The filling factor of the sEMG signal at low contraction forces in the quadriceps muscles is influenced by the thickness of the subcutaneous layer
Fecha
2023Autor
Versión
Acceso abierto / Sarbide irekia
Tipo
Artículo / Artikulua
Versión
Versión publicada / Argitaratu den bertsioa
Identificador del proyecto
Impacto
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10.3389/fphys.2023.1298317
Resumen
Introduction: It has been shown that, for male subjects, the sEMG activity at low contraction forces is normally 'pulsatile', i.e., formed by a few large-amplitude MUPs, coming from the most superficial motor units. The subcutaneous layer thickness, known to be greater in females than males, influences the electrode detection volume. Here, we investigated the influence of the subcutaneous layer t ...
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Introduction: It has been shown that, for male subjects, the sEMG activity at low contraction forces is normally 'pulsatile', i.e., formed by a few large-amplitude MUPs, coming from the most superficial motor units. The subcutaneous layer thickness, known to be greater in females than males, influences the electrode detection volume. Here, we investigated the influence of the subcutaneous layer thickness on the type of sEMG activity (pulsatile vs. continuous) at low contraction forces. Methods: Voluntary surface EMG signals were recorded from the quadriceps muscles of healthy males and females as force was gradually increased from 0% to 40% MVC. The sEMG filling process was examined by measuring the EMG filling factor, computed from the non-central moments of the rectified sEMG signal. Results: 1) The sEMG activity at low contraction forces was ¿continuous¿ in the VL, VM and RF of females, whereas this sEMG activity was ¿pulsatile¿ in the VL and VM of males. 2) The filling factor at low contraction forces was lower in males than females for the VL (p = 0.003) and VM (p = 0.002), but not for the RF (p = 0.54). 3) The subcutaneous layer was significantly thicker in females than males for the VL (p = 0.001), VM (p = 0.001), and RF (p = 0.003). 4) A significant correlation was found in the vastus muscles between the subcutaneous layer thickness and the filling factor (p < 0.05). Discussion: The present results indicate that the sEMG activity at low contraction forces in the female quadriceps muscles is 'continuous' due to the thick subcutaneous layer of these muscles, which impedes an accurate assessment of the sEMG filling process. [--]
Materias
Filling factor,
Form factor,
Interference pattern analysis,
Probability density function (PDF),
sEMG RMS amplitude,
Subcutaneous layer,
Surface EMG
Editor
Frontiers Media
Publicado en
Frontiers in Physiology (2023), vol. 14
Departamento
Universidad Pública de Navarra. Departamento de Ingeniería Eléctrica, Electrónica y de Comunicación /
Universidad Pública de Navarra/Nafarroako Unibertsitate Publikoa. Institute of Smart Cities - ISC /
Nafarroako Unibertsitate Publikoa. Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren Saila
Versión del editor
Entidades Financiadoras
This work has been supported by the Spanish Ministry of Science and Innovation under the project PID 2022-136620OB-I00.