Oliaei Shahram, Ashtiani Mohammed N, Azma Kamran, Saidi Sandra, Azghani Mahmood-Reza
Center of Submarine and Hyperbaric Medicine, Health Deputy of the Iranian Navy, Tehran, Iran; Faculty of Medicine, AJA University of Medical Sciences, Tehran, Iran;
Faculty of Medicine, AJA University of Medical Sciences, Tehran, Iran.
Acta Neurobiol Exp (Wars). 2018;78(1):60-68.
Standing on an unstable platform requires continuous effort of the neuro‑musculoskeletal system. The aim of the present study is to evaluate the ability to remain standing on an unstable platform at different levels of postural and cognitive difficulty. Healthy young males stood in the sagittal plane on an unstable platform supported by a pair of springs with modifiable stiffness. The balance test also assessed different levels of vision and cognitive function. Linear and nonlinear metrics of standing, based on motion captured kinematic data, were assessed to analyze the stability of standing. Results showed that vision plays a significant role in maintaining balance in terms of linear metrics. Elimination of visual feedback changed the direction of body sway and increased standing instability. Placement of low stiffness springs led to unstable standing. The cognitive dual task, however, had no effect on the stability metrics and merely could be revealed in the simplest test condition. Standing on an unstable platform was closely related to visual feedback and decreasing the spring stiffness significantly reduced stability. The roles of cognitive involvement were subdued by increasing the postural difficulty in standing on an unstable platform.
站在不稳定的平台上需要神经肌肉骨骼系统持续发力。本研究旨在评估在不同姿势和认知难度水平下保持站在不稳定平台上的能力。健康年轻男性在矢状面站在一个由一对刚度可调节的弹簧支撑的不稳定平台上。平衡测试还评估了不同水平的视觉和认知功能。基于运动捕捉的运动学数据，对站立的线性和非线性指标进行评估，以分析站立的稳定性。结果表明，就线性指标而言，视觉在维持平衡方面起着重要作用。消除视觉反馈改变了身体摇摆的方向并增加了站立不稳定性。放置低刚度弹簧导致站立不稳定。然而，认知双重任务对稳定性指标没有影响，仅在最简单的测试条件下才会显现出来。站在不稳定平台上与视觉反馈密切相关，降低弹簧刚度会显著降低稳定性。在不稳定平台上站立时，通过增加姿势难度，认知参与的作用会被减弱。
