Immediate Effects of Immersive Biofeedback on Gait in Children With Cerebral Palsy.

Abstract

To investigate the immediate response to avatar-based biofeedback on 3 clinically important gait parameters: step length, knee extension, and ankle power in children with cerebral palsy (CP). Repeated measures design. Rehabilitation clinic. Children with spastic paresis (N=22; 10.5±3.1y), able to walk without assistive devices. Children walked on a treadmill with a virtual reality environment. Following baseline gait analysis, they were challenged to improve aspects of gait. Children visualized themselves as an avatar, representing movement in real time. They underwent a series of 2-minute trials receiving avatar-based biofeedback on step length, knee extension, and ankle power. To investigate optimization of biofeedback visualization, additional trials in which knee extension was visualized as a simple bar with no avatar; and avatar alone with no specific biofeedback were carried out. Gait pattern, as measured by joint angles, powers, and spatiotemporal parameters, were compared between baseline and biofeedback trials. Participants were able to adapt gait pattern with biofeedback, in an immediate response, reaching large increases in ankle power generation at push-off (37.7%) and clinically important improvements in knee extension (7.4^o) and step length (12.7%). Biofeedback on one parameter had indirect influence on other aspects of gait. Children with CP show capacity in motor function to achieve improvements in clinically important aspects of gait. Visualizing biofeedback with an avatar was subjectively preferential compared to a simplified bar presentation of knee angle. Future studies are required to investigate if observed transient effects of biofeedback can be retained with prolonged training to test whether biofeedback-based gait training may be implemented as a therapy tool.