Effect of immersive virtual reality on overground gait stability in children with cerebral palsy: A prospective case-control study

Purpose: To evaluate the effect of walking in a virtual world, particularly on a virtual plank at varying heights, on gait stability in children with cerebral palsy (CP) and typical development (TD). Method: Twenty-two participants with CP (13 males; 11 years 2 months) and twenty-four with TD (10 males; 11 years 11 months) were included. After undergoing clinical gait analysis, participants were immersed in VR via a head-mounted display and walked on a virtual plank at varying heights. Linear mixed-effect models were fitted for: margin of stability (MoS), whole-body angular momentum (WBAM), single limb support % (SLS), variability of step length (SLV), stride width (SWV), and kinematics (GaitSD). Fixed effects were group (CP vs. TD), condition (walking in the real world vs. virtual world) and virtual height. Results: GaitSD and SWV were positively correlated with VR, and lateral MoS was negatively correlated. Lateral MoS and coronal WBAM were positively correlated with CP and VR, while anterior MoS and sagittal WBAM were negatively correlated. Lateral MoS was positively correlated with height in CP, while anterior MoS, sagittal WBAM, SLS, SLV and SWV were negatively correlated. Conclusions: Virtual heights induced gait instability, which was more pronounced in CP than TD. WBAM, SLV, and SLS were the most appropriate biomarkers for defining gait instability.