Does Whole-Body Vibration Improve the Functional Exercise Capacity of Subjects With COPD? A Meta-Analysis

Whole-body vibration (WBV) is considered a type of physical activity based on the assumption that it results in an increase in muscle strength and performance and, therefore, may be a promising way to exercise patients with COPD. A comprehensive database search (PubMed/MEDLINE, LILACS, CINAHL, Web of Science, Scopus, and COCHRANE Library) for randomized trials, including original articles, that compared WBV groups versus control groups was conducted and studies were selected for comparison. The effect of WBV treatment was compared for minimum clinically important differences. The statistical heterogeneity among the studies was assessed using the I² statistic; the results are expressed as percentages. Inconsistencies of up to 25% were considered low, those between 50 and 75% were considerate moderate, and those > 75% were considered high. Risk of bias was classified based on the Cochrane Collaboration tool, the meta-analysis was conducted using RevMan 5.3 software, and the level of evidence was assessed using the GRADE system. The primary outcome was functional exercise capacity. Secondary outcomes were quality of life, performance in activities of daily living, muscle strength of the lower limbs, and possible adverse effects assessed clinically or by subject reports. We included 4 articles involving 185 subjects for analysis. All subjects in the groups undergoing WBV showed improvement in distance walked in the 6-min walk test compared with the control group (57.85 m, 95% CI 16.36-99.33 m). Regarding the secondary end points, just one article reported improved quality of life and activities of daily living. The only article that assessed muscle strength found no difference between the groups. The quality of evidence for functional exercise capacity outcome was considered moderate. WBV seems to benefit subjects with COPD by improving their functional exercise capacity, without producing adverse effects. The quality of evidence is moderate, but the degree of recommendation is strong. (International Prospective Register of Systematic Reviews, http://www.crd.york.ac.uk/prospero, 2015:CRD42015027659.).