University of Belgrade, Faculty of Sport and Physical Education, The Research Centre, Belgrade, Serbia.
University of Belgrade, Institute for Medical Research, Belgrade, Serbia.
Eur J Sport Sci. 2020 Jun;20(5):614-623. doi: 10.1080/17461391.2019.1645886. Epub 2019 Aug 2.
This study aimed to compare the reliability and magnitude of the force-velocity (F-V) relationship parameters between the squat jumps performed from the 90° (SJ90) and self-preferred knee angle (SJ). A secondary aim was to explore the effect of the analysis procedure (force platform [FP] and Samozino's [SAM] method) and the number of loads tested (three- and two-point methods) on the F-V relationships. Twelve men were tested in two sessions during the SJ90 and SJ. Two identical blocks of jumps were performed in each session against three external loads. The F-V relationship parameters (maximum force, maximum velocity, F-V slope and maximum power) were determined at each block through the FP and SAM procedures using the data collected under three (three-point method) or only the two most distant loads (two-point method). The average coefficient of variation (CV) of the four F-V parameters revealed a higher reliability for the SJ90 compared to the SJ (5.86% 7.55%; CV= 1.29) with more pronounced differences using the FP (CV= 1.43) than the SAM procedure (CV= 1.14), and higher reliability for the SAM compared to the FP (6.14% 7.27%; CV= 1.18). The SJ and SAM procedures provided comparable or higher magnitude of the F-V relationship parameters than the SJ90 and FP, respectively. The three- and two-point methods revealed a comparable reliability and trivial differences in the magnitude of the F-V relationship parameters. The routine testing procedure of the F-V relationship could be simplified using the SJ, the SAM procedure and the two-point method.
本研究旨在比较从 90°深蹲跳（SJ90）和自感舒适的膝关节角度深蹲跳（SJ）中获得的力-速度（F-V）关系参数的可靠性和幅度。次要目的是探讨分析程序（力平台[FP]和 Samozino 方法[SAM]）和测试负荷数量（三点和两点法）对 F-V 关系的影响。12 名男性在 SJ90 和 SJ 测试中进行了两次测试。在每个测试中，通过 FP 和 SAM 程序，使用在三个外部负荷下收集的数据，在两个相同的跳块中进行了两次相同的跳块测试。通过 FP 和 SAM 程序，在每个块中使用三点法（three-point method）或仅最远处的两个负载（two-point method）来确定 F-V 关系参数（最大力、最大速度、F-V 斜率和最大功率）。四个 F-V 参数的平均变异系数（CV）显示 SJ90 的可靠性高于 SJ（5.86% 7.55%；CV=1.29），FP 的 CV（1.43）比 SAM 程序（CV=1.14）的差异更明显，而 SAM 的可靠性高于 FP（6.14% 7.27%；CV=1.18）。SJ 和 SAM 程序提供的 F-V 关系参数的幅度与 SJ90 和 FP 相比，具有可比性或更高的幅度。三点和两点法在 F-V 关系参数的可靠性和幅度上具有可比性，差异很小。使用 SJ、SAM 程序和两点法，可以简化 F-V 关系的常规测试程序。
