Muscles of Anterior Compartment of leg

Question 1

Tibialis Anterior (Origin-3, Insertion-2, Innervation, Action-3)

Answer 1

Origin:

• Lateral condyle
• Superior half of lateral surface of tibia
• Interosseous membrane

Insertion:

• Medial and inferior surfaces of medial cuneiform
• Base of 1st metatarsal

Innervation: Deep fibular nerve (L4, L5)

Action:

• Dorsiflexes ankle
• Inverts foot
• Supports medial longitudinal arch

Question 2

Extensor hallucis longus (Origin-2, Insertion, Innervation, Action-2)

Answer 2

Origin:

• Middle part of anterior surface of fibula
• Interosseous membrane

Insertion: Dorsal aspect of base of distal phalanx of great toe (hallux)

Innervation: Deep fibular nerve (L5, S1)

Action:

• Extends great toe
• Dorsiflexes ankle

Question 3

Extensor digitorum longus (Origin-2, Insertion, Innervation, Action-2)

Answer 3

Origin:

• Lateral condyle of tibia
• Interosseous membrane

Insertion: Middle and distal phalanges of lateral 4 digits

Innervation: Deep fibular nerve (L5, S1)

Action:

• Extends lateral 4 digits
• Dorsiflexes ankle

Question 4

Fibularis Tertius (Origin-2, Insertion, Innervation, Action-2)

Answer 4

Origin:

• Inferior 1/3 of anterior surface of fibula
• Interosseous membrane

Insertion: Dorsum of base of 5th metatarsal

Innervation: Deep fibular nerve (L5, S1)

Action:

• Dorsiflexes ankle
• Aids in eversion of foot