Exploratory study of electromyographic behavior of the vastus medialis and vastus lateralis at neuromuscular fatigue onset

This study aimed to determine and analyze the neuromuscular fatigue onset by median frequency (MDF) and the root mean square (RMS) behavior of an electromyographic signal (EMG). Eighteen healthy men with no prior knee problems initially performed three maximum voluntary isometric contractions (MVIC)...

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Detalles Bibliográficos
Autores: Silva, Cristiano Rocha Da [UNESP], Silva, Danilo De Oliveira [UNESP], Ferrari, Deisi, Negrão Filho, Rúben de Faria [UNESP], Alves, Neri, Azevedo, Fábio Mícolis de [UNESP]
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2014
País:Brasil
Institución:Universidade Estadual Paulista (UNESP)
Repositorio:Repositório Institucional da UNESP
Idioma:inglés
OAI Identifier:oai:repositorio.unesp.br:11449/135406
Acceso en línea:http://dx.doi.org/10.1590/s1980-65742014000200012
http://hdl.handle.net/11449/135406
Access Level:acceso abierto
Palabra clave:Electromyography
Fatigue
Isometric contraction
Quadriceps muscle
Electromiografía
Fatiga
Contracción
Isométrica
Músculo cuadríceps
Descripción
Sumario:This study aimed to determine and analyze the neuromuscular fatigue onset by median frequency (MDF) and the root mean square (RMS) behavior of an electromyographic signal (EMG). Eighteen healthy men with no prior knee problems initially performed three maximum voluntary isometric contractions (MVIC). After two days of MVIC test, participants performed a fatiguing protocol in which they performed submaximal knee-extension contractions at 20% and 70% MVIC held to exhaustion. The MDF and RMS values from the EMG signals were recorded from the vastus medialis (VM) and the vastus lateralis (VL). Analysis of the MDF and RMS behavior enabled identification of neuromuscular fatigue onset for VM and VL muscles in 20% and 70% loads. Alterations between the VM and VL in the neuromuscular fatigue onset, at 20% and 70% MVIC, were not significant. These findings suggest that the methodology proposal was capable of indicating minute differences sensible to alterations in the EMG signals, allowing identification of the moment when the MDF and the RMS showed significant changes in behavior. The methodology used was also a viable one for describing and identifying the neuromuscular fatigue onset by means of the analysis of EMG signals.