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Effect of low-level laser therapy (GaAs 904 nm) in skeletal muscle fatigue and biochemical markers of muscle damage in rats

LEAL JUNIOR, Ernesto Cesar Pinto; LOPES-MARTINS, Rodrigo Alvaro Brandao; ALMEIDA, Patricia de; RAMOS, Luciano; IVERSEN, Vegard V.; BJORDAL, Jan Magnus
Fonte: SPRINGER Publicador: SPRINGER
Tipo: Artigo de Revista Científica
Português
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66.43%
We wanted to test if pre-exercise muscle irradiation with 904 nm laser affects the development of fatigue, blood lactate levels and creatine kinase (CK) activity in a rat model with tetanic contractions. Thirty male Wistar rats were divided into five groups receiving either one of four different laser doses (0.1, 0.3, 1.0 and 3.0 J) or a no-treatment control group. Laser irradiation was performed immediately before the first contraction for treated groups. Electrical stimulation was used to induce six tetanic tibial anterior muscle contractions with 10 min intervals between them. Contractions were stopped when the muscle force fell to 50% of the peak value for each contraction; blood samples were taken before the first and immediately after the sixth contraction. The relative peak forces for the sixth contraction were significantly better (P < 0.05) in the two laser groups irradiated with highest doses [151.27% (SD +/- A 18.82) for 1.0 J, 144.84% (SD +/- A 34.47) for 3.0 J and 82.25% (SD +/- A 11.69) for the control group]. Similar significant (P < 0.05) increases in mean performed work during the sixth contraction for the 1.0 and 3.0 J groups were also observed. Blood lactate levels were significantly lower (P < 0.05) than the control group in all irradiated groups. All irradiated groups except the 3.0 J group had significantly lower post-exercise CK activity than the control group. We conclude that pre-exercise irradiation with a laser dose of 1.0 J and 904 nm wavelength significantly delays muscle fatigue and decreases post-exercise blood lactate and CK in this rat model.

Effect of 830 nm low-level laser therapy in exercise-induced skeletal muscle fatigue in humans

LEAL JUNIOR, Ernesto Cesar Pinto; LOPES-MARTINS, Rodrigo Alvaro Brandao; VANIN, Adriane Aver; BARONI, Bruno Manfredini; GROSSELLI, Douglas; MARCHI, Thiago De; IVERSEN, Vegard V.; BJORDAL, Jan Magnus
Fonte: SPRINGER LONDON LTD Publicador: SPRINGER LONDON LTD
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
66.41%
This study aimed to investigate the effect of 830 nm low-level laser therapy (LLLT) on skeletal muscle fatigue. Ten healthy male professional volleyball players entered a crossover randomized double-blinded placebo-controlled trial. Active LLLT (830 nm wavelength, 100 mW output, spot size 0.0028 cm(2), 200 s total irradiation time) or an identical placebo LLLT was delivered to four points on the biceps humeri muscle immediately before exercises. All subjects performed voluntary biceps humeri contractions with a load of 75% of the maximum voluntary contraction (MVC) force until exhaustion. After active LLLT the mean number of repetitions was significantly higher than after placebo irradiation [mean difference 4.5, standard deviation (SD) +/- 6.0, P = 0.042], the blood lactate levels increased after exercises, but there was no significant difference between the treatments. We concluded that 830 nm LLLT can delay the onset of skeletal muscle fatigue in high-intensity exercises, in spite of increased blood lactate levels.

Avaliação da fadiga do músculo multífido lombar e ativação do transverso do abdome em indivíduos com hérnia discal lombar; Evaluation of lumbar multifidus muscle fatigue and activation of the transversus abdominis in patients with lumbar disc herniation

Ramos, Luiz Armando Vidal
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 05/12/2012 Português
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66.46%
Introdução: A dor lombar crônica pode ser definida como dor ou desconforto persistente por mais de 12 semanas nos níveis lombar e sacral da coluna vertebral. Cerca de 5% dos pacientes apresentam comprometimento de raiz nervosa, e uma razão comum é a herniação discal. Os músculos multífido lombar (ML) e transverso do abdome (TrA) são preferencialmente acometidos frente a episódios de dor lombar. Contudo, há escassa literatura que tenha avaliado a fadiga do ML e a capacidade de ativação do TrA em indivíduos com e sem hérnia de disco lombar. Objetivo: Avaliar a fadiga do músculo multífido lombar e a capacidade de ativação do transverso do abdome em indivíduos com hérnia de disco e dor lombar crônica, e controle. Métodos: Participaram do estudo 60 indivíduos com idade entre 20 a 50 anos, divididos em dois grupos: Hérnia Lombar (GHL) com dor há mais de três meses (n=30) e Grupo Controle (GC) sem dor (n=30). A fadiga do multífido lombar foi avaliada com a eletromiografia de superfície durante a realização do teste de esforço de Sorensen e a capacidade de ativação do TrA pela Unidade de Biofeedback Pressórico (UBP). A dor foi avaliada com a escala visual analógica - EVA e questionário McGill de Dor, a incapacidade funcional pelo Índice de incapacidade de Oswestry e o relato de esforço percebido pela escala de Borg. O nível de significância adotado foi de 5%. Na análise dos dados de frequência mediana quanto menor o valor maior a fadiga. Resultados: Houve aumento da fadiga nos dois grupos...

