Bio 218: Muscle Actions

Front 1

Trapezius

Back 1

Elevates shoulder and rotates scapula upward

Front 2

Rhomboid Major

Back 2

Elevates and adducts scapula and rotates it downward

Front 3

Rhomboid Minor

Back 3

Elevates and adducts scapula and rotates it downward

Front 4

Levator Scapulae

Back 4

Elevates scapula and rotates it downward

Front 5

Latissimus Dorsi

Back 5

Extends, adducts, and medially

Front 6

Teres Major

Back 6

extends and rotates shoulder joint medially

Front 7

Teres Minor

Back 7

Lateral rotation and adduction of the arm at the shoulder

Front 8

Infraspinatus

Back 8

Lateral rotation and adduction of the arm at the shoulder

Front 9

Supraspinatus

Back 9

Assists deltoid in abduction of the arm

Front 10

Subscapularis*

Back 10

Medial rotation of the arm at the shoulder

Front 11

Deltoid

Back 11

Flexion and abduction of the arm

Front 12

Triceps Brachii (lateral, long & medial heads)

Back 12

Extends forearm at the elbow

Front 13

Extensor Carpi Ulnaris

Back 13

Extends and adducts hand at wrist joint

Front 14

Extensor Digiti Minimi

Back 14

extends joints of 5th digit and wrist

Front 15

Extensor Digitorium

Back 15

extends wrist and phalanges

Front 16

Extensor Carpi Radialis Longus

Back 16

Extends and abducts hand at wrist joint

Front 17

Extensor Carpi Radialis Brevis

Back 17

Extends and abducts hand at wrist joint

Front 18

Abductor Pollicis Longus

Back 18

abducts joints of thumb and joints of hand

Front 19

Gluteus Maximus

Back 19

extends and rotates thigh laterally at hip joint

Front 20

Gluteus Medius

Back 20

abducts and rotates thigh medially at hip joint

Front 21

Gluteus Minimus

Back 21

abducts and rotates thigh medially at hip joint

Front 22

Piriformis

Back 22

Laterally rotates and abducts thigh at hip joint

Front 23

Biceps Femoris

Back 23

Flexes leg at the knee and extends thigh at the hip

Front 24

Semimembranosus

Back 24

Flexes leg at the knee and extends thigh at the hip

Front 25

Semitendinosus

Back 25

Flexes leg at the knee and extends thigh at the hip

Front 26

Gastrocnemius

Back 26

Plantar flexes foot at the ankle and flexes leg at the knee

Front 27

Soleus

Back 27

Plantar flexes foot at the ankle

Front 28

Plantaris

Back 28

Plantar flexes foot at ankle joint and flexes leg at knee joint

Front 29

Fibularis Longus (Peroneus Longus)

Back 29

plantar flexes and everts foot at ankle

Front 30

Sternocleidomastoid

Back 30

Flexes and rotates head from side to side

Front 31

Pectoralis Major

Back 31

flexes, adducts, rotates shoulder joint medially

Front 32

Pectoralis Minor

Back 32

pulls scapula forward and downward

Front 33

Serratus Anterior

Back 33

pulls scapula forward and upward

Front 34

External Intercostals

Back 34

inhalation

Front 35

Internal Intercostals

Back 35

elevation and depression of ribs

Front 36

External Oblique

Back 36

spine flexion, spine rotation, abdomen compression, and spine lateral flexion

Front 37

Internal Oblique

Back 37

spine flexion, spine rotation, abdomen compression

Front 38

Transverse Abdominis

Back 38

Compress abdomen

Front 39

Rectus Abdominis

Back 39

Flexes vertebral column; compresses abdomen

Front 40

Diaphragm*

Back 40

inhalation

Front 41

Psoas Major*

Back 41

Flexes and laterally rotates thigh at hip; flexes vertebral column

Front 42

Biceps Brachii (long & short heads)

Back 42

Flexes forearm at the elbow and flexes arm at the shoulder

Front 43

Branchialis

Back 43

Flexes forearm at the elbow

Front 44

Coracobrachialis

Back 44

Flexes and adducts arm at shoulder joint

Front 45

Brachioradialis

Back 45

Flexes forearm at the elbow

Front 46

Pronator Teres

Back 46

pronates forearm and hand

Front 47

Flexor Carpi Radialis

Back 47

flexes and abducts wrist

Front 48

Palmaris Longus

Back 48

Weakly flexes hand at wrist joint

Front 49

Flexor Carpi Ulnaris

Back 49

Flexes and adducts hand (ulnar deviation) at wrist joint

Front 50

Flexor Digitorum Superficialis

Back 50

flexes wrist and digits

Front 51

Flexor Digitorium Profundus

Back 51

flexes writst and digits

Front 52

Tensor Fasciae Latae

Back 52

Flexes and abducts thigh at hip joint

Front 53

Sartorius

Back 53

flexes leg and thigh, abducts rotates thigh laterally

Front 54

Vastus Lateralis

Back 54

All four extends leg at knee joint; rectus femoris muscle acting alone also flexes thigh at hip joint

Front 55

Vastus Medialis

Back 55

All four extends leg at knee joint; rectus femoris muscle acting alone also flexes thigh at hip joint

Front 56

Vastus Intermedius

Back 56

All four extends leg at knee joint; rectus femoris muscle acting alone also flexes thigh at hip joint

Front 57

Rectus Femoris

Back 57

All four extends leg at knee joint; rectus femoris muscle acting alone also flexes thigh at hip joint

Front 58

Gracilis

Back 58

Adducts thigh at hip joint, medially rotates thigh, and flexes leg at knee joint

Front 59

Adductor Longus

Back 59

adducts thigh at hip joint

Front 60

Adductor Magnus

Back 60

adducts thigh at hip joint

Front 61

Adductor Brevis

Back 61

Adducts and flexes thigh at hip joint and rotates thigh

Front 62

Tibialis Anterior

Back 62

ankle dorsal flexion, ankle inversion

Front 63

Extensor Digitorium Longus

Back 63

ankle dorsal flexion, toe extension (2nd-5th toes), toe hyperextension, ankle eversion

Front 64

Temporalis

Back 64

Elevates and retracts mandible

Front 65

Frontalis

Back 65

Raises eyebrows & wrinkles forehead

Front 66

Masseter

Back 66

Elevates mandible, as in closing mouth

Front 67

Orbicularis Oculi

Back 67

Closes eye

Front 68

Orbicularis Oris

Back 68

Closes and protrude lips, as in kissing; compresses lips against teeth; and shapes lips during speech

Front 69

Buccinator

Back 69

compresses cheeks (Presses cheeks against teeth and lips, as is blowing, whistling and sucking; draws corner of mouth laterally; and assists in mastication (chewing) by keeping food between the teeth (and not between teeth and cheeks))

Front 70

Digastric

Back 70

Elevates hyoid bone and depresses mandible, as the opening the mouth