The relevance of seesaw devices in postural evaluation and training is gathering growing evidence due to its sensory-motor specificity. Nonetheless, the physiological specificities resulting from the dissociation or not of the seesaws (single vs double) still need to be investigated, in particular by assessing the respective contribution of automatic and voluntary components in the postural control. A protocol based on attention disturbance through a dual-task paradigm was set to establish this contribution. The general assumption was that the larger the dual-task effects, the larger the voluntary component contribution. Based on the larger postural sway induced by the dissociated seesaws, it is expected that the larger dual-task effect occurs in that latter case. The subjects were required to stand with eyes closed on solid ground (SG), a single (SS) and a double (DS) seesaw device while mentally solving or not a navigation task. The movements of the seesaw, placed on a double force platform, were assessed through a frequency analysis of the resultant center-of-pressure displacements along both mediolateral and anteroposterior axes. A larger contribution (p < 0.05) of the voluntary component was observed when subjects were standing on the DS seesaw, especially along the mediolateral axis. This trend is thought to prepare for a step initiation and would be related to the threat encountered by the subjects. In contrast, performing a dual-task protocol does not affect the antero-posterior sway whatever the support conditions. These data give specific pointers for the relative cognitive demand in the postural strategies induced by the double seesaw device.

中文翻译：

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单人跷跷板与双人跷跷板上的直立姿势：自动控制和自愿控制组件是否同样参与平衡控制？

跷跷板设备在姿势评估和训练中的相关性由于其感觉运动特异性而在收集越来越多的证据。尽管如此，仍然需要研究由跷跷板分离与否引起的生理特异性（单支或双支），特别是通过评估自动和自愿组件在姿势控制中的贡献。设置了基于通过双任务范例的注意力障碍的协议来建立这种贡献。一般的假设是，双重任务的影响越大，自愿组成部分的贡献就越大。基于由分离的跷跷板引起的较大的姿势摇摆，预期在后一种情况下发生较大的双重任务效应。要求受试者站立时，双眼紧贴地面（SG），一个单（SS）和一个双（DS）跷跷板设备，同时在精神上解决或不解决导航任务。通过对沿中间外侧和前后轴产生的压力中心位移的频率分析，对置于双力平台上的跷跷板的运动进行了评估。当受试者站在DS跷跷板上时，尤其是在中外侧轴上，观察到自愿分量的贡献更大（p <0.05）。人们认为这种趋势为步伐开始做准备，并且与受试者遇到的威胁有关。相反，无论支持条件如何，执行双重任务协议均不会影响前后摆动。这些数据为由双跷跷板装置引起的姿势策略中的相对认知需求提供了具体的指示。