Lower Extremity Muscle Actions

Question 1

Pectineus

Answer 1

Adducts the thigh and flexes the hip joint

Question 2

Adductor Brevis

Answer 2

Adducts and flexes the thigh, and helps to laterally rotates the thigh

Question 3

Adductor Longus

Answer 3

Adducts and flexes the thigh, and helps to laterally rotate the hip joint

Question 4

Adductor Magnus

Answer 4

Powerful thigh adductor, superior horizontal fibers also help flex the thigh, while vertical fibers help extend the thigh

Question 5

Gracilis

Answer 5

Flexes the knee, adducts the thigh, and helps to medially rotate the tibia on the femur

Question 6

Sartorius

Answer 6

Flexes and laterally rotates the hip joint and flexes the knee

Question 7

Tensor Fascia Lata

Answer 7

Helps stabilize and steady the hip and knee joints by putting tension on the iliotibial band of fascia

Question 8

Rectus Femoris

Answer 8

Extends the knee

Question 9

Vastus Intermedius

Answer 9

Extends the Knee

Question 10

Vastus Medialis

Answer 10

Extends the knee

Question 11

Vastus Lateralis

Answer 11

Extends the knee

Question 12

Hamstrings (Biceps Femoris) Long Head

Answer 12

Flexes the knee, and also rotates the tibia laterally, long head also extends the hip joint

Question 13

Hamstrings (Biceps Femoris) Short Head

Answer 13

Flexes the knee, and also rotates the tibia laterally

Question 14

Hamstrings (Semimembranosus)

Answer 14

Extends the thigh, flexes the knee, and also rotates the tibia medially, especially when the knee is flexed

Question 15

Hamstrings (Semitendonosus)

Answer 15

Extends the thigh and flexes the knee, also rotates the tibia medially, especially when the knee is flexed

Question 16

Tibialis Anterior

Answer 16

Dorsiflexor of ankle and invertor of foot

Question 17

Extensor Digitorum Longus

Answer 17

Extend toes 2-5 and dorsiflexes ankle

Question 18

Extensor Hallucis Longus

Answer 18

Extends the great toe and dorsiflexes ankle

Question 19

Gastrocnemius

Answer 19

Power plantar flexor of ankle

Question 20

Soleus

Answer 20

Powerful plantar flexor of ankle

Question 21

Plantaris

Answer 21

Plantar flexor of ankle, also flexes knee

Question 22

Tibialis Posterior

Answer 22

Principal invertor of foot, also adducts foot, plantar flexes ankle, and helps supinate foot

Question 23

Flexor Digitorum Longus

Answer 23

Flexes toes 2-5, also helps in plantar flexion of ankle

Question 24

Flexor Hallucis Longus

Answer 24

Flexes great toe, helps to supinate ankle, and is a very weak plantar flexor of ankle

Question 25

Popliteus

Answer 25

Rotates the knee medially and flexes the leg on the thigh

Question 26

Peroneus Tertius

Answer 26

Works with the extensor digitorum longus to dorsiflex, evert, and abduct the foot

Question 27

Peroneus Brevis

Answer 27

Everts the foot and plantar flexes the ankle

Question 28

Peroneus Longus

Answer 28

Everts foot and plantar flexes ankle, also helps to support the transverse arch of the foot

Question 29

Extensor Digitorum Brevis

Answer 29

Extends digits 2-4

Question 30

Extensor Hallucis Brevis

Answer 30

Extends digit 1

Question 31

Abductor Hallucis

Answer 31

Abducts and flexes digit 1

Question 32

Flexor Digitorum Brevis

Answer 32

Flexes digits 2-5

Question 33

Abductor Digiti Minimi

Answer 33

Abducts and flexes digit 5

Question 34

Quadratus Plantae

Answer 34

Assists flexor digitorum longus in flexing digits 2-5

Question 35

Lumbricals

Answer 35

Flex proximal phalanges, extend middle and distal phalanges of digits 2-5

Question 36

Flexor Hallucis Brevis

Answer 36

Flexes proximal phalanx of digit 1

Question 37

Adductor Hallucis

Answer 37

Adduct digit 1, assist in transverse arch of foot

Question 38

Flexor Digiti Minimi Brevis

Answer 38

Flexes proximal phalanx of 5th digit

Question 39

Plantar Interossei

Answer 39

Adducts digits 2-4

Question 40

Dorsal Interossei

Answer 40

Abducts digits 2-4