Limited control strategies with the loss of vestibular function
Limited control strategies with the loss of vestibular function
复制标题
DOI：
10.1007/s00221-002-1110-0
复制
发表时间：
2002-08-01
影响因子：
2
通讯作者：
Jeka, JJ
中科院分区：
文献类型：
--
作者：
Creath, R;Kiemel, T;Jeka, JJ
当受试者站在一个不稳定或兼容的支持表面，而不是一个稳定的，前庭信息变得更加重要的姿态控制。我们研究了双侧前庭丧失（BVL）的受试者如何控制他们的直立姿势，在指尖有和没有轻触接触，同时站在支撑表面上，以不同的频率正弦旋转。受试者闭上眼睛站在平台上，平台围绕踝关节中线正下方的轴旋转+/-1.2度，频率范围为0.01至0.4 Hz，用于两种感觉条件：（1）在静止表面上进行轻微的非支撑性触摸（小于IN垂直力）;或（2）指尖保持在接触表面正上方的位置（无接触）。在无触摸和轻触摸条件下，分析BVL受试者与健康对照者的质心（CoM）和手指的增益、相位和变异性。观察到三个重要结果：第一，BVL受试者的CoM增益和变异性明显高于无触摸接触的对照受试者，特别是在较高的平台频率下。第二，轻触接触，BVL和对照组显示出相同的增益，变异性和相位。第三，在对照组中观察到手指和CoM之间的多种关系，而BVL受试者实施了单指/CoM控制方案。结果解释在三个相互作用的因素：前庭系统的传递函数，感觉重新加权机制，和身体的惯性特性。此外，在对照组中观察到的多种控制策略表明，比前庭功能严重减弱的个体更灵活的控制系统。
When subjects stand on an unstable or compliant support surface, rather than a stable one, vestibular information becomes more important for the control of posture. We investigated how subjects with bilateral vestibular loss (BVL) controlled their upright posture, with and without light-touch contact at the fingertip, while standing on a support surface, sinusoidally rotating at different frequencies. Subjects stood with eyes closed on a platform that rotated +/-1.2degrees around an axis directly beneath the midline of the ankle for frequencies ranging from 0.01 to 0.4 Hz for two sensory conditions: (1) with light, nonsupportive touch (less than I N vertical force) on a stationary surface; or (2) with the fingertip held in a position directly above the contact surface (no contact). Gain, phase, and variability of the center of mass (CoM) and the finger were analyzed to compare BVL subjects with healthy controls in the no-touch and light-touch conditions. Three important results were observed: First, CoM gain and variability of BVL subjects was distinctly higher than control subjects with no-touch contact, particularly at the higher platform frequencies. Second, with light-touch contact, BVL and control subjects showed equivalent gain, variability, and phase. Third, multiple relationships between the finger and the CoM were observed in control subjects, whereas BVL subjects implemented a single finger/CoM control scheme. The results are explained in terms of three interacting factors: the transfer function of the vestibular system, a sensory reweighting mechanism, and the inertial properties of the body. Moreover, multiple control strategies observed in control subjects suggest a more flexible control system than that of individuals with severely diminished vestibular function.