IEEE Trans Neural Syst Rehabil Eng. 2021;29:134-143. doi: 10.1109/TNSRE.2020.3038173. Epub 2021 Feb 26.
During walking in neurologically-intact controls, larger mediolateral pelvis displacements or velocities away from the stance foot are accompanied by wider steps. This relationship contributes to gait stabilization, as modulating step width based on pelvis motion (hereby termed a "mechanically-appropriate" step width) reduces the risk of lateral losses of balance. The relationship between pelvis displacement and step width is often weakened among people with chronic stroke (PwCS) for steps with the paretic leg. Our objective was to investigate the effects of a single exposure to a novel force-field on the modulation of paretic step width. This modulation was quantified as the partial correlation between paretic step width and pelvis displacement at the step's start (step start paretic [Formula: see text]). Following 3-minutes of normal walking, participants were exposed to 5-minutes of either force-field assistance (n = 10; pushing the swing leg toward mechanically-appropriate step widths) or perturbations (n = 10: pushing the swing leg away from mechanically-appropriate step widths). This period of assistance or perturbations was followed by a 1-minute catch period to identify after-effects, a sign of altered sensorimotor control. The effects of assistance were equivocal, without a significant direct effect or after-effect on step start paretic [Formula: see text]. In contrast, perturbations directly reduced step start paretic [Formula: see text] (p = 0.004), but were followed by a positive after-effect (p = 0.02). These results suggest that PwCS can strengthen the link between pelvis motion and paretic step width if exposed to a novel mechanical environment. Future work is needed to determine whether this effect is extended with repeated perturbation exposure.
在神经完整的对照组中行走时，远离支撑脚的骨盆较大的横向和纵向位移或速度伴随着较宽的步幅。这种关系有助于步态稳定，因为根据骨盆运动调节步幅（在此称为“机械适当”的步幅）可以降低失去平衡的风险。在慢性脑卒中患者（PwCS）中，与患侧腿的步幅相比，骨盆位移与步幅之间的关系通常较弱。我们的目的是研究单次暴露于新力场对患侧步幅调节的影响。这种调节通过患侧步幅与步幅开始时骨盆位移之间的偏相关来量化（步幅开始时患侧[公式：见正文]）。在正常行走 3 分钟后，参与者暴露于 5 分钟的力场辅助（n=10；推动摆动腿至机械适当的步幅）或干扰（n=10：推动摆动腿远离机械适当的步幅）。在辅助或干扰的这段时间后，进行了 1 分钟的捕获期，以确定后效，这是改变感觉运动控制的迹象。辅助的效果是不确定的，对步幅开始时患侧[公式：见正文]没有直接的显著影响或后效。相比之下，干扰直接降低了步幅开始时患侧[公式：见正文]（p=0.004），但随后出现正的后效（p=0.02）。这些结果表明，如果 PwCS 暴露于新的机械环境中，它可以加强骨盆运动和患侧步幅之间的联系。需要进一步的研究来确定这种效应是否会随着重复干扰暴露而扩展。
