カービングスキーにおける中回りターンの3次元動作分析

抄録

The purposes of this study were to analyze the middle turn techniques in carving ski as between expert and intermediate skiers and to develop teaching methods in carving turn for intermediate skiers. Six male collegiate skiers（expert group, n=3, height: 1.68±0.1m, weight: 61.0±5.2kg, age: 21.3±1.2years and intermediate, n=3, height: 1.73±0.0m, weight: 67.0±10.8kg, age: 19.7±0.6years）participated in this study. All subjects tried 4 parallel middle carving turns. Four synchronized CCD video cameras were used to record the 2 turns （gates 2 and 3）. Three-dimensional coordinates landmarks on skiers and ski were calculated by the DLT method. Analyzed parameters were velocity of center of gravity（CG）, angle of attack, edging angle, leaning angle of skier and fore/back-ward movement of skier. For statistical analysis, Cohen’s d was tested to calculate effect size. A faster velocity of CG was obtained from the expert skiers. The angle of attack showed smaller value in expert skiers than that in intermediate skiers. The edging angles of both skis in expert skiers were larger than those of intermediate skiers. The fore/back-ward movement of skier in both groups was located almost posterior to the vertical vector to the ski sole throughout turns. However backward angles were slightly smaller in expert skiers than in intermediate skiers. The leaning angle of skier displayed a similar pattern to the edging angle in both groups. Suggestions for teaching of carving turn were to start learning with carved turn out of fall line with straight gliding, to carved turn out of fall line with traversing, to keep position forward and to lean to turn inside with more leaning their thigh．