Flexor retinaculum of foot

The flexor retinaculum of foot (laciniate ligament, internal annular ligament) is a strong fibrous band, extending from the bony ankle prominence (malleolus) above, to the margin of the heelbone (calcaneus) below, converting a series of bony grooves in this situation into canals for the passage of the tendons of the flexor muscles and the posterior tibial vessels and tibial nerve into the sole of the foot.