Key Laboratory of Sensing Technology and Biomedical Instrument of Guangdong Province, School of Biomedical Engineering, Sun Yat-sen University, Guangzhou, China.
Department of Kinesiology, Shenyang Sport University, Shenyang, China.
Gait Posture. 2022 Feb;92:212-217. doi: 10.1016/j.gaitpost.2021.11.033. Epub 2021 Nov 27.
Foot orthoses are widely used in runners with pronated feet, who are characterized with large forefoot abduction and arch deformation during gait. However, the relationship between the amount of forefoot and arch orthotic correction and the alterations in foot biomechanics remains unclear.
This study aimed to determine dose-response effects of foot orthoses with forefoot wedge and arch support components on the center of pressure (COP) trajectories and pressure distribution during running in symptomatic pronated feet.
Fifteen recreational runners participated in this study. A pressure plate was used to measure plantar pressures during running with control shoe only and ten foot orthoses, varying in forefoot wedges (5 levels) and arch supports (2 levels). The COP trajectory across the entire stance phase was compared between orthotic and control conditions using one-dimensional statistical parametric mapping. The differences in the force-time integral (FTI) and temporal variables were explored between conditions using repeated measures ANOVAs. The main effect of the two orthotic components and their interaction on tested variables were examined using two-way ANOVAs.
A forefoot wedge, whether laterally or medially located, shifted the COP trajectory laterally during some subphases of running (p < 0.05), while using an arch support only had minimal effect on the COP. Almost all orthoses reduced the FTI on the 2nd metatarsal and medial heel, and only medial forefoot wedges reduced the FTI on the hallux. There was a linear effect of forefoot wedges on the medial-lateral COP displacements during the propulsion phase, but no interactions were found between two orthotic components.
These findings suggest that forefoot orthotic components rather than arch supports are effective in altering forefoot dynamics in runners with pronated feet. This study could have implications for foot orthotic prescription and running-related injury prevention for individuals with pronated feet.
足矫形器在有旋前足的跑步者中广泛应用，这些人在步态中有较大的前足外展和足弓变形。然而，足矫形器前足和足弓矫正量与足部生物力学改变之间的关系尚不清楚。
本研究旨在确定带前足楔形和足弓支撑组件的足矫形器对有症状旋前足跑步时的压力中心（COP）轨迹和压力分布的剂量反应效应。
本研究纳入了 15 名休闲跑步者。使用压力板测量仅穿控制鞋和 10 种足矫形器时的跑步时足底压力，这些足矫形器的前足楔形（5 个水平）和足弓支撑（2 个水平）各不相同。使用一维统计参数映射比较矫形和对照条件下整个站立相的 COP 轨迹。使用重复测量方差分析探讨条件之间力-时积分（FTI）和时间变量的差异。使用双向方差分析检验两个矫形组件的主要效应及其相互作用对测试变量的影响。
无论是侧向还是内侧的前足楔形在跑步的某些亚相时都会使 COP 轨迹向外侧移动（p<0.05），而仅使用足弓支撑对 COP 的影响较小。几乎所有的矫形器都降低了第 2 跖骨和内侧足跟的 FTI，只有内侧前足楔形降低了大脚趾的 FTI。前足楔形对推进阶段的 COP 内外侧位移有线性影响，但两个矫形组件之间没有相互作用。
这些发现表明，在前足有旋前足的跑步者中，前足矫形组件而不是足弓支撑组件更有效地改变前足动力学。本研究可能对有旋前足的人进行足矫形器处方和预防与跑步相关的损伤有意义。
