THE SHORT-TERM EFFECTS OF RHYTHMIC VIBROTACTILE AND AUDITORY BIOFEEDBACK ON THE GAIT OF INDIVIDUALS AFTER WEIGHT-INDUCED ASYMMETRY

Abstract

BACKGROUND: Biofeedback (BFB), the practice of providing real-time sensory feedback has been shown to improve gait rehabilitation outcomes. BFB training through rhythmic stimulation has the potential to improve spatiotemporal gait asymmetries while minimizing cognitive load by encouraging a synchronization between the user’s gait cycle and an external rhythm. OBJECTIVE: The purpose of this work was to evaluate if rhythmic stimulation can improve the stance time symmetry ratio (STSR) and to compare vibrotactile to auditory stimulation. Gait parameters including velocity, cadence, stride length, double support time, and step length symmetry, were also examined. METHODOLOGY: An experimental rhythmic stimulation system was developed, and twelve healthy adults (5 males), age 28.42 ± 10.93 years, were recruited to participate in walking trials. A unilateral ankle weight was used to induce a gait asymmetry to simulate asymmetry as commonly exhibited by individuals with lower limb amputation and other clinical disorders. Four conditions were evaluated: 1) No ankle weight baseline, 2) ankle weight without rhythmic stimulation, 3) ankle weight + rhythmic vibrotactile stimulation (RVS) using alternating motors and 4) ankle weight + rhythmic auditory stimulation (RAS) using a single-tone metronome at the participant’s self-selected cadence. FINDINGS: As expected the STSR became significantly more asymmetrical with the ankle weight (i.e. induced asymmetry condition). STSR improved significantly with RVS and RAS when compared to the ankle weight without rhythmic stimulation. Cadence also significantly improved with RVS and RAS compared to ankle weight without rhythmic stimulation. With the exception of double support time, the other gait parameters were unchanged from the ankle weight condition. There were no statistically significant differences between RVS and RAS. CONCLUSION: This study found that rhythmic stimulation can improve the STSR when an asymmetry is induced. Moreover, RVS is at least as effective as auditory stimulation in improving STSR in healthy adults with an induced gait asymmetry. Future work should be extended to populations with mobility impairments and outside of laboratory settings. Layman's Abstract Providing feedback to users in real-time has been shown to improve walking in many populations with gait deviations. Feedback in the form of rhythmic stimulation involves consistent cues to which the user matches their movement. This work compared the effects of sound-based (RAS) and vibration-based (RVS) stimulation systems on the walking symmetry of healthy adults. A simple stimulation system was used with twelve healthy adults in walking trials. The walking trials included some in which the participant wore an ankle weight on a single leg to create a non-symmetrical walking pattern. Four different conditions were tested: No ankle weight, with an ankle weight, with an ankle weight and RAS, and with an ankle weight and RVS. Walking symmetry improved with both RVS and RAS compared to ankle weight only. Walking speed, cadence, and step length did not change. These findings show that RVS is at least as effective as RAS and may be a useful technique for gait rehabilitation. Future work should involve clinical populations and in real-world settings. Article PDF Link: https://jps.library.utoronto.ca/index.php/cpoj/article/view/36223/29090 How To Cite: Michelini A., Sivasambu H., Andrysek J. The short-term effects of rhythmic vibrotactile and auditory biofeedback on the gait of individuals after weight-induced asymmetry. Canadian Prosthetics & Orthotics Journal. 2022; Volume 5, Issue 1, No.6. https://doi.org/10.33137/cpoj.v5i1.36223 Corresponding Author: Jan Andrysek, PhDBloorview Research Institute, Holland Bloorview Kids Rehabilitation Hospital, Toronto, Canada. E-Mail: jandrysek@hollandbloorview.ca ORCID ID: https://orcid.org/0000-0002-4976-1228