If you are a hillwalker, wherever your preferred stomping ground may be you’ll know the importance of a pack with a good strap system. A comfortable pack will make the difference between tiredness and agony, and can easily add a considerable difference to your daily range.
At Arizona State University’s Human Integration Laboratory, they were approached by the US Army to investigate means by which the effect of carrying a heavy backpack could be mitigated. A soldier’s full kit is extremely heavy, and while the best available webbing systems will make a contribution to the comfort of carrying it, they can only go so far. There is still the jarring effect of the impulse force of such a significant load bearing down on the soldier’s shoulders as it comes down after every step, and this when taken over a lengthy march makes a significant difference to overall endurance.
The ASU lab’s solution was to mount the load on a spring-loaded vertical actuator attached to the pack harness and frame. The on-board microcontroller judges the moment of maximum downward impulse force as the wearer comes down from a step, and applies a corresponding upward force to the actuator. Power comes from a lithium-ion battery pack. The effect is to make the load oscillate up and down, and to lessen the wear and tear on the shoulders. It does not reduce the weight you are carrying, but it does lift it off your shoulders for an instant just when you need it.
There is a video of it being tested in the sun-drenched Arizona mountains, that we’ve placed below the break.