Validation of a Virtual Reality-Based Timed Up-and-Go Test Using Body-Worn Motion Trackers

Background: Full-body motion capture using commercial virtual reality (VR) systems offers unique opportunities for augmenting common functional assessment such as the timed up-and-go (TUG) test. The purpose of this study was to determine whether task performance (chair, walk, turns) during a VR version (vTUG) is parametrically equivalent to the standard test (sTUG). Methods: Twenty healthy adult participants (age 19–71 years) were evaluated with the sTUG followed by the vTUG version of the same test. Body trackers were used to capture kinematics during both tests. TUG time was measured manually with a stopwatch. Tracker data were used to automatically quantify total TUG time and sub-task times for chair, walk and turn portions. Absolute agreement was evaluated using Intraclass Correlation Coefficient (ICC(2,k)) and Bland–Altman analysis. A custom survey was used to evaluate user satisfaction. Results: Very good agreement (ICC > 0.8) was found between sTUG and vTUG for manual and automated measures of total time. ICCs for sub-task times were acceptable (ICC > 0.7) for chair rise, walks and first turn but less so for second turn and sit (ICC < 0.7). User satisfaction was high, and there were no adverse events. Interpretation: The vTUG and sTUG are parametrically equivalent, though sub-task segmentation may require more research. Nevertheless, VR body trackers are a value-added feature whether used with the vTUG or the sTUG and warrant further investigation.