Muscle Actions

Front 1

Masseter

Back 1

elevates mandible

Front 2

Temporalis

Back 2

elevates mandible

Front 3

Digastric: Anterior Belly

Back 3

depresses mandible and/or elevates larynx

Front 4

Digastric: Posterior Belly

Back 4

depresses mandible and/or elevates larynx

Front 5

Mylohyoid

Back 5

elevates floor of mouth, elevates hyoid bone,and/or depresses mandible

Front 6

Sternohyoid

Back 6

depresses hyoid bone and larynx

Front 7

Sternocleidomastoid

Back 7

together flex neck, alone bend side to side

Front 8

Splenius (capitis & cervicis)

Back 8

together extend neck, alone rotates & flexes neck side to side

Front 9

Spinalis Thoracis

Back 9

extends vertebral column

Front 10

Scalenes

Back 10

elevates ribs, flexes neck, rotates and bends neck

Front 11

External Intercostals

Back 11

elevates ribs

Front 12

Internal Intercostals

Back 12

depresses ribs

Front 13

Diaphragm

Back 13

contraction expands thoracic cavity, compresses abdominopelvic cavity

Front 14

External Oblique

Back 14

compresses abdomen; depresses ribs; laterally flexes or rotates vertebral column

Front 15

Internal Oblique

Back 15

compresses abdomen; depresses ribs; laterally flexes or rotates vertebral column

Front 16

Transverse Abdominis

Back 16

compresses abdomen

Front 17

Rectus Abdominis

Back 17

depresses ribs, flexes vertebral column, compresses abdomen

Front 18

Trapezius

Back 18

elevate, retract, depress, or rotate scapula upward and/or elevate clavicle; extend neck

Front 19

Rhomboideus Minor

Back 19

adducts & performs downward rotation of scapula

Front 20

Rhomboideus Major

Back 20

adducts and downward rotation of scapula

Front 21

Levator Scapulae

Back 21

elevates scapula

Front 22

Serratus Anterior

Back 22

protracts shoulder: rotates scapula so glenoid cavity moves superiorly (upward rotation)

Front 23

Pectoralis Minor

Back 23

depresses & protracts shoulder, rotates scapula (glenoid cavity rotates downward), elevates ribs

Front 24

Supraspinatus

Back 24

abduction of arm at the shoulder

Front 25

Infraspinatus

Back 25

lateral rotation of arm at shoulder

Front 26

Deltoid

Back 26

abducts shoulder, flexion and extension, medial and lateral rotation of humerus

Front 27

Teres Minor

Back 27

lateral rotation of arm at shoulder

Front 28

Teres Major

Back 28

extension, adduction & medial rotation of arm at shoulder

Front 29

Subscapularis

Back 29

medial rotation of arm at shoulder

Front 30

Pectoralis Major

Back 30

flexion, adduction & medial rotation of arm at shoulder

Front 31

Latissimus Dorsi

Back 31

extension, adduction, and medial rotation of arm at shoulder

Front 32

Coracobrachialis

Back 32

adduction and flexion of arm at shoulder

Front 33

Triceps Brachii

Back 33

extension at elbow, extension & adduction of arm at shoulder

Front 34

Brachialis

Back 34

flexion at elbow

Front 35

Brachioradialis

Back 35

flexion at elbow

Front 36

Pronator Teres

Back 36

pronates forearm and hand by medial rotation of radius at radioulnar joints & flexion at elbow

Front 37

Flexor Carpi Radialis

Back 37

flexion and abduction of hand at wrist

Front 38

Flexor Carpi Ulnaris

Back 38

flexion and adduction of hand at wrist

Front 39

Extensor Carpi Ulnaris

Back 39

extension and adduction of hand at wrist

Front 40

Extensor Carpi Radialis Brevis

Back 40

extension and abduction of hand at wrist

Front 41

Extensor Carpi Radialis Longus

Back 41

extension an abduction of hand at wrist

Front 42

Supinator

Back 42

supinates forearm and hand by lateral rotation of radius at radioulnar joints

Front 43

Biceps Brachii

Back 43

flexion of forearm at elbow and shoulder; supination

Front 44

Palmaris Longus

Back 44

flexion of hand at wrist

Front 45

Extensor Digitorum

Back 45

extension of hand and fingers at finger joints and wrist

Front 46

Iliacus

Back 46

Flexion of thigh at hip

Front 47

Psoas Major

Back 47

Flexion of thigh at hip and/or lumbar intervertebral joints

Front 48

Pectineus

Back 48

Flexion, medial rotation, and adduction of thigh at hip

Front 49

Adductor longus

Back 49

Adduction, flexion, and medial rotation of thigh at hip

Front 50

Adductor magnus

Back 50

adduction of thigh at hi , flexion & medial rotation of thigh, extension & lateral rotation of thigh

Front 51

Gracilis

Back 51

Flexion at knee; adduction and medial rotation of thigh at hip

Front 52

Sartorius

Back 52

Flexion at knee; flexion and lateral rotation of thigh at hip

Front 53

Rectus femoris

Back 53

Extension of lower leg at knee; flexion of thigh at hip

Front 54

Vastus lateralis

Back 54

Extension of lower leg at knee

Front 55

Vastus medialis

Back 55

Extension of lower leg at knee

Front 56

Vastus intermedius

Back 56

Extension of lower leg at knee

Front 57

Semimembranousus

Back 57

Flexion at knee; extension and medial rotation of thigh at hip

Front 58

Semitendinosus

Back 58

Flexion at knee; extension and medial rotation of thigh at hip

Front 59

Biceps femoris

Back 59

Flexion at knee; extension and lateral rotation of thigh at hip

Front 60

Gluteus maximus

Back 60

Extension and lateral rotation of thigh at hip; helps stabilize the extended knee

Front 61

Gluteus medius

Back 61

Abduction and medial rotation of thigh at hip

Front 62

Tensor fasciae latae

Back 62

Flexion and medial rotation of thigh at hip

Front 63

Gastrocnemius

Back 63

Plantar flexion at ankle; inversion; flexion at knee

Front 64

Soleus

Back 64

Plantar flexion at ankle; postural muscle when standing

Front 65

Tibialis anterior

Back 65

Dorsiflexion at ankle; inversion of foot

Front 66

Peroneus longus (aka Fibularis longus)

Back 66

Eversion of foot and plantar flexion at ankle; supports ankle; supports longitudinal arch

Front 67

Extensor digitorum longus

Back 67

Extension of toes; dorsiflexes ankle; everts foot