Equivalent Fall Height and Aerial Maneuver Difficulty Both Influence Landing Stability on World Cup Slopestyle Rollover Jumps For Skiers and Snowboarders.

This study investigates how landing stability on slopestyle jumps is affected by jump design and the athletes' aerial maneuvers, in World Cup skiers and snowboarders. The data were recorded on rollover jumps from a World Cup Slopestyle competition using a geodetic video method, allowing for a reconstruction of the athletes' center of mass trajectories in 3D-space and calculation of equivalent fall height (EFH). Aerial maneuvers and landing stability were assessed by human raters. A generalized estimating equations method with binary logistic regression was performed to investigate how aerial maneuvers and EFH impact landing stability (surrogate measure of potential injury risk). EFH increased the log odds for unstable landings for both skiers and snowboarders. Although five aerial maneuver factors affected landing stability for snowboarders (angular velocity, rotational axis, number of rotations, with interaction effects between multiaxial maneuvers and frontside rotation or switch landing), skiers landing stability was only affected by the number of rotations. This, along with the way skiers and snowboarders are attached to their equipment and their ability to compensate for instability in the landing, may explain why snowboarders show unstable landings more often than skiers. On this study's rollover jumps with generally low EFH, landing stability was regulated by both EFH and aerial maneuvers. As maneuver complexity and EFH have an influence on both performance and landing stability, it appears important that course builders emphasize the construction of safe jumps and athletes generate a good understanding of potential injury risk and performance reward when jumping.