Neural Mechanisms of Anticipatory Balance Control

Abstract

Anticipatory balance control is complex motor control ability that human use at workplace and other everyday physical activities. This study investigated the neural mechanism of anticipatory postural balance when participants were exposed to controlling upright stance posture in various balance difficulty levels. A total of 15 healthy male participants without any prior history of physical or neurological disorders took part in the study. A Biodex balance system was utilized to perform the balance control task. A 10-20 international system was used to collect EEG data on 19 brain locations. The participants were assigned three upright stance conditions: 1) standing on the balance platform when the platform was completely stable (baseline), 2) balancing on the platform in gradually increasing instability level, and 3) balancing on the platform in gradually increasing the stability level. Each of second and third condition consisted of a 30-second trial. Each channel EEG data was further decomposed into five frequency bands, such as, delta (0.5-4 Hz), theta (4-8 Hz), alpha (8-12 Hz), Beta (12-30 Hz), gamma1 (30-40 Hz) and gamma2 (40-80 Hz). Balance performance showed that anticipatory control of balance was better for condition where balance surface progressively changes from completely stable to relatively stable level compared to progressively changes from completely unstable to relatively unstable level. Brain mechanisms as measured by electroencephalogram (EEG) showed a general pattern of alpha band power decrease and high frequency gamma band power increase between resting and task condition.