Muscle Actions- Back and Lower Extremity

Question 1

Erector Spinae

Answer 1

extension & lateral flexion of the vertebral column

Question 2

Semispinalis

Answer 2

extension & contralateral rotation of the vertebral column

Question 3

Multifidus and Rotatores

Answer 3

stabilizes vertebrae, and assists with extension & rotation of the vertebral column

Question 4

Iliacus

Answer 4

flexes thigh and stabilizes hip joint

Question 5

Psoas

Answer 5

flexes thigh and stabilizes hip joint

Question 6

Rectus Femoris

Answer 6

flexes thigh, and extends leg

Question 7

Sartorius

Answer 7

flexes, abducts & laterally rotates thigh, and flexes leg

Question 8

Tensor Fasciae Latae

Answer 8

abducts, flexes & medially rotates thigh, and assists in maintaining extended leg

Question 9

Vastus intermedius

Answer 9

extends leg

Question 10

Vastus lateralis

Answer 10

extends leg

Question 11

Vastus medialis

Answer 11

extends leg

Question 12

Adductor brevis

Answer 12

adducts thigh

Question 13

Adductor longus

Answer 13

adducts & flexes thigh

Question 14

Adductor magnus

Answer 14

adducts (adductor part) & extends (hamstring part) thigh

Question 15

Gracilis

Answer 15

flexes & medially rotates the leg, and adducts thigh

Question 16

Pectineus

Answer 16

adducts & flexes thigh

Question 17

Obturator Externus

Answer 17

laterally rotates thigh

Question 18

Gemellus Inferior

Answer 18

laterally rotates thigh

Question 19

Gemellus superior

Answer 19

laterally rotates thigh

Question 20

Gluteus maximus

Answer 20

extends & laterally rotates thigh, & tenses fascia lata (iliotibial tract)

Question 21

Gluteus medius

Answer 21

abducts & medially rotates thigh; and keeps the pelvis level when opposite leg is raised

Question 22

Gluteus minimis

Answer 22

abducts & medially rotates thigh; and keeps the pelvis level when opposite leg is raised

Question 23

Obturator Internus

Answer 23

laterally rotates thigh

Question 24

Piriformis

Answer 24

abducts & laterally rotates thigh

Question 25

Quadratus Femoris

Answer 25

laterally rotates thigh

Question 26

Biceps femoris

Answer 26

flexes leg (both heads) & extends thigh (long head only)

Question 27

Semimembranosus

Answer 27

extends thigh & flexes leg

Question 28

Semitendinosus

Answer 28

extends thigh & flexes leg

Question 29

Extensor Digitorum Longus

Answer 29

dorsiflexes ankle, and extends digits 2-5 (IP & MP)

Question 30

Extensor Hallucis Longus

Answer 30

dorsiflexes ankle, and extends great toe (MP & IP)

Question 31

Peroneus Tertius

Answer 31

dorsiflexes ankle, and everts foot

Question 32

Tibialis anterior

Answer 32

dorsiflexes ankle, and inverts foot

Question 33

Perioneus longus

Answer 33

plantar flexes ankle, and everts foot

Question 34

Peroneus brevis

Answer 34

plantar flexes ankle, and everts foot

Question 35

Flexor digitorum longus

Answer 35

plantar flexes ankle, and flexes digits 2-5 (MP & IP)

Question 36

Flexor hallucis longus

Answer 36

plantar flexes ankle, and flexes great toe (MP & IP)

Question 37

Gastrocnemius

Answer 37

flexes leg, and plantar flexes ankle

Question 38

Plantaris

Answer 38

flexes leg, and plantar flexes ankle

Question 39

Popliteus

Answer 39

unlocks knee during (initial) flexion

Question 40

Soleus

Answer 40

plantar flexes ankle

Question 41

Tibialis Posterior

Answer 41

plantar flexes ankle, and inverts foot

Question 42

Abductor Digiti Minimi

Answer 42

abducts & flexes 5th digit

Question 43

Abductor Hallucis

Answer 43

flexes & abducts great toe

Question 44

Adductor Hallucis

Answer 44

adducts great toe

Question 45

Extensor Digitorum Brevis

Answer 45

extension of digits 2-5 (MP & IP)

Question 46

Extensor Hallucis Brevis

Answer 46

extension of great toe (MP)

Question 47

Flexor digitorum accessorius

Answer 47

assists flexor digitorum longus

Question 48

Flexor digitorum brevis

Answer 48

flexes toes (proximal IP)

Question 49

Flexor digiti minimi

Answer 49

flexion of 5th digit (MP)

Question 50

Flexor Hallucis brevis

Answer 50

flexion of great toe (MP)

Question 51

Interossei-dorsal

Answer 51

abducts (MP) & flexes (MP) & extends (IP) digits 2-4

Question 52

Interossei-plantar

Answer 52

adducts & flexes (MP) & extends (IP) digits 3-5

Question 53

Lumbricals

Answer 53

flexes proximal phalanges (MP), and extend IP joints