Bioengineering and Biomechanics Laboratory, Federal University of Goiás, Goiânia, Brazil.
Department of Human Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam Movement Science, Amsterdam, The Netherlands.
Gait Posture. 2020 Jul;80:68-73. doi: 10.1016/j.gaitpost.2020.05.035. Epub 2020 May 25.
Control of body orientation requires head motion detection by the vestibular system and small changes with respect to the gravitational acceleration vector could cause destabilization.
We aimed to compare the effects of different head orientations on gait stability in young adults, dancers and older adults.
Three groups of 10 subjects were evaluated, the first composed of young adults (aged 18-30 years), the second composed of young healthy dancers under high performance dance training (aged 18-30 years), and the third group composed of community-dwelling older adults (aged 65-80 years). Participants walked on a treadmill at their preferred speed in four distinct head orientation conditions for four minutes each: control (neutral orientation); dynamic yaw (following a target over 45° bilaterally); up (15° neck extension), and down (40° neck flexion). Foot and trunk kinematic data were acquired using a 3D motion capture system and the gait pattern was assessed by basic gait parameters (step length, stride width and corresponding variability) and gait stability (local divergence exponents and margins of stability). Main effects of conditions and groups, as well as their interaction effects, were evaluated by repeated-measures analysis of variance.
Interactions of group and head orientation were found for both step length and stride width variability; main effects of head orientation were found for all evaluated parameters and main effects of group were found for step length and its variability and local divergence exponents in all directions.
As expected, the older adults group showed less stable gait (higher local divergence exponent), the shortest step length and greater step length variability. However, contrary to expectation, the dancers were not more stable. The yaw condition was the most challenging for all groups and the down condition seemed to be least challenging.
身体方向的控制需要前庭系统检测头部运动，而相对于重力加速度向量的微小变化可能会导致不稳定。
我们旨在比较不同头部姿势对年轻成年人、舞者和老年人步态稳定性的影响。
评估了三组 10 名受试者，第一组由年轻成年人（18-30 岁）组成，第二组由接受高水平舞蹈训练的年轻健康舞者（18-30 岁）组成，第三组由社区居住的老年人（65-80 岁）组成。参与者在跑步机上以自己喜欢的速度行走，在四个不同的头部姿势条件下，每个姿势持续四分钟：对照（中立姿势）；动态偏航（双侧跟随目标超过 45°）；上（15°颈部伸展）和下（40°颈部屈曲）。使用三维运动捕捉系统采集足部和躯干运动学数据，通过基本步态参数（步长、步宽和相应的变异性）和步态稳定性（局部散度指数和稳定极限）评估步态模式。采用重复测量方差分析评估条件和组的主要效应以及它们的交互效应。
发现组和头部姿势对步长和步宽变异性都有交互作用；头部姿势对所有评估参数都有主要影响，组对步长及其变异性和所有方向的局部散度指数都有主要影响。
正如预期的那样，老年组表现出更不稳定的步态（更高的局部散度指数）、最短的步长和更大的步长变异性。然而，与预期相反，舞者并不更稳定。偏航条件对所有组都是最具挑战性的，而下倾条件似乎最不具挑战性。
