Effectiveness of motor imagery and action observation on functional variables: An umbrella and mapping review with meta-meta-analysis.

To assess the current evidence on motor imagery (MI) and action observation (AO) and their influence on functional variables. We conducted 3 meta-meta-analyses (MMA) to determine the effectiveness of MI and AO on arm functionality, performance on activities of daily living and gait mobility in stroke patients. For arm functionality, MMA revealed a statistically significant large effect size (standardised mean difference [SMD] = 1.05; 95 % CI 0.50-1.60; p<.001) but with evidence of heterogeneity (Q=55.67, p<.001, I2=93 %). For arm performance in activities of daily living, MMA revealed a significantly large effect size (SMD=1.76; 95 % CI 1.10-2.43; p<.001) but also with evidence of heterogeneity (Q=1.62, p=.44, I2=90 %). MMA showed no significant effects favouring intervention regarding gait mobility. The results of the systematic reviews showed that movement representation techniques combined with the usual treatment have a positive impact on improving function, with a very low to moderate quality of evidence for all variables except for range of motion in acute disorders and strength. MI and AO showed positive results for improving functional variables.