In tarsal tunnel syndrome, which nerve is most commonly involved due to compression?

• A. Common peroneal nerve
• B. Tibial nerve
• C. Sural nerve
• D. Saphenous nerve

Answer: (B)

Tarsal tunnel syndrome involves compression of the tibial nerve as it travels behind the medial malleolus under the flexor retinaculum. This location makes the tibial nerve the most commonly affected structure, because it provides both motor to intrinsic foot muscles and sensory innervation to the plantar surface of the foot. When compressed, you typically see pain, numbness, or burning on the bottom of the foot and sometimes weakness of toe flexors and intrinsic foot muscles. The other nerves listed aren’t the primary structures in this tunnel: the common peroneal nerve runs around the fibular head and is implicated in different compressions, while the sural and saphenous nerves are mainly cutaneous branches that don’t pass through the tarsal tunnel.