College of Health Professions, Medical University of South Carolina, Charleston, SC, USA.
College of Health Professions, Medical University of South Carolina, Charleston, SC, USA; Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC, USA.
J Biomech. 2021 Nov 9;128:110738. doi: 10.1016/j.jbiomech.2021.110738. Epub 2021 Sep 7.
People with chronic stroke (PwCS) are susceptible to mediolateral losses of balance while walking, possibly due in part to inaccurate control of mediolateral paretic foot placement. We hypothesized that mediolateral foot placement errors when stepping to stationary or shifting visual targets would be larger for paretic steps than for steps taken by neurologically-intact individuals, hereby referred to as controls. Secondarily, we hypothesized that paretic foot placement errors would be correlated with previously identified deficits in isolated paretic hip abduction accuracy. 34 PwCS and 12 controls walked overground on an instrumented mat used to quantify foot placement location relative to parallel lines separated by various widths (10, 20, 30 cm). With stationary step width targets, foot placement errors were larger for paretic steps than for either non-paretic or control steps, most notably for the narrowest prescribed step width (mean absolute errors of 3.9, 2.3, and 1.9 cm, respectively). However, no differences in foot placement accuracy were observed immediately following visual target shifts, as all groups required multiple steps to achieve the new prescribed step width. Paretic hip abduction accuracy was moderately correlated with mediolateral foot placement accuracy when stepping to stationary targets (r = 0.49), but not shifting targets (r = 0.16). The present results suggest that a reduced ability to accurately abduct the paretic leg contributes to inaccurate paretic foot placement. However, the need to ensure mediolateral walking balance through mechanically-appropriate foot placement may often override the prescribed goal of stepping to visual targets, a concern of particular importance for narrow steps.
慢性脑卒中患者（PwCS）在行走时容易出现横向平衡丧失，这可能部分是由于对横向瘫痪足放置的控制不准确。我们假设在向静止或移动的视觉目标跨步时，瘫痪足的放置误差会比神经健全个体（以下简称对照组）的跨步更大。其次，我们假设瘫痪足的放置误差与先前确定的孤立瘫痪髋关节外展准确性缺陷相关。34 名 PwCS 和 12 名对照组在一个仪器化的垫子上进行了实地行走，该垫子用于量化相对于两条平行线（间隔 10、20、30 厘米）的脚放置位置。对于固定步宽目标，瘫痪步的脚放置误差大于非瘫痪步或对照组步，尤其是在最窄的规定步宽时（分别为 3.9、2.3 和 1.9 厘米的平均绝对误差）。然而，在视觉目标转移后，没有观察到脚放置准确性的差异，因为所有组都需要多次跨步才能达到新的规定步宽。在向静止目标跨步时，瘫痪髋关节外展准确性与横向脚放置准确性中度相关（r=0.49），但与移动目标无关（r=0.16）。本研究结果表明，准确外展瘫痪腿的能力下降导致了不准确的瘫痪足放置。然而，通过机械上适当的足放置来确保横向行走平衡的需要，可能经常会超过向视觉目标跨步的规定目标，这对于狭窄的步幅是一个特别重要的关注点。
