title: Effects of linear versus sigmoid coding of visual or audio biofeedback for the control of upright stance.
abstract: 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.
authors.affiliation: Department of Electronics, Computer Science, and Systems at the University of Bologna, 40136 Bologna, Italy. mdozza@deis.unibo.it
authors.forename: Marco
authors.initials: M
authors.lastname: Dozza
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Chiari
authors.forename: Frantisek
authors.initials: F
authors.lastname: Hlavacka
authors.forename: Angelo
authors.initials: A
authors.lastname: Cappello
authors.forename: Fay B
authors.initials: FB
authors.lastname: Horak
mesh_terms: D001307:Auditory Perception / Q000502:physiology*; D001676:Biofeedback, Psychology / Q000502:physiology*; D003198:Computer Simulation; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008954:Models, Biological; D018482:Muscle, Skeletal / Q000294:innervation / Q000502:physiology; D017711:Nonlinear Dynamics; D004856:Postural Balance / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*