Muscles of Anterior Leg

Question 1

Name the 4 muscles in the anterior compartment of the leg.

Answer 1

Tibialis anterior, extensor digitorum longus, extensor hallucis longus, fibularis tertius

Question 2

What is the action of the muscles of the anterior leg?

Answer 2

. Dorisflexion and inversion of foot at ankle joint

. Extensor digitorum longus and extensor hallucus longus extend toes

Question 3

What is the innervation of the anterior leg muscles? What is the spinal root value of this?

Answer 3

Deep fibular nerve (L4-L5)

Question 4

What is the blood supply of the anterior leg muscles?

Answer 4

Anterior tibial artery

Question 5

Where is the tibialis anterior located?

Answer 5

On the lateral edge of the tibia

Question 6

What are the attachments of the tibialis anterior?

Answer 6

Originates from lateral surface of tibia, attaches to medial cuneiform and base of metatarsal 1

Question 7

What is the action of tibialis anterior?

Answer 7

Dorisflexion and inversion of foot at ankle joint

Question 8

What is the innervation of the tibialis anterior?

Answer 8

Deep fibular nerve

Question 9

Where is the extensor digitorum longus?

Answer 9

Lateral and deep to tibialis anterior

Question 10

What are the attachments of the extensor digitorum longus?

Answer 10

Originates from lateral condyle of tibia and medial surface of fibula, fibres converge into tendon, which travels down dorsal surface of foot, splitting into 4 with each inserting into one of the lateral toes

Question 11

What does the extensor digitorum longus do?

Answer 11

Dorisflexion and extension of the four lateral toes

Question 12

What is the innervation of the extensor digitorum longus?

Answer 12

Deep fibular nerve

Question 13

Where is the extensor hallucis longus located?

Answer 13

Deep to the extensor digitorum longus and tibialis anterior, deep to them both

Question 14

What are the attachments of the extensor hallucis longus?

Answer 14

Originates from the medial surface of fibular shaft, tendon crosses anterior to ankle joint and attaches to base of distal phalanx of the great toe

Question 15

What is the action of the extensor hallucis longus?

Answer 15

Dorisflexion of foot, extension of great toe

Question 16

What is the innervation of the extensor hallucis longus?

Answer 16

Deep fibular nerve

Question 17

What is ‘special’ about the fibularis tertius muscles?

Answer 17

They aren’t present in all individuals and in some people are considered part of the extensor digitorum longus

Question 18

What is the action of the fibularis tertius?

Answer 18

Dorisflexion and eversion of the foot

Question 19

What is the innervation of the fibularis tertius muscles?

Answer 19

Deep fibular nerve

Question 20

What is footdrop a clinical sign of? How does this most commonly occur and what is the consequence?

Answer 20

. Paralysis of the anterior leg muscles
. Most commonly occurs when there’s damage to the common fibular nerve (from which the deep fibular nerve arises)
. This means the posterior leg muscles are unopposed so there’s unopposed plantarflexion

Question 21

What are the attachments of the fibularis tertius?

Answer 21

Originates from lower part of extensor digitorum longs, tendon descends with EDL then attaches to metatarsal 5