Anterior Compartment of the Leg

Question 1

Origin and Insertion of Tibialis Anterior muscle? Action?

Answer 1

O: lateral tibia condyle I: inferior and medial aspect of the Cuniform bone and base of the 1st metatarsal - Invert and dorsiflex the foot at the ankle - stabilize the arch (maintaining the medial arch of the foot) during weight bearing locomotion

Question 2

This muscle is deep to the Tibialis Anterior muscle Origin, Insertion and Action?

Answer 2

Extensor Hallicis Longus runs in front of the ankle O: anterior surface of the fibula, interosesseous membrane I: inserts into the distal great toe A: dorsiflex the ankle and extend the big toe

Question 3

Most lateral muscle in the anterior compartment of the leg.

Answer 3

Extensor Digitorum Longus O: anterior fibula, interosseous membrane I: the tendon of the distal phalanges of the distal four toes A: dorsiflex the ankle and extend the four toes

Question 4

Deep Peroneal nerve innervates?

Answer 4

The main nerve of the lateral compartment of the leg It also innervates the anterior leg muscles Nerve root L5-S1

Question 5

Peroneus Tertious Muscle

Answer 5

Considered to be a separate muscle from the EDL.

O: lower lateral fibula & interosseous membrane

I: tendon runs down the ankle to insert into the base of the 5th metatarsal Weakly dorsiflex at the ankle - not present in all humans… may have evolved during upright walking

Question 6

The course of the deep fibular nerve, branches, and muscular and cutaneous innervation

Answer 6

enters the anterior compartment of the leg by piercing the deep inter muscular septum & the EDL muscle - descends down the anterior compartment with the anterior tibial artery in front of the interroseous membrane and deep to tibialis anterior and as it descends it innervates all the muscles in the anterior compartment of the leg… it further descend down the front of the ankle joint and lateral to the tibias anterior tendon and then it travels to the dorsum of the foot and innervates the extensor hallucis brevis& the EDB on the dorm of the foot. Finally it ends as a cutaneous branch to supply the patch of skin between the 1st and 2nd toe

Question 7

Injury to the deep fibular nerve will result in….

Answer 7

foot drop

Question 8

Blood supply to the anterior compartment is provided by the…..

Answer 8

Anterior tibial artery

Question 9

Anterior Tibial Artery describe the course, branches or tributaries

Answer 9

• branches off from the popliteal artery at the border of the inferior popliteal muscle then enter the anterior compartment to descend through the anterior compartment with the deep fibular nerve… The anterior tibial artery ends at the ankle joint to continue as the DORSALIS PEDIS ARTERY at the front of the ankle…. travels between the tendon of EHL and EDL …can be palpated at the level of the navicular

Question 10

What is the main nerve & blood vessel that supplies the anterior compartment of the leg?

Answer 10

All the anterior leg muscles are innervated by the muscular branches of the

Deep Peroneal Nerve,

Tibialis anterior, L4, L5

Extensor Dig. Longus, L5, S1

Extensor Hall. Longus, L5, S1,

Fibularis Tertius, L5, S1

Anterior Tibialis Artery

Question 11

All the anterior compartment of the leg muscles are innervated by the

Answer 11

deep muscular branches of the peroneal nerve

Question 13

Action of the anterior leg muscles

Answer 13

The anterior compartment of the legs mainly dorsiflex the ankle and invert the foot