Muscle Actions

Question 1

Extensor Carpi Radialis Brevis

Answer 1

Extends wrist, radially deviates wrist (abduction)

Question 2

Extensor Carpi Ulnaris

Answer 2

Extends wrist, ulnar deviates wrist (adduction)

Question 3

Flexor Carpi Ulnaris

Answer 3

Flexes wrist, ulnar deviates wrist (adduction)

Question 4

Flexor Carpi Radialis

Answer 4

Flexes wrist, radially deviates wrist (abduction)

Question 5

Extensor Digitorum

Answer 5

Extends digits of hand and wrist

Question 6

Flexor Digitorum

Answer 6

Flexes digits of hand and wrist

Question 7

Brachialis

Answer 7

Flexes elbow (as in raising forearm)

Question 8

Pronator Teres

Answer 8

Pronates forearm at elbow (as in twisting forearm toward body)

Question 9

Biceps Brachii

Answer 9

Flexes elbow, supinates forearm

Question 10

Triceps Brachii

Answer 10

Extends forearm at elbow (long head also stabilizes shoulder)

Question 11

Subscapularis

Answer 11

Medially rotates humerus at shoulder and stabilizes shoulder

Question 12

Supraspinatus

Answer 12

Abducts arm at shoulder and stabilizes shoulder

Question 13

Infraspinatus

Answer 13

Laterally rotates humerus at shoulder and stabilizes shoulder

Question 14

Teres Minor

Answer 14

Adducts and laterally rotates humerus at shoulder and stabilizes shoulder

Question 15

Deltoid (Anterior)

Answer 15

Flexion and medial rotation of humerus at shoulder

Question 16

Deltoid (Middle)

Answer 16

Abducts humerus at shoulder (as in upward flap)

Question 17

Deltoid (Posterior)

Answer 17

Extension and lateral rotation of humerus

Question 18

Pectoralis Major

Answer 18

Flexion, adduction, medial rotation of humerus at shoulder (as in bench press)

Question 19

Latissimus Dorsi

Answer 19

Extension, adduction, medial rotation of humerus at shoulder

Question 20

Levator Scapula

Answer 20

Elevates, adducts (retracts) scapula (as in bring shoulder to ear)

Question 21

Rhomboideus Major

Answer 21

Adducts (retracts) scapula (as in pulling shoulders back and up)

Question 22

Serratus Anterior

Answer 22

Abducts scapula (to raise arm and pull shoulder forward, as in punching)

Question 23

Trapezius (Upper)

Answer 23

Elevates scapula (as in shrugging)

Question 24

Trapezius (Middle)

Answer 24

Retracts and elevates scapula (as in pulling shoulders back and up)

Question 25

Trapezius (Lower)

Answer 25

Retracts and depresses scapula (as in pulling shoulders back and down)

Question 26

Zygomatic Major

Answer 26

Draws angle mouth up (as in a smile)

Question 27

Frontalis

Answer 27

Raise eyebrow, wrinkle forehead

Question 28

Orbicularis Oris

Answer 28

Squeezes closed and protrudes lips (as in kissing)

Question 29

Buccinator

Answer 29

Compresses cheek (as in sucking)

Question 30

Orbicularis Oculi

Answer 30

Squeezes eyes closed (as in squinting)

Question 31

Sternocleidomastoid

Answer 31

Flexes neck (as in cocking head to one side, or flex down, or flex down if both)

Question 32

Splenius Capitus

Answer 32

Extends or hyperextends neck (as if looking up)

Question 33

Gluteus Maximus

Answer 33

Extends hip (as in pushing down on a stair), rotates femur laterally

Question 34

Adductor Magnus

Answer 34

Extends hip and adducts femur

Question 35

Tensor Fasciae Latae

Answer 35

Tenses or stabilizes hip and knee joints

Question 36

Adductor Longus

Answer 36

Flexes hip, adducts leg

Question 37

Psoas Major

Answer 37

Flexes hip (as in lifting leg to place on stair)

Question 38

Gracilis

Answer 38

Adducts thigh, flexes knee

Question 39

Pectineus

Answer 39

Adducts, flexes, medially rotates thigh at hip

Question 40

Sartorius

Answer 40

Flexes hip and flexes knee, laterally rotates thigh (crossed legs position)

Question 41

Spinalis Thoracis

Answer 41

Unilaterally: Lateral flexion of the vertebral column. Bilaterally: Extension and hyperextension of the vertebral column.

Question 42

Rectus Abdominis

Answer 42

Compresses abdomen, flexes vertebral column

Question 43

External Intercostals

Answer 43

Pulls ribs up toward origin, elevates ribcage to cause inspiration.

Question 44

Diaphragm

Answer 44

Drops down to enlarge thoracic cavity, causing inspiration.

Question 45

Gastrocnemius

Answer 45

Plantar flexion at ankle, flexes knee

Question 46

Soleus

Answer 46

Plantar flexion at ankle

Question 47

Tibialis Anterior

Answer 47

Dorsiflexion and inversion at ankle

Question 48

Masseter

Answer 48

Elevates mandible (as in closing mouth)

Question 49

Temporalis

Answer 49

Elevates mandible.

Question 50

Platysma

Answer 50

Pulls lower lip down (as in frowning) Lowers jaw (as in opening mouth)

Question 51

Rectus Femoris

Answer 51

Extends knee, flexes hip

Question 52

Vastus Lateralis

Answer 52

Extends knee

Question 53

Vastus Medialis

Answer 53

Extends knee

Question 54

Vastus Intermedius

Answer 54

Extends knee

Question 55

Biceps Femoris

Answer 55

Flexes and laterally rotates knee, extends and adducts hip.

Question 56

Semimembranosus

Answer 56

Flexes knee

Question 57

Semitendinosus

Answer 57

Flexes knee