Evaluation of Novel Vibrotactile Biofeedback Coding Schemes for Gait Symmetry Training

Gait rehabilitation is often considered as one of the most important factor in the betterment of quality of life after trauma. The use of haptic biofeedback as a gait rehabilitation tool needs extensive investigation. Recently, we developed a wearable system that captures gait data using instrumented insoles and provides real-time vibrotactile cueing to augment gait symmetry training. In this paper, we updated our system to generate novel modes of vibrotactile feedback based on symmetry ratio. We have evaluated the efficacy of these different modes of feedback in delivering cues for gait symmetry training. These novel modes for gait symmetry related task are based on vibration on-time and intensity, and their relation (proportional or inversely-proportional) with the error in symmetry ratio. Twelve young healthy adults participated in walking trials, where the objective of the trial was to achieve a target gait symmetry ratio while utilizing the vibrotactile biofeedback. Using dependent t-tests, we found improved achievement of a target gait symmetry ratio while utilizing the proportionally varying on-time or intensity based biofeedback modes compared to no biofeedback mode (P-value < 0.05). Furthermore, two-way repeated measures ANOVA revealed a statistically significant difference in symmetry ratio for relation type variations (proportional or inversely-proportional) in biofeedback (P-value < 0.001, partial eta squared = 0.764). The outcomes of this study pave the way towards the application of this system for training of individuals suffering from gait asymmetry.