Immediate effects of immersive biofeedback on gait in children with cerebral palsy.

OBJECTIVE: To investigate the immediate response to avatar-based biofeedback on three clinically important gait parameters; step length, knee extension and ankle power, in children with cerebral palsy (CP).

DESIGN: Repeated measures design.

SETTING: Rehabilitation clinic.

PARTICIPANTS: Twenty-two children with spastic paresis (10y4m±3y1m), able to walk without assistive devices.

INTERVENTION: Children walked on a treadmill with 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 two-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 a further trial with avatar alone, and no specific biofeedback were carried out.

MAIN OUTCOME MEASURES: Gait pattern, as measured by joint angles, powers and spatiotemporal parameters, were compared between baseline and biofeedback trials.

RESULTS: 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 (7.4o ) and step length (12.7%). Biofeedback on one parameter had indirect influence on other aspects of gait.

CONCLUSION: 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.