The effect of virtual reality interventions on physical activity in children and adolescents with early brain injuries including cerebral palsy

Abstract

SIR–Cerebral palsy describes a group of permanent disorders in the development of movement and posture that causes activity limitations, attributed to non-progressive disturbances occurring in the developing brain.1 Despite the known health benefits of regular participation in physical activity, people with cerebral palsy tend to participate less than their typically developing peers and less than recommended guidelines.2 Physical activity is defined as ‘any body movement using skeletal muscles that results in energy expenditure’.3 According to the International Classification of Functioning, Disability and Health (ICF), activity is divided into domains of capacity and performance.4 Physical activity performance can be defined as activity undertaken by a person as part of their regular daily life. It is important to differentiate this from ‘capacity’, which is what a person can achieve in an experimental setting, such as a walking distance or strength test. There is preliminary evidence that interventions can increase physical activity in children with cerebral palsy.5 Internet-delivered ‘active’ video games are emerging as a popular modality for children especially where there are limitations in community access to interventions. Virtual reality creates interactive simulations that allow participants to interact with the system through movement of their body through 3D space.6 These have the potential to deliver novel and intensive therapies to children. Internet-delivered systems have the potential to overcome inequity of access to services to children in isolated areas where services can be limited. Reviews of evidence suggest that active game playing and internet-based interventions can increase physical activity in typically developing children.7-9 There are no published systematic reviews of the efficacy of virtual reality training on physical activity in children with cerebral palsy. This study aimed to systematically review the literature for effectiveness and utility of virtual reality interventions on increasing physical activity capacity and performance in young people with cerebral palsy. Given this a new area of research, the population of interest was expanded to include children and adolescents with traumatic- (TBI) or acquired- (ABI) brain injuries. Databases including Medline (Pubmed), CINAHL, SPORTDIscus, Embase, The Cochrane Library, and Scopus were systematically searched for relevant literature using the following keywords: ‘Cerebral Palsy’ or ‘brain injury’, ‘physical activity’ and ‘virtual reality’. The search was limited to studies published from 2000 to October 2011 as virtual reality interventions were not commonly available prior to 2000. Studies were included if they met the following selection criteria: (1) more than 80% of the total sample included children and adolescents (aged 6–18y) with a diagnosis of cerebral palsy, ABI or TBI; (2) measured physical activity capacity and/or performance; and (3) the intervention was provided through virtual reality medium. Studies were excluded if they were not published in English (owing to a lack of translation services). As there were thought to be few publications investigating this topic, all study types were included. The title and abstract of all retrieved references were screened by two authors (LM, SO) independently. Full texts were then obtained for references which looked to meet inclusion criteria. Targeted reference scanning and citation tracking of key articles was used to minimize the chance of missing key studies. Upon disagreement, all authors discussed the selection. The Downs and Black10 scale was used to assess the methodological quality of randomized and non-randomized studies. A version of Cohen’s11 d was used to calculate effect size (Meanpost-treatment−Meanpre-treatment/SDpre-treatment). These were calculated for outcomes where means, standard deviations (SD), and participant numbers were reported or could be deduced. Where median and interquartile ranges (IQR) were presented, median was taken to represent the mean score and the IQR was divided by 1.35. Effect sizes allow an understanding of the magnitude of impact across the studies. These were classified as small (0.2), medium (0.5), and large (0.8).11 Initial database searching yielded 208 titles and abstracts. One hundred and ninety-five were excluded after initial review and 13 full text papers were obtained. Only four studies met the inclusion criteria. No studies investigating children and adolescents with ABI or TBI were found. Participants in all studies trained at least 20 minutes a session, mostly daily. Interventions ranged from 5 days to 20 weeks. Total dose of therapy was typically between 7.5 and 11 hours, with the exception of Mitii. This program was able to deliver intensive therapy remotely with a total dose of 70 hours (Table I). Only one of the studies looked primarily at physical activity performance following virtual reality intervention.12 Others looked at gross motor or upper limb function, and balance or impairment measures, and included a measure of physical activity as a secondary outcome (Table