Effect of whole-body vibration training on bone mineral density in older adults: a systematic review and meta-analysis

Background: Whole-body vibration (WBV) aims to increase bone mineral density (BMD) using vertical mechanical accelerations from the plantar surface of the feet through the muscles and bones. A vibration platform is used for this purpose. This systematic review (PROSPERO-CRD 42023395390) analysed the effects of WBV training on BMD at anatomical sites most affected by osteoporotic fractures in older adults. Methodology: Systematic searches were conducted in the databases. Randomized controlled studies quantifying aerial BMD (aBMD) using the dual-energy X-ray absorptiometry method before and after WBV training in adults aged 55 and older were included. Independent reviewers performed methodological quality analysis (TESTEX) and assessed the risk of bias, and the GRADE scale determined the certainty of evidence in the results of the selected studies. The aBMD values from anatomical sites in the femoral neck, total proximal femur, and lumbar spine from WBV training protocols were included in the meta-analysis. The forest plot was generated using the random-effects model, and the effect size was measured by Hedges' g. Results: Seven studies involving 202 participants were included, with TESTEX = 12.6 (excellent quality) and risk of bias (43% low risk, and 57% some concerns), demonstrating with low heterogeneity, a significant effect of WBV training on total femur aBMD (g = 0.28 (small), p = 0.04). However, in spite of the low heterogeneity, the femoral neck (g = 0.15 (trivial), p = 0.19) and lumbar spine (g = 0.13 (trivial), p = 0.31) regions did not show a significant effect with WBV training. Conclusions: The results showed with low certainly evidence that WBV training had a statistically significant effect on total femur aBMD but not on femoral neck and lumbar spine.