Influence of Skinfold Thickness in Mechanomyography Features

Abstract

The assessment and physiological register of muscular tissue can be done through mechanomyography (MMG). The oscillation of muscular displacement is acquired on the skin surface, insomuch that the skinfold thickness can influence in MMG response. The aim of this study is verify the influence of different skinfold thickness on MMG features responses. Triaxial MMG was used over the rectus femoris muscle belly of ten volunteers during maximal voluntary contraction. MMG spectral and temporal analyses were made and specific features (root mean square (RMS), Integral (Int), mean frequency (MF), zero-crossing (ZC), and μ3) were correlated with skinfold thickness. Moderate and high negative correlation occurred to MMG mean frequency in axes X (ρ = - 0.57) and Y (ρ = -0.75), respectively. As the fat tissue behaves like a low-pass filter, i.e. the thicker his skinfold the shorter its bandwidth; therefore, the skinfold thicknesses result in lower frequency responses. So, hereafter these results may be applied to calibrate MMG responses as biofeedback systems in, for instance, neuroprostheses.