INTRODUCTION: Supej et al. (2005) introduced a method of computing the instantaneous mechanical energy losses of a skier to his surroundings as a measure of turn quality. Characterizing how elements of technique influence energy dissipation may help our understanding of how technique and performance relate. The purpose of this study was to determine the time-course of ski and center of mass (COM) motion characteristics and their relationship to mechanical energy dissipation (EDiss) in Slalom. METHODS: Six members of the Norwegian men's Europa Cup team were analyzed through 2 turns during a race Simulation. 3-D positions were determined from 4 panning cameras and control points distributed near the course (Nachbauer et al., 1996). Mechanical energy was determined knowing the COM velocity and altitude. EDISS was then calculated by differentiating mechanical energy with respect to altitude (Supej et al., 2005). Measures of the skier's COM fore/aft position (POSF/A) (Schiefermüller et al., 2005); outside ski edge angle (ÖSKI); and outside ski attack angle (ySKi) were calculated. Ensemble averages, Standard deviations (SD) and Pearson product-moment correlation coefficients with EDiss were determined for each measure. RESULTS & DISCUSSION: The ensemble averages ±SD for 0SKi, /SKI, and EDISS are presented in Figure 1. Relatively high correlations with EDISS were found for POSF/A (r=0.73) and 9SK\ (r=0.77) indicating that these Parameters' time courses are similar to that of EDISS- A surprisingly low correlation was found for YSKI (r=0.32). CONCLUSION: The high correlations for POSF/A and OSKl suggest that these parameters may be important in determining EDISS. Interestingly, although some subjects had large YSKI (Figure 1B), this did not necessarily correspond to increased EDISS.
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