INTRODUCTION: The biomechanical relationship between walking and gliding was investigated in an elite-class cross-country skier. A high-resolution pressure measurement plate served as the experimental platform. With additional video analyses, a holistic picture of the biomechanical processes was obtained. METHODS: For stance and gait analysis, a 2 m long and 60 cm wide pressure measurement plate was used, with 15.700 sensors integrated into its surface. A textile ski slope from Mr. Snow (Germany) served as the track for the approx. 4 m long run-up area. This was brought to the same height as the pressure measurement plate. A 0.3 mm thin polyethylene sheet (Dyneema, Netherlands) was used as a sliding surface on the pressure measurement plate. The camera was placed at mid-height of the pressure measurement plate. At the time of the measurements, the athlete had a pronounced hallux valgus on the left foot that was very swollen and already red in color. RESULTS AND DISCUSSION: The experimental procedure was initiated by a gait analysis. The corresponding gait pattern showed significant differences in pressure distribution between the left and right foot. In particular, the initial contact between the foot and the pressure measurement plate was pain-avoiding, although this was not intended by the athlete. Interestingly, similar patterns were obtained when sliding over the plate with skis. The pressure distribution showed a lower intensity under the left ski and it can be concluded that the tribology is also affected by the different forces applied. Force differences between left and right skis are accompanied by different frictional forces. As a consequence, the athlete experiences a twist along the vertical body axis, which has a detrimental effect on the propulsive force during double pole skiing. Based on these measurements and taking into account the development of pain, the athlete decided to undergo surgery, see Figure 1. This intervention, which was not risk-free, could probably have been avoided by the early use of measurements on the pressure measurement plate. In the meantime, such measurements can directly initiate the production of suitable insoles. REFERENCES: Hallux valgus und Langlauf, geht das?, Matthias Scherge, Svenja List, Jens Hollenbacher, GLIDING, 3(2022), 17-22
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