Biomedical Engineering, Schulich School of Engineering, University of Calgary, Alberta, Canada; Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Alberta, Canada.
Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Alberta, Canada.
J Biomech. 2020 Jan 2;98:109448. doi: 10.1016/j.jbiomech.2019.109448. Epub 2019 Oct 23.
Clinicians, podiatrists and researchers have been quantifying foot posture and movement in various speed conditions and populations. Common variables to assess foot posture/movement are the Foot Posture Index (FPI-6), Achilles tendon angle (β), rear foot angle (γ) and longitudinal arch angle (LAA). These variables were frequently used in clinical and biomechanical settings. This study aimed to determine the relationship between the biomechanical variables (β, γ & LAA) in static and dynamic conditions and the clinically used FPI-6 and their redundancy. Forty participants performed bipedal standing, over ground walking and running trials. Manual assessment data (FPI-6), kinematic data and ground reaction forces were collected. Discrete biomechanical variables (β, γ & LAA) were calculated at various time points (e.g. heel strike). A Principal Component Analysis (PCA) was performed to quantify the contribution of each variable to the overall variance in the data set. Spearman correlations were used to assess the relationship between the sub-measures of the FPI-6 and the biomechanical variables. Two major components were found that explained 85.2% of the overall variance, consisting of LAA and β variables, respectively. Only LAA variables showed significant, but moderate correlations (r < -0.6) with the fifth sub-measurement of the FPI-6. The LAA and β describe independent movements, which dominate foot posture/movement in static and dynamic conditions. The FPI-6 sub-measurements did not closely reflect static nor dynamic behavior of the rear and mid foot. The FPI-6 and biomechanical variables may not be used interchangeably for screening or grouping individuals according to their foot posture/movement.
临床医生、足病医生和研究人员一直在各种速度条件和人群中量化足姿和足部运动。评估足姿/运动的常用变量包括足姿指数（FPI-6）、跟腱角（β）、后足角（γ）和纵弓角（LAA）。这些变量在临床和生物力学环境中经常使用。本研究旨在确定静态和动态条件下生物力学变量（β、γ和 LAA）与临床常用的 FPI-6 及其冗余之间的关系。40 名参与者进行了双足站立、地面行走和跑步试验。收集了手动评估数据（FPI-6）、运动学数据和地面反作用力。在不同时间点（例如足跟触地）计算离散生物力学变量（β、γ和 LAA）。进行主成分分析（PCA）以量化每个变量对数据集总方差的贡献。使用 Spearman 相关分析评估 FPI-6 的子测量与生物力学变量之间的关系。发现有两个主要成分，分别由 LAA 和 β 变量组成，解释了 85.2%的总方差。只有 LAA 变量与 FPI-6 的第五个子测量值显示出显著但中等程度的相关性（r < -0.6）。LAA 和 β 描述了独立的运动，这些运动在静态和动态条件下主导足姿/运动。FPI-6 子测量值不能很好地反映后足和中足的静态和动态行为。FPI-6 和生物力学变量可能不能互换使用，根据个体的足姿/运动来进行筛选或分组。
