A model for the relation between the displacement of the ankle and the center of pressure in the frontal plane, during one-leg stance

We present and validate a model for the relation between the horizontal, frontal plane displacement of the ankle, representing frontal plane foot tilt, and the frontal plane displacement of the Center of Pressure (CoP) during one-leg stance. It is concluded that the frontal plane movements of the CoP should be regarded not as a measure of body sway, as is often done, but as a measure for the tilting movements of the foot as a mechanism for balance control. Foot breadth affects the gain of this mechanism in terms of CoP displacement and can potentially affect balance control.