The increasing importance of Ashi Waza, in high level competition. (Their Biomechanics, and small changes in the form)

In this paper we are interested, both: at the description of Biomechanics of the Ashi Waza techniques, with precision of few of them, members of the Japanese, so called, Ko Waza group; and at the biomechanical analysis of the small changes in the applicative form of them. These small changes, from the basic movement defined by Kodokan and show in thousand books, probably born from practical competitive situations. They are today become the usual applicative form, not only present among the various National Federations, but also in Japan itself among Universities dojos and the Kodokan. Among the Ko Waza techniques, we will select for our analysis only the following: Ko Uchi Gari , Ko Soto Gari, Ko Uchi Barai, Ko Soto Barai, Ko Soto Gake , Ko Uchi Gake That are considered by Japanese followers different throwing techniques, as the different names show us. But from the Biomechanical point of view all these Kodokan throws are based on the same physical principle and practically on the same movements.