Background

Changes in gait due to an ankle foot orthosis (AFO) have been shown to be impacted by the sagittal plane alignment of the AFO, but there is variability in practice and lack of consensus as to how this alignment should be measured. The neutral angle is a measure of AFO alignment that has the potential to be used by various specialties that prescribe, provide, and analyze AFOs. Currently, a lack of validated measurement methods prevents the neutral angle from being used in various clinical settings. Two experimental neutral angle measurement methods are proposed to address this shortcoming: a portable low-cost method for use during AFO fabrication and fitting, and a laboratory-based method for use during dynamic three-dimensional gait analysis (3DGA).

Research question

What is the concurrent validity of the two experimental neutral angle measurement methods against the gold standard?

Methods

The gold standard neutral angle measurement (NA_GOLD) was prospectively collected during a static 3DGA trial for 19 pediatric AFOs from 10 individuals. While NA_GOLD was being collected, the neutral angle was simultaneously measured using digital differential inclinometers (NA_INCL). Within the same 3DGA session, the neutral angle was also measured during the swing phase of gait (NA_SWING). The NA_INCL and NA_SWING measurements were compared to NA_GOLD using repeated measures ANOVA, ICC, and bootstrapped errors-in-variables regressions.

Results

Repeated measures ANOVA indicated no differences between measurement methods (p = 0.43) and ICC analysis indicated good absolute agreement (ICC(A-1) = 0.85). Mean absolute deviations between the NA_INCL and NA_SWING with NA_GOLD measurements were 2.4 ° and 1.9 °, with standard deviations of 2.9 ° and 2.7 °, respectively. Maximum observed differences were less than 7 °. The NA_INCL and NA_SWING methods explained 74 % and 81 % of the variance in NA_GOLD, respectively.

Significance

The concurrent validity of two new neutral angle measurement methods provides alternative means to assess AFO alignment in the clinic.

中文翻译：

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临床护理中测量踝足矫形器对齐的替代方法

背景

由于踝足矫形器 (AFO) 引起的步态变化已被证明受 AFO 矢状面对齐的影响，但实践中存在差异，并且对于如何测量这种对齐缺乏共识。中性角是 AFO 对齐的一种度量，它有可能被规定、提供和分析 AFO 的各种专业使用。目前，由于缺乏经过验证的测量方法，因此无法在各种临床环境中使用中性角。提出了两种实验中性角测量方法来解决这一缺点：一种用于 AFO 制造和装配过程中的便携式低成本方法，以及一种用于动态三维步态分析 (3DGA) 的基于实验室的方法。

研究问题

两种实验性中性角测量方法对黄金标准的同时有效性是什么？

方法

黄金标准中性角测量值 (NA _GOLD ) 是在静态 3DGA 试验期间前瞻性收集的，该试验对来自 10 个个体的 19 个儿科 AFO 进行了研究。在收集NA _{GOLD 的}同时，使用数字差分倾角仪 (NA _INCL )同时测量中性角。在同一个 3DGA 会话中，还在步态摆动阶段 (NA _SWING )测量中性角。NA _INCL和 NA _SWING测量值与 NA _GOLD使用重复测量方差分析、ICC 和自举变量误差回归进行比较。

结果

重复测量方差分析表明测量方法之间没有差异 (p = 0.43)，ICC 分析表明绝对一致 (ICC(A-1) = 0.85)。NA _INCL和 NA _SWING与 NA _GOLD测量值之间的平均绝对偏差为 2.4° 和 1.9°，标准偏差分别为 2.9° 和 2.7°。观察到的最大差异小于 7°。NA _INCL和 NA _SWING方法分别解释了 NA _{GOLD 中}74% 和 81% 的方差。

意义

两种新的中性角测量方法的同时有效性提供了在临床中评估 AFO 对齐的替代方法。