Effects of mirror therapy on motor and functional recovery of the upper extremity in subacute stroke: Systematic review and meta-analysis.

No study in the review blinded the patients or the therapists delivering the treatment, so both the person doing the therapy and the person receiving it knew which group they were in. Five of the six trials showing a bimanual mirror therapy advantage gave the experimental group more total training time than the control group, and the control group did not receive an equivalent dose of alternative therapy. The extra practice may account for part or all of the benefit. Only two trials used the unimanual (unaffected arm only) approach, so the finding that it did not show a benefit rests on very little data. Only two trials measured quality of life, with 74 participants total, so the null finding on quality of life is underpowered. Only one trial reported follow-up data, so there is no information on whether any benefit lasted beyond the 3 to 6 week intervention. The authors note that only English-language studies were included, despite searching databases for English and Chinese publications.

The authors declared no conflicts of interest. The work was funded by the National Science and Technology Council.

Do not read the bimanual mirror therapy benefit as proof the mirror itself is the active ingredient. Five of the six trials showing a positive result gave the mirror group more total training time than the control group, and the control group did not receive an equivalent dose of alternative therapy. The extra practice, not the mirror, may explain the difference.