A preliminary characterization of a whole body vibration platform prototype for medical and rehabilitation application

Whole-body vibration (WBV) is receiving increasing interest as an exercise intervention in physiology and rehabilitation. Although there are many commercial and professional WBV platforms to provide controlled vibrations, very few have actually been tested in terms of amplitude (mm), frequency spectra (Hz) and shape of the vibratory motion wave. In this regard a prototype of a novel WBV platform where the vibration amplitude can be set to three values in the frequency range 20-60 Hz is here proposed. The device has been preliminarily characterized by processing the measurement signal from a piezoelectric monoaxial accelerometer mounted in the center of the WBV plate. In particular the accelerometer signal has been processed to evaluate frequency spectrum, waveform shape and displacement. Moreover to evaluate the performance of the prototype, same tests were carried out on an equivalent professional WBV platform, so that data coming from the two platforms have been compared and commented: test results have shown that the vibrations produced by the two WBV plates are very similar, nevertheless it has been found that the prototype works with a maximum error of about 5 % in frequency, that is less than in the other devices, furthermore the greater distortion of the signal is always at the twice of the operating frequency (second harmonic). Further investigations are needed to complete the characterization of the prototype and assess the vibration amplitude is not load dependent.