Within-session and between-session effects of auditory biofeedback training on center of pressure location during gait in patients with chronic ankle instability

Objectives: To establish preliminary gait training dosage parameters for patients with chronic ankle instability (CAI) by determining the within-session and between-session effects of auditory biofeedback training on center of pressure (COP) location during gait. Design: Observational Longitudinal. Setting: Laboratory. Participants: 19 participants with CAI, 8 participants who did not receive auditory biofeedback (NoFeedback group) and 11 participants who did receive auditory biofeedback (AuditoryFeedback group) over an 8-session 2-week intervention. Main outcome measures: COP location was measured at the start and at each 5-min interval during treadmill walking across all eight 30-min training sessions. Results: The AuditoryFeedback group had significant within-session lateral-to-medial shifts in COP location during only session-1 at the 15-min (45% of stance; peak mean difference 1/4 4.6 mm), 20-min (35% and 45%; 4.2 mm), and 30-min time intervals (35% and 45%; 4.1 mm). Furthermore, the AuditoryFeedback group had significant between-session lateral-to-medial shifts in COP location at session-5 (35-55% of stance; 4.2 mm), session-7 (35%-95%; 6.7 mm), and session-8 (35%-95%; 7.7 mm). The NoFeedback group had no significant changes in COP location within-sessions or between-sessions. Conclusions: Participants with CAI who received auditory biofeedback during gait needed an average of 15-min during session-1 to meaningfully shift their COP location medially and 4-sessions before retaining the adapted gait pattern.