Gonzalez-Rubio Marcela, Velasquez Nicolas F, Torres-Oviedo Gelsy
Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States.
Front Hum Neurosci. 2019 Jul 3;13:207. doi: 10.3389/fnhum.2019.00207. eCollection 2019.
Split-belt treadmills that move the legs at different speeds are thought to update internal representations of the environment, such that this novel condition generates a new locomotor pattern with distinct spatio-temporal features compared to those of regular walking. It is unclear the degree to which such recalibration of movements in the spatial and temporal domains is interdependent. In this study, we explicitly altered subjects' limb motion in either space or time during split-belt walking to determine its impact on the adaptation of the other domain. Interestingly, we observed that motor adaptation in the spatial domain was susceptible to altering the temporal domain, whereas motor adaptation in the temporal domain was resilient to modifying the spatial domain. This non-reciprocal relation suggests a hierarchical organization such that the control of timing in locomotion has an effect on the control of limb position. This is of translational interest because clinical populations often have a greater deficit in one domain compared to the other. Our results suggest that explicit changes to temporal deficits cannot occur without modifying the spatial control of the limb.
以不同速度移动腿部的分带式跑步机被认为会更新对环境的内部表征，因此这种新情况会产生一种与正常行走相比具有独特时空特征的新运动模式。目前尚不清楚在空间和时间域中这种运动重新校准的相互依赖程度。在本研究中，我们在分带式行走过程中明确改变受试者在空间或时间上的肢体运动，以确定其对另一域适应的影响。有趣的是，我们观察到空间域中的运动适应容易受到时间域改变的影响，而时间域中的运动适应对空间域的改变具有弹性。这种非互惠关系表明存在一种层次组织，即运动中的时间控制对肢体位置控制有影响。这具有转化研究意义，因为临床人群通常在一个域中比另一个域有更大的缺陷。我们的结果表明，在不改变肢体空间控制的情况下，无法明确改变时间缺陷。
