AUTHOR=Stavridis Ioannis , Smilios Ilias , Tsopanidou Angela , Economou Theodosia , Paradisis Giorgos 

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

JOURNAL=Frontiers in Sports and Active Living

VOLUME=1

YEAR=2019

URL=https://www.frontiersin.org/journals/sports-and-active-living/articles/10.3389/fspor.2019.00026

DOI=10.3389/fspor.2019.00026

ISSN=2624-9367

ABSTRACT=<p>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 [<italic>HZT-F</italic><sub>0</sub>], velocity [<italic>HZT-V</italic><sub>0</sub>], power [<italic>HZT-Pmax</italic>], the proportion of the theoretical maximal effectiveness of force application in the antero-posterior direction [<italic>RFmax</italic>], and the rate of decrease in the ratio of horizontal force [<italic>DRF</italic>]). 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 [<italic>VTC-F</italic><sub>0</sub>], velocity [<italic>VTC-V</italic><sub>0</sub>], and power [<italic>VTC-Pmax</italic>]). The female sprinters showed higher statistical differences for <italic>HZT-Pmax</italic> (2.46 ± 0.67, <italic>d</italic> = 2.1, <italic>p</italic> = 0.004), <italic>HZT-V</italic><sub>0</sub> (0.45 ± 0.18, <italic>d</italic> = 1.4, <italic>p</italic> = 0.03), and <italic>RFmax%</italic> (2.9 ± 0.9%, <italic>d</italic> = 1.8, <italic>p</italic> = 0.01) than female hurdlers. No statistical differences were observed for <italic>HZT-F</italic><sub>0</sub> (0.69 ± 0.3, <italic>d</italic> = 1.15, <italic>p</italic> = 0.07), <italic>DRF%</italic> (−0.24 ± 0.4%, <italic>d</italic> = 0.3, <italic>p</italic> = 0.62), <italic>VTC-F</italic><sub>0</sub> (−2.1 ± 3.8, <italic>d</italic> = 0.3, <italic>p</italic> = 0.59), <italic>VTC-V</italic><sub>0</sub> (0.25 ± 0.31, <italic>d</italic> = 0.5, <italic>p</italic> = 0.45), and <italic>VTC-Pmax</italic> (1.75 ± 2.5, <italic>d</italic> = 0.4, <italic>p</italic> = 0.5). Female sprinters are able to apply higher horizontally-oriented forces onto the ground during the acceleration phase than female hurdlers.</p>