LADAPT Loiret, Centre de Soins de Suite et de Réadaptation; CIAMS, Université Paris-Saclay; CIAMS, Université d'Orléans.
CIAMS, Université Paris-Saclay; CIAMS, Université d'Orléans; Université Libre de Bruxelles, Belgique.
J Vis Exp. 2022 Jul 26(185). doi: 10.3791/64088.
Gait initiation (GI), the transient phase between orthograde posture and steady-state locomotion, is a functional task and an experimental paradigm that is classically used in the literature to obtain insight into the basic postural mechanisms underlying body motion and balance control. Investigating GI has also contributed to a better understanding of the physiopathology of postural disorders in elderly and neurological participants (e.g., patients with Parkinson's disease). As such, it is recognized to have important clinical implications, especially in terms of fall prevention. This paper aims to provide scholars, clinicians, and higher education students information on the material and method developed to investigate GI postural organization via a biomechanical approach. The method is based on force platform recordings and the direct principle of mechanics to compute the kinematics of the center of gravity and center of pressure. The interaction between these two virtual points is a key element in this method since it determines the conditions of stability and whole-body progression. The protocol involves the participant initially standing immobile in an upright posture and starting to walk until the end of an at least 5 m track. It is recommended to vary the GI velocity (slow, spontaneous, fast) and the level of temporal pressure - gait may be initiated as soon as possible after the deliverance of a departure signal (high level of temporal pressure) or when the participant feels ready (low level of temporal pressure). Biomechanical parameters obtained with this method (e.g., duration and amplitude of anticipatory postural adjustments, step length/width, performance, and stability) are defined, and their computation method is detailed. In addition, typical values obtained in healthy young adults are provided. Finally, critical steps, limitations, and significance of the method with respect to the alternative method (motion capture system) are discussed.
步态启动（GI）是指从垂直姿势到稳定运动之间的瞬态阶段，它是一种功能任务和实验范式，通常用于文献中，以深入了解身体运动和平衡控制的基本姿势机制。研究 GI 还有助于更好地理解老年人和神经参与者（例如帕金森病患者）的姿势障碍的生理病理学。因此，它被认为具有重要的临床意义，特别是在预防跌倒方面。本文旨在为学者、临床医生和高等教育学生提供有关通过生物力学方法研究 GI 姿势组织的材料和方法的信息。该方法基于力台记录和力学直接原理来计算重心和压力中心的运动学。这两个虚拟点之间的相互作用是该方法的关键要素，因为它决定了稳定性和整个身体进展的条件。该方案包括参与者最初以直立姿势静止站立并开始行走，直到至少 5 米轨道的尽头。建议改变 GI 速度（慢、自发、快）和时间压力水平 - 可以在发出出发信号后尽快开始步态（高时间压力水平）或当参与者感觉准备好时（低时间压力水平）。该方法获得的生物力学参数（例如，预期姿势调整的持续时间和幅度、步长/宽度、性能和稳定性）被定义，并详细说明了其计算方法。此外，还提供了健康年轻成年人的典型值。最后，讨论了该方法相对于替代方法（运动捕捉系统）的关键步骤、局限性和意义。
