Electromyographic parameters analysis during fatiguing isometric contractions tests and the effect of a short period endurance training
Autor(a) principal: | |
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Data de Publicação: | 2007 |
Tipo de documento: | Artigo |
Idioma: | por |
Título da fonte: | Motriz (Online) |
Texto Completo: | https://www.periodicos.rc.biblioteca.unesp.br/index.php/motriz/article/view/620 |
Resumo: | The aim of the present was to analyze the behavior of the electromyographic and amplitude and frequency variables of the longuissimus thoracis muscle during fatiguing test and the effect of a short endurance training. Participated in this study 20 male health subjects, divided into two groups: control group (CG) and training groups (TG). The EMG signals were detected using disposable pre-gelled bipolar surface electrodes (Medi-Trace) with 1cm of diameter and positioned with an inter-electrode distance of 3cm. The electrodes were placed in a bipolar configuration bilaterally over the right longissimus thoracis and left longissimus thoracis muscles leveled at the spinous process L1, displaced 3cm laterally. The EMG system consisted of surface electrodes, electrodes cables and tip plugs, and a biological signal acquisition module with four channels. A gain of 1000, a high pass filter of 20Hz, the low pass filter of 500Hz and the sampling frequency rate of 1000Hz was used. On the day of the experiment the subjects were positioned in the MA ISOSTATION equipment. The trunk was maintained with a flexion of 45º confirmed by goniometer. After, the subjects performed isometric trunk extensions until fatigue. The contraction force value and EMG was recorded. A visual feedback had been provided to subjects to maintain force level as long as possible at 30%, 40%, 50% and 60%. The training was accomplished three times a week during four weeks. The amplitude and frequency parameters of the EMG signal in each test was associated to the exhaustion time within each one of the four load percentages in order to obtain the initial values and the slopes with the linear regression straight lines. The results showed the possibility in identifying the electromyographic fatigue threshold (EMGFT) by means the load combination and by means the 30 seconds protocol. It is also possible to note highs reliable values to the amplitude and frequency variables. Analyzing the frequency banding it is possible to note that the low frequencies are more affected by the fatigue process. Besides, the initial values to the root mean square (RMS) are influenced by the load level, and the median frequency (MF) and the mean power frequency (MPF) are not. About the training protocol, it was verify an increase in the endurance time (ET) to the pos training condition. No difference was found to the EMG variables after training. |
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Electromyographic parameters analysis during fatiguing isometric contractions tests and the effect of a short period endurance trainingAnálise de parâmetros eletromiográficos durante testes de contrações isométricas fatigantes e do efeito de um treinamento de resistência de curta duraçãoBiomecânica. Eletromiografia. Coluna. Fadiga. Treinamento.The aim of the present was to analyze the behavior of the electromyographic and amplitude and frequency variables of the longuissimus thoracis muscle during fatiguing test and the effect of a short endurance training. Participated in this study 20 male health subjects, divided into two groups: control group (CG) and training groups (TG). The EMG signals were detected using disposable pre-gelled bipolar surface electrodes (Medi-Trace) with 1cm of diameter and positioned with an inter-electrode distance of 3cm. The electrodes were placed in a bipolar configuration bilaterally over the right longissimus thoracis and left longissimus thoracis muscles leveled at the spinous process L1, displaced 3cm laterally. The EMG system consisted of surface electrodes, electrodes cables and tip plugs, and a biological signal acquisition module with four channels. A gain of 1000, a high pass filter of 20Hz, the low pass filter of 500Hz and the sampling frequency rate of 1000Hz was used. On the day of the experiment the subjects were positioned in the MA ISOSTATION equipment. The trunk was maintained with a flexion of 45º confirmed by goniometer. After, the subjects performed isometric trunk extensions until fatigue. The contraction force value and EMG was recorded. A visual feedback had been provided to subjects to maintain force level as long as possible at 30%, 40%, 50% and 60%. The training was accomplished three times a week during four weeks. The amplitude and frequency parameters of the EMG signal in each test was associated to the exhaustion time within each one of the four load percentages in order to obtain the initial values and the slopes with the linear regression straight lines. The results showed the possibility in identifying the electromyographic