Department of Research, Sint Maartenskliniek, 6500 GM Nijmegen, The Netherlands.
Department of Rehabilitation, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525 AJ Nijmegen, The Netherlands.
Sensors (Basel). 2021 Feb 2;21(3):985. doi: 10.3390/s21030985.
Previous research showed that an Inertial Measurement Unit (IMU) on the anterior side of the shank can accurately measure the Shank-to-Vertical Angle (SVA), which is a clinically-used parameter to guide tuning of ankle-foot orthoses (AFOs). However, in this context it is specifically important that differences in the SVA are detected during the tuning process, i.e., when adjusting heel height. This study investigated the validity of the SVA as measured by an IMU and its responsiveness to changes in AFO-footwear combination (AFO-FC) heel height in persons with incomplete spinal cord injury (iSCI). Additionally, the effect of heel height on knee flexion-extension angle and internal moment was evaluated. Twelve persons with an iSCI walked with their own AFO-FC in three different conditions: (1) without a heel wedge (refHH), (2) with 5 mm heel wedge (lowHH) and (3) with 10 mm heel wedge (highHH). Walking was recorded by a single IMU on the anterior side of the shank and a 3D gait analysis (3DGA) simultaneously. To estimate validity, a paired t-test and intraclass correlation coefficient (ICC) between the SVA and SVA were calculated for the refHH. A repeated measures ANOVA was performed to evaluate the differences between the heel heights. A good validity with a mean difference smaller than 1 and an ICC above 0.9 was found for the SVA during midstance phase and at midstance. Significant differences between the heel heights were found for changes in SVA ( = 0.036) and knee moment ( = 0.020) during the midstance phase and in SVA ( = 0.042) and SVA ( = 0.006) at midstance. Post-hoc analysis revealed a significant difference between the ref and high heel height condition for the SVA ( = 0.005) and knee moment ( = 0.006) during the midstance phase and for the SVA ( = 0.010) and SVA ( = 0.006) at the instant of midstance. The SVA measured with an IMU is valid and responsive to changing heel heights and equivalent to the gold standard 3DGA. The knee joint angle and knee joint moment showed concomitant changes compared to SVA as a result of changing heel height.
先前的研究表明，小腿前侧的惯性测量单元 (IMU) 可以准确测量小腿到垂直角度 (SVA)，这是一种用于指导踝足矫形器 (AFO) 调整的临床参数。然而，在这种情况下，特别重要的是在调整过程中，即在调整鞋跟高度时，检测到 SVA 的差异。本研究旨在探讨 IMU 测量的 SVA 在不完全性脊髓损伤 (iSCI) 患者中的 AFO-鞋类组合 (AFO-FC) 鞋跟高度变化时的有效性及其反应性。此外，还评估了鞋跟高度对膝关节屈伸角度和内力矩的影响。12 名 iSCI 患者在三种不同条件下穿着自己的 AFO-FC 行走：(1) 无鞋跟楔形物 (refHH)，(2) 5mm 鞋跟楔形物 (lowHH) 和 (3) 10mm 鞋跟楔形物 (highHH)。小腿前侧的单个 IMU 和三维步态分析 (3DGA) 同时记录行走。为了评估有效性，在 refHH 条件下，计算了 SVA 和 SVA 之间的配对 t 检验和组内相关系数 (ICC)。采用重复测量方差分析评估鞋跟高度之间的差异。在中足阶段和中足阶段，SVA 的平均差值小于 1，ICC 大于 0.9，表明其具有良好的有效性。在中足阶段，SVA 和膝关节力矩的变化（=0.036）和 SVA 和 SVA 的变化（=0.042）之间存在显著差异。中足阶段 SVA（=0.005）和膝关节力矩（=0.006）以及中足瞬间 SVA（=0.010）和 SVA（=0.006）的后验分析显示，ref 和 high 鞋跟高度条件之间存在显著差异。IMU 测量的 SVA 在改变鞋跟高度时是有效且敏感的，与黄金标准 3DGA 相当。膝关节角度和膝关节力矩的变化与 SVA 相比，由于鞋跟高度的变化而发生协同变化。
