Ankle and foot

Sustentaculum tali

How to find it: About a thumb's width distal to the medial malleolus; a small ledge you can support from below.
What you use it for: Carries the talus and the plantar calcaneonavicular (spring) ligament; a reference point when assessing a collapsed medial arch.
On the bone: Calcaneus
Body region: Ankle and foot