So I was reading up "Zero Moment Point -Thirty Five Years of Its Life" by Vukobratic for a presentation, and is said something like this: So if I am reading this right, it's saying the point where the GRF is acting upon will shift based on the magnitude of the force created by the orientation of the upper portions of the robot. The greater the horizontal component of the Moment M_A, the farther away from the ankle the point will be. (fig d in uploaded diagram). However, it also goes on to say that Okay, so if the upper body's movements are greater than can be compensated for by the shifting of the GRF focus point (is that right?), than the foot will experience a torque equivalent to the uncompensated for force? Huh? I'm confused.