Whole Body Vibration Treatments in Postmenopausal Women Can Improve Bone Mineral Density: Results of a Stimulus Focussed Meta-Analysis

Abstract

Whole body vibration treatment is a non-pharmacological intervention intended to stimulate muscular response and increase bone mineral density, particularly for postmenopausal women. The literature related to this topic is controversial, heterogeneous, and unclear despite the prospect of a major clinical effect.The aim of this study was to identify and systematically review the literature to assess the effect of whole body vibration treatments on bone mineral density (BMD) in postmenopausal women with a specific focus on the experimental factors that influence the stimulus. Nine studies fulfilled the inclusion criteria, including 527 postmenopausal women and different vibration delivery designs. Cumulative dose, amplitudes and frequency of treatments as well as subject posture during treatment vary widely among studies. Some of the studies included an associated exercise training regime. Both randomized and controlled clinical trials were included. Whole body vibration was shown to produce significant BMD improvements on the hip and spine when compared to no intervention. Conversely, treatment associated with exercise training resulted in negligible outcomes when compared to exercise training or to placebo. Moreover, side-alternating platforms were more effective in improving BMD values than synchronous platforms and mechanical oscillations of magnitude higher than 3 g and/or frequency lower than 25 Hz were also found to be effective. Treatments with a cumulative dose over 1000 minutes in the follow-up period were correlated to positive outcomes.Our conclusion is that whole body vibration treatments in elderly women can reduce BMD decline.However, many factors (e.g., amplitude, frequency and subject posture) affect the capacity of the vibrations to propagate to the target site; the adequate level of stimulation required to produce these effects has not yet been defined. Further biomechanical analyses to predict the propagation of the vibration waves along the body and assess the stimulation levels are required.

The Use of Vibration as Physical Exercise and Therapy

“…Vibration exercise is a new and effective measure to prevent muscular atrophy and osteoporosis [34]. Osteoporosis is a disorder described by low bone mass and structural deterioration of bone tissue leading to bone fragility and an increased risk of hip, spine, and wrist fractures [35]. The latter could be associated with osteoarthritis leading to several histopathological changes and determining an endogenous cellular response [2,36].…”

Morphological and nociceptive effects of mechanical vibration on the sciatic nerve of oophorectomized Wistar rats

“…In the present study, the vibration, using the parameters analyzed, showed no signs of injury to the sciatic nerve after 4 or 8 weeks. This divergence with the studies mentioned above could be due to the difference in cumulative dose, which is described as the total time of exposure to vibration and considers the number of weekly sessions and the duration of the stimulus 14 . In studies by Baig, Guarino, Lipschutz, Winkelstein 18 and Kartha, Zeeman and Baig 17 , although the researchers used the vibration for only 7 days, they used twice the daily time of the present study.…”

“…The responses of therapy with a vibrating platform depend on the parameters to be used 13 , with time being a key variable, as prolonged exposure can cause damage to the tissue [14][15][16][17][18][19] . This prolonged exposure (daily and weekly) of the peripheral nerve to the vibration is widely studied in an occupational scope.…”

Deviations in Whole-Body Vibration Training Devices: A Narrative Review

“…The intensity of WBVT mainly is regulated by the duration of each training session, the frequency, the amplitude and the body position as well as by exercises performed on the device [5][6][7]. One of the most important research questions regarding the use of WBVT is to identify the ideal composition of these parameters and the appropriate mode of vibration for each intention [7][8][9]. All training parameters and their interaction are resulting in a specific exercise stimulus, influencing the effects of the exercise [10].…”

“…It is assumed, that such divergences might be due to between manufacturers and device types varying drives, the rigidity of used materials as well as possible software failures [9,11]. According to the available published literature, no published research results regarding potential divergences of the actually applied amplitude were identified.…”