"There has been a lot of technical talk about this backpack . Watts, energy. power and so forth. It is much simpler than that...tell me, if it is on a suspension  mechanism, doesn't the pack remain almost stationary when one is running other than the forward movement of course.  Isn't the energy to jerk the pack up and down to the frequency of the wearers running, more than to just simply hold it. And isn't eliminating shock fatigue really the purpose of this contraption. Why do they make running shoes? Its like anytime you accelerate a mass, it requires more energy than if you dont. You dont get enough rest on the  down stoke of the backpack to compensate for the upward acceleration or push."