Anterior Leg

Question 1

Name the muscles in the anterior leg compartment

Answer 1

Tibialis Anterior
Extensor Digitorum Longus
Extensor Hallucis Longus
Peroneus Tertius

Question 2

Give the origin, insertion, innervation, action, and test for:

Tibialis Anterior

Answer 2

Origin:
Lateral surface of tibia (inc. lateral tibial condyle) + interosseous membrane

Insertion:
Medial cuneiform + Metatarsal 1

Innervation:
Deep peroneal nerve (L4,5)

Action:

• Main Dorsiflexer
• Invert the ankle

Test:
Dorsiflex ankle against resistance. Can see + palpate tendon.

Question 3

Give the origin, insertion, innervation, action, and test for:

Extensor Digitorum Longus

Answer 3

Origin:
Lateral tibial + lateral condyle of tibia + medial surface of fibula + interosseous membrane

Insertion:
Splits into 4 tendons to insert into middle + distal phalanges of lateral 4 toes.

Innervation:
Deep Peroneal Nerve (L4,5)

Action:

• Extend toes
• Dorsiflex ankle

Test:
-Dorsiflex lateral 4 toes against resistance. If normal, tendons can be seen and palpated.

Question 4

Give the origin, insertion, innervation, action, and test for:

Extensor Hallucis Longus

Answer 4

Origin:
Middle part of anterior fibula + interosseous membrane

Insertion:
Dorsal aspect of base of distal phalanx of great toe

Innervation:
Deep Peroneal nerve (L4,5)

Action:

• Extend the great toe
• Dorsiflex the ankle

Test:
-Dorsiflex the great toe against resistance (if normal, tendons can be seen and palpated).

Question 5

Give the origin, insertion, innervation, action, and test for:

Peroneus Tertius

Answer 5

Origin:
Branches off from inferior part of Extensor Digitorum Longus and follows it to the dorsum of the foot.

Insertion:
5th metatarsal

Innervation:
Deep Peroneal nerve (L4,5)

Action:

• Dorsiflex the ankle
• Evert the ankle

Test:
None listed.