Validation of the filling factor index to study the filling process of the sEMG signal in the quadriceps

Date

2023

Director

Publisher

Elsevier
Acceso abierto / Sarbide irekia
Artículo / Artikulua
Versión publicada / Argitaratu den bertsioa

Project identifier

  • MICINN//PID2022-136620OB-I00/
Impacto
Google Scholar
No disponible en Scopus

Abstract

Introduction: The EMG filling factor is an index to quantify the degree to which an EMG signal has been filled. Here, we tested the validity of such index to analyse the EMG filling process as contraction force was slowly increased. Methods: Surface EMG signals were recorded from the quadriceps muscles of healthy subjects as force was gradually increased from 0 to 40% MVC. The sEMG filling process was analyzed by measuring the EMG filling factor (calculated from the non-central moments of the rectified sEMG). Results: (1) As force was gradually increased, one or two prominent abrupt jumps in sEMG amplitude appeared between 0 and 10% of MVC force in all the vastus lateralis and medialis. (2) The jumps in amplitude were originated when a few large-amplitude MUPs, clearly standing out from previous activity, appeared in the sEMG signal. (3) Every time an abrupt jump in sEMG amplitude occurred, a new stage of sEMG filling was initiated. (4) The sEMG was almost completely filled at 2–12% MVC. (5) The filling factor decreased significantly upon the occurrence of an sEMG amplitude jump, and increased as additional MUPs were added to the sEMG signal. (6) The filling factor curve was highly repeatable across repetitions. Conclusions: It has been validated that the filling factor is a useful, reliable tool to analyse the sEMG filling process. As force was gradually increased in the vastus muscles, the sEMG filling process occurred in one or two stages due to the presence of abrupt jumps in sEMG amplitude.

Description

Keywords

EMG filling, Filling factor, Form factor, Interference pattern, Probability Density Function (PDF), Surface EMG

Department

Ingeniería Eléctrica, Electrónica y de Comunicación / Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren

Faculty/School

Degree

Doctorate program

item.page.cita

Rodriguez-Falces, J., Malanda, A., Mariscal, C., Niazi, I. K., & Navallas, J. (2023). Validation of the filling factor index to study the filling process of the sEMG signal in the quadriceps. Journal of Electromyography and Kinesiology, 72, 102811. https://doi.org/10.1016/j.jelekin.2023.102811

item.page.rights

© 2023 The Authors. This is an open access article under the CC BY-NC-ND license.

Licencia

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