Effects of linear versus sigmoid coding of visual or audio biofeedback for the control of upright stance

Marco Dozza, Lorenzo Chiari, Frantisek Hlavacka, Angelo Cappello, Fay B. Horak

Research output: Contribution to journalArticle

27 Scopus citations


Although both visual and audio biofeedback (BF) systems for postural control can reduce sway during stance, a direct comparison between the two systems has never been done. Further, comparing different coding designs of audio and visual BF may help in elucidating how BF information is integrated in the control of posture, and may improve knowledge for the design of innovative BF systems for postural control. The purpose of this paper is to compare the effects of linear versus sigmoid coding of trunk acceleration for audio and visual BF on postural sway in a group of eight, healthy subjects while standing on a foam surface. Results showed that sigmoid-coded audio BF reduced sway acceleration more than did a linear-coded audio BF, whereas a linear-coded visual BF reduced sway acceleration more than a sigmoid-coded visual BF. In addition, audio BF had larger effects on reducing center of pressure (COP) displacement whereas visual BF had larger effects on reducing trunk sway. These results suggest that audio and visual BF for postural control benefit from different types of sensory coding and each type of BF may encourage a different type of postural sway strategy.

Original languageEnglish (US)
Article number13
Pages (from-to)505-512
Number of pages8
JournalIEEE Transactions on Neural Systems and Rehabilitation Engineering
Issue number4
StatePublished - Dec 1 2006



  • Accelerometer
  • Acoustic and visual feedback
  • Balance
  • Center of pressure
  • Postural control

ASJC Scopus subject areas

  • Internal Medicine
  • Neuroscience(all)
  • Biomedical Engineering

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