Dynamic and isometric protocols of knee extension: Effect of fatigue on the EMG signal

Página do item simplificado
dc.contributor.authorDias da Silva, S. R. [UNESP]
dc.contributor.authorGonçalves, Mauro [UNESP]
dc.contributor.institutionUniversidade Estadual Paulista (Unesp)
dc.date.accessioned2014-05-27T11:21:48Z
dc.date.available2014-05-27T11:21:48Z
dc.date.issued2006-01-01
dc.description.abstractThe objective of this study was to analyze the electromyographic (EMG) signal behavior of rectus femoris (RF), vastus medialis (VM), vastus lateralis (VL) and biceps femoris (caput longum) (BFCL) from nine women during fatiguing dynamic and isometric knee extensions tests and to determine their EMGFT (Electromyographic Fatigue Threshold). Surface electrodes, biological signal acquisition module, analogical-digital converter board and specific software were used. The RMS (Root Mean Square) values obtained from concentric phase (80 to 30 degrees) of the dynamic knee extension andfrom isometric contraction were correlated with time on each load by linear regression analysis. The respective slopes were correlated with the correspondent load to determine the EMGFT. Force (Kgf) and median frequency - MF (Hz) obtained during MIVC (Maximal Isometric Voluntary Contraction) performed before and after the fatiguing tests were calculated in Matlab environment. The results demonstrated that the endurance time decreases with higher loads the EMG amplitude increase with time and was greater at higher loads, between muscles in dynamic exercise the RF and VL showed higher slopes, and in isometric exercise the VL showed the same behavior The EMGFT values were similar in both exercises; the force values predominantly decreased after fatiguing tests; however the MF only decreased after some loads. The protocols proposed allowed standardizing protocols at least to induce the fatigue process and to determine the EMGFT as an endurance indicative, which may be used to evaluate the effectiveness of rehabilitative or training interventions indicated to reduce muscle weakness and fatigue.en
dc.description.affiliationBiomechanic Laboratory São Paulo State University UNESP, Avenida 24A n 1515 - Bela Vista, Rio Claro, São Paulo
dc.description.affiliationUnespBiomechanic Laboratory São Paulo State University UNESP, Avenida 24A n 1515 - Bela Vista, Rio Claro, São Paulo
dc.format.extent35-42
dc.identifier.citationElectromyography and Clinical Neurophysiology, v. 46, n. 1, p. 35-42, 2006.
dc.identifier.issn0301-150X
dc.identifier.lattes3023304896722902
dc.identifier.scopus2-s2.0-33644982615
dc.identifier.urihttp://hdl.handle.net/11449/68762
dc.language.isoeng
dc.relation.ispartofElectromyography and Clinical Neurophysiology
dc.rights.accessRightsAcesso restrito
dc.sourceScopus
dc.subjectDynamic contraction
dc.subjectElectromyography
dc.subjectIsometric contraction
dc.subjectKnee
dc.subjectMuscle fatigue
dc.subjectadult
dc.subjectanalog digital converter
dc.subjectbiceps femoris muscle
dc.subjectcalculation
dc.subjectclinical protocol
dc.subjectcomputer program
dc.subjectcontrolled study
dc.subjectcorrelation analysis
dc.subjectdisplay system
dc.subjectdynamic exercise
dc.subjectdynamics
dc.subjectelectrode
dc.subjectelectromyogram
dc.subjectendurance
dc.subjectfemale
dc.subjecthuman
dc.subjecthuman experiment
dc.subjectknee
dc.subjectleg movement
dc.subjectleg muscle
dc.subjectmuscle fatigue
dc.subjectmuscle force
dc.subjectmuscle isometric contraction
dc.subjectmuscle training
dc.subjectmuscle weakness
dc.subjectnormal human
dc.subjectrectus femoris muscle
dc.subjectrehabilitation
dc.subjectsignal processor
dc.subjectstandardization
dc.subjectstatistical analysis
dc.subjectvastus lateralis muscle
dc.subjectweight bearing
dc.subjectAdolescent
dc.subjectAdult
dc.subjectFemale
dc.subjectHumans
dc.subjectMuscle Contraction
dc.subjectMuscle Fatigue
dc.subjectQuadriceps Muscle
dc.subjectReference Values
dc.subjectWeight-Bearing
dc.titleDynamic and isometric protocols of knee extension: Effect of fatigue on the EMG signalen
dc.typeArtigo
unesp.author.lattes3023304896722902
unesp.campusUniversidade Estadual Paulista (Unesp), Instituto de Biociências, Rio Claropt

Arquivos

Coleções

Artigos - Educação Física - IBRC