II). Studies were either single-arm pilot studies with few participants or case series, providing low-level evidence.10 Physical activity capacity, measured using functional strength and mobility, improved following training with both Wii Sports (Nintendo EAD) and the Mitii program (Mitii Development A/S, Copenhagen, Denmark; Table II).13, 14 Physical activity performance measured using SenseWear-Pro3 Armband (BodyMedia Inc., Pittsburgh, PA, USA) activity monitors was found to increase significantly following training with the Playstation 2 EyeToy (Sony Computer Entertainment), though capacity assessed using the 1-minute walk test did not improve (Table II).12 A 5-day intensive burst of IREX (GestureTek Health, Toronto, Canada) therapy was found to increase and maintain walking distance over 6 minutes, though timed up and down stairs test did not change (Table II).15 Large effects were seen for functional strength outcomes following Mitii training, though only side-steps and sit-to-stand were significant (Table II).13 Effect sizes from the studies by Sundland and Brien were small to medium; however, large SDs and confidence intervals meant that these were not statistically significant (Table II).12, 15 Meta-analysis was not possible as all included studies were pre-post designs and there was substantial variation in interventions and outcomes assessed. This review set out to establish if virtual reality interventions were able to increase physical activity capacity and/or performance in children with CP or early brain injury. Systematic searching was only able to identify four studies which investigated the impact of virtual reality on physical activity. These studies provided evidence of a positive effect, though their methodological quality was limited. It should be noted that the Downs and Black scale is designed for the critical appraisal of randomized and non-randomized trials. Given the designs of the included studies, all studies obtained low scores using this checklist. Virtual reality as an intervention for children with cerebral palsy is relatively new and research is rapidly evolving. So far the emphasis has been on establishing the feasibility of virtual reality as a therapeutic modality for rehabilitation. This review has demonstrated there has been less research investigating the ability of virtual reality systems to increase physical activity capacity and performance in this population. This should be an important next step for research. Children today, particularly those with disabilities, spend increased time in sedentary screen-based leisure activities, such as watching television or playing video games. This displaces more active behaviours which contribute to obesity and other adverse health outcomes.7 Given that people with cerebral palsy tend to participate in less physical activity than their typically developing peers this is an important health promotion consideration. Interventions which use screen time to increase physical activity have the potential to overcome these adverse health outcomes yet still appeal to children. High quality research that assesses the efficacy of virtual reality interventions against all dimensions of the ICF,4 including the translation of strength and fitness into increased physical activity performance is required. A child or adolescent may be able to perform well in an experimental setting, but whether they translate this ability in daily life is arguably more important for participation and long-term health and well-being. This could be achieved by objectively monitoring habitual physical activity levels using activity monitors before and after intervention ensuring sufficient participant numbers and a strong study design. While limited conclusions can be drawn about the effect of virtual reality on physical activity in children with early brain injuries including cerebral palsy at this stage, the evidence for typically developing children is promising. Systematic reviews have found that computer- or web-based interventions increased physical activity levels, though long-term effects were limited.8, 9 Active video games have been shown to elicit greater energy expenditure and translate into increased habitual physical activity.7 When used for paediatric rehabilitation in children with cerebral palsy, virtual reality systems which use more ‘active’ games utilizing whole body movements and standing positions have the potential to increase energy expenditure and therefore physical activity levels. As demonstrated from this review, virtual reality interventions have the ability to deliver interventions remotely at a similar or greater intensity to one-on-one therapies. As an example, Mitii provided up to 70 hours of total therapy. This means that these systems may have the added benefit of increasing physical activity capacity and performance in addition to more rehabilitation aligned goals. Future high-quality research into the effectiveness of virtual reality interventions in children and adolescents with cerebral palsy would benefit from the inclusion of measures of physical activity capacity and performance to confirm this. APA Scholarship (LM, SO); QCMRI Science Scholarship (SO); NHMRC Career Development Award (RB); and Foundation for Children Grant (RB, JZ).