Studies on the Estimation of Muscular Tension and the Action of Antagonists in Skiing

Abstract

Analyzing activity of the muscles in human motion is one of the most important things in the development of sports science. In this study, in order to evaluate the activity of the muscles in skiing turns by means of biomechanical analysis, the following experiments were conducted. The first experiment was with regard to the measurement of the state of human motion and the external force acting on the body. The motion of a skier was measured by magnetic position-sensors. The reaction force from the snow surface to the skier was measured by use in 6 axis force sensors embedded in the bottom of ski boots. Then the joint moment and muscular tension could be calculated by using a rigid link model and a musculo-skeletal model respectively. Furthermore, in the calculation of the join moment, the results calculated by static and kinetic analysis were compared and discussed. It was found that the calculated values by these two methods almost agreed. The experimental results showed that characteristics of the physical exercise in skiing turn can be evaluated through the analysis of activity of the muscles. However, the action of antagonists cannot be included in the value of muscular tension calculated through the motion analysis. Therefore, in the next experiment, a change of EMG of the lower limb in the motion simulated to the skiing turn will be measured in a room to estimate the effect of the action of antagonists. Our evaluation method stated in this paper is useful not only for biomechanical analysis of ski sport but also for developing ski goods.