http://www.youtube.com/watch?v=KX77Tzn1 ... re=related
I think here is quite an excellent of the liveliness in the lower body in generating the power of Xing I, I don't speak the language and know that I am missing a lot in his explanation, but I can see the machanics , and at about 5:35 he gives quite a graphic demonstration of the power generation and how it is the ground that allows us to create such force. I see one of the most common mistakes in Xing I as the flatfooted stepping that many think is being rooted, yet it is not , it is simply double weighting, to strike you end up using the upper body, when landing the strike, the power must go to the ground and back up to create any force, much like a shorted eletrical current causing a flickering light.