Tarsal tunnel syndrome involves compression of the tibial nerve behind the medial malleolus, beneath the flexor retinaculum. Which specific muscles in the foot would be denervated?
- A Peroneus longus and brevis
- B Intrinsic muscles of the foot (except extensor digitorum brevis) ✓
- C Tibialis anterior and extensor hallucis longus
- D Gastrocnemius and soleus
Correct answer: B. Intrinsic muscles of the foot (except extensor digitorum brevis)
Explanation
The tibial nerve passes through the tarsal tunnel (between the medial malleolus and flexor retinaculum on the medial side of ankle), where it divides into medial plantar, lateral plantar, and medial calcaneal nerves. These supply all intrinsic muscles of the foot (abductor hallucis, flexor digitorum brevis, lumbricals, flexor hallucis brevis, abductor digiti minimi, quadratus plantae, interossei) except extensor digitorum brevis (supplied by deep peroneal nerve). Peroneal muscles and tibialis anterior are in the leg, supplied before the tarsal tunnel.
Reference: BD Chaurasia's Human Anatomy, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.