Department of Biomedical Engineering, Stevens Institute of Technology, Hoboken, NJ, USA.
Department of Orthopaedics, Brown University, Providence, RI, USA; Lifespan Biostatistics, Epidemiology, and Research Design Core, Rhode Island Hospital, Providence, RI, USA.
J Biomech. 2022 Aug;141:111206. doi: 10.1016/j.jbiomech.2022.111206. Epub 2022 Jun 20.
This study evaluated frontal-plane dynamic balance control during 90° left turns while walking. Ten healthy young adults performed straight-line gait, pre-planned turns, and turns cued visually (late-cued turns). We quantified rotational balance control via the range of frontal-plane angular momentum (Hf) about the center of mass (COM), and the relative positioning of the COM and the feet using the horizontal distance from the COM to the lateral edge of the base of support (lateral distance) and the mediolateral margin of stability (MOS). We hypothesized that the Hf range would increase and the lateral distance and MOS minima would decrease during each turn type vs. straight-line gait and during late-cued vs. pre-planned turns. We found that the range of Hf was significantly greater during each turn type vs. straight-line gait and during late-cued vs. pre-planned turns. Also, the lateral distance minima were significantly smaller during turns vs. straight-line gait, and during pre-planned vs. late-cued turns. Our hypotheses about MOS were partially supported because the MOS minima patterns were specific to right or left steps and were not significantly different between straight-line gait and pre-planned turns overall, but the right step's MOS minima were more negative during late-cued vs. pre-planned turns and between either turn and straight-line gait. Finally, we observed slower gait speeds, fewer footfalls, shorter turn phase duration, and different turn strategies used during late-cued vs. pre-planned turns. Overall, these findings reveal multifaceted control of frontal-plane balance during turns encountered during everyday mobility.
本研究评估了 90°左转时行走过程中的额状面动态平衡控制。10 名健康的年轻人进行了直线行走、预先计划的转弯和视觉提示的转弯（后期提示转弯）。我们通过质心（COM）周围额状面角动量（Hf）的范围以及 COM 和脚的相对位置来量化旋转平衡控制，使用 COM 到支撑基底外侧边缘的水平距离（外侧距离）和横向稳定性边缘（MOS）来表示。我们假设，与直线行走相比，在每种转弯类型和后期提示转弯与预先计划转弯相比时，Hf 范围会增加，而外侧距离和 MOS 最小值会减少。我们发现，与直线行走相比，每种转弯类型和后期提示转弯的 Hf 范围都显著增加。此外，与直线行走相比，转弯时的外侧距离最小值明显减小，而与预先计划转弯相比，后期提示转弯时的外侧距离最小值也减小。我们关于 MOS 的假设得到了部分支持，因为 MOS 最小值的模式是特定于右侧或左侧的步长，并且在直线行走和预先计划转弯之间总体上没有显著差异，但与预先计划转弯相比，后期提示转弯时右侧步长的 MOS 最小值更负，而且在任何转弯和直线行走之间也是如此。最后，我们观察到在后期提示转弯与预先计划转弯相比时，步行速度更慢、脚步更少、转弯阶段持续时间更短以及使用了不同的转弯策略。总的来说，这些发现揭示了日常活动中转弯时额状面平衡的多方面控制。
