when i was in the army,i saw corp of engenires guys able to walk in a mine field on this foam mattress plates attached to their feet. now, i understand that this is possible because the foam spread their weight ( pressure?) along a bigger area,thus reducing pressure,how is the foam able to do it? a thin piece of paper attached to your feet will not have the same pressure reducing effect,....why? does it has to do with thickness?.... would a plate of wood achieve the same "weight distribution" result?