Simultaneous control of dynamic standing posture on an oscillating platform and the upper limb movement in adults and children

我们研究了成人（15名男性和15名女性，年龄19-23岁）和儿童（20名男孩和11名女孩，年龄5-6岁）在振荡平台上动态站立姿势和上肢运动的同时控制。振动台安装有力平台，振幅为2.5 cm，频率为0.5 Hz，沿正弦波方向振荡。将显示在人脸显示器上的目标点以20度视角、0.3 Hz频率沿横向正弦方向移动。上肢运动是通过电位器的电信号被控制在侧向方向来拾取的。在显示器上还设计了一个由上肢控制的跟踪点，用于跟踪目标点。肢体训练结束后静立1分钟（对照组）测量肢体运动。之后，重复震荡6次，每次震荡1分钟。第1、6次试验同时进行肢体运动。所有受试者足压中心波动的平均速度在第3次试验前迅速下降，此后无明显变化。在第6次试验中，男女成人组和男孩的速度均显著高于第5次试验。在第一次试验中，成人组和儿童组的肢体追踪表现最低。对照组与成人组在追踪表现上无显著差异。儿童组第6次试验的表现明显低于对照组。结果表明：(1)随着姿势控制的自动化，动态站立姿势和上肢运动的同时控制能力得到提高；(2)儿童尤其是男孩的改善程度不如成人。

We investigated simultaneous control of dynamic standing posture on an oscillating platform and the upper limb movement in adults (15 men and 15 women, aged 19-23 yrs.) and children (20 boys and 11 girls, aged 5-6 yrs.).The oscillating table mounted with a force platform was oscillated sinusoidaly in anteroposterior direction with 2.5 cm amplitude and 0.5 Hz frequency. A target spot, which was presented on a face mounting display, was moved sinusoidaly in lateral direction with visual angle of 20 degrees and 0.3 Hz frequency. Upper limb movement was picked up using electric signal of a potentiometer that was controlled toward lateral direction. A tracing spot for following the target spot, which was controlled by the upper limb, was also presented on the display. The limb movement was measured for 1 minute in quiet standing (Control) after the limb training session. After that, the floor oscillation for 1 minute was repeated 6 times. The limb movement was simultaneously performed in the 1st and 6th trials.For all subjects, the mean speed of the fluctuation of center of foot pressure decreased rapidly until the 3rd trial, exhibiting no significant change thereafter. The speed in the 6th trial was significantly increased relative to that in the 5th trial for both sexes of adult-group and for boys. The limb tracing performance was the lowest in the 1st trial in adult-and child-groups. No significant difference in the tracing performance was found between Control and the 6st trials for adult-group. The performance of the 6th trial in child-group was significantly lower than that of Control trial.These results suggest that (1) simultaneous control of dynamic standing posture and the upper limb movement improves with automatization of the postural control ; (2) the improvement in children, especially in boys, was inferior to that in adults.