myology of the foot and lower leg

Question 1

what are the 4 compartments of extrinsic musculature of the lower leg

Answer 1

-superficial posterior
-deep posterior
-lateral
- anterior

Question 2

what muscle group is found in the superficial posterior compartment

Answer 2

plantarflexors

Question 3

what muscle group is found in the deep posterior compartment

Answer 3

toe flexors/ invertors/ plantarflexors

Question 4

what muscle group is found in the lateral compartment

Answer 4

evertors/ plantarflexors

Question 5

what muscle group is found in the anterior compartment

Answer 5

dorsiflexors/ invertors/ toe extensors

Question 6

what nerve supplies the posterior compartments

Answer 6

tibial nerve S1, 2

Question 7

what nerve supplies the anterior compartment

Answer 7

deep peroneal nerve

Question 8

what nerve supplies the lateral compartment

Answer 8

superficial peroneal nerve

Question 9

define an extrinsic muscle

Answer 9

a muscle whose origin is distant from its area of action

Question 10

what is a retinaculum

Answer 10

a band of thickened, deep fascia

Question 11

what are the 4 retinaculae of the ankle

Answer 11

-flexor
superior extensor
inferior extensor
peroneal

Question 12

what are the functions of the retinaculae

Answer 12

-binds tendons down to bone
-prevents bowstringing of muscles (where force is only produced by tendons) allowing muscles to produce good force

Question 13

describe the plantar aponeurosis (fascia)

Answer 13

thick dense connective tissue on sole of foot
originates from tuberosity of calcaneus to metatarsal heads
bears 15% of load on foot
stores energy for propulsion

Question 14

what muscles are found in the 1st layer of the foot

Answer 14

abductor hallucis
flexor digitorum brevis
abductor digiti minimi

Question 15

what muscles are found in the 2nd layer of the foot

Answer 15

lumbricals
quadratus plantae

Question 16

what tendons are found in the 2nd layer of the foot

Answer 16

flexor digitorum longus
flexor hallucis longus

Question 17

what muscles are in the 3rd layer of the foot

Answer 17

adductor hallucis
flexor digiti minimi brevis
flexor hallucis brevis

Question 18

what muscles are in the 4th layer of the foot

Answer 18

dorsal interossei
plantar interossei

Question 19

what tendons are in the 4th layer of the foot

Answer 19

peroneus longus
tibialis posterior

Question 20

gastrocnemius action

Answer 20

plantarflexion and knee flexion

Question 21

gastrocnemius origin

Answer 21

medial head- medial supracondylar ridge and adductor tubercle of femur
lateral head- lateral condyle of femur

Question 22

gastrocnemius insertion

Answer 22

via tendocalcaneus into posterior surface calcaneus

Question 23

soleus origin

Answer 23

soleal line on posterior surface of tibia

Question 24

soleus insertion

Answer 24

via tendocalcaneous with gastroc into posterior surface calcaneus

Question 25

gastrocnemius and soleus nerve supply

Answer 25

tibia nerve S1,2

Question 26

tibialis posterior action

Answer 26

inverts and plantarflexes foot

Question 27

tibialis posterior origin

Answer 27

upper part posterior surface of tibia and fibula, interosseous membrane

Question 28

tibialis posterior insertion

Answer 28

tubercle of navicular and medial cuneiform with expansions to all tarsal bones except talus

Question 29

tibialis posterior nerve supply

Answer 29

tibial nerve L4,5

Question 30

Flexor hallucis longus action

Answer 30

plantarflexes big toe and then ankle

Question 31

flexor hallucis longus origin

Answer 31

lower 2/3rds posterior fibula

Question 31

flexor hallucis longus insertion

Answer 31

plantar surface base of distal phalanx of hallucis

Question 31

flexor hallucis longus nerve supply

Answer 31

tibial nerve s1,2

Question 32

tibialis anterior origin

Answer 32

upper 2/3rds lateral surface tibia and interosseous membrane

Question 33

tibialis anterior insertion

Answer 33

medial side of medial cuneiform and base 1st metatarsal

Question 34

tibialis anterior nerve supply

Answer 34

deep peroneal nerve L4, 5