Author(s): OEPPERT, T., KLEIN, J., SCHAPSCHROEER, M., ALT, T., ABEL, T., Institution: GERMAN SPORTS UNIVERSITY COLOGNE, Country: GERMANY, Abstract-ID: 1605

INTRODUCTION:
Sprint performance emerges from complex whole-body coordination, for which spatiotemporal variables offer a practical first-layer description. However, absolute spatiotemporal values provide limited insight into performance interpretation and coaching. Ratio-based descriptors have therefore been proposed to characterize movement patterns and categorize athletes (1). Nevertheless, it remains unclear whether these patterns are conserved across sprint phases, or whether specific patterns are related to superior acceleration or maximal velocity performance. Thus, this study aimed to assess phase-specific movement pattern subgroups and phase-to-phase changes from acceleration to maximal velocity.
METHODS:
53 male (100 m PB: 10.75 ± 0.45 s) and 52 female (12.11 ± 0.51 s) sprinters performed three 20 m acceleration and three maximal velocity sprints (≥ 30 m run-up). Spatiotemporal parameters were recorded using infrared photocells, averaged across 20 m during acceleration and derived from the fastest four-step interval at maximal velocity. Variables were normalized to leg length and movement patterns were described using step length-step rate (SL/SR) and contact-to-flight time (CT/FT) ratios. Ratios were z-score standardized within each sex, classifying athletes into four subgroups. Differences in velocity at 20 m and maximal sprinting speed (MSS) between subgroups were analyzed using one-way ANOVA with post-hoc tests. Pattern changes between phases were quantified using displacement vector magnitude and direction in SL/SR-CT/FT space. Directional consistency of pattern changes was then assessed using Rayleigh's test. Athletes were stratified into faster and slower groups using a sex-specific median split of MSS.
RESULTS:
During acceleration, velocity at 20 m did not differ between pattern subgroups (all p > 0.19). In contrast, MSS differed significantly between subgroups in both sexes (men: p = 0.001; women: p = 0.003), with faster sprinters characterized by lower CT/FT ratios, while SL/SR was not performance discriminative. Movement patterns differed across race phases. Faster athletes (men: MSS = 10.64 vs. 10.03 m/s; women: 9.43 vs. 8.76 m/s) exhibited significant directional clustering of pattern changes from acceleration to maximal velocity towards reduced CT/FT (men: R = 0.45, p = 0.01; women: R = 0.63, p < 0.001), whereas slower athletes showed no directional consistency (R ≤ 0.37, p > 0.05).
CONCLUSION:
Movement patterns during sprinting are phase-specific rather than fixed individual traits. While effective acceleration can be achieved through multiple coordination solutions, higher MSS depends on a systematic reorganization towards lower CT/FT ratios. Superior sprinters are distinguished by greater and more directionally consistent reorganization of movement patterns across race phases, identifying phase-dependent coordination as a key determinant of sprint performance.
REFERENCES:
1) Van Oeveren et al., Sports Biomech, 2021