Design and Evaluation of Virtual Reality-Based Therapy Games with Dual Focus on Therapeutic Relevance and User Experience for Children with Cerebral Palsy

Objective: Virtual reality (VR)-based therapy for motor rehabilitation of children with cerebral palsy (CP) is growing in prevalence. Although mainstream active videogames typically offer children an appealing user experience, they are not designed for therapeutic relevance. Conversely, rehabilitation-specific games often struggle to provide an immersive experience that sustains interest. This study aims to design and evaluate two VR-based therapy games for upper and lower limb rehabilitation and to evaluate their efficacy with dual focus on therapeutic relevance and user experience. Materials and Methods: Three occupational therapists, three physiotherapists, and eight children (8-12 years old), with CP Level I-III on the Gross Motor Function Classification System, evaluated two games for the Microsoft (R) (Redmond, WA) Kinect (TM) for Windows and completed the System Usability Scale (SUS), Physical Activity Enjoyment Scale (PACES), and custom feedback questionnaires. Results: Children and therapists unanimously agreed on the enjoyment and therapeutic value of the games. Median scores on the PACES were high (6.24-0.95 on the 7-point scale). Therapists considered the system to be of average usability (50th percentile on the SUS). The most prevalent usability issue was detection errors distinguishing the child's movements from the supporting therapist's. The ability to adjust difficulty settings and to focus on targeted goals (e.g., elbow/shoulder extension, weight shifting) was highly valued by therapists. Conclusions: Engaging both therapists and children in a user-centered design approach enabled the development of two VR-based therapy games for upper and lower limb rehabilitation that are dually (a) engaging to the child and (b) therapeutically relevant.