I started this blog with the objective of stimulating thinking and discussion among serious skiers, racers, ski pros and coaches about the mechanics, biomechanics and physics of skiing. Ingrained and accepted beliefs in skiing, that have little or no basis in science, have created resistance to ideas that question these beliefs .
The response to a post serves as a barometer of the type of audience my blog is connecting with. Since my post on excessive ramp angle as a stance killer stimulated interest in my post on the meaning of high COP pressures reported in University of Ottawa studies, I have decided to delay my post on my vision of a standard specification for boot boards and instead provide links to two papers below that are related to the Ottawa studies.
In the first paper (1), the authors correctly identify the moment of force created on the outside foot and ski of a turn by an offset in the alignment of the opposing force applied to the ski by the weight of a skier Fr with the ground reaction force F Ground as shown in Figure 2 below from the paper. The resulting drift angle creates medial compression of the associated knee joint.
In the second paper (2), the authors also correctly identify the moment of force created on the outside foot and ski of a turn by an offset in the alignment of the force applied by the weight of the skier with the ground reaction force, GRF as shown in Figure 1 below from the paper. Sketches a) and b) show the effect of greater width of the ski underfoot in increasing the length of the moment arm.
The authors of both of the papers recognize the problem; an offset in the alignment of opposing applied and ground reaction forces sets up a moment arm that causes the outside ski to rotate out of the turn. Each of the papers attempts to resolve the problem in a different manner.
Do either of the approaches presented in the 2 papers cited above address the problem?
…… to be continued.
1. An innovative ski-boot: Design, numerical simulations and testing
2. The Waist Width of Skis Influences the Kinematics of the Knee Joint in Alpine Skiing