Department of Motion Science, Institute of Sport Science, Friedrich-Schiller-University Jena, Jena, Thuringia, Germany; Department of Neurology/Department of Orthopedic Surgery, Bayreuth Hospital, Bayreuth, Bavaria, Germany.
Department for the Psychology of Human Movement and Sport, Institute of Sport Science, Friedrich-Schiller-University Jena, Thuringia, Germany.
Gait Posture. 2019 Jun;71:38-43. doi: 10.1016/j.gaitpost.2019.04.014. Epub 2019 Apr 13.
The unexpectedness of ground-contact onset in stepping down due, e.g., to a camouflaged curb during ongoing gait may impose potential postural control challenges, which might be deteriorated when walking faster.
Does traversing camouflaged versus visible curbs, at a fast walking velocity, induce more unstable body configurations, assessed by a smaller anteroposterior "margin of stability" (MoS)?
For twelve healthy participants, we investigated MoS at foot touchdown in descent and in the first recovery step from 0- and 10-cm visible and camouflaged curbs at comfortable (1.22 ± 0.08 m/s) and fast (1.71 ± 0.11 m/s) walking velocities. Three-way (velocity, elevation, visibility) and two-way (velocity, visibility) repeated-measurement ANOVAs were performed to determine their interactions on MoS, and its determining parameters, during curb negotiation and recovery step, respectively.
No greater postural instability when traversing a camouflaged versus visible curb at a faster walking velocity during curb descent, indicated by no three-way interaction effects on MoS. However, an elevation-by-visibility interaction showed a dramatic decrease of MoS when descending a 10-cm camouflaged versus visible curb. This was because of a farther anterior displacement of center-of-mass with a larger velocity. Furthermore, the walking velocity was independently associated with a smaller MoS and a more anteriorly-shifted center-of-mass with a higher velocity. In the recovery step, participants demonstrated a reduced stability of the body configuration when walking faster or recovering from a camouflaged than from a visible curb. The mentioned result implies that the potential to increase the base-of-support to compensate for an increased center-of-mass velocity, induced by an increased walking velocity, is limited.
Despite a significant independent main effect of walking velocity, a more unstable postural control observed during traversing of camouflaged versus visible curbs was found not to be walking velocity-related in young individuals. Further research, including elderly may shed more light on these results.
在行走过程中，例如，当遇到伪装的路缘石时，脚步着地的突发性可能会对姿势控制造成潜在的挑战，而当行走速度加快时，这种挑战可能会恶化。
以较快的步行速度穿越伪装和可见的路缘时，是否会因身体配置更不稳定而导致更小的前后向“稳定性边界”（MoS）？
对于 12 名健康参与者，我们在舒适（1.22±0.08m/s）和快速（1.71±0.11m/s）步行速度下，研究了在 0 和 10cm 可见和伪装的路缘石下降和第一次恢复步时，脚部触地时的 MoS。分别进行了三向（速度、高度、可见度）和双向（速度、可见度）重复测量方差分析，以确定它们在跨越路缘石时的相互作用，以及在恢复步时对 MoS 及其决定参数的相互作用。
在快速行走速度下，穿越伪装路缘石与可见路缘石时，没有更大的姿势不稳定性，MoS 没有三向交互作用。然而，在下降 10cm 伪装和可见路缘石时，存在一个高度-可见度的交互作用，MoS 显著降低。这是由于质心的更大速度导致的更靠前的位移。此外，行走速度与更小的 MoS 和更高的速度相关的更向前的质心位移独立相关。在恢复步中，参与者表现出在快速行走或从伪装路缘恢复时，身体配置的稳定性降低。这一结果意味着，通过增加行走速度来增加质心速度的可能性，以补偿支撑基础的增加是有限的。
尽管行走速度有显著的独立主要影响，但在穿越伪装和可见路缘时观察到的更不稳定的姿势控制，在年轻人中与行走速度无关。进一步的研究，包括老年人的研究，可能会对这些结果有更深入的了解。
