Extensor Hallucis Brevis Flashcards

Study the extensor hallucis brevis muscle, including its origin, insertion, innervation, blood supply, anatomical relations, and function.

Card 1 of 22Question

What is the extensor hallucis brevis?

A short intrinsic muscle on the dorsum of the foot that extends the great toe.

In This Section

1. What is the extensor hallucis brevis?

A short intrinsic muscle on the dorsum of the foot that extends the great toe.

2. Which muscular compartment of the foot contains the extensor hallucis brevis?

The dorsal muscular compartment of the foot.

3. How is the extensor hallucis brevis related to the extensor digitorum brevis?

It forms the medial portion of the extensor digitorum brevis muscle complex.

4. Where does the extensor hallucis brevis originate?

From the superolateral surface of the calcaneus, near the sinus tarsi.

5. Where does the extensor hallucis brevis insert?

On the dorsal aspect of the base of the proximal phalanx of the great toe.

6. Which toe is acted upon by the extensor hallucis brevis?

The great toe, also called the hallux.

7. What is the primary action of the extensor hallucis brevis?

Extension of the great toe at the first metatarsophalangeal joint.

8. Does the extensor hallucis brevis directly extend the interphalangeal joint of the great toe?

No. Its primary action is at the metatarsophalangeal joint.

9. Which nerve supplies the extensor hallucis brevis?

The deep fibular nerve, also called the deep peroneal nerve.

10. Which branch of the deep fibular nerve innervates the extensor hallucis brevis?

The lateral terminal branch.

11. Which spinal nerve roots contribute to the innervation of the extensor hallucis brevis?

Primarily L5 and S1.

12. Which artery primarily supplies the extensor hallucis brevis?

The lateral tarsal artery, a branch of the dorsalis pedis artery.

13. What is the course of the extensor hallucis brevis tendon?

It runs distally and medially across the dorsum of the foot toward the great toe.

14. How does the extensor hallucis brevis tendon relate to the extensor hallucis longus tendon?

It generally approaches the great toe lateral to the extensor hallucis longus tendon.

15. Which muscle works with extensor hallucis brevis to extend the great toe?

The extensor hallucis longus muscle.

16. How does the distal attachment of extensor hallucis brevis differ from that of extensor hallucis longus?

Extensor hallucis brevis inserts on the proximal phalanx, while extensor hallucis longus inserts on the distal phalanx.

17. Is the extensor hallucis brevis an intrinsic or extrinsic foot muscle?

An intrinsic foot muscle because its origin and insertion are both within the foot.

18. What is the relationship of extensor hallucis brevis to the inferior extensor retinaculum?

Its proximal muscle belly lies deep to part of the inferior extensor retinaculum.

19. What movement may become weaker after injury to the nerve supplying extensor hallucis brevis?

Extension of the great toe at the metatarsophalangeal joint.

20. Which nerve lesion can cause atrophy of both extensor hallucis brevis and extensor digitorum brevis?

A lesion of the lateral terminal branch of the deep fibular nerve.

21. How can the extensor hallucis brevis contribute to normal walking?

It assists great toe extension during foot clearance and positioning of the toes.

22. Which tendon must remain functional for strong extension of the great toe's interphalangeal joint?

The extensor hallucis longus tendon.