Kinematic considerations for achieving the quadruple axel jump: comparison with triple axel jumps among world-class figure skaters using tracking data.

In figure skating, achieving higher scores often relies on the successful execution of difficult jumps, e.g., quadruple jumps. According to previous biomechanical studies, jump heights do not change significantly even with more rotational jumps. However, strategies employed by top skaters to acquire new jumps are unclear. Therefore, this study aimed to investigate specific kinematic strategies used by skaters to perform the quadruple axel jump (4A), focusing on two skaters (skaters A and B) who attempted this jump in competitions. Using data from the Ice Scope tracking system, this study analysed the vertical height, horizontal distance, take-off speed, landing speed, and height-to-distance ratio of the jumps. Both skaters achieved higher vertical heights in their 4A attempts than in their triple axel jump (3A) attempts. Notably, Skater A's successful 4A and Skater B's downgraded 4A had significantly greater vertical heights than the average 3As among world-class skaters. This suggests a strategic shift towards increasing the vertical height to master 4As, contrary to previous biomechanical research that did not emphasise vertical height. These findings update existing theories on figure skating research and provide insights into training strategies for mastering difficult jumps.