Effects of Vibration Training on Bone Mineral Density and Balance in Postmenopausal Women with Osteopenia: A Systematic Review with Meta-Analysis

Background: Osteopenia is highly prevalent after menopause and increases the risk of osteoporosis, falls, and fragility fractures. Whole-body vibration has been proposed as a low-impact exercise strategy, but its clinical effectiveness remains uncertain. This systematic review with meta-analysis aims to analyze the effects of whole-body vibration on bone mineral density and balance in postmenopausal women with osteopenia. Methods: Five electronic databases were searched following PRISMA guidelines. Randomized controlled trials including postmenopausal women diagnosed with osteopenia by dual-energy X-ray absorptiometry were included. Methodological quality, risk of bias, and certainty of evidence were assessed using TESTEX, RoB 2, and GRADE, respectively. Effect sizes were calculated using Hedges’ g with 95% confidence intervals. Results: Five randomized controlled trials involving 248 women were included. Interventions lasted from 8 weeks to 12 months. Whole-body vibration did not produce significant improvements in bone mineral density at the tibia, radius, or lumbar spine, nor did it significantly improve balance compared with control conditions. The certainty of evidence was low for bone mineral density and very low for balance, mainly due to risk of bias, small sample sizes, and imprecision. Conclusions: Current evidence does not provide sufficient support for clinically meaningful improvements in BMD or balance following WBV in postmenopausal women with osteopenia. Nevertheless, conclusions remain uncertain because they are based on only five randomized controlled trials and very few studies per pooled outcome. Therefore, WBV cannot currently be recommended as a stand-alone intervention for improving BMD or balance, but neither can a potentially beneficial effect be definitively excluded. Larger, adequately powered, and methodologically rigorous trials are required before firm clinical recommendations can be established.