Analysis and Modelling of Muscles Motion during Whole Body Vibration

Abstract

The aim of the study is to characterize the local muscles motion in individuals undergoing whole body mechanical stimulation. In this study we aim also to evaluate how subject positioning modifies vibration dumping, altering local mechanical stimulus. Vibrations were delivered to subjects by the use of a vibrating platform, while stimulation frequency was increased linearly from 15 to 60 Hz. Two different subject postures were here analysed. Platform and muscles motion were monitored using tiny MEMS accelerometers; a contra lateral analysis was also presented. Muscle motion analysis revealed typical displacement trajectories: motion components were found not to be purely sinusoidal neither in phase to each other. Results also revealed a mechanical resonant-like behaviour at some muscles, similar to a second-order system response. Resonance frequencies and dumping factors depended on subject and his positioning. Proper mechanical stimulation can maximize muscle spindle solicitation, which may produce a more effective muscle activation.

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

“…Whereas a divergence up to 10% between the preset and the actual applied frequency can be accepted in practice and hardly in research, a divergence of more than 10% cannot be accepted neither in practice nor in research, because a different stimulus might result in different effects [6]. As a result of divergences of more than 10% it will be difficult to identify the most effective range of frequencies for specific intentions.…”

“…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].…”

Application of Ensemble Averaging to the Analysis of Electromyography Recordings under Whole Body Vibratory Stimulation

“…The extent of the vibration efficacy is commonly evaluated by means of surface electromyography (EMG) analysis in muscles under stimulation. Vibrations, however, not only result in the undoubting muscle stimulation, but also produce disturbances of the electrochemical potentials at electrode/electrolyte/skin and skin layers/tissues interfaces [6][7][8][9][10][11]. These alterations could generate electrical voltages at recording site (up to 5-10 mV), which add to the EMG as peculiar artifacts named motion artifacts.…”

A lumped parameter model for the analysis of the motion of the muscles of the lower limbs under whole-body vibration

“…These devices produce mechanical oscillations in a frequency range of about 10 to 80 Hz and peak to peak amplitudes of 1 to 10 mm [2]. The mechanical stimulus reaches different target muscles depending on the specific postures assumed by subjects standing on the platform [3].…”

“…978-1-4799-3163-7/13/$31.00 ©2013 IEEE Specific modelling has been developed to analyse resonance of body segments and muscles at different conditions (postures and frequencies) [3] but further studies are needed to achieve a more complete understanding of biomechanical response of body subjected to mechanical oscillations.…”