AUTHOR=Perez Jerome , Guilhem Gaël , Brocherie Franck 

TITLE=Truncated Estimation of Skating Force-Velocity Profiling When Using High-Speed Video-Based Methods Compared to Radar-Derived Processing

JOURNAL=Frontiers in Bioengineering and Biotechnology

VOLUME=9

YEAR=2021

URL=https://www.frontiersin.org/journals/bioengineering-and-biotechnology/articles/10.3389/fbioe.2021.661744

DOI=10.3389/fbioe.2021.661744

ISSN=2296-4185

ABSTRACT=<p>This study aimed to compare the force-velocity mechanical variables derived from high-speed video- and radar-based method during forward skating sprint in ice hockey. Thirteen elite female ice hockey players performed two 40-m forward skating sprints to determine, in the horizontal plane, maximal velocity reached (V<sub>max</sub>), relative maximal theoretical force (F<sub>0</sub>), maximal theoretical velocity (V<sub>0</sub>), relative maximal power (P<sub>max</sub>), linear slope of the force-velocity relationship (FV slope), maximal value of the ratio of force (RF<sub>max</sub>) and index of force application technique (Drf). Two different high-speed video-based methods adding a time shift (ST-TS) or not (ST) were used and independently compared to the radar-derived method. ST and ST-TS showed significant mean differences (all <italic>p</italic> &lt; 0.002) compared to radar-derived processing for all variables except for V<sub>0</sub> (<italic>p</italic> = 0.26) and V<sub>max</sub> (<italic>p</italic> = 0.13) inferred from ST. In reference to radar-derived variables, ST-TS significantly induced <italic>larger</italic> lower values compared to radar of the main forward skating sprint determinants (P<sub>max</sub>, F<sub>0</sub>, RF<sub>max</sub> and Drf) and <italic>moderate-to-large</italic> overestimation for velocity variables (V<sub>0</sub> and V<sub>max</sub>). Correlations between ST or ST-TS and radar-derived methods ranged from <italic>trivial</italic> for velocity variables to <italic>very large</italic> for force and power variables. Consequently, practitioners must be aware that using such high-speed video-based methods would permit to determine mechanical variables at the cost of much lower accuracy and reliability than the radar-derived method.</p>