Advanced Extensor Hallucis Brevis Quiz

Q1. Why can deep fibular nerve injury on the dorsum of the foot weaken extensor hallucis brevis?

• It has no peripheral nerve supply
• Its motor supply is derived from the deep fibular nerve
• It is supplied only by the sural nerve
• Its motor supply is derived from the tibial nerve

Q2. Why can the short extensor muscle belly serve as a landmark during dorsal foot dissection?

• It identifies the plantar aponeurosis
• It marks the course of the posterior tibial artery behind the medial malleolus
• It marks the popliteal fossa
• It helps orient the dissection to deep fibular nerve and dorsal arterial branches

Q3. How can an anatomical variant of extensor hallucis brevis affect dorsal foot surgery?

• Variant slips can alter expected tendon and soft tissue relationships
• It eliminates the first metatarsal
• It relocates the tibial nerve to the dorsum
• It changes the number of tibial condyles

Q4. Why does extensor hallucis brevis primarily extend the proximal phalanx rather than directly extending the distal phalanx?

• Its origin is on the distal phalanx
• It crosses only the ankle joint
• Its insertion is on the proximal phalanx
• Its tendon inserts on the plantar plate

Q5. What deficit would be most anatomically consistent with isolated loss of extensor hallucis brevis?

• Loss of knee extension
• Reduced assistance to great toe metatarsophalangeal extension
• Complete loss of ankle plantarflexion
• Complete loss of toe flexion

Q6. Why is complete loss of great toe extension unlikely after an isolated extensor hallucis brevis injury?

• Flexor hallucis longus becomes an extensor
• The plantar fascia actively extends the toe
• The tibialis posterior inserts on the distal phalanx
• Extensor hallucis longus provides an independent extensor force

Q7. Which relationship explains why dorsal swelling or trauma can affect extensor hallucis brevis function?

• It lies inside the calcaneus
• It is protected deep within the posterior leg
• Its dorsal position leaves it relatively exposed to local soft tissue injury
• It is enclosed by the plantar aponeurosis

Q8. Why is the distinction between extensor hallucis brevis and extensor hallucis longus important when assessing tendon injury?

• They are the same muscle with a single tendon
• Their separate tendons and insertions can produce partially preserved extension
• Both insert only on the calcaneus
• Neither crosses the first metatarsophalangeal joint

Q9. How does the calcaneal origin of extensor hallucis brevis support its classification as an intrinsic foot muscle?

• Both its origin and insertion are contained within the foot
• Its tendon passes through the tarsal tunnel from the leg
• It originates above the knee
• It originates from the fibular shaft

Q10. Which statement best integrates the anatomy of extensor hallucis brevis?

• It is a calcaneal-origin dorsal intrinsic muscle that assists great toe extension and is supplied by the deep fibular nerve
• It is a leg muscle that inserts on the distal phalanx through the tarsal tunnel
• It is a lateral ankle muscle that everts the foot
• It is a plantar tibial-nerve muscle that flexes the great toe