Department of Orthopedic Surgery, Klinikum Bayreuth GmbH, 95445 Bayreuth, Germany.
Department of Neurology, Klinikum Bayreuth GmbH, 95445 Bayreuth, Germany.
Sensors (Basel). 2021 Jun 10;21(12):4001. doi: 10.3390/s21124001.
The evaluation of local divergence exponent (LDE) has been proposed as a common gait stability measure in people with multiple sclerosis (PwMS). However, differences in methods of determining LDE may lead to different results. Therefore, the purpose of the current study was to determine the effect of different sensor locations and LDE measures on the sensitivity to discriminate PwMS. To accomplish this, 86 PwMS and 30 healthy participants were instructed to complete a six-minute walk wearing inertial sensors attached to the foot, trunk and lumbar spine. Due to possible fatigue effects, the LDE short (50% of stride) and very short (5% of stride) were calculated for the remaining first, middle and last 30 strides. The effect of group (PwMS vs. healthy participants) and time (begin, mid, end) and the effect of Expanded Disability Status Scale (EDSS) and time were assessed with linear random intercepts models. We found that perturbations seem to be better compensated in healthy participants on a longer time scale based on trunk movements and on a shorter time scale (almost instantaneously) according to the foot kinematics. Therefore, we suggest to consider both sensor location and time scale of LDE when calculating local gait stability in PwMS.
局部离散步数指数（LDE）的评估已被提议作为多发性硬化症患者（PwMS）的一种常用步态稳定性测量方法。然而，确定 LDE 的方法的差异可能导致不同的结果。因此，本研究的目的是确定不同传感器位置和 LDE 测量方法对区分 PwMS 的敏感性的影响。为了实现这一目标，86 名 PwMS 和 30 名健康参与者被要求穿着附着在脚、躯干和腰椎上的惯性传感器完成六分钟步行。由于可能存在疲劳效应，因此对于剩余的前、中、后 30 步，计算了 LDE 短（50%步长）和极短（5%步长）。使用线性随机截距模型评估了组（PwMS 与健康参与者）和时间（开始、中间、结束）以及扩展残疾状况量表（EDSS）和时间的影响。我们发现，根据躯干运动，健康参与者在较长的时间尺度上似乎更好地补偿了扰动，而根据脚部运动学，在较短的时间尺度上（几乎瞬间）更好地补偿了扰动。因此，我们建议在计算 PwMS 的局部步态稳定性时，同时考虑传感器位置和 LDE 的时间尺度。
