Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX, USA.
Department of Health Sciences and Research, College of Health Professions, Medical University of South Carolina, Charleston, SC, USA.
J Biomech. 2021 Jan 4;114:110113. doi: 10.1016/j.jbiomech.2020.110113. Epub 2020 Nov 19.
Turning is an important activity of daily living and often compromised post-stroke. The fall rate for individuals post-stroke while turning is nearly four times as high compared to healthy adults, with most falls resulting in injury. Thus, there is a need for evidence-based rehabilitation targets to improve turning performance for individuals post-stroke. To produce well-coordinated movements, muscles can be organized into muscle modules (i.e., groups of co-excited muscles). Post-stroke these modules can be merged, leading to impaired muscle coordination and walking performance. However, the relationship between impaired coordination and turning performance is not well understood. Thus, the purpose of this study was to analyze the influence of impaired muscle coordination (i.e., merged modules) on turning performance (i.e., time and number of steps required to complete a turn, and smoothness and balance control during the turn). Individuals post-stroke and healthy controls performed three tasks including overground straight-line walking, a 90-degree turn, and a 180-degree turn. The number of muscle modules during straight-line walking were determined using non-negative matrix factorization. During 180-degree turning, those with two modules took longer to turn, used more steps and had less smooth movement. Those with reduced module complexity exhibited diminished balance control during both 90-degree and 180-degree turning. These results suggest obtaining independent modules should be an important aim in locomotor therapies aimed at improving turning performance. In addition, the time it takes to complete a 180-degree turn may provide useful clinical insight into impaired muscle coordination post-stroke.
转身是日常生活中的一项重要活动，而中风后往往会受到影响。中风后个体在转身时的跌倒率比健康成年人高近四倍，大多数跌倒都会导致受伤。因此，需要有循证康复目标来提高中风后个体的转身表现。为了产生协调的动作，肌肉可以组织成肌肉模块（即，共同兴奋的肌肉群）。中风后，这些模块可能会合并，导致肌肉协调性受损和行走表现受损。然而，肌肉协调性受损与转身表现之间的关系尚不清楚。因此，本研究的目的是分析肌肉协调性受损（即合并的模块）对转身表现（即完成转身所需的时间和步数，以及转身过程中的平稳性和平衡控制）的影响。中风后个体和健康对照组进行了三项任务，包括地面直线行走、90 度转弯和 180 度转弯。使用非负矩阵分解确定直线行走过程中的肌肉模块数量。在 180 度转弯时，具有两个模块的人转身时间更长，使用的步数更多，运动不够平稳。模块复杂性降低的人在 90 度和 180 度转弯时平衡控制能力下降。这些结果表明，获得独立模块应该是旨在改善转身表现的运动疗法的一个重要目标。此外，完成 180 度转弯所需的时间可能为了解中风后肌肉协调性受损提供有用的临床见解。
