Bilateral movement training and stroke motor recovery progress: a structured review and meta-analysis

Abstract

The purpose was to conduct a structured review and meta-analysis to determine the cumulative effect of bilateral arm training on motor capabilities post stroke. Forty-eight stroke studies were selected from three databases with 25 comparisons qualifying for inclusion in our meta-analysis. We identified and coded four types of bilateral arm interventions with 366 stroke patients. A random effects model using the standardized mean difference technique determined a large and significant effect size (0.734; SE=0.125), high fail-safe N (532), and medium variability in the studies (I(2)=63%). Moderator variable analysis on the type of bilateral training revealed two large and significant effects: (a) BATRAC (0.842; SE=0.155) and (b) coupled bilateral and EMG-triggered neuromuscular stimulation (1.142; SE=0.176). These novel findings provide strong evidence supporting bilateral arm training with the caveat that two coupled protocols, rhythmic alternating movements and active stimulation, are most effective.

Figure 1

Forest plot: random effects model. The column farthest right is the individual effect size for each comparison in alphabetical order (same order as Table 4). Tick marks represent effect sizes, and lengths of the horizontal lines are the 95% confidence intervals. Lines that do not intercept the 0.0 vertical line make a contribution to the cumulative effect. The black diamond at the bottom of the forest plot is the overall effect size.

Figure 2

Funnel plot evaluating publication bias. Each individual study is represented by a circle: an effect size (x-axis) and standard error (y-axis). The greater the symmetry, the less is the concern with publication bias. Given that a majority of the 25 circles are on the right side of the funnel plot (right of the overall effect size vertical line: diamond on x-axis), then a potential bias effect is apparent.

Figure 3

Best estimate funnel plot of an unbiased effect (i.e., symmetrical funnel): open circles and diamond represent original 25 comparisons whereas black circles and diamond represent imputed comparisons. This funnel plot balances the studies toward symmetry by adding seven black circles to the left side (negative effects) of the vertical line (cumulative effect).