Effect of altered sensory conditions on multivariate descriptors of human postural sway
Effect of altered sensory conditions on multivariate descriptors of human postural sway
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DOI：
10.1007/s002210050506
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发表时间：
1998-09-01
影响因子：
2
通讯作者：
Horak, FB
中科院分区：
文献类型：
--
作者：
Kuo, AD;Speers, RA;Horak, FB
摇摆的多变量描述符被用来测试改变的感觉条件是否不仅会导致摇摆量的变化，还会导致姿势协调的变化。采用缩角和臀角协方差特征向量的特征值和方向作为多变量描述符。这些数量是在14名健康成人受试者中进行的感觉组织测试中测量的，该测试会破坏用于空间定位的视觉和体感信息。多变量方差分析和判别分析表明，导致的摇摆变化至少具有双变量特征，视觉和体感条件会产生明显的姿势协调变化。当支撑面摇摆参照破坏体感信息时，发现最显著的变化（P = 3.2）。10(-10))。由此产生的协方差测量表明，受试者不仅更容易摇摆，而且还使用类似于髋部策略的增加的髋关节运动。无论是闭上眼睛还是参照周围的视觉环境造成的视觉破坏，也会导致摇摆改变（P = 1.7）。10(-10))，与平台摆动参考相比，质心的运动比例更大。判别分析表明，最优单变量测量最多可以解释90%由于感觉条件改变而导致的行为。剩下的10%，虽然较小，但是非常重要的姿势控制变化，取决于感官条件。结果表明，躯干和腿部的正常姿势协调需要躯体感觉和视觉信息，并且每种感觉模式对姿势控制都有独特的贡献。下降姿势指令本质上是多元的，每个关节的运动都受到来自多个传感器输入的唯一影响。
Multivariate descriptors of sway were used to test whether altered sensory conditions result not only in changes in amount of sway but also in postural coordination. Eigenvalues and directions of eigenvectors of the covariance of shnk and hip angles were used as a set of multivariate descriptors. These quantities were measured in 14 healthy adult subjects performing the Sensory Organization test, which disrupts visual and somatosensory information used for spatial orientation. Multivariate analysis of variance and discriminant analysis showed that resulting sway changes were at least bivariate in character, with visual and somatosensory conditions producing distinct changes in postural coordination. The most significant changes were found when somatosensory information was disrupted by sway-referencing of the support surface (P = 3.2 . 10(-10)). The resulting covariance measurements showed that subjects not only swayed more but also used increased hip motion analogous to the hip strategy. Disruption of vision, by either closing the eyes or sway-referencing the visual surround, also resulted in altered sway (P = 1.7 . 10(-10)), with proportionately more motion of the center of mass than with platform sway-referencing. As shown by discriminant analysis, an optimal univariate measure could explain at most 90% of the behavior due to altered sensory conditions. The remaining 10%, while smaller, are highly significant changes in posture control that depend on sensory conditions. The results imply that normal postural coordination of the trunk and legs requires both somatosensory and visual information and that each sensory modality makes a unique contribution to posture control. Descending postural commands are multivariate in nature, and the motion at each joint is affected uniquely by input from multiple sensors.