What you're saying is correct Andrew_Patton. I'm not arguing with that. However, foam weapons have a very practical use. Beginners with Nunchakus are going to clock themselves sooner or later. I've known someone who knocked himself out with a metal pair of nunchakus. My sensei, fractured a bone in his elbow with his first wooden home made pair. Yes, foam weapons will throw off weight and speed, but they're forgiving.