Head-Mounted Displays for Upper Limb Stroke Rehabilitation: A Scoping Review

Virtual Reality Therapy for Upper Limb Motor Impairments in Patients With Stroke: A Systematic Review and Meta-Analysis

BACKGROUND AND PURPOSE

Stroke is a major cause of disability in adults. Motor recovery through conventional therapy (CT) is a fundamental approach but can sometimes face challenges related to motivation. Virtual reality (VR) rehabilitation, specifically non-immersive VR, is an alternative therapy aimed at improving upper limb motor function and, consequently, functional independence in daily living activities. However, its effectiveness is still being evaluated. Therefore, a meta-analysis was conducted to evaluate the effectiveness of non-immersive VR in upper limb motor function, manual dexterity and the improvement of daily living activities in stroke patients.

METHODS

The control groups included physical therapy or occupational therapy. We searched IEEE Digital Library, PubMed, SciELO, Scopus, PEDro, Web of Sciences and ScienceDirect until December 2023 and identified randomized controlled trials (RCTs). Quality and risk were assessed using the revised Cochrane Collaboration tool, PEDro scale, OCEBM, and GRADE. Publication bias and sensitivity analyses were also evaluated. The standardized mean difference (SMD) effect size was calculated to assess the effectiveness of VR therapy compared with conventional therapy. Subgroup analyses were subsequently performed to mitigate the observed heterogeneity and provide further clarity to the results.

RESULTS

In line with previous research, using VR shows improvements in motor function and manual dexterity for stroke patients. Subgroup analyses reveal that the benefits of VR interventions are most pronounced during the acute and subacute recovery stages, particularly in motor function and manual dexterity. Furthermore, combining VR with traditional therapy seems to yield better outcomes in motor function and manual dexterity compared with VR alone. Notably, the type of VR control-whether sensory or manual-or whether the game is commercially available or rehabilitation-specific, does not seem to influence the outcomes. VR interventions lasting less than 4 weeks are effective in improving both motor function and manual dexterity, whereas interventions of 4 weeks or longer only show significant benefits in motor function.

DISCUSSION

These findings highlight the versatility and potential of VR as a complementary tool in neurorehabilitation.

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.

The Use of Head-Mounted Display Systems for Upper Limb Kinematic Analysis in Post-Stroke Patients: A Perspective Review on Benefits, Challenges and Other Solutions

In recent years, there has been a notable increase in the clinical adoption of instrumental upper limb kinematic assessment. This trend aligns with the rising prevalence of cerebrovascular impairments, one of the most prevalent neurological disorders. Indeed, there is a growing need for more objective outcomes to facilitate tailored rehabilitation interventions following stroke. Emerging technologies, like head-mounted virtual reality (HMD-VR) platforms, have responded to this demand by integrating diverse tracking methodologies. Specifically, HMD-VR technology enables the comprehensive tracking of body posture, encompassing hand position and gesture, facilitated either through specific tracker placements or via integrated cameras coupled with sophisticated computer graphics algorithms embedded within the helmet. This review aims to present the state-of-the-art applications of HMD-VR platforms for kinematic analysis of the upper limb in post-stroke patients, comparing them with conventional tracking systems. Additionally, we address the potential benefits and challenges associated with these platforms. These systems might represent a promising avenue for safe, cost-effective, and portable objective motor assessment within the field of neurorehabilitation, although other systems, including robots, should be taken into consideration.