Audio-biofeedback improves balance in patients with bilateral vestibular loss

Objective: To evaluate the effectiveness of an audio-biofeedback (ABF) system for improving balance in patients with bilateral vestibular loss (BVL). Design: Before-after trial. Setting: University balance disorders laboratory. Participants: Nine subjects with BVL and 9 unaffected subjects as controls. Intervention: Trunk acceleration ABF while standing on foam with eyes closed. Main Outcome Measure: Balance stability was evaluated according to the following parameters: the root mean square of (1) the center of pressure (COP) displacements and of (2) the trunk accelerations; the COP bandwidth; the time spent by the participant within ±1° threshold from their baseline COP position; and the mean accelerations of the trunk while the participant was swaying outside this ±1° threshold. Results: Participants with BVL had significantly larger postural sway than did unaffected participants. Those with BVL, while using ABF, decreased sway area by 23%±4.9%, decreased trunk accelerations by 46%±9.9%, and increased time spent within ±1° sway threshold by 195%±34.6%. Conclusions: ABF improved stance stability of participants with BVL by increasing the amount of postural corrections.