Fig. 1
From: Frequency-dependent force direction elucidates neural control of balance
a Net ground reaction force, F, made up of horizontal and vertical components, \(F_x\) and \(F_z\), acts at the center of pressure, CoP, and has an orientation, \(\theta _F\). The center of mass, CoM, is also shown. b Two force vectors from two different time points, which are defined by their respective \(\theta _F\) and CoP, intersect at the intersection point, IP