Postural balance during standing at varying virtual heights in children with and without cerebral palsy: a prospective case-control study.

This prospective case-control study explores the possibility to use virtual height exposure for postural balance studies. The study aimed to investigate the effect of standing in a virtual environment on a plank at ground level (VR0) compared to 10 m above virtual ground (VR10) on postural balance. Included were 22 children with cerebral palsy (CP) (age range 8-16 years; male/female: 13/9) and 24 children with typical development (TD) (age range 8-18 years; male/female: 10/14). Participants were instructed to stand still for 40s on two force plates while wearing a head-mounted display, which delivered the virtual environment. Postural balance was quantified via (1) the 95% prediction ellipse area, (2) the average centre of pressure (CoP) velocity, and (3) the CoP amplitude in anteroposterior and mediolateral direction. Additionally, self-reported instability and fear of falling was assessed using a 11-point numeric rating scale. Children with CP tended to exhibit increased median ellipse area, median anteroposterior amplitude, and median velocity from VR0 to VR10 and compared to children with TD, although differences were not statistically significant. Furthermore, median values of self-reported instability and fear of falling increased from VR0 to VR10 in both groups. Our findings suggest that virtual heights may induce changes in postural balance. Therefore, virtual height exposure coupled with force plate measurements may be a promising tool to quantify postural balance.