Article Text

Effect of ski geometry and standing height on kinetic energy: equipment designed to reduce risk of severe traumatic injuries in alpine downhill ski racing
  1. Matthias Gilgien1,
  2. Jörg Spörri2,
  3. Josef Kröll2,
  4. Erich Müller2
  1. 1Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
  2. 2Department of Sport Science and Kinesiology, University of Salzburg, Hallein-Rif, Austria
  1. Correspondence to Matthias Gilgien, Department of Physical Performance, Norwegian School of Sport Sciences, Sognsveien 220, Oslo 0806, Norway; matthias.gilgien{at}nih.no

Abstract

Background Injuries in downhill (DH) are often related to high speed and, therefore, to high energy and forces which are involved in injury situations. Yet to date, no study has investigated the effect of ski geometry and standing height on kinetic energy (EKIN) in DH. This knowledge would be essential to define appropriate equipment rules that have the potential to protect the athletes’ health.

Methods During a field experiment on an official World Cup DH course, 2 recently retired world class skiers skied on 5 different pairs of skis varying in width, length and standing height. Course characteristics, terrain and the skiers’ centre of mass position were captured by a differential Global Navigational Satellite System-based methodology. EKIN, speed, ski–snow friction force (FF), ground reaction force (FGRF) and ski–snow friction coefficient (CoeffF) were calculated and analysed in dependency of the used skis.

Results In the steep terrain, longer skis with reduced width and standing height significantly decreased average EKIN by ∼3%. Locally, even larger reductions of EKIN were observed (up to 7%). These local decreases in EKIN were mainly explainable by higher FF. Moreover, CoeffF differences seem of greater importance for explaining local FF differences than the differences in FGRF.

Conclusions Knowing that increased speed and EKIN likely lead to increased forces in fall/crash situations, the observed equipment-induced reduction in EKIN can be considered a reasonable measure to improve athlete safety, even though the achieved preventative gains are rather small and limited to steep terrain.

  • Biomechanics
  • Injury prevention
  • Global positioning system
  • Speed
  • Sports medicine

This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/

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