts mandible

zygomatic major

origin: N/A

insertion: N/A

action: abducts corners of lips and elevates them

Buccinator

origin: N/A

insertion: N/A

action: aids in sucking , smiling, and chewing

levator labii superioris

origin: N/A

insertion: N/A

action: elevates the upper lip

superior rectus

origin: N/A

insertion: N/A

action: elevates eye

inferior rectus

origin: N/A

insertion: N/A

action: depresses eye

lateral rectus

origin: N/A

insertion: N/A

action: abducts eye

medial rectus

origin: N/A

insertion: N/A

action: adducts eye

inferior oblique

origin: N/A

insertion: N/A

action: abducts and elevates eye

superior oblique

origin: N/A

insertion: N/A

action: abducts dresses eye