Variability of Timing Parameters of Starts Performed by Lugers with Different Competitive Experience

The sport of luge belongs to the group of sports known as “sliding sports”. These sports employ special iced sliding tracks for their activities. Start plays an important role in performance in all sliding sports, the sport of luge not being an exception. What sets aside the sport of luge from other sliding sports is a way the start is performed – athletes use their arms’ and upper body strength for initial acceleration rather than legs. Since start is considered an important technical element in sliding sports, athletes spend a lot of time practicing it. Not only sliding tracks serve for this purpose, but also specially built start ramps and other constructions. Start in the sport of luge actually initiates before time counting is open – it begins at start handles already, where lugers make a start jerk; but according to International Luge Federation (FIL) rules start light barrier at luge tracks is located 5 – 10 m further ahead of start handles, though this distance is considerably shorter at training start ramps. After leaving the start handles athletes continue their efforts to gain higher speed by pushing off the ice surface with fingers or palms. Little had been published so far about characteristics of starts in the sport of luge. The aim of this study is to investigate variability of time parameters that lugers show during this important part of a run. This would enhance understanding of biomechanics of starts in luge that is essential for further development of sliding sports, and provide basis for following research. Data for this study were collected during two training camps with ten days interval between them, and one competitive event that took place immediately after the second training camp. Five athletes with different competitive experience participated in the study. All starts were performed on a special iced start ramp that is constructed for trainings in sliding sports. Average values of interval times typical to female lugers during starts were previously reported (Федотова и др., 2010). In this study we concentrated rather on repeatability of measured times than their average values. Measured times include total start time and interval times: times of push-offs from the ice and times of activities that contribute to initial jerk. Total start times were collected using photocells (Brower Timing Systems). Other times were calculated using motion analysis software SIMI Motion (SIMI Reality Motion Systems GmbH) from high-speed video records performed with two Basler A602fc cameras (Basler AG) at frequency 100 frames per second (fps), and one Casio EX-FH20 digital camera (Casio Computer Co., Ltd.) at 210 fps. The study had shown that athletes with less competitive experience tend to show larger span of push-off times values than more experienced athletes. However, the most experienced athlete had the largest span of the total start time values among all participants