JMIR Publications

ABSTRACT

Background:

People with multiple sclerosis (PwMS) were highly exposed to falling risk, with approximately half experiencing at least one fall within six months. Multidirectional step training has shown potential in fall prevention in older adults, and stepping-based interventions have been explored in PwMS, although with inconsistent effects on fall reduction. Mixed reality (MR), within the broader field of extended reality (XR), offers immersive, adaptive, and home-based rehabilitation opportunities. However, the successful implementation of MR-based serious games requires structured co-design processes integrating patient, clinician, and technical perspectives.

Objective:

This study describes the co-design and prototyping of a home-based MR serious game called Head Your Limits for volitional step training in PwMS.

Methods:

A three-phase user-centred co-design process, inspired by ISO 9241-210 principles, was implemented. Phase 1 involved two online focus groups with PwMS (n=14) to identify experiential needs and design preferences. Phase 2 included an interdisciplinary focus group with clinicians (n=4) and one engineer to define clinical and technical requirements. Phase 3 consisted of in-person hands-on testing of two MR prototypes (“Clock” and “Grapes”) with PwMS (n=9). Iterative refinement followed each phase, translating stakeholder-derived requirements into architectural modifications of the MR application.

Results:

Five primary patient-derived requirements emerged: real-time multisensory feedback, gamification and motivation, personalized progress tracking, visual accessibility, and ergonomic comfort. Clinicians emphasized adaptive difficulty, cognitive-motor integration, biomechanical validity, and caregiver-compatible safety. Prototype comparison revealed that floor-level targets induced cervical discomfort and postural compensation, whereas auditory guidance reduced head flexion. The final application repositioned targets at eye level and implemented head-mounted display tracking to ensure appropriate center-of-mass displacement, preserve proprioceptive engagement, enable caregiver proximity, and integrate gamified feedback and performance reporting.

Conclusions:

Iterative stakeholder engagement enabled resolution of common tensions in rehabilitation technology design, including sensory reliance, ergonomic burden, biomechanical validity, and motivational engagement. The transition to eye-level, head-mediated interaction emerged as a pivotal architectural solution integrating therapeutic, ergonomic, and experiential objectives. The structured co-design framework aligns with contemporary human-centred digital health development models. Through a rigorous user-centred co-design process, we developed an MR serious game for volitional step training in PwMS that integrates biomechanical validity, safety, and engagement. Although clinical effectiveness remains to be tested, this study provides a transparent methodological framework for the development of XR-based neurorehabilitation technologies.