AUTHOR=Hodson-Tole Emma F. , Wakeling James M. TITLE=Movement Complexity and Neuromechanical Factors Affect the Entropic Half-Life of Myoelectric Signals JOURNAL=Frontiers in Physiology VOLUME=8 YEAR=2017 URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2017.00679 DOI=10.3389/fphys.2017.00679 ISSN=1664-042X ABSTRACT=
Appropriate neuromuscular functioning is essential for survival and features underpinning motor control are present in myoelectric signals recorded from skeletal muscles. One approach to quantify control processes related to function is to assess signal variability using measures such as Sample Entropy. Here we developed a theoretical framework to simulate the effect of variability in burst duration, activation duty cycle, and intensity on the Entropic Half-Life (EnHL) in myoelectric signals. EnHLs were predicted to be <40 ms, and to vary with fluctuations in myoelectric signal amplitude and activation duty cycle. Comparison with myoelectic data from rats walking and running at a range of speeds and inclines confirmed the range of EnHLs, however, the direction of EnHL change in response to altered locomotor demand was not correctly predicted. The discrepancy reflected different associations between the ratio of the standard deviation and mean signal intensity (