Abstract

The early flight in ski-jumping represents the transition phase from take-off to stable flight and lasts approximately one second. Along with the take-off phase, the early flight is the most critical phase in ski-jumping. Considering the significance of this phase, the number of studies investigating the early flight is surprisingly low. To date, only two studies have been published on 3D kinematics of the early flight of the V-technique. Data from one study was collected during competition (Arndt et al. 1995) and the other collected data during training conditions (Schwameder & Müller 1995). The factors related to performance of the early flight can be separated into ballistic variables (paths and velocities of the center of gravity (COG)) and aerodynamic variables (postures represented by segment angles of the flying system). The initial conditions of the early flight result from the take-off phase. During take-off, the goal of the jumper is to achieve a high vertical velocity component in combination with a high angular momentum to guarantee forward rotation of the body in order to achieve a stable flight position as soon as possible. It can be easily shown that the change in direction of the force vector affects the rotational component more so compared with the translational component (Schwameder et al. 2000). Consequently, for the quality of the take-off and the early flight, take-off power and take-off technique have to be considered. Due to the changes in techniques, equipment and material used, new studies are necessary to better understand the function of the transition from take-off to stable flight corresponding to the early flight phase in ski-jumping. Thus, the purposes of this study were (1) to describe the kinematics of the early flight during competition, (2) to analyze aerodynamic variables related to performance and (3) to analyze ballistic variables related to performance. It was hypothesised that the variables analyzed differ between groups of different levels. Einleitung gekürzt