title: Postural sway and rhythmic electroencephalography analysis of cortical activation during eight balance training tasks.
abstract: BACKGROUND
  The purpose of this study was to investigate the changes in the Power Spectrum Density (PSD) of the electroencephalography (EEG) in common sensorimotor balance training tasks of varying difficulty. Sensorimotor balance exercises including alteration of vision, base of support or surface compliance are used to improve postural control. These exercises are presumed to induce supraspinal adaptation, however, there were no studies that investigated the power changes of the cortical activity in these static balance tasks. Our objective was to provide evidence in the cortical involvement with the static balance tasks frequently used in sensorimotor training.
  
  
  METHODS
  Postural sway and EEG changes of alpha, beta and sigma wave bands were measured in seventeen participants during eight balance tasks of varying difficulty with eyes open and closed, feet in tandem or apart and on foam or a firm surface.
  
  
  RESULTS
  The power of beta and sigma bands increased significantly at the parietal and central area of the brain in tasks with eyes open together with one sensory factor (base of support or surface compliance) or two sensory factors (base of support and surface compliance) altered, and in task with three sensory factors (vision, base of support and surface compliance) altered from the control task.
  
  
  CONCLUSIONS
  This study demonstrated the cortical involvement in the sensorimotor balance tasks, suggesting that these exercises may induce cortical adaptation for postural control. The results support subcortical control with increased task difficulty and the increase in cortical processing when task became extremely challenging.
authors.affiliation: Department of Physical Therapy, School of Allied Health Professions, Loma Linda University, CA, USA.
authors.forename: Yuen Yi F
authors.initials: YY
authors.lastname: Tse
authors.forename: Jerrold S
authors.initials: JS
authors.lastname: Petrofsky
authors.forename: Lee
authors.initials: L
authors.lastname: Berk
authors.forename: Noha
authors.initials: N
authors.lastname: Daher
authors.forename: Everett
authors.initials: E
authors.lastname: Lohman
authors.forename: Michael S
authors.initials: MS
authors.lastname: Laymon
authors.forename: Paula
authors.initials: P
authors.lastname: Cavalcanti
mesh_terms: D000328:Adult; D001931:Brain Mapping; D058256:Brain Waves / Q000502:physiology*; D002540:Cerebral Cortex / Q000502:physiology*; D004566:Electrodes; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D004856:Postural Balance / Q000502:physiology*; D013647:Task Performance and Analysis