fatigue threshold (EMGFT) by means the load combination and by means the 30 seconds protocol. It is also possible to note highs reliable values to the amplitude and frequency variables. Analyzing the frequency banding it is possible to note that the low frequencies are more affected by the fatigue process. Besides, the initial values to the root mean square (RMS) are influenced by the load level, and the median frequency (MF) and the mean power frequency (MPF) are not. About the training protocol, it was verify an increase in the endurance time (ET) to the pos training condition. No difference was found to the EMG variables after training.O objetivo do presente estudo foi analisar o comportamento de variáveis de amplitude e freqüência do sinal eletromiográfico (EMG) do músculo longuíssimo do tórax durante exercícios isométricos fatigantes e o efeito de um treinamento de resistência de curta duração. Participaram deste estudo 20 voluntários do gênero masculino, divididos em dois grupos: grupo controle (GC) e grupo treinamento (GT). Utilizou-se eletrodos de superfície bipolares passivos de Ag/AgCl (MEDITRACE), com área efetiva de captação de 1cm de diâmetro, dispostos sobre os músculos longuíssimo do tórax direito e esquerdo, no nível da vértebra L1 e 3cm lateralmente, com 3cm de distância inter-eletrodos; um módulo de aquisição de sinais biológicos de quatro canais calibrado com freqüência de amostragem de 1000Hz, ganho em 1000 vezes, filtro de passa alta de 20Hz e passa baixa de 500Hz, no qual foram conectados os eletrodos. No teste os voluntários executaram contrações isométricas do músculo longuíssimo do tórax até a exaustão a 30%, 40%, 50% e 60% da contração isométrica voluntária máxima, no equipamento MA ISOSTATION 2001 e na posição de 45 graus de flexão do quadril. Foi utilizada uma célula de carga acoplada a um indicador digital promovendo um retorno visual aos voluntários para que estes pudessem controlar a carga que está sendo tracionada durante o teste. O treinamento de resistência teve duração de quatro semanas, sendo realizado três vezes por semana. Os valores obtidos das variáveis de amplitude e freqüência do sinal EMG em cada uma das coletas em cada teste foram correlacionadas com o tempo por meio de uma regressão linear, obtendo assim os valores iniciais e os slopes em cada carga pré e pós treino. Os resultados apontaram a possibilidade em se identificar o limiar de fadiga eletromiográfico (EMGLF) nas diversas combinações de cargas e inclusive por meio de protocolo de teste de 30 segundos para o músculo longuíssimo do tórax. As variáveis de amplitude e freqüência do sinal EMG apresentaram altos valores de reprodutibilidade. No domínio das freqüências as bandas de freqüência do sinal, as mais baixas são as mais influenciadas pelo processo de fadiga sendo que no domínio do tempo os valores iniciais de root mean square (RMS) são influenciados pelo nível de carga não ocorrendo o mesmo para os valores iniciais de freqüência mediana (FM) e freqüência média (Fmed), portanto os parâmetros de amplitude são mais indicados para verificação de nível de contração muscular do que parâmetros de freqüência do sinal EMG. Quanto ao protocolo de treino, foi verificado que o tempo de resistência isométrica (TRI) foi significantemente maior para a condição pós-treino do GT comparada à condição pré-treino do GT e comparada à condição pós-treino do GC. Nenhuma diferença foi encontrada na análise entre as condições pré-treino e pós-treino para ambos os grupos bilateralmente, para todas as variáveis eletromiográficas.Universidade Estadual Paulista - Câmpus de Rio Claro2007-04-05info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionapplication/pdfhttps://www.periodicos.rc.biblioteca.unesp.br/index.php/motriz/article/view/62010.5016/620Motriz. Journal of Physical Education. UNESP; V. 13, N. 1 (2007); 79-79Motriz Revista de Educação Física; V. 13, N. 1 (2007); 79-791980-6574reponame:Motriz (Online)instname:Universidade Estadual Paulista (UNESP)instacron:UNESPporhttps://www.periodicos.rc.biblioteca.unesp.br/index.php/motriz/article/view/620/533Cardozo, Adalgiso Coscratoinfo:eu-repo/semantics/openAccess2013-04-19T15:16:49Zoai:periodicos.rc.biblioteca.unesp.br:article/620Revistahttp://www.periodicos.rc.biblioteca.unesp.br/index.php/motrizPUBhttps://old.scielo.br/oai/scielo-oai.phpmotriz@rc.unesp.br||mauerber@rc.unesp.br||azanesco@rc.unesp.br1980-65741415-9805opendoar:2013-04-19T15:16:49Motriz (Online) - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
Electromyographic parameters analysis during fatiguing isometric contractions tests and the effect of a short period endurance training Análise de parâmetros eletromiográficos durante testes de contrações isométricas fatigantes e do efeito de um treinamento de resistência de curta duração |
title |
Electromyographic parameters analysis during fatiguing isometric contractions tests and the effect of a short period endurance training |
spellingShingle |
