Perceptual distortion in virtual reality and its impact on dynamic postural control

Author(s):  
Hirofumi Ida ◽  
Sambit Mohapatra ◽  
Alexander S. Aruin
2021 ◽  
Vol 11 (4) ◽  
pp. 1510
Author(s):  
Charles Morizio ◽  
Maxime Billot ◽  
Jean-Christophe Daviet ◽  
Stéphane Baudry ◽  
Christophe Barbanchon ◽  
...  

People who survive a stroke are often left with long-term neurologic deficits that induce, among other impairments, balance disorders. While virtual reality (VR) is growing in popularity for postural control rehabilitation in post-stroke patients, studies on the effect of challenging virtual environments, simulating common daily situations on postural control in post-stroke patients, are scarce. This study is a first step to document the postural response of stroke patients to different challenging virtual environments. Five subacute stroke patients and fifteen age-matched healthy adults were included. All participants underwent posturographic tests in control conditions (open and closed eyes) and virtual environment without (one static condition) and with avatars (four dynamic conditions) using a head-mounted device for VR. In dynamic environments, we modulated the density of the virtual crowd (dense and light crowd) and the avoidance space with the avatars (near or far). Center of pressure velocity was collected by trial throughout randomized 30-s periods. Results showed that more challenging conditions (dynamic condition) induced greater postural disturbances in stroke patients than in healthy counterparts. Our study suggests that virtual reality environments should be adjusted in light of obtaining more or less challenging conditions.


Author(s):  
Arūnė Dūdaitė ◽  
Vilma Juodžbalienė

Research background. Virtual reality and visual feedback improve motor performance, motor function and balance, so we want to fnd if it affects the function of legs and balance of children with spastic hemiplegia. Research aim was to establish if the use of virtual reality and visual feedback with traditional physiotherapy improve the function of legs and balance of children with cerebral palsy. Methods. Nine children with cerebral palsy participated in the research. Participants were randomly divided into two groups – virtual reality group (n = 6) and control (n = 3). Virtual reality group practised exergaming and stretching exercises for 10 weeks, twice a week. Control group practiced conventional physiotherapy and stretching exercises for 6 weeks, twice a week. We measured the range of motion of the lower limb, spasticity of the lower limb using Modifed Ashworth’o Scale, static, dynamic balance, trunk coordination using Trunk Impairment Scale at the start and the end of the research, and balance using Pediatric Balance Scale. Results. Virtual reality and visual feedback reduced the spasticity of the lower limb, improved balance and postural control for children with cerebral palsy, but it did not improve the range of motion of the lower limb of children with cerebral palsy. Conclusions. Virtual reality and visual feedback did not improve the range of motion of the lower limb of children with cerebral palsy. Virtual reality and visual feedback reduced spasticity of the lower limb, improved balance and postural control for children with cerebral palsy.Keywords. Cerebral palsy, virtual reality, visual feedback, postural control, muscle architecture.


2020 ◽  
Vol 33 ◽  
Author(s):  
João Paulo Paes ◽  
Alaércio Perotti Junior ◽  
Ana Maria Forti Barela ◽  
José Angelo Barela

Abstract Introduction: Considered the second leading cause of death worldwide, stroke leads to several consequences resulting from the injury in regions responsible for the processing of sensorimotor information, leading to deficits in the maintenance and performance of postural control. Objective: To relate the performance of postural control during upright stance and a virtual reality task in post-stroke individuals. Method: Nine post-stroke individuals, aged 30 to 76 years, characterized by the Berg balance scale, Fugl - Meyer scale and Mini Mental State Examination participated in this study. Postural performance was measured by the center of pressure under bipedal conditions, in anteroposterior and mediolateral directions and unipedal with the affected and unaffected sides, using a force platform. Virtual reality performance was measured by distance and time required to perform a task in the Nintendo Wii®. Results: Revealed significant correlations between distance and displacement time of the affected side (distance x disc_affected = 0.667 | p = 0.025; time x disc_affected = 0.683 | p = 0.021) and between variables time and mean amplitude of mediolateral oscillation (time x amo_ml = -0.733 | p = 0.012), time and mediolateral and anteroposterior mean velocity (time x vm_ml = -0.617 | p = 0.038; time x vm_ap = -0.833 | p = 0.003) and between time and area (time x area = -0.633 | p = 0.034). Conclusion: the performance of standing postural control in post-stroke individuals, represented by measures of weight discharge and variables of postural control, presented a significant relation with the variables of virtual reality.


2019 ◽  
Vol 8 (4) ◽  
pp. 294-300
Author(s):  
Camila Souza Miranda ◽  
Tatiana de Paula Oliveira ◽  
Joyce Xavier Muzzi Gouvêa ◽  
Danielle Borrego Perez ◽  
Amélia Pasqual Marques ◽  
...  

Author(s):  
Suelen Cesaroni ◽  
Adriana Marques da Silva ◽  
Maurício Malavasi Ganança ◽  
Heloisa Helena Caovilla

2019 ◽  
Vol 9 (11) ◽  
pp. 113 ◽  
Author(s):  
Harish Chander ◽  
Sachini N. K. Kodithuwakku Arachchige ◽  
Christopher M. Hill ◽  
Alana J. Turner ◽  
Shuchisnigdha Deb ◽  
...  

Background: Virtual reality (VR) is becoming a widespread tool in rehabilitation, especially for postural stability. However, the impact of using VR in a “moving wall paradigm” (visual perturbation), specifically without and with anticipation of the perturbation, is unknown. Methods: Nineteen healthy subjects performed three trials of static balance testing on a force plate under three different conditions: baseline (no perturbation), unexpected VR perturbation, and expected VR perturbation. The statistical analysis consisted of a 1 × 3 repeated-measures ANOVA to test for differences in the center of pressure (COP) displacement, 95% ellipsoid area, and COP sway velocity. Results: The expected perturbation rendered significantly lower (p < 0.05) COP displacements and 95% ellipsoid area compared to the unexpected condition. A significantly higher (p < 0.05) sway velocity was also observed in the expected condition compared to the unexpected condition. Conclusions: Postural stability was lowered during unexpected visual perturbations compared to both during baseline and during expected visual perturbations, suggesting that conflicting visual feedback induced postural instability due to compensatory postural responses. However, during expected visual perturbations, significantly lowered postural sway displacement and area were achieved by increasing the sway velocity, suggesting the occurrence of postural behavior due to anticipatory postural responses. Finally, the study also concluded that VR could be used to induce different postural responses by providing visual perturbations to the postural control system, which can subsequently be used as an effective and low-cost tool for postural stability training and rehabilitation.


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