haha... well, thats debatable i guess. you could argue that flexability is part of evolution.... keeping us from getting hurt in the hunting and fighting world of ancient man?
i was going to do some Muay Thai stuff just to check it out and for exercise, but decided agianst it. i'm not too afraid of getting beat up a little, but a normal person getting kicked in the ribs can absorb that hit pretty well by the spine and ribs flexing. my spine doesn't flex so my ribs take all that hit along with the couple of functioning vertebrea that do actually work. i didn't think the risk was worth it... instead i ride dirtbikes. way safer... haha