Lateral and Anterior Leg Musculature

Question 1

Peroneus (fibularis) longus

Answer 1

Origin:
- Head of fibula
- Upper half of fibula
Insertion:
- Base of 1st metatarsal
- 1st cuneiform
- Base of 2nd metatarsal (sometimes)
Action:
- Everts & horizontally abducts foot
- Weakly plantarflexes foot
Nerve:
- Superficial peroneal (fibular)
- L4-5, S1

Question 2

Peroneus (fibularis) brevis

Answer 2

Origin:
- Lower half of fibula
Insertion:
- Tuberosity on lateral aspect of base of 5th metatarsal
Action:
- Everts & horizontally abducts foot
- Weakly plantarflexes foot
Nerve:
- Superficial peroneal (fibular)
- L4-5, S1

Question 3

Tibialis anterior

Answer 3

Origin:
- Lateral tibial condyle
- Anterolateral surface of tibia
Insertion:
- Medial & plantar surface of base of 1st metatarsal
- Medial & plantar surface of 1st cuneiform
Action:
- Dorsiflexes foot
- Helps invert & horizontally adduct  foot
Nerve:
- Deep peroneal
- L4-5, S1

Question 4

Extensor hallucis longus

Answer 4

Origin:
- Medial aspect of fibula
- Interosseus membrane
Insertion:
- Dorsal surface of base of proximal & distal phalanx of hallux
Action:
- Extends distal phalanx of big toe
- Weakly dorsiflexes the foot
- Weakly inverts and adducts foot
Nerve:
- Deep peroneal
- L4-5, S1

Question 5

Extensor digitorum longus

Answer 5

Origin:
- Upper anterior surface of fibula
- Interosseus membrane
Insertion:
- Dorsal surface of the bases of the middle & distal phalanxes of the 2nd-5th rays
Action:
- Extends lateral 4 toes
- Weakly dorsiflexes & everts foot
Nerve:
- Deep peroneal
- L4-5, S1

Question 6

Peroneus (fibularis) Tertius

Answer 6

Origin:
- Distal 1/3 of anterior fibula
Insertion:
- Dorsal surface of the base of the 5th metatarsal
Action:
- Weakly dorsiflexes & everts foot
Nerve:
- Deep peroneal
- L4-5, S1