Time series analysis of postural responses to combined visual pitch and support surface tilt.
Time series analysis of postural responses to combined visual pitch and support surface tilt.
复制标题
对组合视觉倾斜和支撑表面倾斜的姿势反应的时间序列分析。
DOI：
10.1016/j.neulet.2011.01.024
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发表时间：
2011
影响因子：
2.5
通讯作者：
Keshner,EmilyA
中科院分区：
文献类型：
--
作者：
Slaboda,JillC;Lauer,Richard;Keshner,EmilyA
使用时间序列分析的目的是提供关于曲线或函数的信息的解释，例如动态、生物力学数据。我们评估了一种时间序列分析方法在评估暴露于连续旋转的视野和倾斜的支撑面时姿势反应变化的应用。应用功能主成分分析(FPCA)对22名20-39岁的年轻人的重心轨迹进行了分析。在固定的表面上或在支撑表面背屈倾斜3度(30°/S)后，结合视野在30°和45°处的连续上下俯仰旋转/S。这种分析工具的有用之处在于每条曲线都被视为独立的观察，允许传统的主成分分析应用于曲线分析。FPCA的结果突出了COM曲线中的5个不同的时间段，解释了数据中91%的变异性。如果我们依靠短暂性干扰的开始和偏移来区分反应，那么年轻人改变他们的COM以响应视野运动的这些时期是不可能被识别的。在支撑面倾斜和支撑面恢复到中性位置期间，年轻人对视觉运动的反应使他们的COM显著移位。我们的结果表明，当应用于姿势数据中出现的微小但复杂的变化时，fPCA是一种可行的方法，并可能允许更好地理解与病理和干预一起发生的时间依赖过程。
The purpose of using time-series analyses is to provide interpretation of information on curves or functions, such as dynamic, biomechanical data. We evaluated the application of one method of time-series analysis for assessing changes in postural responses when exposed to a continuously rotating visual field combined with a tilted support surface. Functional Principal Component Analysis (fPCA) was applied to center of mass (CoM) trajectories collected from 22 young adults (20–39 y.o.) on a fixed surface or following a 3 degree (30°/s) dorsiflexion tilt of the support surface combined with continuous upward or downward pitch rotation of the visual field at 30 and 45°/s. The usefulness of this analytical tool is that each curve is treated as a distinct observation by itself, allowing for traditional PCA to be applied to the analysis of curves. Results of the fPCA highlighted 5 distinct time periods in the CoM curves that explained 91% of the variability in the data. These periods in which the young adults altered their CoM in response to visual field motion would not have been identified if we had relied on the onset and offset of the transient disturbance to distinguish responses. Young adults significantly displaced their CoM in response to visual motion over both the period of support surface tilt and while the support surface returned to a neutral position. Our results indicate that fPCA is a viable method when applied to the small but complex changes that emerge in postural data and might allow for a better understanding of time dependent processes occurring with pathology and intervention.