I've been looking at some videos on footwork and they say when lunging land on your heels and roll forward. Isn't landing on the heel bad for the body? I read the foot is designed in such a way that the forefoot should be the first to hit the ground so it can absorb most of the shock. If the heel hits the ground then the shock is transferred up the leg to the knees and hips. If anyone can shed light on this, it would be much appreciated.