Enqvist Jonas, Holmberg L Joakim, Moberg Mathias, Arndt Anton
Department of physiology, nutrition and biomechanics, Swedish School of Sport and Health Sciences, Stockholm, Sweden.
Ski Team Sweden Alpine & Skicross, Åre, Sweden.
Sports Biomech. 2024 Sep 16:1-21. doi: 10.1080/14763141.2024.2393198.
Stiffness (k) describes a material's resistance to deformation and is useful for understanding neuromuscular function, performance, and injury risk. The aim of this study is to compare the lower limb stiffness method (), which uses only force plate data, with methods combining force plate and motion capture data to calculate stiffness during the eccentric phase of a countermovement.
Twelve resistance-trained males: age 24.9 (4.4) years, height 1.81 (0.05) m, weight 88.2 (14) kg) performed three maximal effort countermovement jumps (CMJ). Data were collected synchronously using three-dimensional (3D) kinematic and kinetic data (dual force plate setup). Lower limb stiffness (z), joint stiffness (x, y, and z), and leg stiffness (linear, sagittal plane, and 3D) were calculated for the eccentric phase of all CMs.
showed high concurrent validity with strong correlations to kinetic-kinematic methods ( = 0.90-0.97, < 0.05). A linear mixed model revealed no significant differences in k-values between and leg stiffness, indicating high concurrent validity.
offers valid and valuable information affecting performance, injury risk, and return-to-sport decisions.
The findings suggest that is a valid method for calculating stiffness in CMJs and equal to 3D leg stiffness.
刚度（k）描述了材料对变形的抵抗力，有助于理解神经肌肉功能、运动表现和受伤风险。本研究的目的是比较仅使用测力台数据的下肢刚度计算方法与结合测力台和运动捕捉数据来计算反向运动离心阶段刚度的方法。
12名经过阻力训练的男性（年龄24.9（4.4）岁，身高1.81（0.05）米，体重88.2（14）千克）进行了三次最大努力的反向运动跳跃（CMJ）。使用三维（3D）运动学和动力学数据（双测力台设置）同步收集数据。计算了所有CMJ离心阶段的下肢刚度（z）、关节刚度（x、y和z）以及腿部刚度（线性、矢状面和3D）。
[未提及具体方法名称]与动力学 - 运动学方法具有高度的同时效度，相关性很强（r = 0.90 - 0.97，p < 0.05）。线性混合模型显示[未提及具体方法名称]与腿部刚度的k值之间无显著差异，表明具有高度的同时效度。
[未提及具体方法名称]提供了影响运动表现、受伤风险和恢复运动决策的有效且有价值的信息。
研究结果表明，[未提及具体方法名称]是计算CMJ中刚度的有效方法，且等同于3D腿部刚度。
