Background

Studies have found that toe-in gait reduced the peak knee adduction moment (KAM) during early stance, while toe-out gait reduced the peak KAM during late stance. However, some other studies found that toe-in or toe-out gait could reduce the KAM throughout stance phase. There is still a divergence of opinion on the use of toe-in or toe-out gait for reducing the KAM.

Research question

This study aimed to investigate whether static foot posture affected participants’ biomechanical responses to three self-selected foot progression angles (FPA): neutral, toe-out and toe-in.

Methods

Twenty-seven healthy participants were recruited for this FPA gait modification experiment and classified into three groups: neutral (n = 8), supination (n = 9) and pronation (n = 10), based on the Foot Posture Index (FPI). The kinematic and kinetic data were recorded with Vicon motion capture system and three force plates. The knee adduction moment and ankle eversion moment were calculated using an inverse dynamics model. The effect of the FPA modification on the knee loading parameters was analysed by the Friedman non-parametric test.

Results

The KAM results in the neutral group showed that the toe-in gait modification reduced the first peak of the KAM (KAM1), while the KAM1 was increased in the supination group. The effect of the FPA modification on the KAM1 did not reach significance in the pronation group. The toe-out gait modification reduced the second peak (KAM2) regardless of the static posture.

Significance

Different static foot postures were correlated with different peak KAM during the early stance phase due to FPA modification. These data suggest that the assessment of static foot posture provides a reference on how to offer adequate FPA modification for knee OA patients with different foot postures.

中文翻译：

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在具有不同静态脚姿势的健康参与者中，修改脚的前进角度对膝盖负荷参数的影响。

背景

研究发现，在步态初期，脚趾步态可降低峰值膝关节内收力矩（KAM），而在步态后期则脚趾外步态可降低峰值KAM。但是，其他一些研究发现，在步态阶段，步入或步出步态可以降低KAM。关于使用前入或外出步态来降低KAM仍存在分歧。

研究问题

这项研究的目的是调查静态脚姿是否会影响参与者对三种自选脚部前进角度（FPA）的生物力学响应：中性，脚趾向外和脚趾向内。

方法

FPA步态调整实验招募了27名健康参与者，并根据脚姿指数（FPI）将其分为三组：中性（n = 8），旋后（n = 9）和内旋（n = 10）。运动和动力学数据用Vicon运动捕捉系统和三个测力板记录。使用逆动力学模型计算膝盖的内收力矩和踝关节外伸力矩。FPA修改对膝关节负重参数的影响通过弗里德曼非参数检验进行了分析。

结果

中性组的KAM结果表明，脚趾步态改变降低了KAM的第一个峰（KAM1），而旋后组中KAM1升高。FPA修饰对KAM1的影响在前旋组中不显着。无论静态姿势如何，脚趾步态调整都会降低第二个峰值（KAM2）。

意义

由于FPA的修改，在站立初期，不同的静态足部姿势与不同的峰值KAM相关。这些数据表明，静态脚姿势的评估为如何为具有不同脚姿势的膝OA患者提供足够的FPA调节提供了参考。