Muscles of the anterior compartment of the lower leg

Question 1

Tibialis anterior

Answer 1

Origin:

• Lateral surface of tibia and adjacent interosseous membrane

Insertion:

• Medial and inferior surfaces of medial cuneiform and adjacent surfaces on base of metatarsal I

Innervation:

• Deep fibular nerve (L4, L5)

Function:

• Dorsiflexion of foot at ankle joint, inversion of foot, dynamic support of medial arch of foot

Question 2

Extensor hallucis longus

Answer 2

Origin:

• Middle one half of medial surface of fibula and adjacent surface of interosseous membrane

Insertion:

• Dorsal surface of base of distal phalanx of great toe

Innervation:

• Deep fibular nerve (L5, S1)

Function:

• Extension of great toe and dorsiflexion of foot

Question 3

Extensor digitorum longus

Answer 3

Origin:

• Proximal one half of medial surface of fibula and related surface of lateral tibial condyle

Insertion:

• Via dorsal digital expansions into bases of distal and middle phalanges of lateral four toes

Innervation:

• Deep fibular nerve (L5, S1)

Function:

• Extension of lateral four toes and dorsiflexion of foot

Question 4

Fibularis tertius

Answer 4

Origin:

• Distal part of medial surface of fibula

Insertion:

• Dorsomedial surface of base of metatarsal V

Innervation:

• Deep fibular nerve (L5, S1)

Function:

• Dorsiflexion and eversion of foot