2-D forward dynamics simulation of gait adaptation to muscle weakness in elderly gait
2-D forward dynamics simulation of gait adaptation to muscle weakness in elderly gait
复制标题
老年人步态肌肉无力的步态适应的二维正向动力学模拟
DOI：
10.1016/j.gaitpost.2021.01.011
复制
发表时间：
2021
期刊：
影响因子：
2.4
通讯作者：
Tanaka Masao
中科院分区：
文献类型：
--
作者：
Arakawa Tatsuya;Otani Tomohiro;Kobayashi Yo;Tanaka Masao
背景与肌无力相关的步态特征的变化在以前的研究中已有报道。人体步态被认为是一种基于运动准则的适应个体特征和周围环境的周期性运动。基于这一假设，老年人的步态特征可能是由对肌无力的适应引起的，研究问题：肌无力的步态适应在老年人步态发展中起什么作用，老年人步态适应的标准是什么？方法采用二维神经-肌肉-骨骼模型，通过计算正向动力学仿真，研究了肌无力步态适应对稳态步态特征的影响。对于步态适应，我们测试了两个运动标准：（一）能量成本最小化，这是一个广泛使用的标准，为健康的成年人;和（二）能量率最小化，根据现有的测量老年人步态characteristics. ResultsProgressionof肌无力增强关节角运动和最小脚趾间隙的减少，并最终导致下降。步态适应肌肉无力成功地形成了稳定的步行模式，无论运动标准，即使在肌肉无力的30%，这代表了中度的老年肌肉无力。当使用标准（i）时，关节运动的时间过程与健康成人相似，并且在整个步态周期中发现相对高水平的肌肉激活以补偿肌肉无力。当使用标准（ii）时，肌肉活动水平低于标准（i）以最小化能量率，并且所构建的步态成功地捕获了先前研究中报道的老年步态特征。而老年人在步态适应中可能使用与健康成年人不同的运动标准。
BackgroundAge-related changes of human gait characteristics associated with muscle weakness have been reported in previous studies. Human gait is considered as a cyclic motion adapted to individual body-characteristics and the surrounding-environment based on motion criteria. Based on this hypothesis, elderly gait characteristics may be caused by an adaptation to muscle weakness.Research questionWhat role does gait adaptation to muscle weakness play in the development of elderly gait, and what criteria are used in elderly gait adaptation?MethodsWe examined the effects of gait adaptation to muscle weakness on steady gait characteristics using computational forward dynamics simulation with a two-dimensional neuro-musculo-skeletal model. For gait adaptation, we tested two motion criteria: (i) energy cost minimization, which is a widely used criterion for healthy adults; and (ii) energy rate minimization, based on existing measurements of elderly gait characteristics.ResultsProgression of muscle weakness enhanced the reduction of joint angle motion and minimum toe clearance, and finally resulted in falling. Gait adaptation to muscle weakness successfully formed stable walking patterns regardless of motion criteria, even at muscle weakness of 30 %, which represents a moderate degree of elderly muscle weakness. When criterion (i) was used, the time courses of joint motion were similar to those of healthy adults and a relatively high level of muscle activation was found in the whole gait cycle to compensate for muscle weakness. When criterion (ii) was used, the muscle activity level was lower than that of criterion (i) to minimize the energy rate, and the constructed gait successfully captured the characteristics of elderly gait reported in previous studies.SignificanceThese findings suggest that gait adaptation to muscle weakness plays an essential role in the development of stable gait characteristics, whereas elderly people might use a different motion criterion compared with healthy adults in gait adaptation.