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

我们研究了同时控制摆动平台上动态站立姿势和上肢运动的成年人(15名男性和15名女性，年龄19-23岁)。儿童(男20例，女11例，年龄5~6岁)，摆台安装测力平台，摆动方向为正弦，振幅2.5 cm，频率0.5 Hz。在人脸贴装显示器上呈现的目标光点以正弦方向横向移动，视角为20度，频率为0.3赫兹。利用电位器的电信号来检测上肢的运动，该电位器被控制在横向。显示器上还显示了由上肢控制的跟踪目标点的跟踪点。肢体训练结束后，安静站立(对照组)测量肢体运动1min。之后，将地板振动1分钟重复6次。在第1次和第6次试验中同时进行肢体运动，所有受试者的足底压力中心波动的平均速度在第3次试验前迅速下降，此后没有明显变化。与第5次相比，第6次试验的速度显著提高，无论是成年组还是男童。在第一次试验中，成人组和儿童组的肢体跟踪性能最低。对照组与成年组第6次实验在追踪成绩上无显著差异。结果表明：(1)动态站立姿势和上肢运动的同时控制随着姿势控制的自动化而提高；(2)儿童，尤其是男孩，其改善程度不如成人。

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.