Objective: To compare the effects of unilateral and bilateral training on upper limb function after stroke with regard to two key factors: severity of upper limb paresis and time of intervention post-stroke.
Design: Systematic review and meta-analysis of randomized controlled trials.
Methods: Two authors independently selected trials for inclusion, assessed the methodological quality and extracted data. Study outcomes were pooled by calculating the (standardized) mean difference ((S)MD). Sensitivity analyses for severity and time of intervention post-stroke were applied when possible.
Results: All 9 studies involving 452 patients showed homogeneity. In chronic patients with a mild upper limb paresis after stroke a marginally significant SMD for upper limb activity performance (SMD 0.34; 95% confidence interval): 0.04-0.63), and marginally significant MDs for perceived upper limb activity performance (amount of use: MD 0.42; 95% confidence interval: 0.09-0.76, and quality of movement: MD 0.45; 95% confidence interval: 0.12-0.78) were found in favour of unilateral training. All other MDs and SMDs were non-significant.
Conclusion: Unilateral and bilateral training are similarly effective. However, intervention success may depend on severity of upper limb paresis and time of intervention post-stroke.