Physical work capacity required to avoid ski accidents examined using the equations of ski-skier system motion

Abstract

Alpine skiing is a dangerous sport. According to Japanese legal precedent in ski accident cases, the skier has an obligation to foresee and avoid any dangers in skiing. The purposes of this study were 1) to identify the human physical work capacity required to avoid a ski accident using the equations of the ski-skier motions and 2) to study ski accidents from point of the human physical capacity or condition. To undertake this study, the power to control the velocity in skiing was calculated using the equation of ski-skier system motion. The calculated power, for example, to control the ski-skier system velocity of 15m/s was 3933.0 (W), with an air resistance coefficient of 0.5, θ was 30 degrees and the weight was 65.0kg. On the other hand, the maximum anaerobic powers (Pmax) and the wingate powers (P40) (which was the explosive capacity) of 12 subjects were measured using a bicycle ergometer. Furthermore, the vertical jump power (VJP) in each subject was measured using a force platform. As an example of these measurement results, the average of the Pmax was 862.9 (W). From these results, it was thought to be difficult to avoid ski accident completely using only the human physical work capacity.