Validity and reliability of an IMU-based method to detect APAs prior to gait initiation.
Validity and reliability of an IMU-based method to detect APAs prior to gait initiation.
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DOI：
10.1016/j.gaitpost.2015.08.015
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发表时间：
2016-01
期刊：
影响因子：
2.4
通讯作者：
Horak FB
中科院分区：
文献类型：
--
作者：
Mancini M;Chiari L;Holmstrom L;Salarian A;Horak FB
步态开始之前的预期姿势调整（APA）已在传统的实验室环境中进行了大量研究，使用脚下的测力板来表征压力中心的位移。然而，临床试验和临床实践将受益于便携式，廉价的方法来表征APA。因此，本研究的主要目的是：1）开发一种新的，自动IMU为基础的方法来检测和表征APA在步态启动和2）测量其重测信度。实验I在实验室中进行，以确定基于IMU的方法在10名PD受试者（关闭药物治疗）和12名对照受试者中的有效性。实验二进行了临床，以确定重测信度的IMU为基础的方法在不同的一组17个早期至中度，治疗受试者与PD（测试药物）和17个年龄匹配的对照组。结果表明，步态起始特征（APA和第一步）检测与我们的新方法显着相关的特征与力板和运动分析系统计算。用惯性传感器或测力板测量的APA大小在PD受试者中显著小于对照受试者（p<0.05）。两组的惯性传感器测量的步态起始特征的重测信度为中等至优秀（.56<ICC<.82）。我们的研究结果支持的可行性，自动表征姿势准备和步态启动与身体佩戴的惯性传感器，这将是实用的无人监督的临床和家庭环境。
Anticipatory postural adjustments (APAs) prior to gait initiation have been largely studied in in traditional, laboratory settings using force plates under the feet to characterize the displacement of the center of pressure. However clinical trials and clinical practice would benefit from a portable, inexpensive method for characterizing APAs. Therefore, the main objectives of this study were: 1) to develop a novel, automatic IMU-based method to detect and characterize APAs during gait initiation and 2) to measure its test-retest reliability. Experiment I was carried out in the laboratory to determine the validity of the IMU-based method in ten subjects with PD (OFF medication) and 12 control subjects. Experiment II was carried out in the clinic, to determine test-retest reliability of the IMU-based method in a different set of 17 early-to-moderate, treated subjects with PD (tested ON medication) and 17 age-matched control subjects. Results showed that gait initiation characteristics (both APAs and 1st step) detected with our novel method were significantly correlated to the characteristics calculated with a force plate and motion analysis system. The size of APAs measured with either inertial sensors or force plate were significantly smaller in subjects with PD than in control subjects (p<0.05). Test-retest reliability for the gait initiation characteristics measured with inertial sensors was moderate-to-excellent (.56<ICC<.82) for both groups. Our findings support the feasibility of automatically characterizing postural preparation and gait initiation with body-worn inertial sensors that would be practical for unsupervised clinical and home settings.