Epicranial Frontal belly

Action: Raises the eyebrows
Origin: Epicranial aponeurosis
Insertion: Skin of eyebrows and nose

Epicranial Occipital belly

Action: Fixes aponeurosis and pulls scalp posteriorly
Origin: Occipital and temporal bones
Insertion: Epicranial aponeurosis

Orbicularis oculi

Action: Closes eye
Origin: Frontal and maxillary bones
Insertion: Eyelid

Zygomaticus

Action: Raises lateral corners of the mouth
Origin: Zygomatic bone
Insertion: Skin and muscle at corner of mouth

Risorius

Action: Draws corner of lip laterally
Origin: Fascia of masseter
Insertion: Skin at angle of mouth

Orbicularis oris

Action: Closes lips
Origin: Maxilla and mandible
Insertion: Muscle and skin at angles of the mouth

Mentalis

Action: Wrinkles chin
Origin: Mandible
Insertion: Skin of chin

Buccinator

Action: Compresses cheek
Origin: Maxilla and mandible
Insertion: Orbicularis oris

Platysma

Action: Tenses skin of neck
Origin: Fascia of chest
Insertion: Mandible and skin at corner of mouth

Masseter

Action: Closes jaw
Origin: Zygomatic arch
Insertion: Angle, ramus of mandible

Temporalis

Action: Closes jaw
Origin: Temporal fossa
Insertion: Coronoid process

Sternocleidomastoid

Action: Flexes, laterally rotates head
Origin: Manubrium, medial clavicle
Insertion: Mastoid process of temporal bone and superior nuchal line of occipital bone

Scalenes (Anterior, Middle, Posterior)

Action: Elevate ribs 1 and 2
Origin: Cervical vertebrae
Insertion: First two ribs

Splenius capitis, cervicis

Action: Extends head
Origin: Cervical and thoracic vertebrae
Insertion: Mastoid process of temporal bone, occipital bone, transverse processes of C C 2 4

Iliocostalis

Action: Extends and laterally flexes vertebral column, extends head and rotates toward same side
Origin: Iliac crests, ribs
Insertion: Angles of ribs, cervical vertebrae

Longissimus

Action: Extends and laterally flexes vertebral column, extends head and rotates toward same side
Origin: Vertebral column
Insertion: Cervical and thoracic vertebrae, ribs

Spinalis

Action: Extends and laterally flexes vertebral column, extends head and rotates toward same side
Origin: Thoracic and lumbar vertebrae
Insertion: Thoracic and cervical vertebrae

External intercostals

Action: Elevates ribs
Origin: Inferior border of upper rib
Insertion: Superior border of rib below

Internal intercostals

Action: Compresses and depresses ribcage
Origin: Superior border of rib below
Insertion: Inferior border of upper rib

Diaphragm

Action: Flattens during inspiration
Origin: Internal surface of ribcage and sternum, lower costal cartilages, lumbar vertebrae
Insertion: Central tendon

Rectus abdominis

Action: Flexes and rotates vertebral column
Origin: Pubic crest and symphysis
Insertion: Xiphoid process, lower costal cartilages

External oblique

Action: Flexes vertebral column, rotates and flexes vertebral column laterally, compresses abdomen
Origin: Lower ribs
Insertion: Linea alba, pubic crest, tubercle, iliac crest

Internal oblique

Action: Flexes vertebral column, rotates and flexes vertebral column laterally, compresses abdomen
Origin: Lumbar fascia, iliac crest
Insertion: Linea alba, pubic crest, costal margin, and lower ribs

Transversus abdominis

Action: Compresses abdomen
Origin: Lumbar fascia, iliac crest, lower costal cartilages
Insertion: Linea alba, pubic crest

Pectoralis minor

Action: Fixes ribs, protracts and depresses scapula
Origin: Ribs 3–5
Insertion: Coracoid process

Serratus anterior

Action: Rotates scapula
Origin: Ribs 1–8
Insertion: Medial border of
scapula

Subclavius

Action: Fixes and depresses pectoral girdle
Origin: Costal cartilage of rib 1
Insertion: Clavicle

Trapezius

Action: Fixes, elevates, retracts, and rotates scapula
Origin: Occipital condyle, vertebral column
Insertion: Acromion, spine of scapula, lateral third of clavicle

Levator scapulae

Action: Elevates, adducts scapula
Origin: Vertebral transverse processes
Insertion: Medial border of scapula

Rhomboids (major, minor)

Action: Fixes scapula
Origin: Vertebral spinous processes
Insertion: Medial border of scapula

Pectoralis major

Action: Flexes, adducts, medially rotates arm
Origin: Clavicle, sternum, costal cartilages
Insertion: Greater tubercle

Deltoid

Action: Abducts arm
Origin: Acromion, spine of scapula, lateral third of clavicle
Insertion: Deltoid tuberosity

Latissimus dorsi

Action: Extends, adducts, medially rotates arm
Origin: Vertebrae, ribs, iliac crest, inferior angle of scapula
Insertion: Humerus

Subscapularis

(part of rotator cuff)

Action: Medially rotates arm
Origin: Subscapular fossa
Insertion: Lesser tubercle

Supraspinatus

(part of rotator cuff)

Action: Abducts arm
Origin: Supraspinous fossa
Insertion: Greater tubercle

Infraspinatus

(part of rotator cuff)

Action: Laterally rotates arm
Origin: Infraspinous fossa
Insertion: Greater tubercle

Teres minor

(part of rotator cuff)

Action: Laterally rotates arm
Origin: Lateral border of scapula
Insertion: Greater tubercle

Teres major

Action: Extends, medially rotates, adducts arm
Origin: Inferior angle of scapula
Insertion: Lesser tubercle

