Enumerated from the medial side, the four canals which it forms transmit the tendons of the tibialis posterior and flexor digitorum longus muscles; the posterior tibial artery and tibial nerve, which run through a broad space beneath the ligament; and lastly, in a canal formed partly by the talus, the tendon of the flexor hallucis longus.
Tarsal tunnel syndrome can be caused by entrapment of the tibial nerve beneath the flexor retinaculum of the foot.
[1] This is characterized by pain, numbness, and tingling of the medial plantar surface of the foot.
[2] Tinel's sign can be elicited by tapping the part of the flexor retinaculum of the foot over the tibial nerve.
[3] This article incorporates text in the public domain from page 489 of the 20th edition of Gray's Anatomy (1918)