Walking in immersive virtual reality (VR) environments is often disrupted by gait (i.e., walking patterns) instability, a challenge that is further exacerbated for individuals with mobility impairments. This study examines the effectiveness of multimodal feedback by integrating auditory, vibrotactile, and visual cues in improving walking performance within VR. A total of 68 participants, equally divided between those with mobility impairments and those without, completed walking tasks under multiple feedback conditions. Walking velocity was the primary performance metric, supplemented by subjective assessments of mental workload, fatigue, presence, usability, and simulator sickness. Results revealed that multimodal feedback significantly enhanced walking velocity compared to unimodal and bimodal conditions, with statistical analysis confirming strong improvements (p < .001). Participants also reported a favorable user experience under multimodal conditions despite slightly increased cognitive demand. These findings highlight the potential of integrated sensory feedback to mitigate gait disturbances in VR, promoting safer and more accessible locomotion for users with and without mobility impairments.

Extended reality (XR) systems offer transformative potential for healthcare in domains ranging from surgical planning to remote rehabilitation and mental‐health therapy. The rich streams of sensor, biometric, and environmental data that enable these applications, however, also create novel and poorly understood privacy and security vulnerabilities: adversaries can exploit unencrypted signaling, sensor side‐channels, and application‐layer flaws to infer sensitive patient information or disrupt clinical workflows. Nevertheless, there aren’t many thorough Systematization of Knowledge (SoK) that examine XR for healthcare at the moment. In this SoK, we survey 65 peer‐reviewed works published between 2017 and 2024 across leading XR, security, and privacy venues, synthesizing a unified threat taxonomy that spans device, network, user and cloud layers. We introduce a quantitative evaluation framework XR-PRISM (Privacy and Risk Impact Scoring Metric), drawing on adapted risk scores, detection performance, and usability assessments to rigorously assess the level of security and privacy risks. Our analysis reveals critical gaps: over 70% of countermeasures lack standardized risk evaluations, fewer than 15% include high prerequisites to launch an attack, and reproducibility is hampered by scarce artifact releases. Finally, we chart a research roadmap advocating for open benchmark suites with shared datasets, artifact disclosure policies, cloud‐layer protections, and robust detection and recovery mechanisms. By quantifying “what works—and by how much,” this SoK provides a data‐driven foundation for developing secure, privacy‐preserving, and usable XR healthcare technologies.

This research aims to examine the effects of various vibrotactile feedback techniques on gait (i.e., walking patterns) in virtual reality (VR). Prior studies have demonstrated that gait disturbances in VR users are significant usability barriers. However, adequate research has not been performed to address this problem. In our study, 39 participants (with mobility impairments: 18, without mobility impairments: 21) performed timed walking tasks in a real-world environment and identical activities in a VR environment with different forms of vibrotactile feedback (spatial, static, and rhythmic). Within-group results revealed that each form of vibrotactile feedback improved gait performance in VR significantly compared to the no vibrotactile condition in VR for individuals with and without mobility impairments. Moreover, spatial vibrotactile feedback increased gait performance significantly in both participant groups compared to other vibrotactile conditions.

Enhancing user experience and performance, including task load in immersive environments, requires accurate prediction of user gaze point, reaction time, and mental and physical load uptake. Current gaze prediction approaches focus primarily on motion-based information, lacking physiological data, which leads to poor prediction accuracy in highly dynamic virtual reality (VR) environments. Traditional cognitive load measurements rely on post-task analysis without proper multimodal data integration and fail to capture the real-time dynamics of user states during interaction. Likewise, reaction time or attention load are often assessed only after the interaction, without using real-time immersive sensor data, which limits adaptive responsiveness. To tackle these limitations, we leveraged a comprehensive multimodal dataset - VRWalking, which recorded timestamped eye-tracking metrics, physiological signals (heart rate and galvanic skin response), and behavioral performance data during real-time engagement in a VR environment. We developed a unified multitask model based on the MultiPatchFormer architecture, which processes multimodal VR signals through dual patch projection branches for gaze and classification inputs. The model employs multiscale patch embeddings, cross-attention between gaze and classification pathways, channel attention, and transformer encoders to jointly predict continuous user gaze and classify reaction time, cognitive load (mental load and physical load). Our methodology achieved excellent predictive performance: 95.64% for reaction time, 98.01% for mental load, and 97.45% for physical load, with a MAPE (Mean Absolute Percentage Error) of 15.24% for gaze prediction. We applied Shapley Additive explanations (SHAP) analysis to interpret the model’s behavior across all features, including eye-tracking, head-tracking, and physiological signals. The analysis revealed which features most influenced the predictions of user gaze, reaction time, mental load, and physical load. Our methods, while based only on the VRWalking dataset, demonstrated strong performance across all tasks, suggesting promising potential for real-world VR applications such as interactive training systems that respond to user attention lapses, educational platforms that adapt to cognitive load, and performance assessments that consider physiological indicators.

Maintaining balance in immersive virtual reality (VR) environments poses a significant challenge for users, particularly affecting those with pre-existing balance disorders. This study investigates the efficacy of multimodal feedback-comprising auditory, vibrotactile, and visual stimuli-in mitigating balance issues within VR. A sample of 68 participants, divided equally between individuals with balance deficits related to multiple sclerosis and those without, was evaluated. The research explored the impact of various feedback conditions on balance performance. The results demonstrated that the multimodal feedback condition significantly enhanced balance control compared to other conditions, with statistical analysis confirming this improvement (p<.001). These findings underscore the potential of integrated sensory feedback in addressing balance-related difficulties in VR, thereby improving the overall accessibility and user experience for individuals affected by balance impairments. This research contributes valuable insights into optimizing VR environments for enhanced stability and user comfort.

