Bony landmark · Ankle

Medial malleolus

Malleolus medialis

The medial malleolus is the knob on the inner side of the ankle: the lower end of the shin bone reaching down past the joint. The deltoid ligament, the strong fan that stops the ankle rolling outwards, anchors to it. Behind it runs a tunnel — the tarsal tunnel — carrying the tibialis posterior and toe flexor tendons, the posterior tibial artery and the tibial nerve down into the sole. It sits higher and further forward than the knob on the outer side, and that asymmetry is part of why an ankle rolls inwards more easily than out.