ANTERIOR Fascial Compartment of the Lower Limb

Question 1

Tibialis Anterior

Intrinsic or Extrinsic?
Origin
Insertion
Nerve supply
Action

Answer 1

Extrinsic

Origin: Lateral surface of shaft of tibia and interosseous memberane

Insertion: Medial cuneiform and base of 1st metatarsal bone

Nerve supply: Deep peroneal nerve

Action: Extends the foot at ankle joint; inverts foot at subtalar and transverse tarsal joints; holds up medial longitudinal arch of the foot

Question 2

Extensor Digitorum Longus

Intrinsic or Extrinsic?
Origin
Insertion
Nerve supply
Action

Answer 2

Extrinsic

Origin: Anterior surface of shaft of fibula

Insertion: Extensor expansion of lateral four toes

Nerve supply: Deep peroneal nerve

Action: Extends toes; extends foot at ankle joint

Question 3

Peroneus Tertius

Intrinsic or Extrinsic?
Origin
Insertion
Nerve supply
Action

Answer 3

Extrinsic

Origin: Anterior surface of shaft of fibula

Insertion: Base of 5th metatarsal bone

Nerve supply: Deep peroneal nerve

Action: Extends foot at ankle joint; everts foot at subtalar and transverse tarsal joints

Question 4

Extensor Hallucis Longus

Intrinsic or Extrinsic?
Origin
Insertion
Nerve supply
Action

Answer 4

Extrinsic

Origin: Anterior surface of shaft of fibula

Insertion: Base of distal phalanx of hallux

Nerve supply: Deep peroneal nerve

Action: Extends big toe; extends foot at ankle joint; inverts foot at subtalar and transverse tarsal joints

Question 5

Extensor Digitorum Brevis

Intrinsic or Extrinsic?
Origin
Insertion
Nerve supply
Action

Answer 5

Intrinsic

Origin: Calcaneum

Insertion: By four tendons into the proximal phalanx of the hallux and long extensor tendons to 2nd, 3rd and 4th toes

Nerve supply: Deep peroneal nerve

Action: Extends toes