Relationships between skinfold thickness and electromyographic and mechanomyographic amplitude recorded during voluntary and non-voluntary muscle actions.
BACKGROUND
The purpose of this study was to examine possible correlations between skinfold thicknesses and the a terms from the log-transformed electromyographic (EMGRMS) and mechanomyographic amplitude (MMGRMS)-force relationships, EMG M-Waves, and MMG gross lateral movements (GLM).


METHODS
Forty healthy subjects performed a 6-s isometric ramp contraction from 5% to 85% of their maximal voluntary contraction with EMG and MMG sensors placed on the vastus lateralis (VL) and rectus femoris (RF). A single electrical stimulus was applied to the femoral nerve to record the EMG M-waves and MMG GLMs. Skinfold thickness was assessed at the site of each electrode. Pearson's product correlation coefficients were calculated comparing skinfold thicknesses with the a terms from the log-transformed EMGRMS-and MMGRMS-force relationships, EMG M-waves, and MMG GLMs.


RESULTS
There were no significant cor1relations (p>0.05) between the a terms and skinfold thicknesses for the RF and VL from the EMGRMS and MMGRMS-force relationships. However, there were significant correlations (p<0.05) between skinfold thicknesses and the EMG M-waves and MMG GLMs for the RF (r=-0.521, -0.376) and VL (r=-0.479, -0.484).


CONCLUSIONS
Relationships were only present between skinfold thickness and the amplitudes of the EMG and MMG signals during the non-voluntary muscle actions.
Neuromechanics Laboratory, Department of Health, Sport and Exercise Sciences, University of Kansas, Lawrence, KS, United States.
Michael A
MA
Cooper
Neuromechanics Laboratory, Department of Health, Sport and Exercise Sciences, University of Kansas, Lawrence, KS, United States. Electronic address: t.herda@ku.edu.
Trent J
TJ
Herda
Applied Physiology Laboratory, Department of Health, Sport and Exercise Sciences, University of Kansas, Lawrence, KS, United States.
John P
JP
Vardiman
Applied Physiology Laboratory, Department of Health, Sport and Exercise Sciences, University of Kansas, Lawrence, KS, United States.
Phillip M
PM
Gallagher
Neuromechanics Laboratory, Department of Health, Sport and Exercise Sciences, University of Kansas, Lawrence, KS, United States.
Andrew C
AC
Fry
D000328:Adult; D004566:Electrodes; D004576:Electromyography / Q000379:methods*; D005260:Female; D005267:Femoral Nerve; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D052097:Quadriceps Muscle; D012815:Signal Processing, Computer-Assisted; D012885:Skinfold Thickness; D055815:Young Adult
Electromyography; Mechanomyography; Skinfold thickness