The impact of bilateral therapy on upper limb function after chronic stroke: a systematic review

Purpose. To determine the evidence for bilateral therapy interventions aimed at improving upper limb (UL) function in adults with a range of UL activity limitations due to a first time chronic stroke. Method. Seven databases were searched prior to 2008 for articles reporting experimental studies investigating bilateral UL interventions on functional outcome in participants with a first stroke, 6 or more months prior. Included articles were evaluated with the quality index, a tool which evaluates the quality of both randomised and non-randomised studies. Data relating to study design and functional outcome were extracted. Results. Nine articles were included; three reported on randomised controlled trials (RCT) and six on cohort studies. Eight studies incorporated a mechanical device as their bilateral intervention. Bilateral arm training with rhythmic auditory cueing (BATRAC) was the most commonly used mechanically based intervention, and three of the four uncontrolled BATRAC studies reported significant improvements in UL function post-intervention, however these results were not substantiated by a RCT study of the BATRAC intervention. One study demonstrated significant functional improvements after 6 days of training with a non-mechanical bilateral task. Of the four studies that performed a follow-up assessment, three reported significant improvement in UL function. Quality index ratings of the included studies ranged from 18 to 25 out of 27. Conclusion. There is some evidence that bilateral therapy improves function in adults with chronic stroke, however more quality RCTs are required to strengthen this evidence.