Author(s): FAY, L., MERZ, C., KERSTING, U., GORGES, T., FRIEDL, F., DONATH, L., Institution: GERMAN SPORT UNIVERSITY COLOGNE, Country: GERMANY, Abstract-ID: 2689

INTRODUCTION:
Freestyle snowboard halfpipe involves complex aerial rotations requiring precise in-flight control. Trampolines provide a safe off-snow environment to develop and stabilize these skills. Biomechanical analyses have shown distinct execution strategies and phase-dependent variability in snowboard aerials [1]. Research on expertise suggests that skill level influences how movement variability is organised and controlled [2]. This study investigates execution variability during trampoline-based snowboard rotations across different skill levels to identify differences between novice and elite athletes and explore indicators of movement consistency that may improve readiness for progression to on-snow training.
METHODS:
Four elite male snowboard halfpipe athletes (23 ± 4 years; 74 ± 8.8 kg; 178 ± 7.8 cm; 10 ± 9 years experience), members of the German national team competing at an international level (World Cup), performed a total of 181 tricks with rotations of 360° in different directions on a freestyle trampoline using a bounce board. Twelve novices (4 female, 8 male; 23 ± 3 years; 66 ± 6.9 kg; 174 ± 7.9 cm) with an artistic gymnastics background but no halfpipe experience performed 783 trick rotations under the same conditions. The novices learned different 360° rotational tricks through standardised video-based instruction. Body kinematics were captured using inertial motion capture (Xsens, 18 IMUs, 240 Hz).
RESULTS:
Analyses showed performance-level differences in airtime variability and movement amplitudes, with elite athletes displaying lower coefficients of variation (CV: 5–7%) than novices (CV: 11–17%). Rotational amplitudes were more variable in novices than elites for head motion (CV: 90–152% vs 54–90%) and hip motion (CV: 95–106% vs 79–95%), whereas flexion/extension amplitudes were lower (head: 40–56% vs 26–40%; hip: 34–42% vs 27–34%), indicating more stable coordination in elite athletes. Linear models revealed group effects for hip rotation and flexion/extension amplitudes (all p<0.01), while head amplitudes showed no group differences; peak timing occurred earlier in novices and showed strong group effects for hip and head with additional trick effects (p<0.01).
CONCLUSION:
Lower execution variability in elite athletes suggests more stable coordination during flight. Quantifying execution stability during trampoline training may support skill learning regarding readiness to progress to on-snow practice.

[1] Bacik, B., Kurpas, W., Marszałek, W., Wodarski, P., Sobota, G., Starzyński, M., & Gzik, M. (2020). Movement variability during the flight phase in a single back sideflip (wildcat) in snowboarding. Journal of Human Kinetics, 72(1), 29–38. https://doi.org/10.2478/hukin-2019-0006
[2] Wagner, H., Pfusterschmied, J., Klous, M., von Duvillard, S. P., & Müller, E. (2012). Movement variability and skill level of various throwing techniques. Human Movement Science, 31(1), 78–90. https://doi.org/10.1016/j.humov.2011.05.005