BACKGROUND: Recovery of upper limb function after stroke secondary to ischemia or hemorrhage is crucial for patients' independence in daily living and quality of life. Virtual reality (VR) is a promising computer-based technology designed to enhance the effects of rehabilitation
however, the results of VR-based interventions remain equivocal. OBJECTIVE: This study aims to review the plausible factors that may have influenced VR's therapeutic effects on improving upper limb function in patients with stroke, with the goal of synthesizing an optimal VR intervention protocol. METHODS: The databases PubMed, EMBASE, Web of Science, and Cochrane Library were queried for English-language papers published from May 2022 onward. Two reviewers independently extracted data from the included papers, and discrepancies in their findings were resolved through consensus during joint meetings. The risk of bias was assessed using the Physiotherapy Evidence Database Scale and the Methodological Index for Non-Randomized Studies. Outcome variables included the Action Research Arm Test, Box-Block Test, Functional Independence Measure, Upper Extremity Fugl-Meyer Assessment, and Wolf Motor Function Test. The plausible factors examined were age, total dosage (hours), trial length (weeks), session duration (hours/session), frequency (sessions/week), and VR content design. The Bonferroni adjustment was applied to P values to prevent data from being incorrectly deemed statistically significant. RESULTS: The final sample included 15 articles with a total of 1243 participants (age range 48.6-75.59 years). Participants in the VR therapy (VRT) group (n=455) demonstrated significantly greater improvements in upper limb function and independence in activities of daily living compared with those in the conventional therapy group (n=301). Significant factors contributing to improved outcomes in upper limb function were younger age (mean difference [MD] 5.34, 95% CI 2.18-8.5, P<
.001
I2=0%), interventions lasting more than 15 hours (MD 9.67, 95% CI 4.19-15.15, P<
.001
I2=0%), trial lengths exceeding 4 weeks (MD 4.02, 95% CI 1.39-6.65, P=.003
I2=15%), and more than 4 sessions per week (MD 3.48, 95% CI 0.87-6.09, P=.009
I2=0%). However, the design of the VR content, including factors such as the number of features (eg, offering exercise and functional tasks
individualized goals
activity quantification
consideration of comorbidities and baseline activity level
addressing patient needs
aligning with patient background such as education level
patient-directed goals and interests
goal setting
progressive difficulty levels
and promoting self-efficacy), did not demonstrate significant effects (MD 3.89, 95% CI -6.40 to 1.09
effect Z=1.36, P=.16). CONCLUSIONS: Greater VR effects on improving upper limb function in patients with stroke were associated with higher training doses (exceeding 15 hours) delivered over 4-6 weeks, with shorter sessions (approximately 1 hour) scheduled 4 or more times per week. Additionally, younger patients appeared to benefit more from the VR protocol compared with older patients.