  In this invited lecture the biomechanical analysis of tactical tools utilized
by top athletes in high level competition is presented. In the first part, the
lecture starts with a very short summary of the researches carried out on
biomechanics, thermal exchange and metabolic energy expenditure related to judo
throwing technique. In the second part it is developed the specific analysis of
the technical tactical support tools.These tools allow to enhance the
effectiveness of the athletes special throwing techniques,Tokui Waza,increasing
the probability to obtain Ippon. The last part of the lecture emphasizes,the
physics and biomechanics connected to judo competition that is defined as:an
interacting complex nonlinear system, with chaotic and fractals aspect.This
system must be analyzed studying the motion of couple of athletes system and
evaluating their interaction,throws.Brownian tools are today the actual most
sophisticated way of modeling motion in competition, starting from fractals
till to multifractals aspects.If we study the specific mechanics of several
throwing action in real competitions we can face some interesting physical
aspects not totally well known, like almost plastic collision between extended
bodies and for some Lever techniques we have to solve dynamical problem of
bodies with variable mass that differs from the well known Classical Mechanics
with constant mass. In effect, in such a situation,the general methodological
approach of mechanics must be properly modified; considering a deformable body
with a finite extension, where special emphasis is given to the variable
rotational inertia during throw, with interesting consequences about balance,
linear and rotational momentum and motion of center of mass.
