Abstract

During the rebuilding of the BergIsel ski jumping hill, a new biomechanical measurement system was installed. The system consists of seven force platforms which were placed about 10.5 m along the jumping table and six high speed cameras to film the take-off and the flight phases. Five elite ski jumpers, each with three training jumps, were analyzed. In order to assess the accuracy of the measuring systems, velocity of the centre of mass during take-off was calculated from the kinematically and dynamically measured data and then compared. Additionally, each jump was digitized three times by two different persons to determine the error of semimanual digitizing. The results showed that the velocity of the centre of mass differed by an average of 5 % with a maximum difference of 30 %. The maximum difference between the repeated digitized data of the joint angles was three degrees. From the results we concluded that the data are good enough for precise describing jumping movement of elite ski jumpers. However, the large differences between the two methods of calculating velocities of the centre of mass must be further examined. Verf.-Referat