Avatar projection and movement analysis system using an inside-out tracking virtual reality device: enabling the virtual reality multi-target stepping task outside the laboratory

Introduction Immersive virtual reality (VR) can simulate diverse walking environments and manipulate visual information while walking. We recently developed a VR Multi-Target Stepping (VR-MTS) task to assess anticipatory control of foot placement. However, conventional VR walking systems frequently rely on motion capture systems, which are costly and spatially restrictive. In this study we compared the measurement accuracy of the developed new VR-MTS system against that of a marker-based motion-capture system. Methods Ten young adults (mean age 25.6 ± 4.2 years) participated in this study. Motion data were simultaneously recorded from a marker-based motion capture system and the VR device as participants performed three gait tasks. The mean absolute error (MAE) and Pearson’s correlation coefficient ( R xy ) were calculated for the head position, right foot position, and left foot position. Results and discussion Across many indices, MAE was small (<30 mm) and correlations were very strong ( R xy > 0.9), indicating that the developed VR system achieves measurement accuracy comparable to that of a marker-based motion capture system. This approach could broaden access to motion analysis and foot avatar projection by eliminating the need for expensive and spatially demanding motion capture systems.