The effect of whole body vibration exposure on muscle or bone morphology and function in older adults: A systematic review of the literature

Context and objective: The aim of this study was to examine the effect of whole body vibration (WBV), a novel exercise modality, on muscle or bone morphology and function in older adults. Methods: A literature search of published randomised controlled trials (RCTs) was conducted using multiple databases and hand searching for study designs reporting the effects of WBV in older adults on any outcomes related to muscle function, or muscle or bone morphology. Concomitant exercise was only included if the control group performed the same exercise as the active WBV group, but without vibration. Results: Six RCTs met the inclusion criteria of this review, three reporting measures of muscle only, two assessing bone measures only and one detailing measures of both bone and muscle. Study design varied greatly across the six trials and only six of 35 musculoskeletal outcomes analysed were statistically significant. All statistically significant improvements were of muscle function. Conclusions: The published literature to date provides only weak support for the efficacy of WBV exposure for muscle function, muscle morphology, or bone architecture in older adults. Irregularities in study design and WBV protocols across the literature and poor quality trials contribute to this inconsistency, revealing the need for more uniformity in future trials. Future research should be more robust in design, include larger cohorts, longer interventions and standardisation of protocols. They should also investigate the optimal dose-response relationships and variation in vibration characteristics, to determine the true efficacy, clinical relevance, and underlying mechanisms of muscle and bone adaptations. (C) 2010 Elsevier Ireland Ltd. All rights reserved.