Virtual Reality Exercise Improves Mobility After Stroke
An Inpatient Randomized Controlled Trial
Background and Purpose—Exercise using virtual reality (VR) has improved balance in adults with traumatic brain injury and community-dwelling older adults. Rigorous randomized studies regarding its efficacy, safety, and applicability with individuals after stroke are lacking. The purpose of this study was to determine whether an adjunct VR therapy improves balance, mobility, and gait in stroke rehabilitation inpatients.
Methods—A blinded randomized controlled trial studying 59 stroke survivors on an inpatient stroke rehabilitation unit was performed. The treatment group (n=30) received standard stroke rehabilitation therapy plus a program of VR exercises that challenged balance (eg, soccer goaltending, snowboarding) performed while standing. The control group (n=29) received standard stroke rehabilitation therapy plus exposure to identical VR environments but whose games did not challenge balance (performed in sitting). VR training consisted of 10 to 12 thirty-minute daily sessions for a 3-week period. Objective outcome measures of balance and mobility were assessed before, immediately after, and 1 month after training.
Results—Confidence intervals and effect sizes favored the treatment group on the Timed Up and Go and the Two-Minute Walk Test, with both groups meeting minimal clinical important differences after training. More individuals in the treatment group than in the control group showed reduced impairment in the lower extremity as measured by the Chedoke McMaster Leg domain (P=0.04) immediately after training.
Conclusions—This VR exercise intervention for inpatient stroke rehabilitation improved mobility-related outcomes. Future studies could include nonambulatory participants as well as the implementation strategies for the clinical use of VR.
Clinical Trial Registration—URL: http://www.ANZCTR.org.au/. Unique identifier: ACTRN12613000710729.
After a stroke, patients are often left with disabling motor impairments that disrupt balance and mobility, leading to reduced function and quality of life.1 Virtual reality (VR) exercise programs use computer-simulated interactive environments to promote movement and have been shown to improve clinical measures of functional mobility in adolescents with cerebral palsy,2 traumatic brain injury survivors,3 and community-living older adults.4 Rigorous studies, including inpatient populations, are lacking to confirm the benefits of VR for poststroke rehabilitation.5
The main objective of this randomized controlled trial was to examine the effect of VR exercise, as a supplement to a conventional inpatient stroke rehabilitation program, on outcome measures of balance, mobility, and motor impairment. We hypothesized that an intensive inpatient VR-based exercise program designed to challenge dynamic stability in standing would result in greater improvements in objective measures of dynamic stability than a similar period of exposure to VR performed while sitting and thus not a challenge to dynamic stability.
A secondary objective included determining whether improvements persisted 1 month after discharge from the inpatient rehabilitation setting. We hypothesized that both groups would maintain gains in dynamic stability, with the treatment group retaining a higher level of improvement compared with the control group.
The study was a blinded, parallel-group randomized controlled trial with balanced (1:1) randomization considering 2 factors (age and preintervention Berg Balance Scale score) and was conducted on the inpatient stroke rehabilitation unit at the Élisabeth Bruyère Hospital between May 2011 and March 2013. Participants signed informed consent forms approved by the Research Ethics Board of Bruyère Continuing Care.
Patients were included in the present study if they: (1) were ≥18 years of age; (2) could stand unaided for 1 minute at the time of enrollment; and (3) could provide informed consent. Patients were excluded if they presented with: (1) severe cognitive impairments (unable to follow instructions); (2) an unstable medical condition; (3) vestibular deficits or vertigo; or (4) seizure activity in the previous 6 months.
Of the 330 patients admitted to the stroke rehabilitation unit, 74 were enrolled, and outcome measures were assessed on 59 (30 treatment and 29 control) immediately after the final training session (POST) and on 52 (28 treatment and 24 control) 1 month after the cessation of training (1 MO; see flowchart in Figure I in the online-only Data Supplement). The first 30 participants were randomly assigned through coin-toss method to the control or treatment group, with subsequent participants being allocated using age and Berg Balance Scale scores to minimize group differences. Participants in the treatment group interacted with the VR games (eg, soccer goaltending, snowboarding) in a standing position, thereby challenging their balance and weight shifting. In contrast, individuals in the control group were seated and played games that did not require any weight shifting within their base of support. Participants in both groups completed 10 to 12 sessions of 20 minutes of interactive VR exercise using the Interactive Rehabilitation Exercise software (IREX; GestureTek; Toronto, Ontario, Canada; for a detailed description of individual games, see Methods in the online-only Data Supplement)6 in addition to their regular inpatient rehabilitation therapy sessions. Exposure time to VR exercise was similar in both groups (treatment group=176.6 minutes±27.8 SD; control=179.1 minutes±14.6 SD; P=0.584). Both the research assistant performing the assessments/evaluations and the participants were blinded to group allocation.