Electromyographic parameters analysis during fatiguing isometric contractions tests and the effect of a short period endurance training Cardozo, Adalgiso Coscrato Biomecânica. Eletromiografia. Coluna. Fadiga. Treinamento. |
title_short |
Electromyographic parameters analysis during fatiguing isometric contractions tests and the effect of a short period endurance training |
title_full |
Electromyographic parameters analysis during fatiguing isometric contractions tests and the effect of a short period endurance training |
title_fullStr |
Electromyographic parameters analysis during fatiguing isometric contractions tests and the effect of a short period endurance training |
title_full_unstemmed |
Electromyographic parameters analysis during fatiguing isometric contractions tests and the effect of a short period endurance training |
title_sort |
Electromyographic parameters analysis during fatiguing isometric contractions tests and the effect of a short period endurance training |
author |
Cardozo, Adalgiso Coscrato |
author_facet |
Cardozo, Adalgiso Coscrato |
author_role |
author |
dc.contributor.author.fl_str_mv |
Cardozo, Adalgiso Coscrato |
dc.subject.por.fl_str_mv |
Biomecânica. Eletromiografia. Coluna. Fadiga. Treinamento. |
topic |
Biomecânica. Eletromiografia. Coluna. Fadiga. Treinamento. |
description |
The aim of the present was to analyze the behavior of the electromyographic and amplitude and frequency variables of the longuissimus thoracis muscle during fatiguing test and the effect of a short endurance training. Participated in this study 20 male health subjects, divided into two groups: control group (CG) and training groups (TG). The EMG signals were detected using disposable pre-gelled bipolar surface electrodes (Medi-Trace) with 1cm of diameter and positioned with an inter-electrode distance of 3cm. The electrodes were placed in a bipolar configuration bilaterally over the right longissimus thoracis and left longissimus thoracis muscles leveled at the spinous process L1, displaced 3cm laterally. The EMG system consisted of surface electrodes, electrodes cables and tip plugs, and a biological signal acquisition module with four channels. A gain of 1000, a high pass filter of 20Hz, the low pass filter of 500Hz and the sampling frequency rate of 1000Hz was used. On the day of the experiment the subjects were positioned in the MA ISOSTATION equipment. The trunk was maintained with a flexion of 45º confirmed by goniometer. After, the subjects performed isometric trunk extensions until fatigue. The contraction force value and EMG was recorded. A visual feedback had been provided to subjects to maintain force level as long as possible at 30%, 40%, 50% and 60%. The training was accomplished three times a week during four weeks. The amplitude and frequency parameters of the EMG signal in each test was associated to the exhaustion time within each one of the four load percentages in order to obtain the initial values and the slopes with the linear regression straight lines. The results showed the possibility in identifying the electromyographic fatigue threshold (EMGFT) by means the load combination and by means the 30 seconds protocol. It is also possible to note highs reliable values to the amplitude and frequency variables. Analyzing the frequency banding it is possible to note that the low frequencies are more affected by the fatigue process. Besides, the initial values to the root mean square (RMS) are influenced by the load level, and the median frequency (MF) and the mean power frequency (MPF) are not. About the training protocol, it was verify an increase in the endurance time (ET) to the pos training condition. No difference was found to the EMG variables after training. |
publishDate |
2007 |
dc.date.none.fl_str_mv |
2007-04-05 |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
https://www.periodicos.rc.biblioteca.unesp.br/index.php/motriz/article/view/620 10.5016/620 |
url |
https://www.periodicos.rc.biblioteca.unesp.br/index.php/motriz/article/view/620 |
identifier_str_mv |
10.5016/620 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.relation.none.fl_str_mv |
https://www.periodicos.rc.biblioteca.unesp.br/index.php/motriz/article/view/620/533 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Universidade Estadual Paulista - Câmpus de Rio Claro |
publisher.none.fl_str_mv |
Universidade Estadual Paulista - Câmpus de Rio Claro |
dc.source.none.fl_str_mv |
Motriz. Journal of Physical Education. UNESP; V. 13, N. 1 (2007); 79-79 Motriz Revista de Educação Física; V. 13, N. 1 (2007); 79-79 1980-6574 reponame:Motriz (Online) instname:Universidade Estadual Paulista (UNESP) instacron:UNESP |
instname_str |
Universidade Estadual Paulista (UNESP) |
instacron_str |
UNESP |
institution |
UNESP |
reponame_str |
Motriz (Online) |
collection |
Motriz (Online) |
repository.name.fl_str_mv |
Motriz (Online) - Universidade Estadual Paulista (UNESP) |
repository.mail.fl_str_mv |
motriz@rc.unesp.br||mauerber@rc.unesp.br||azanesco@rc.unesp.br |
_version_ |
1800215768815632384 |