Background

Centre of pressure (CoP) location error is common when predicting inverse dynamic parameters during gait. Tolerance levels of error have been previously reported. However, the clinical impact of gait velocity on CoP error has not been considered.

Research Question: What is the clinical impact of CoP error with increasing gait velocity on predicted inverse dynamic parameters during gait in children with typical development?

Methods

Three-dimensional kinematic and kinetic data were recorded at three self-selected velocities on children with typical development (walking, fast instructed walking and running). CoP location error was applied in 3 mm increments up to a maximum of 12 mm in an anteroposterior direction. Differences in maximum kinetic parameters between increments and gait velocities were assessed in conjunction with changes in GDI-kinetic.

Results

Relative error (difference expressed as a % of maximum moment) decreased at all joints as gait velocity increased. The GDI-kinetic was only clinically significant for the self-selected walking condition at 9 mm and 12 mm respectively.

Significance

The GDI-kinetic difference remained below the threshold for fast walking and running which suggested that CoP error of up to 12 mm in the 3D optoelectric / force plate configuration would be acceptable if subjects were assessed under these conditions.

中文翻译：

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步态速度增加时的压力误差中心：对典型发育儿童步态中预测的逆向动力学的临床影响。

背景

在步态中预测逆动态参数时，压力中心（CoP）位置误差很常见。先前已经报告了误差的容忍度。但是，尚未考虑步态速度对CoP误差的临床影响。

研究问题：典型发育儿童的步态加快时，CoP错误对步态逆动态参数预测的临床影响是什么？

方法

在三个具有典型发育（走路，快速指示的走路和跑步）的儿童的三个自选速度下记录了三维运动学和动力学数据。在前后方向上以3 mm的增量应用CoP定位误差，最大12 mm。结合GDI动力学的变化评估了最大动力学参数在步幅和步态速度之间的差异。

结果

随着步态速度的增加，所有关节的相对误差（差异表示为最大力矩的百分比）减小。对于自行选择的步行条件，分别在9 mm和12 mm时，GDI动力学仅在临床上有意义。

意义

GDI动力学差异仍低于快速行走和跑步的阈值，这表明如果在这些条件下评估受试者，则3D光电/力板配置中的CoP误差高达12 mm是可以接受的。