Marco Dozza - PhD in Bioengineering, 2003-2007

Biofeedback Systems for Postural Control

33rd SfN Meeting 8·12 November 2003 - New Orleans (LA) USA

• F.B. Horak, M. Dozza , R.J. Peterka, C. Wall III, and L. Chiari, “Effects of audio biofeedback on postural stability of subjects with vestibular loss”, Proc. if the the Society for Neuroscience 33rd Annual Meeting, Program No. 272.9, New Orleans (LA), USA, 8-12 November 2003.



Abstract - The extent to which subjects with profound loss of vestibular function can substitute alternative sensory information to control body sway is unknown. We investigated the effect of a new audio-biofeedback (ABF) system on postural stability during stance. ABF consisted of sound waves representing 2D trunk kinematic (position, velocity and acceleration) information. When the sway was outside a 1-degree threshold area, frequency and amplitude modulation signaled anterior-posterior trunk sway and left-right ear volume balance signaled left-right sway. Nine subjects with bilateral loss of vestibular function (VS) and nine age-matched control subjects (CS) attempted to use this ABF to minimize postural sway in stance with eyes closed and/or with foam under their feet. Results in the condition of eyes closed with foam under the feet showed that use of audio biofeedback 1) decreased center of pressure (CoP) sway area (23% CS, 38% VS); 2) increased the percentage of time CoP was inside the sway threshold (103% CS, 196% VS); and 3) decreased the mean displacement of CoP outside the threshold area (16% CS, 25% VS). The effect of ABF was significantly larger for the vestibular loss group than for the control group, especially when visual and somatosensory information was restricted. In fact, without ABF, vestibular loss subjects' sway area was 67% larger than control subjects' sway on the foam with eyes closed, whereas with ABF, it was only 36% larger than controls. These encouraging results suggest that a balance prosthesis may be feasible in the future.

Supported by NIH grants DC 01849 and DC06201.

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