Cognitive demands of postural control during continuous rotational perturbations of the support surface

This research explored the effect of the level of balance challenge on the cognitive demands of dynamic balance. The postural task was maintaining balance while standing on a rotating platform that moved about the axis of the ankle joint in the pitch plane. Different frequencies and amplitudes of perturbation were employed to introduce different levels of balance challenge. The cognitive task was a silent word identification task. Results showed no significant difference in the participants' performance on the cognitive task in any of the dual-task conditions in comparison with their performance in the "cognitive only" condition. Furthermore, regardless of the level of balance challenge concurrent performance of the cognitive task did not affect the balance control strategies adopted by our participants. The lack of interference between the cognitive task and the present postural task might be due to the fact that the rotational perturbations induced very small Center of Mass (COM) displacements at all frequencies which were under the automatic control.