Center of pressure velocity autocorrelation as a new measure of postural control during quiet stance
Center of pressure velocity autocorrelation as a new measure of postural control during quiet stance
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压力中心速度自相关作为安静姿势期间姿势控制的新措施
DOI：
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发表时间：
2013
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通讯作者：
H. Poizner
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作者：
M. Hernandez;Cory Stevenson;J. Snider;H. Poizner
福尔斯是老年人死亡和严重损伤的重要原因，尤其是在患有神经系统疾病的人群中。保持平衡和姿势控制的能力通常使用用测力平台收集的压力中心（COP）数据来评估。最近的方法，如稳定图扩散分析（SDA）已经研究了随机特性的COP，但需要大量的，长期的试验可靠的措施。为了进一步了解姿势控制的基本动力学过程，我们提出了一个新的概念框架，研究人类姿势控制使用COP速度自相关函数（COP-VAF），并比较其结果SDA。五名健康的年轻参与者在安静的站立条件下进行了研究，无论是睁着眼睛还是闭着眼睛。COP轨迹分析使用传统的姿势测量，SDA，和COP-VAF。结果表明，COP-VAF导致可重复的，生理上有意义的措施，可以区分姿势控制差异，在健康的个人和没有视力。更具体地说，视觉反馈被发现显着降低的峰值COP速度自相关值和幅度的第一个最小值，而增加的扩散系数。这一结果被解释为一个指示，视觉输入用于快速消除任何振荡运动在安静的立场，并利用一个较小的势场，以保持平衡。与SDA相比，COP-VAF测量提供了更简洁可靠的姿势控制测量（COP-VAF与SDA测量的组内相关系数（ICC）分别为0.23-0.87和0.05-0.91）。这项工作表明，我们可以进一步扩展我们的理解背后的姿势控制在安静的立场使用COP-VAF的潜在机制，并可能应用这种分析在量化未来的神经康复干预，旨在改善平衡。
Falls are a significant cause of mortality and serious injury in older adults and particularly in people with neurological disorders. The ability to maintain balance and postural control is commonly evaluated using center of pressure (COP) data collected with a force platform. Recent methods such as the Stabilogram Diffusion Analysis (SDA) have examined the stochastic characteristics of the COP but require numerous, long duration trials for reliable measures. To further our understanding of the underlying dynamical processes in postural control, we propose a new conceptual framework for studying human postural control using the COP velocity autocorrelation function (COP-VAF), and compare its results to SDA. Five healthy young participants were studied under quiet standing conditions with either eyes open or closed. COP trajectories were analyzed using both traditional posturographic measures, SDA, and the COP-VAF. It is shown that the COP-VAF leads to repeatable, physiologically meaningful measures that can distinguish postural control differences with and without vision in healthy individuals. More specifically, visual feedback was found to significantly decrease the peak COP velocity autocorrelation value and magnitude of the first minimum, while increasing the diffusion coefficient. This result is interpreted as an indication that visual input serves to rapidly eliminate any oscillatory motion in quiet stance and utilizes a smaller potential field to maintain balance. In contrast to SDA, COP-VAF measures provide a more concise and reliable measure of postural control (intraclass coefficient correlation (ICC) = 0.23-0.87 vs. 0.05-0.91 in COP-VAF vs. SDA measures, respectively). This work suggests that we can further extend our understanding of the underlying mechanisms behind postural control in quiet stance using the COP-VAF and may apply this analysis in quantifying future neurorehabilitative interventions aimed at improving balance.