Differences in the Force Velocity Mechanical Profile and the Effectiveness of Force Application During Sprint-Acceleration Between Sprinters and Hurdlers.

This cross-sectional study aimed to compare the horizontal and vertical force-velocity profile between female sprinters and hurdlers. Twelve high-level athletes (6 sprinters and 6 hurdlers) participated in this investigation. The testing procedures consisted of two maximal 40-m sprints and five to six vertical jumps with additional loads. For the sprint-acceleration performance, the velocity-time data, recorded by a high-speed camera, was used to calculate the variables of the horizontal F-V profile (theoretical maximal values of force [ ], velocity [ ], power [], the proportion of the theoretical maximal effectiveness of force application in the antero-posterior direction [], and the rate of decrease in the ratio of horizontal force []). The best trial of each vertical jumping condition, obtained by an optical measurement system, was used to determine the components of the vertical F-V profile (theoretical maximal values of force [ ], velocity [ ], and power []). The female sprinters showed higher statistical differences for (2.46 ± 0.67, = 2.1, = 0.004), (0.45 ± 0.18, = 1.4, = 0.03), and (2.9 ± 0.9%, = 1.8, = 0.01) than female hurdlers. No statistical differences were observed for (0.69 ± 0.3, = 1.15, = 0.07), (-0.24 ± 0.4%, = 0.3, = 0.62), (-2.1 ± 3.8, = 0.3, = 0.59), (0.25 ± 0.31, = 0.5, = 0.45), and (1.75 ± 2.5, = 0.4, = 0.5). Female sprinters are able to apply higher horizontally-oriented forces onto the ground during the acceleration phase than female hurdlers.