Increasing Braking and Amortization Forces during the Countermovement Jump Does Not Necessarily Improve Jump Height.

IF 1.9 3区 医学 Q2 SPORT SCIENCES
Journal of Human Kinetics Pub Date : 2024-09-26 eCollection Date: 2024-10-01 DOI:10.5114/jhk/190451
Daichi Nishiumi, Norikazu Hirose
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引用次数: 0

Abstract

This study aimed to investigate the acute effects of altering the braking rate of force development (B-RFD) and amortization force (Amf) during countermovement jumps (CMJs) on CMJ height. Nineteen healthy men and women with training experience participated, performing six CMJ variations at different velocities (preferred and fast) and depths (knee angles: 60°, 90°, and 120°). The measured variables included CMJ height, B-RFD, Amf, and impulses during the early and latter halves of the concentric phase (EI and LI, respectively). A two-way analysis of variance was employed, along with a correlational analysis of the rates of change for each variable. Significant velocity and depth effects were observed for B-RFD and Amf (p < 0.05). However, there was no significant velocity effect on CMJ height. No significant correlations were observed between the rates of change in B-RFD and Amf with CMJ height. Additionally, a high or a very high correlation (r ≥ 0.67) was observed between the rate of change in B-RFD and Amf with the rate of change in EI, while a moderate negative correlation (r = -0.43 to -0.53) was found between the rate of change in EI and LI. These findings suggest that improvements in B-RFD and Amf were associated with improvements in EI, while improvements in EI led to a reduction in LI, and consequently, improvements in B-RFD and Amf were not associated with an increase in CMJ height. In other words, improvements in B-RFD and Amf did not necessarily contribute to improvements in CMJ height.

增加反向运动跳跃时的制动力和摊销力并不一定能提高跳跃高度。
本研究旨在探讨改变反向运动跳(CMJ)过程中的制动发力率(B-RFD)和摊销力(Amf)对 CMJ 高度的急性影响。19 名有训练经验的健康男性和女性参加了此次研究,他们以不同的速度(优先和快速)和深度(膝关节角度:60°、90° 和 120°)完成了六种 CMJ 变化。测量变量包括 CMJ 高度、B-RFD、Amf 以及同心阶段早期和后期的脉冲(分别为 EI 和 LI)。采用了双向方差分析,并对每个变量的变化率进行了相关分析。B-RFD 和 Amf 的速度和深度效应显著(p < 0.05)。然而,速度对 CMJ 高度没有明显影响。在 B-RFD 和 Amf 的变化率与 CMJ 高度之间没有观察到明显的相关性。此外,B-RFD 和 Amf 的变化率与 EI 的变化率之间呈高度或极高度相关(r ≥ 0.67),而 EI 的变化率与 LI 之间呈中度负相关(r = -0.43 至 -0.53)。这些结果表明,B-RFD 和 Amf 的改善与 EI 的改善相关,而 EI 的改善导致 LI 的降低,因此,B-RFD 和 Amf 的改善与 CMJ 高度的增加无关。换句话说,B-RFD 和 Amf 的改善并不一定有助于 CMJ 高度的改善。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
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来源期刊
Journal of Human Kinetics
Journal of Human Kinetics 医学-运动科学
CiteScore
4.80
自引率
0.00%
发文量
83
审稿时长
3 months
期刊介绍: The Journal of Human Kinetics is an open access interdisciplinary periodical offering the latest research in the science of human movement studies. This comprehensive professional journal features articles and research notes encompassing such topic areas as: Kinesiology, Exercise Physiology and Nutrition, Sports Training and Behavioural Sciences in Sport, but especially considering elite and competitive aspects of sport. The journal publishes original papers, invited reviews, short communications and letters to the Editors. Manuscripts submitted to the journal must contain novel data on theoretical or experimental research or on practical applications in the field of sport sciences. The Journal of Human Kinetics is published in March, June, September and December. We encourage scientists from around the world to submit their papers to our periodical.
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