Clinical assessments of balance and mobility were completed 3 times: before the VR training, at POST, and 1 MO. The primary outcome measure was the Timed Up and Go test (TUG). Secondary outcome measures included the Two-Minute Walk Test (TMWT) and the Chedoke McMaster Stroke Assessment Scale Leg domain.
To test our hypothesis, the differences in improvements between groups are reported with 95% confidence intervals and effect sizes for the TUG and the TMWT. Because scores on the Chedoke McMaster Stroke Assessment Scale Leg domain ranged from 5 to 7, the data were transformed to a count data set in which a participant’s score improved (+1), remained the same (0), or decreased (−1) from before the VR training to POST. The Fisher Exact test for count data was used to determine between-group differences in improvements on the Chedoke McMaster Stroke Assessment Scale Leg domain. Analysis focused on those completing the study and was not intention to treat.
Demographic data for the 2 groups before the VR training are presented in Table 1. The VR training sessions did not lead to any falls, seizures, shortness of breath, or fainting. Confidence intervals and the effect sizes for the TUG and the TMWT are shown in the Figure.
Both groups met minimal clinical important difference values at POST for the TUG7 and the TMWT7 (Table 2). More individuals in the treatment than the control group showed improvements on the Chedoke McMaster Stroke Assessment Scale Leg domain at POST (P=0.04) and 1 MO (P=0.02).
This study is the first randomized controlled trial demonstrating the positive effects on balance and mobility outcomes of a standing VR training program supplementing an inpatient stroke rehabilitation program. As expected from previous work on stroke rehabilitation,7 the participants in both groups improved and reached the minimal clinical important differences for the TUG and the TMWT. However, there was a greater improvement in the treatment group with the addition of the standing VR intervention that the authors think is clinically meaningful. Such difference in improvements between groups was not significant for the TUG and the TMWT. This is likely because the study was underpowered. Post hoc power analysis suggests that 20 additional subjects per group would be needed to achieve statistical significance.
The results occurred in a group of higher functioning stroke patients (high score on the functional independence measure and ambulatory with or without the use of aids) who were also receiving intensive inpatient rehabilitation therapies. Therefore, the results here cannot necessarily be generalized to all stroke subgroup populations.
The improvement between before the VR training and 1 MO was relatively similar between both groups, indicating that the control group continued to make gains on balance and mobility outcome measures, reaching similar performance levels as the treatment group. We did not control or document activity levels (eg, additional physiotherapy or other exercise programs) of participants between POST and 1 MO, and therefore, we are unable to explain the difference in recovery rate after POST.
This study has shown that VR balance and mobility exercise are positive additions to inpatient stroke rehabilitation. Future studies will include nonambulatory inpatient participants, as well as explore administrative/scheduling challenges of an inpatient-based VR program for inpatient rehabilitation.
We sincerely thank the participants, the inpatient stroke rehabilitation staff, and Paddi O’Hara and Gloria Baker.
Sources of Funding
This study was supported by the Dr Tony Hakim Innovative Stroke Research Award, Heart and Stroke Foundation Centre for Stroke Recovery, and a personal donation from Tony and Elizabeth Graham. D. McEwen holds a Queen Elizabeth II Graduate Scholarship in Science and Technology and a University of Ottawa Excellence Scholarship.
The online-only Data Supplement is available with this article at http://stroke.ahajournals.org/lookup/suppl/doi:10.1161/STROKEAHA.114.005362/-/DC1.
- Received March 4, 2014.
- Accepted March 25, 2014.
- © 2014 American Heart Association, Inc.
- Hackett ML,
- Anderson CS
- Hiengkaew V,
- Jitaree K,
- Chaiyawat P