Effects of Whole Body Vibration in Different Devices on Bone and Muscle Mass in Postmenopausal Women

Postmenopausal women suffer from a series of negative health factors, such as decreased bone and muscle mass and physical performance, increasing the risk of falls and decreasing quality of life. Therefore, intervention strategies aimed at mitigating these factors are essential. A technique that has been studied and can reverse these factors is whole-body vibration (WBV), however studies present contradictory results and the main confounding factor appears to be related to the type of vibration (synchronous or side-alternating). Therefore, the primary objective of this project is to verify the effects of 12 months of whole-body vibration on different devices on bone mineral density measurements in postmenopausal women. As a secondary objective, the effects on muscle mass, physical performance, quality of life and falls will be verified. 127 postmenopausal women will participate in the study and will be randomized to: triplanar vibration (synchronous); side-alternating vibration; or false vibration. The interventions will last 12 months and will occur three times a week on non-consecutive days. The following assessments will be carried out at baseline, 6-months and 12-months: bone mineral density and muscle mass by DXA equipment, muscle thickness by ultrasound, peak torque of the knee extensor and flexor muscles by an isokinetic dynamometer, hand grip, balance static postural and vertical jump on a force platform, dynamic balance using the Timed Up and Go test, SPPB battery, fear (FES-I) and incidence of falls and quality of life (SF-36).