Muscle Actions

Front 1

Occipitofrontalis

Back 1

raise eyebrow, pull scalp posteriorly

Front 2

epicranius

Back 2

raise eyebrow, pull scalp posteriorly

Front 3

orbicularis oculi

Back 3

closes eye.

Front 4

oribularis oris

Back 4

purses lips

Front 5

buccinator

Back 5

compresses cheek. holds food between teeth

Front 6

zygomaticus

Back 6

raises lateral corner of the mouth

Front 7

risorius

Back 7

laughter muscle

Front 8

masseter

Back 8

closes the jaw and elevates mandible

Front 9

temporalis

Back 9

closes the jaw, elevates mandible, aids in grinding movements

Front 10

pterygoids

Back 10

synergist of masseter and temporalis

Front 11

sternocleidomastoid

Back 11

flexes neck when both contract

rotate head when acting independently

Front 12

capitus group

Back 12

extend, bend & rotate head

Front 13

erector spinae group

Back 13

extend and laterally bend the vertebral column

Front 14

scalene group

Back 14

flex and slightly rotate the neck

Front 15

external oblique

Back 15

compress the abdomen & bend the vertebral column laterally when the R or L contracts independently

Front 16

internal oblique

Back 16

compress the abdomen & bend the vertebral column laterally when the R or L contracts independently

Front 17

transversus abdominis

Back 17

compress the abdomen

Front 18

rectus abdominis

Back 18

compresses abdominal contents, flexes vertebral column

Front 19

diaphragm

Back 19

involuntary skeletal muscle for inhalation

Front 20

external intercostals

Back 20

pull the rib cage up and out and aid in inhalation

Front 21

internal intercostals

Back 21

pull the rib cage down and aid in inhalation

Front 22

trapezius

Back 22

elevates shoulders, extends and pulls head laterally

Front 23

serratus anterior

Back 23

pulls shoulders anteriorly and inferiorly; stabalizes sholder

Front 24

rhomboideus

Back 24

steadies; elevates and retracts scapula

Front 25

pectoralis minor

Back 25

draws scapula anterior and inferior. draws ribs upward

Front 26

levator scapulae

Back 26

elevates scapula and bends neck laterally

Front 27

2 upper arm flexors

Back 27

1. coracobrachialis

2. pectoralis major

Front 28

2 upper arm extensors

Back 28

1. teres major

2. latissimus dorsi

Front 29

coracobrachialis

Back 29

flexes and adducts

Front 30

pectoralis major

Back 30

pulls body up when arm is fixed

Front 31

teres major

Back 31

extends, adducts and rotates medially

Front 32

latissiumus dorsi

Back 32

extends, adducts and rotates arm medially

Front 33

2 Abductors of Upper Arm

Back 33

1. Supraspinatus

2. deltoid

Front 34

supraspinatus

Back 34

abducts arm

Front 35

deltoid

Back 35

major arm abductor, rotates arm laterally, anterior fibers flex arm, posterior fibers extend arm

Front 36

3 Rotators of Upper Arm

Back 36

1. Subscauplaris

2. Infraspinatus

3. teres minor

Front 37

subscapularis

Back 37

medial, internal rotation of arm

Front 38

infraspinatus

Back 38

lateral/external rotation of arm

Front 39

teres minor

Back 39

lateral/external rotation of arm

Front 40

3 Flexors of Forearm

Back 40

1. biceps brachii

2. brachialis

3. brachioradialis

Front 41

biceps brachii

Back 41

flexes and supinates forearm. weakly flexes upper arm

Front 42

brachialis

Back 42

most powerful forearm flexor

Front 43

brachioradials

Back 43

flexes forearm

Front 44

Triceps brachii

Back 44

Extensor. The sole powerful extensor of the posterior humerus

Front 45

3 Rotators of the Forearm

Back 45

1. supinator

2. pronator teres

3. pronator quadratus

Front 46

pronator teres

Back 46

pronates forearm

Front 47

pronator quadratus

Back 47

pronates forearm

Front 48

3 Hand Flexors

Back 48

*All on anterior forearm

1. flexor carpi radialis

2. palmaris longus

3. flexor carpi ulnaris

Front 49

flexor carpi radialis

Back 49

powerful flexor and adductor of the hand/wrist

Front 50

palmaris longus

Back 50

flexor of the hand, tenses the palmar fasica

Front 51

flexor carpi ulnaris

Back 51

powerful flexor and adductor of the hand

Front 52

4 Extensors of the Hand

Back 52

*All on the posterior forearm

1. extensor carpi radialis longus

2. extensor carpi radialis brevis

3. Extensor Digitorum

4. extensor carpi ulnaris

Front 53

extensor carpi radialis longus

Back 53

extends and abducts hand

Front 54

extensor carpi radialis brevis

Back 54

extends and abducts hand

Front 55

extensor digitorium

Back 55

extends and abducts fingers and extends hand

Front 56

extensor carpi ulnaris

Back 56

extends and abducts hand

Front 57

psoas major

Back 57

flex the thigh

Front 58

iliacus

Back 58

flex the thigh

Front 59

tensor fasciae latae

Back 59

abducts, medially rotates and flexes thigh

Front 60

gluteus maximus

Back 60

extends and rotates thigh laterally

Front 61

gluteus medius

Back 61

abducts and medially rotates thigh

Front 62

3 adductors of the thigh

Back 62

1. adductor longus

2. adductor magnus

3. gracilis

Front 63

adductor longus

Back 63

adducts, flexes and laterally rotates thigh

Front 64

adductor magnus

Back 64

adducts, also extends, rotates and stabilizes thigh

Front 65

gracilis

Back 65

adducts leg, also flexes knee and rotates thigh

Front 66

4 Flexors of Lower Leg

Back 66

1. Biceps femoris

2. Semitendinus

3. semimembranosus

4. sartorius

*first 3 are hamstrings

Front 67

biceps femoris

Back 67

flex knee and extend thigh

Front 68

semitendinosus

Back 68

flex knee and extend thigh

Front 69

semimembranosus

Back 69

flex knee and extend thight

Front 70

sartorius

Back 70

flexes thigh and knee, adducts, lateral rotation

Front 71

4 Extensors of Lower Legs (Quadriceps)

Back 71

1. rectus femoris

2. vasus lateralis

3. vasus medialis

4. vasus intermedius

Front 72

Quadriceps

Back 72

extends the leg at the knee.

Front 73

rectus femoris

Back 73

extends the leg at the knee and flexes the thigh

Front 74

tibialis anterior

Back 74

dorsiflexes and inverts foot

Front 75

gastrocnemius

Back 75

plantar flexes foot and flexes leg

Front 76

soleus

Back 76

plantar flexes foot

Front 77

tibialis posterior

Back 77

inversion and plantar flexion of foot

Front 78

peroneus/ fibularis longus

Back 78

eversion and plantar flexion of the foot