HARP

things being worn to see what happens. There’s a lot of these, but look at the obvious, how little it matters. Those two rising humps (against gravity) persist. Thus we see asymmetrical (R&L) peaks over the Right & Left stance phase. You just know (as we have been hinting) these peaks are when we are at midstance (HARP line = vertical) for each leg. Why asymmetrical? Not doing the same test thing to each side. We can GUESS what a ‘FORCE PLATE’ graph would look like! Landing on the plate will drive it down as Isaac Newton pushes the pelvis up as the pelvis rises over the foot. That interplay of landing and actual weight produces a hump that is about 30% greater downward measured pressure than actual body weight. So the force on the floor is almost the same graph with just a different Y label. Pelvis is height above floor. Force plate [aka ground reaction] is pounds or kilos or any pressure type you like. The plate was designed originally to test thoroughbred horse kick thrust out of the starting gate. Gate analysis!! I like that. The ground reaction M shape has its middle V part less than the weight of the person as weight shift from right to left (or L==>R) is partially flight. Interestingly, if the subject slows down more (dampening the pendulum?) then the ground force gets LARGER as feet are now truly supporting the body above which also sways more-so to the supporting side.