A quantitative assessment of the hand kinematic features estimated by the oculus Quest 2

In the past decade, immersive virtual reality (VR) has garnered significant interest due to its capacity to ability a strong sense of presence and allow users to act in virtual environments. In particular, VR has been increasingly used in clinical settings to present scenarios for motor rehabilitation purposes. Existing research efforts mostly focus on investigating the clinical effectiveness of different routines. However, modern VR systems, in addition to presenting scenarios, also have hand motion tracking capabilities that could be potentially used to gather clinically relevant kinematic data from the patients while they execute the VR tasks. Here, we quantitatively assess the capability of tracking hand movements of a popular VR system, the Oculus Quest 2 by Meta, by comparing its kinematic measures with those provided by a commercial marker-based motion capture system. Our findings suggest that the Quest 2 provides reasonably reliable estimates of hand position and velocity. Estimates of acceleration are noisier and might be sometime unsuitable for kinematic assessments. Notably, the accuracy of the kinematic estimates varies across spatial directions. Estimates along the left/right direction are the most accurate, followed by estimates along the up/down axis. Estimates along the near/far axis appear to be the noisiest. Furthermore, we also found that Quest 2 can provide fine-grained measures of grip aperture, but the precision of these measures might be affected by the subject's head movements while wearing the system. Our results suggest that modern VR devices, in addition to presenting immersive scenarios, could be potentially used in rehabilitation settings also to provide clinically relevant kinematic measures that can potentially inform medical decisions.