Coracobrachialis

Action: Flexes, adducts arm
Origin: Coracoid process
Insertion: Humerus

Triceps brachii

Action: Extends forearm
Origin: Scapula, humerus
Insertion: Olecranon

Biceps brachii

Action: Flexes and supinates forearm
Origin: Coracoid process, glenoid cavity
Insertion: Radial tuberosity

Brachialis

Action: Flexes forearm
Origin: Humerus
Insertion: Coronoid process

Brachioradialis

Action: Flexes forearm
Origin: Humerus
Insertion: Radial styloid process

Pronator teres

Action: Pronates forearm
Origin: Medial epicondyle of humerus, coronoid process
Insertion: Radius

Flexor carpi radialis

Action: Flexes wrist, abducts hand
Origin: Medial epicondyle of humerus
Insertion: Second and third metacarpals

Palmaris longus

Action: Tenses skin and fascia of palm
Origin: Medial epicondyle of humerus
Insertion: Palmar aponeurosis

Flexor carpi ulnaris

Action: Flexes wrist, adducts hand
Origin: Medial epicondyle, olecranon
Insertion: Pisiform, hamate, and fifth metacarpal

Flexor digitorum superficialis

Action: Flexes wrist and middle phalanges of fingers 2–5
Origin: Medial epicondyle of humerus
Insertion: Middle phalanges of fingers 2–5

Extensor carpi radialis longus and brevis

Action: Extends and abducts wrist
Insertion: Third metacarpal

Extensor digitorum

Action: Extends fingers
Origin: Lateral epicondyle of humerus
Insertion: Distal phalanges of fingers 2–5

Extensor carpi ulnaris

Action: Extends and adducts wrist
Origin: Lateral epicondyle of humerus, ulna
Insertion: Fifth metacarpal

Thenar Muscles

Action: Abducts, adducts, flexes, and opposes thumb
Origin: Flexor retinaculum, carpals, metacarpals II–IV
Insertion: Proximal phalanx and metacarpal I

Hypothenar Muscles

Action: Abducts, flexes little finger, opposes thumb
Origin: Carpals and flexor retinaculum
Insertion: Proximal phalanx of little finger

Iliacus

Action: Flexes thigh at trunk, flexes vertebral column laterally
Origin: Iliac fossa, crest, and sacrum
Insertion: Lesser trochanter

Psoas major

Action: Flexes thigh at trunk, flexes vertebral column laterally
Origin: Lumbar vertebrae
Insertion: Lesser trochanter

Sartorius

Action: Flexes, abducts, medially rotates thigh, flexes knee
Origin: Anterior superior iliac spine
Insertion: Medial proximal tibia

Adductor magnus

Action: Adducts, flexes, extends, medially rotates thigh
Origin: Ischial and pubic rami, ischial tuberosity
Insertion: Linea aspera

Adductor longus

Action: Adducts, flexes, medially rotates thigh
Origin: Pubis
Insertion: Linea aspera

Adductor brevis

Action: Adducts, flexes, medially rotates thigh
Origin: Pubis
Insertion: Linea aspera

Gracilis

Action: Adducts, flexes, medially rotates thigh
Origin: Pubis, ischial ramus
Insertion: Tibia

Rectus femoris

Action: Extends knee, flexes thigh
Origin: Anterior inferior iliac spine, acetabulum
Insertion: Patella, tibial tuberosity via patellar ligament

Vastus lateralis

Action: Extends knee
Origin: Greater trochanter, linea aspera
Insertion: Patella, tibial tuberosity via patellar ligament

Vastus medalis

Action: Extends knee
Origin: Linea aspera
Insertion: Patella, tibial tuberosity via patellar ligament

Vastus intermedius

Action: Extends knee
Origin: Proximal shaft of femur
Insertion: Patella, tibial tuberosity via patellar ligament

Gluteus maximus

Action: Extends thigh
Origin: Ilium, sacrum, coccyx
Insertion: Gluteal tuberosity of femur, iliotibial tract

Gluteus medius

Action: Abducts, medially rotates thigh
Origin: Ilium
Insertion: Greater trochanter

Gluteus minimus

Action: Abducts, medially rotates thigh
Origin: Ilium
Insertion: Greater trochanter

Biceps femoris

Action: Extends thigh, flexes knee
Origin: Ischial tuberosity, linea aspera
Insertion: Head of fibula, lateral condyle of tibia

Semitendinosus

Action: Extends thigh, flexes knee
Origin: Ischial tuberosity
Insertion: Tibia

Semimembranosus

Action: Extends thigh, flexes knee
Origin: Ischial tuberosity
Insertion: Medial condyle of tibia, lateral condyle of femur

Tibialis anterior

Action: Dorsiflexes foot
Origin: Tibia, interosseous membrane
Insertion: Medial cuneiform, metatarsal I

Extensor digitorum longus

Action: Extends toes
Origin: Tibia, fibula, interosseous membrane
Insertion: Middle and distal phalanges of toes 2–5

Fibularis (peroneus) longus and brevis

Action: Plantar flexes and everts foot
Origin: Fibula
Insertion: Metatarsal I, medial cuneiform

Gastrocnemius

Action: Plantar flexes foot
Origin: Medial and lateral condyles of femur
Insertion: Calcaneus

Soleus

Action: Plantar flexes foot
Origin: Tibia, fibula, interosseous membrane
Insertion: Calcaneus

Flexor digitorum longus

Action: Plantar flexes and inverts foot, flexes toes
Origin: Posterior tibia
Insertion: Tendon passes behind medial malleolus to distal phalanges of toes 2–5

Tibialis posterior

Action: Inverts foot
Origin: Tibia, fibula, interosseous membrane
Insertion: Tendon passes behind medial malleolus, under arch, to tarsals and metatarsals II–IV