Kim Yushin, Koh Kyung, Yoon BumChul, Kim Woo-Sub, Shin Joon-Ho, Park Hyung-Soon, Shim Jae Kun
Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Korea.
Department of Kinesiology, University of Maryland, 0110F School of Public Health, 4200 Valley Drive, College Park, MD, 20742, USA.
Exp Brain Res. 2017 Dec;235(12):3543-3552. doi: 10.1007/s00221-017-5074-5. Epub 2017 Sep 6.
The hand, one of the most versatile but mechanically redundant parts of the human body, suffers more and longer than other body parts after stroke. One of the rehabilitation paradigms, task-oriented rehabilitation, encourages motor repeatability, the ability to produce similar motor performance over repetitions through compensatory strategies while taking advantage of the motor system's redundancy. The previous studies showed that stroke survivors inconsistently performed a given motor task with limited motor solutions. We hypothesized that stroke survivors would exhibit deficits in motor repeatability and adaptive compensation compared to healthy controls in during repetitive force-pulse (RFP) production tasks using multiple fingers. Seventeen hemiparetic stroke survivors and seven healthy controls were asked to repeatedly press force sensors as fast as possible using the four fingers of each hand. The hierarchical variability decomposition model was employed to compute motor repeatability and adaptive compensation across finger-force impulses, respectively. Stroke survivors showed decreased repeatability and adaptive compensation of force impulses between individual fingers as compared to the control (p < 0.05). The stroke survivors also showed decreased pulse frequency and greater peak-to-peak time variance than the control (p < 0.05). Force-related variables, such as mean peak force and peak force interval variability, demonstrated no significant difference between groups. Our findings indicate that stroke-induced brain injury negatively affects their ability to exploit their redundant or abundant motor system in an RFP task.
手作为人体最具多功能性但在机械方面又存在冗余的部位之一，中风后比身体其他部位遭受的痛苦更多、持续时间更长。一种康复模式，即任务导向性康复，鼓励运动的可重复性，也就是通过补偿策略在利用运动系统冗余的同时，在重复过程中产生相似运动表现的能力。先前的研究表明，中风幸存者在执行给定的运动任务时，运动解决方案有限且表现不一致。我们假设，与健康对照组相比，中风幸存者在使用多根手指进行重复力脉冲（RFP）产生任务时，在运动可重复性和适应性补偿方面会表现出缺陷。17名偏瘫中风幸存者和7名健康对照者被要求用每只手的四根手指尽可能快地反复按压力传感器。采用分层变异性分解模型分别计算手指力脉冲之间的运动可重复性和适应性补偿。与对照组相比，中风幸存者各手指间力脉冲的可重复性和适应性补偿降低（p < 0.05）。中风幸存者的脉冲频率也低于对照组，峰峰值时间方差更大（p < 0.05）。与力相关的变量，如平均峰值力和峰值力间隔变异性，在两组之间没有显著差异。我们的研究结果表明，中风引起的脑损伤会对他们在RFP任务中利用其冗余或丰富的运动系统的能力产生负面影响。
