Figure 3.

The foot columns and subtalar-joint motion in the closed kinetic chain. These combined frontal-plane and transverse-plane motions occur simultaneously, resulting in a multiplanar rotation. This is different from single-plane, noncardinal motion and is a multiplanar rotary motion that is similar to the motion occurring at the knee. A, Supination. “Stacking” of the medial foot column laterally and vertically over the lateral foot column results in a higher, narrower foot. B, Pronation. “Unstacking” of the medial foot column medially away from the lateral foot column results in a wider, flatter foot.