Muscles in the Anterior Compartment of the Leg

Question 1

How many muscles are there in the anterior compartment of the leg?

Answer 1

4

Question 2

What are the muscles in the anterior compartment of the leg?

Answer 2

Tibialis anterior
Extensor digitorum longus
Extensor hallucis longus
Fibularis tertius

Question 3

What do the muscles of the anterior compartment of the leg collectively act to do?

Answer 3

Dorsiflex and invert the foot at the ankle joint

Question 4

What muscles extend the toes?

Answer 4

The extensor digitorum longus and extensor hallucis longus

Question 5

What are all the muscles in the anterior compartment of the leg innervated by?

Answer 5

The deep fibular nerve (L4-L5)

Question 6

What is the arterial supply of all the muscles in the anterior compartment of the leg?

Answer 6

The anterior tibial artery

Question 7

Where is the tibialis anterior muscle located?

Answer 7

Alongside the lateral surface of the tibia

Question 8

How is the action of the tibialis anterior tested?

Answer 8

The patient can be asked to stand on their heels

Question 9

What is the proximal attachment of the tibialis anterior?

Answer 9

Lateral condyle and superior half of lateral surface of tibia and interosseous membrane

Question 10

What is the distal attachment of the tibialis anterior?

Answer 10

Medial and inferior surfaces of medial cuneiform and base of 1st metacarpal

Question 11

What is the main action of the tibialis anterior?

Answer 11

Dorsiflexes ankle

Inverts foot

Question 12

Where does the extensor digitorum longus lie?

Answer 12

Lateral and deep to the tibialis anterior

Question 13

Where can the tendons of the extensor digitorum longus be palpated?

Answer 13

On the dorsal surface of the foot

Question 14

What is the proximal attachment of the extensor digitorum longus?

Answer 14

Lateral condyle of the tibia and superior three quarters of the medial surface of the fibula and interosseous membrane

Question 15

What is the distal attachment of the extensor digitorum longus?

Answer 15

Middle and distal phalanges of lateral four digits

Question 16

What is the main action of the extensor digitorum longus?

Answer 16

Extends lateral four digits

Dorsiflexes ankle

Question 17

Where is the extensor hallicus longus located?

Answer 17

Deep to the EDL and TA

Question 18

What is the proximal attachment of the extensor hallucis longus?

Answer 18

Middle part of anterior surface of fibula and interosseous membrane

Question 19

What is the distal attachment of the extensor hallucis longus?

Answer 19

Dorsal aspect of base of distal phalanx of great toe (hallux)

Question 20

What is the main action of the extensor hallucis longus?

Answer 20

Extends great toe

Dorsiflexes ankle

Question 21

Where does the fibularis tertius muscle arise from?

Answer 21

The most inferior part of the EDL

Question 22

Is the fibularis testis present in all individuals?

Answer 22

Yes

Question 23

What is the proximal attachment of the fibularis tertius?

Answer 23

Inferior third of anterior surface of fibula and interosseous membrane

Question 24

What is the distal attachment of the fibularis tertius?

Answer 24

Dorsum of base of 5th metatarsal

Question 25

What is the main action of the fibularis tertius?

Answer 25

Dorsiflexes ankle

Aids in eversion of foot

Question 26

What is footdrop?

Answer 26

A clinical sign indicating paralysis of the muscles in the anterior compartment of the leg

Question 27

When is footdrop most commonly seen?

Answer 27

When the common fibular nerve is damaged

Question 28

What arises from the common fibular nerve?

Answer 28

The deep fibular nerve

Question 29

What happens in footdrop?

Answer 29

The muscles in the anterior compartment are paralysed, and so the unopposed pull of the plantarflexor muscles (found in the posterior leg) produces pernament plantarflexion

Question 30

What can footdrop interfere with?

Answer 30

Walking

Question 31

Why can footdrop interfere with walking?

Answer 31

The affected limb can drag along the ground

Question 32

How can dragging of the foot with footdrop be circumvented?

Answer 32

The patient can flick the foot outwards while walking, known as an ‘eversion flick’.