Background
To date, interest in using virtual reality (VR) devices in the orthopedic field is growing. However, few studies employ VR systems in patients with shoulder musculoskeletal disorders during rehabilitation. Some recent studies have shown that VR systems are good candidates for increasing patient engagement and motivation to follow the prescribed rehabilitation. In the orthopedic field, tracking shoulder kinematics is essential to objectively evaluate clinically relevant parameters that could be helpful in choosing the most appropriate rehabilitation pathways and evaluating the progress throughout the therapeutic paths.
AIMS
Among the VR devices on the market, one of the newest was selected, namely Oculus Quest 2. As this device is intended to be used in the future during the rehabilitation of patients with shoulder musculoskeletal disorders, an evaluation of its performance and usability was necessary.
Methods
In this study, an Oculus Quest 2 consisting of two Oculus Touch Controllers and one Head-Mounted Display (HMD) was used. The Unity software was used to implement custom applications to track and register the position and orientation of the controller and HMD and create a virtual environment in which the represented environment requires the execution of movements typically performed during the rehabilitation of patients with shoulder disorders, such as elevations in the sagittal and frontal plane, and internal-external rotation. To investigate the VR system's translational and rotational accuracy, two custom-made structures were designed to move and rotate the controller along and around the x-, y-, and z-axes of the 3D space. Moreover, questionnaires were administered to assess the usability of the VR device.
Results
Results showed that Oculus Quest 2, which employs inside-out tracking, is accurate enough to measure position and orientation, so it represents a good candidate for future applications of immersive VR systems during rehabilitation sessions of patients with shoulder musculoskeletal disorders. The encouraging results about its usability also provided valuable suggestions for optimizing the VR application for future patients use.
Discussion
The future of VR systems in clinical settings is growing rapidly because of the high user engagement and its applicability in an unstructured environment. The virtual environment offered by the VR-based rehabilitation systems could intensify patients’ motivation to manage more actively their rehabilitation pathway. The immersive experience offered by Oculus Quest 2 can provide patients with vibrotactile feedback indicating the correctness or otherwise of the performed exercises. Moreover, the difficulty level of the required exercises could be tuned based on the recovery process of shoulder functionalities.