Sudden movement of platform and postural stability

当公共汽车开始移动时，车内站着的人继续保持直立姿势，这就是所谓的姿势反应。什么样的信息会引起这种反应？这个问题还没有得到回答。本文的目的是研究体位反应与前庭信息的相关性。在这项研究中，我们开发了一种新的装置来刺激受试者的前后方向或左右方向。该装置可能产生的刺激要点如下。a)平台速度：50、100、200、300mm /秒。b)平台移动距离：10、50、100、150毫米)等速时间：50、200毫秒（秒）两种移动方式：单向、前进、后退。受试者站在安装在本仪器平台上的稳定仪上，头部左侧装有加速度传感器。通过足压力中心的移动来评价体位反应和体位摇摆。这些记录的数据以100hz的数据采样率输入计算机并进行分析。对8名受试者进行了检查。在平台启动后，每个实验对象的头部都出现了加速。这种头部加速的潜伏期是恒定的，而不是刺激方向和速度的变化。另一方面，姿势反应的潜伏期随刺激加速度的增加而成比例缩短。从这些结果来看，在这种刺激中观察到的头部加速度似乎不是姿势反应的触发因素。

When a bus begins to move, a standing person in the car continues upright posture using so-called postural response. What kind of information provokes this response? This question has not been answered yet. The purpose of this paper is to research the correlation between postural response and vestibular information. In this research, we developed the new device to stimulate a subject in forward-backward direction or right-left direction. A gist of possible stimulations by this device are as following.a) Velocity of platform : 50, 100, 200, 300 mm/seconds.b) Distance of platform movement : 10, 50, 100, 150 mmc) Time for constant velocity : 50, 200 millisecondsd) Two kinds of moving : one way, go and backThe subject stands on the stabilometry equipped on the platform of this apparatus and being attached sensor of the acceleration on left side of his head. Postural response and postural sway was evaluated by moving of center of foot pressure. These recorded data were taken into computer with 100 Hz of data sampling rate and analyzed. Eight subjects were examined. Each subject showed head acceleration just after the platform's starting. The latency of this head acceleration was constant instead of variability of directions and velocity of stimulations. On the other hands, the latency of postural responses was shortened in proportion to increase of acceleration of stimulation. From these results, this head acceleration observed in this stimulation seemed not to be a trigger of postural response.