Electromyographic fatigue threshold of the biceps brachii muscle during dynamic contraction

Oliveira, Anderson de Souza Castelo; Gonçalves, M.; Cardozo, A. C.; Barbosa, F. S S
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 167-175
Português
Relevância na Pesquisa
56.56%
The purpose of this study was to identify the Electromyographic Fatigue Threshold (EMG FT) of the biceps brachii muscle bilaterally during the elbow flexion in tests performed in different times: 30 second test, 1 minute test and fatiguing test, in concentric (CC) and eccentric (EC) phases. Nine healthy young men performed the elbow flexion with loads corresponding at 25%, 35% and 45% of the one repetition maximum (1-RM) in separate days. The results indicated that the test applied for the biceps brachii muscle during elbow flexion induced a progressive increment of EMG activity with time indicating muscle fatigue and allowed the identification of the EMG FT. The three tests presented no difference of EMG FT between CC and EC phases bilaterally.

Electromyographic fatigue threshold of the biceps brachii: The effect of endurance time

Oliveira, A. S C; Cardozo, A. C.; Barbosa, F. S S; Gonçalves, M.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 37-42
Português
Relevância na Pesquisa
56.55%
Muscle fatigue can be a limiting factor to determine index as the electromyographic fatigue threshold (EMGFT) due the alterations in motivation and disconfots. This way, the purpose of this study was to identify the right biceps brachii and left biceps brachii obtained from repetitive elbow flexions at each 10% of total time. Nine healthy subjects performed the exercise named biceps curl until exhaustion with 25%, 35%, and 45% of one repetition maximum, in three different days. EMG amplitude (root mean square - RMS) was obtained for concentric contractions during these load levels and correlated with time to determine the slope values for each load and them detemine the EMGFT. The EMGFT was obtained within of each 10% of total time and they were compared by analysis of variance. The results showed a progressive increase in RMS with time, for both muscles in all loads, characterizing the muscle fatigue process, and for the EMGFT values ware not found predominantly significant differences between the execution time, as well as between muscles (right biceps × left biceps). This protocol allowed to identify the EMGFT to both muscles during the biceps curl, which was similar at different percentage of total time, indicating the possibility to reduce the length of the contraction test without the need to maintain the contraction until exhaustion. Further studies are needed to evaluate the applicability of this method to determining the effects on performance.

The effect of muscle fatigue on the last stride before stepping down a curb

Barbieri, Fabio Augusto; Lee, Yun-Ju; Gobbi, Lilian Teresa Bucken; Pijnappels, Mirjam; Van Dieën, Jaap H.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 542-546
Português
Relevância na Pesquisa
66.62%
The stride before landing may be important during stepping down. The aim of this study was to analyze variability of the kinematics and muscle activity in the final stride before stepping down a curb, with and without ankle and knee muscle fatigue. Ten young participants walked at self-selected speed and stepped down a height difference (10-cm) in ongoing gait. Five trials were performed before and after a muscle fatigue protocol (one day: ankle muscle fatigue, another day: knee muscle fatigue). The analysis focused on the trailing leg during the last but one and the last step on the higher level. Kinematics and muscle activity were recorded. Fatigue increased variability of foot-step horizontal distance in the last step on the higher level of the trailing limb, as well as in the first steps on the lower level for both limbs. This appeared due to an increase in the range of motion of the knee joint after both fatigue protocols. Participants additionally showed an increased ankle and hip ROM and decreased knee ROM. Our results suggest a loss of control under fatigue reflected in a higher variability of trailing and leading limb-step horizontal distances, with compensatory changes to limit fatigue effects, such as a redistribution of movement over joints. © 2012 Elsevier B.V.

