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

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).

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.

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.

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.