The use of Head-Mounted Displays (HMDs) in Virtual Reality (VR) can cause gait disturbance problems for users because they are unable to see the real world while in VR. This is particularly challenging for individuals with mobility impairments who rely heavily on visual cues to maintain balance. The limited research that has been conducted on this issue has not focused on ways to solve it. IN this study, we investigated how different visual feedback methods affect walking patterns (i.e., gait) in VR. The study involved 50 participants, including 25 individuals with mobility impairments due to multiple sclerosis and 25 without mobility impairments. The participants completed timed walking tasks in both the real world and in VR environments that included various types of visual feedback, such as spatial, static, and rhythmic. The results showed that static and rhythmic visual feedback significantly improved gait performance in VR for people with mobility impairments compared to no visual feedback in VR. The results will help to make more accessible virtual environments for people with mobility impairments.

Immersive Virtual Reality (VR) users often experience difficulties with maintaining their balance. This issue poses a significant challenge to the widespread usability and accessibility of VR, particularly for individuals with balance impairments. Previous studies have confirmed the existence of balance problems in VR, but little attention has been given to addressing them. To investigate the impact of different feedback modalities (auditory, vibrotactile, and visual) on balance in immersive VR, we conducted a study with 50 participants, consisting of 25 individuals with balance impairments due to type 2 diabetes and 25 without balance impairments. Participants were asked to perform standing reach and grasp tasks. Our findings indicated that auditory and vibrotactile techniques improved balance significantly (p<.001) in immersive VR for participants with and without balance impairments, while visual techniques only improved balance significantly for participants with balance impairments. Also, auditory and vibrotactile feedback techniques improved balance significantly more than visual techniques. Spatial auditory feedback outperformed other conditions significantly for all people. This study presents implementations and comparisons of potential strategies that can be implemented in future VR environments to enhance standing balance and promote the broader adoption of VR.

Users of head-mounted displays (HMDs) for virtual reality (VR) sometimes have balance issues since HMDs impede their view of the outside world. This has a greater impact on people with balance impairments since many rely more heavily on their visual cues to keep their balance. This is a significant obstacle to the universal usability and accessibility of VR. Although previous studies have verified the imbalance issue, not much work has been done to diminish it. In this study, we investigated how to increase VR balance by utilizing additional visual cues. To examine how different visual approaches (static, rhythmic, spatial, and center of pressure (CoP) based feedback) affect balance in VR, we recruited 100 people (50 with balance impairments due to multiple sclerosis and 50 without balance impairments) across two different geographic locations (United States and Bangladesh). All people completed both standing visual exploration as well as standing reach and grasp tasks. Results demonstrated that static, rhythmic, and CoP visual feedback approaches enhanced balance significantly ( ) in VR for people with balance impairments. The methods described in this study could be applied to design more accessible virtual environments for people with balance impairments.

The objective of this study is to investigate the impact of several auditory feedback modalities on gait (i.e., walking patterns) in virtual reality (VR). Prior research has substantiated gait disturbances in VR users as one of the primary obstacles to VR usability. However, minimal research has been done to mitigate this issue. We recruited 39 participants (with mobility impairments: 18, without mobility impairments: 21) who completed timed walking tasks in a real-world environment and the same tasks in a VR environment with various types of auditory feedback. Within-subject results showed that each auditory condition significantly improved gait performance while in VR $(p \lt$.001) compared to the no auditory condition in VR for both groups of participants with and without mobility impairments. Moreover, spatial audio improved gait performance significantly $(p \lt$.001) compared to other auditory conditions for both groups of participants. This research could help to make walking in VR more accessible for people with and without mobility impairments.

Virtual Reality (VR) users often experience postural instability, i.e., balance problems, which could be a major barrier to universal usability and accessibility for all, especially for persons with balance impairments. Prior research has confirmed the imbalance effect, but minimal research has been conducted to reduce this effect. We recruited 42 participants (with balance impairments: 21, without balance impairments: 21) to investigate the impact of several auditory techniques on balance in VR, specifically spatial audio, static rest frame audio, rhythmic audio, and audio mapped to the center of pressure (CoP). Participants performed two types of tasks - standing visual exploration and standing reach and grasp. Within-subject results showed that each auditory technique improved balance in VR for both persons with and without balance impairments. Spatial and CoP audio improved balance significantly more than other auditory conditions. The techniques presented in this research could be used in future virtual environments to improve standing balance and help push VR closer to universal usability.

Virtual Reality (VR) users often encounter postural instability, i.e., balance issues, which can be a significant impediment to universal usability and accessibility, particularly for those with balance impairments. Prior research has validated imbalance issues, but little effort has been made to mitigate them. We recruited 39 participants (with balance impairments: 18, without balance impairments: 21) to examine the effect of various vibrotactile feedback techniques on balance in virtual reality, specifically spatial vibrotactile, static vibrotactile, rhythmic vibrotactile, and vibrotactile feedback mapped to the center of pressure (CoP). Participants completed standing visual exploration and standing reach and grasp tasks. According to within-subject results, each vibrotactile feedback enhanced balance in VR significantly (p <.001) for those with and without balance impairments. Spatial and CoP vibrotactile feedback enhanced balance significantly more (p <.001) than other vibrotactile feedback. This study presents strategies that might be used in future virtual environments to enhance standing balance and bring VR closer to universal usage.