We have studied the ski boots design based on the characteristic of the frame of the Japanese player experimentally to shorten finish time for the purpose of the improvement of the competition results of the alpine skiing player. However, understanding and the practicing of the technique to use the potential of the tool are important as well as modifying the design of the tool for shortening of the finish time. This paper focuses on the energy dissipation by the bending motion and the energy increase by the stretching motion at the change of turn, and clarify a turn technique to shorten the finish time. We analyzed the influence of energy balance during the joint movements on the finish time with posture analysis of the movie of world cup competitions by using a 3DCAD model. The results shows that shortening the finish time is achieved by reducing the number of bending motion and increasing the number of stretching motion while downhill. In addition, this paper shows that the joints motions of the skier during downhill can be estimated precisely by proposed analysis method using 3DCAD model.
