Hite Mia D, Simms Anton J, Stewart Michael J, Chowning Luke D, Harry John R
Department of Kinesiology & Sport Management, Texas Tech University, Lubbock TX, USA.
Department of Kinesiology & Sport Management, Texas Tech University, Lubbock TX, USA.
J Biomech. 2025 May;184:112645. doi: 10.1016/j.jbiomech.2025.112645. Epub 2025 Mar 24.
The way in which different levels of effort affect countermovement jump (CMJ) landing characteristics and strategies remains unclear. The purpose of this study was to investigate differences in CMJ landing performance and related joint-level strategies across various levels of perceived effort. Twenty-four recreationally active individuals (12 Male: age = 23 ± 5 years, mass = 83.8 ± 14.5 kg, height = 1.8 ± 0.1 m; 12 Female: age = 23 ± 2 years, mass = 62.6 ± 12.0, height = 1.6 ± 0.1) performed five sets of three CMJs. Three-dimensional kinematic and ground reaction force (GRF) data were collected for each trial. Landing performance index (LPI), peak vGRF, and durations of the loading, attenuation, and control phases of the landing were obtained. Total lower body joint work (TW) as well as hip, knee and ankle contributions were calculated for 100 %, 75 %, 50 %, and 25 % perceived effort level for each phase of the landing. One-way repeated measures ANOVA tests (α = 0.05) were used to identify differences between each of the effort levels for all variables of interest. The best landing performances occurred during the 100 % condition, and while patterns in significant differences between levels of effort were not observed throughout all variables of interest, the TW during attenuation phase exhibited the most significant variability between levels of perceived effort. In addition, changes in the dependent variables did not coincide with proportional changes in level of effort. The results of the joint contributions suggest that levels of perceived effort may not stimulate desired changes in landing performance or joint mechanics.
不同努力程度如何影响反向纵跳（CMJ）着陆特征和策略仍不清楚。本研究的目的是调查不同感知努力程度下CMJ着陆表现及相关关节水平策略的差异。24名有运动习惯的个体（12名男性：年龄 = 23 ± 5岁，体重 = 83.8 ± 14.5千克，身高 = 1.8 ± 0.1米；12名女性：年龄 = 23 ± 2岁，体重 = 62.6 ± 12.0千克，身高 = 1.6 ± 0.1米）进行了五组，每组三次的CMJ动作。每次试验收集三维运动学和地面反作用力（GRF）数据。获得着陆表现指数（LPI）、峰值垂直GRF以及着陆加载、缓冲和控制阶段的持续时间。计算了着陆各阶段在100%、75%、50%和25%感知努力水平下的下肢总关节功（TW）以及髋、膝和踝关节的贡献。使用单向重复测量方差分析测试（α = 0.05）来确定所有感兴趣变量在各努力水平之间的差异。最佳着陆表现出现在100%条件下，虽然在所有感兴趣变量中未观察到努力水平之间显著差异的模式，但缓冲阶段的TW在感知努力水平之间表现出最显著的变异性。此外，因变量的变化与努力水平的比例变化不一致。关节贡献结果表明，感知努力水平可能不会刺激着陆表现或关节力学产生期望的变化。
