The Leg: Muscles, Blood Supply And Innervation

Question 1

What is the role of the anterior compartment of the leg?

Answer 1

It is responsible for dorsiflexion of ankle and extension of toes, innervated by the deep perineal nerve. It receives blood supply from the anterior tibial artery.

Question 2

Which muscles are in the anterior leg compartment?

Answer 2

Tibialis anterior
Fibularis tertius
Extensor hallucis longus
Extensor digitorum longus

Innervated by the deep peroneal/fibular nerve, along with the space between the 1st and 2nd toe. It is a branch of the common fibular nerve. Blood supply is the anterior tibial artery

Question 3

What is the role of tibialis anterior?

Answer 3

Attaches from tibia to 1st metatarsal for dorsiflexion and inversion. It is innervated by the deep peroneal nerve and supplied by anterior tibial artery.

Question 4

What is the role of the extensor hallucis longus?

Answer 4

Extrinsic muscle of the foot from the fibula and interosseus membrane which attaches to the 1st toe for extension and dorsiflexion. It is innervated by the deep peroneal nerve.

Question 5

What is the role of the fibularis tertius?

Answer 5

From the lower part of the fibula to attach to 5th metatarsal, innervated by deep peroneal/fibular nerve.

Question 6

What is the role of the lateral compartment of the leg?

Answer 6

Responsible for plantarflexion and eversion of ankle, innervated by the superficial fibular nerve. Blood supply is the fibular artery.

Question 7

Which muscles are present in the lateral compartment?

Answer 7

Fibularis longus
Fibularis brevis
They receive blood supply from the fibular artery, innervated by the superficial fibular nerve.

Question 8

What is the role of the fibularis longus?

Answer 8

From head and mid shaft of fibula to the 1st metatarsal and medial cuneiform for eversion, innervated by the superficial fibular nerve and blood supply via fibular artery.

Question 9

What is the role of the fibularis brevis?

Answer 9

From mid shaft of fibula to the 5th metatarsal for ankle eversion.

Question 10

What is the role of the posterior compartment of the leg?

Answer 10

Posterior compartment is important for plantarflexion and toe flexion, innervated by the tibial nerve. Blood supply is from the posterior tibial artery.

Question 11

Which muscles are present in the superficial layer of posterior compartment?

Answer 11

Gastrocnemius
Soleus
Plantaris

These are supplied by the sural artery, a branch of the popliteal/.

Question 12

What is the role of the gastrocnemius?

Answer 12

Arises from the 2 lateral femoral condyles to attach to the Achilles tendon for plantarflexion. Innervated by tibial nerve and posterior tibial artery.

Question 13

What is the role of the soleus?

Answer 13

Arises from the tibia and fibula to attach to Achilles tendon for plantarflexion. Innervated by tibial nerve and posterior tibial artery. It lies deep to the gastrocnemius.

Question 14

What is the role of the plantaris muscle?

Answer 14

Thin muscle which arises from the supracondyle of femur to attach to the Achilles tendon for plantarflexion. Innervated by tibial nerve and posterior tibial artery.

Question 15

What makes up the Achilles tendon?

Answer 15

Formed of the gastrocnemius, soleus and the plantaris for attachment to the calcaneus.

Question 16

Which muscles make up the deep posterior leg compartment?

Answer 16

Popliteus muscle
Tibialis posterior
Flexor digitorum longus
Flexor hallucis longus

Same innervation as the superficial compartment by tibial nerve and posterior tibial artery for plantarflexion.

Question 17

What is the role of the popliteus?

Answer 17

Oblique muscle from lateral condyle of femur to fibular condyle. This is an important muscle for unlocking the knee when extended via lateral rotation. Innervated by tibial nerve and posterior tibial artery.

Question 18

What is the role of the tibialis posterior?

Answer 18

Arises from the interosseus memrbrane to travel through tarsal tunnel and attach to the navicular bone of tarsal for **plantarflexion of ankle and inversion. ** Innervated by tibial nerve and posterior tibial artery.

Question 19

What is the role for the flexor digitorum longus?

Answer 19

Arises from tibia on the same side as the tibialis posterior to enter tarsal tunnel and insert into digits 2-5 for plantarflexion and toe flexion of digits 2-5. Innervated by tibial nerve and posterior tibial artery.

Question 20

What is the role of the flexor hallucis longus?

Answer 20

Lower fibula to 1st toe for plantarflexion of ankle and toe plantarflexion, travels through the tarsal tunnel. Innervated by tibial nerve and posterior tibial artery.

Question 21

What is the role of the extensor digitorum longus?

Answer 21

Extrinsic muscle of the anterior leg compartment from the fibula and interosseus to the digits 2-5 on the anterior aspect of the foot.

Question 22

What does the deep peroneal nerve innervate?

Answer 22

Anterior leg compartment

Question 23

What is the innervation to the medial side of the foot?

Answer 23

Sapphenous nerve, which is a continuation of the femoral nerve.

Question 24

What provides cutaneous innervation to the lateral side of the foot?

Answer 24

Sural nerve, formed of the joining of the tibial and common fibular nerve.

Question 25

What provides cutaneous innervation to the heel?

Answer 25

Tibial nerve branches.