Department of Kinesiology, The Pennsylvania State University, University Park, PA 16802 USA.
Department of Engineering Science & Mechanics, The Pennsylvania State University, University Park, PA 16802 USA.
J Biomech. 2024 Nov;176:112361. doi: 10.1016/j.jbiomech.2024.112361. Epub 2024 Oct 5.
People with balance impairments often struggle performing turns or lateral maneuvers, which can increase risk of falls and injuries. Here we asked how people's mediolateral balance is impacted when walking on non-straight winding paths. Twenty-four healthy adults (12F / 12M; 25.8±3.5 yrs) participated. Each walked on each of six paths projected onto a treadmill, comprised of three pseudo-random path oscillation frequency combinations (straight, slowly-winding, quickly-winding), each presented at either wide or narrow width. We quantified stepping errors as the percent of steps taken off each path. We quantified minimum mediolateral Margin of Stability (MoS) at each step and calculated means (μ) and standard deviations (σ) for each trial. We calculated lateral Probability of Instability (PoI) as participants' statistical risk of taking unstable (MoS < 0) steps. On narrower paths, participants made more stepping errors and walked with smaller μ(MoS) for all path frequencies (p < 0.001), and exhibited increased PoI on the straight and slowly-winding paths (p < 0.001). On winding paths, participants made progressively more stepping errors and walked with smaller μ(MoS) as oscillation frequency increased on narrow paths (all p < 0.001) and on the wide quickly-winding paths (all p < 0.001). They also consistently walked with larger σ(MoS), and increased PoIon higher sinuosity paths of both widths (all p < 0.001). Though many took numerous unstable steps, no participant fell. Our results demonstrate healthy adults' ability both to trade off increased risk of lateral instability for greater maneuverability, and to employ highly-versatile stepping strategies to maintain balance while walking.
平衡障碍患者在进行转弯或横向动作时常常感到困难，这会增加摔倒和受伤的风险。在这里，我们想了解人们在走非直线蜿蜒路径时的横向平衡是如何受到影响的。24 名健康成年人（12 名女性/12 名男性；25.8±3.5 岁）参与了研究。每个人都在跑步机上走了六种路径中的每一种，这些路径由三种伪随机路径摆动频率组合（直的、缓慢的、快速的）组成，每种路径呈现宽或窄两种宽度。我们将步幅误差量化为离开每条路径的步数百分比。我们量化了每个步幅的最小横向稳定性余量（MoS），并计算了每个试验的平均值（μ）和标准差（σ）。我们将横向不稳定性概率（PoI）计算为参与者采取不稳定（MoS<0）步的统计风险。在较窄的路径上，参与者的步幅误差更大，在所有路径频率下的μ（MoS）都更小（p<0.001），并且在直的和缓慢的路径上表现出更高的 PoI（p<0.001）。在蜿蜒的路径上，随着摆动频率的增加，参与者的步幅误差越来越大，μ（MoS）也越来越小，在较窄的路径（所有 p<0.001）和较宽的快速蜿蜒路径上（所有 p<0.001）都是如此。他们也一直走得更大的σ（MoS），并在两种宽度的更高正弦度路径上增加了 PoI（所有 p<0.001）。尽管许多人采取了许多不稳定的步骤，但没有参与者摔倒。我们的结果表明，健康成年人既有能力在横向不稳定风险增加和更大的机动性之间进行权衡，也有能力在行走时采用高度灵活的步幅策略来保持平衡。
