Mechanism of Ski-Turning in Wedeln -Bend and Stretch of Knee Angle, and Vertical component-

The aim of the study is to investigate the mechanism of ski-turning in terms of the relation between the bend and stretch of knee angle and weighting or lightening. Observations were to be made out on the snow garden, but we were obliged to take the following process: First, wedeln which was demonstrated by 3 skiers (two S. A. J. instructors and one S. A. J. sub-instructor) was filmed (16mm film camera 64PPS). Secondly, the same subjects were ordered to do the same act, in the same rhythm of bending and stretching knees, on a weighting-machine in a laboratory. Those quantities and action patterns were recorded; in this way, the practice action on the snow garden was supposed through the experimental result in the laboratory. Further, the relation between several varieties of rhythm of bending and stretching knees and the variation of weight was considered, as it came to be supposed that variation of rhythm was to be referable to weight. Then we came to the following conclusions: (1) The ski-turning can be divided into 3 phases; they are up-phase, change-phase and down-phase; (2) the Up-phase; the knee bends gradually, and a pair of skies begins to move in a contrary direction; (3) the Change-phase; the knee stretches to the maximum, and there appear lightening in standing and weighting in stooping down. The ski-edge changes; (4) the Down phase; the knee bends gradually, then weighting follows, and the ski is 'Spurred' by its being pushed by the heel; (5) against our expectation, the ski, in the case both of the maximum-lightening in standing and of the maximum-stretching, doesn't go along the fall-line; (6) if the time of bending knees and that of stretching them in one action are equal in length, the continuance of the up-phase tends to extend; (7) if the time of stretching knees extends the continuance of the change-phase extends, and if it shortens, that of the down-phase extends; (8) the quantity of maximum lightening is controlled by the time of bending or stretching knees (if the time in bending is shorter than that of stretching, the former controls the quantity of maximum-lightening, and if the time in stretching is shorter, it controls the quantity, and there is a tendency that the greater the differance of the time required between bending and stretching is, the more remarkable the quantity of maximum-lightening is