Joint · Ankle

Subtalar joint

Articulatio subtalaris

The joint between the talus and the heel bone, just below the ankle. This is where the foot rolls in and out — the motion people mean when they talk about pronation and supination. It sits on an oblique axis, so it does not move in a single plane: one movement tips the foot in three directions at once. It is the foot's adaptor. On landing it unlocks and lets the foot mould to the ground; at push-off it locks and turns the foot into a rigid lever.