Effect of 808 nm low-level laser therapy in exercise-induced skeletal muscle fatigue in elderly women

Toma, Renata Luri; Tucci, Helga Tatiana; Moreira Antunes, Hanna Karen; Pedroni, Cristiane Rodrigues; Oliveira, Anamaria Siriani de; Buck, Isabela; Ferreira, Pryscilla Dieguez; Vassao, Patricia Gabrielle; Muniz Renno, Ana Claudia
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica Formato: 1375-1382
Português
Relevância na Pesquisa
66.51%
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Aging process involves several structural changes in muscle tissue which lead to decrease in musculoskeletal function. One of the most common physiological modifications is the increase in fatigability in elderly people, which leads to inability to maintain strength and motor control. In this context, low-level laser therapy (LLLT) has demonstrated positive results in reducing fatigue during physical exercise. Thus, this study aimed to investigate the effects of LLLT on skeletal muscle fatigue in elderly women. Twenty-four subjects divided in two groups entered a crossover randomized triple-blinded placebo-controlled trial. Active LLLT (808 nm wavelength, 100 mW, energy 7 J) or an identical placebo LLLT was delivered on the rectus femoris muscle immediately before a fatigue protocol. Subjects performed a fatigue protocol which consisted of voluntary isotonic contractions of knee flexion-extension performed with a load corresponding to 75 % of 1-MR (Maximum Repetition) during 60 s. Surface electromyography (SEMG) signals were recorded from rectus femoris muscle of dominant lower limb to evaluate peripheral fatigability using median frequency analysis of SEMG signal. The number of repetitions of flexion-extension during fatigue protocol was also compared between groups. The values of median frequency were used to calculate the slope coefficient. The results showed no difference in the slope comparing placebo LLLT and active LLLT groups (p = 0.293). However...

Interactions of age and leg muscle fatigue on unobstructed walking and obstacle crossing

Barbieri, Fabio Augusto; Rocha dos Santos, Paulo Cezar; Simieli, Lucas; Orcioli-Silva, Diego; van Dieen, Jaap H.; Bucken Gobbi, Lilian Teresa
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 985-990
Português
Relevância na Pesquisa
66.57%
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Older adults commonly report muscle fatigue, which may be associated with reduced walking ability. Elderly may have insufficient awareness of the balance threat caused by muscle fatigue. The aim of this study was to analyze the interaction effects of aging and leg muscle fatigue on gait parameters in walking and obstacle crossing. One hundred and twenty men, who were divided in six groups according to their age (20-29 years, 30-39 years, 40-49 years, 50-59 years, 60-69 years, above 70 years), participated in this study. Participants performed three trials of unobstructed level ground walking and obstacle crossing during walking before and after quadriceps muscle fatigue. To induce fatigue, participants performed a repeated sit-to-stand task from a chair with arms across the chest to a pre-determined cadence (30 cycles/min) using a metronome. Spatial-temporal gait parameters (stride length, duration, and speed, step width, and trailing and leading heel-clearance) were analyzed, and compared by two-way ANOVA (group and fatigue). The results confirmed our hypothesis, showing age-related effects of leg muscles fatigue in both gait conditions. From 40 years old, participants modulated spatial-temporal and vertical impulses in both tasks more in response to fatigue than younger participants...

Effect of triceps surae and quadriceps muscle fatigue on the mechanics of landing in stepping down in ongoing gait

Barbieri, F. A.; Gobbi, L. T. B.; Lee, Y. J.; Pijnappels, M.; van Dieen, J. H.
Fonte: Taylor & Francis Ltd Publicador: Taylor & Francis Ltd
Tipo: Artigo de Revista Científica Formato: 934-942
Português
Relevância na Pesquisa
66.59%
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); The aim of this study was to evaluate the effects of muscle fatigue of triceps surae and quadriceps muscles in stepping down in ongoing gait. We expected that the subjects would compensate for muscle fatigue to prevent potential loss of balance in stepping down. A total of 10 young participants walked over a walkway at a self-selected velocity to step down a height difference of 10-cm halfway. Five trials were performed before and after a muscle fatigue protocol. Participants performed two fatigue protocols: one for ankle muscle fatigue and another for knee muscle fatigue. Kinematics of and ground reaction forces on the leading leg were recorded. Fatigue did not cause a change in the frequency of heel or toe landing. Our results indicate that in stepping down fatigue effects are compensated by redistributing work to unfatigued muscle groups and by gait changes aimed at enhancing balance control, which was however only partially successful.Practitioner Summary: Problems with transitions between levels in gait are common causes of falls. Fatigue can affect the ability to dissipate energy gained during the step down. The main finding was that young adults recruited unfatigued muscle groups and adjusted their gait pattern to compensate the fatigue effects during landing.

Analysis of localized muscle fatigue in elderly women with and without a history of falls using electromyographic signal frequency parameters

Silva, Lissara Ellen; Pedroni, Cristiane Rodrigues; Navega, Marcelo Tavella; Scheicher, Marcos Eduardo
Fonte: Universidade Federal de Santa Catarina Publicador: Universidade Federal de Santa Catarina
Tipo: Artigo de Revista Científica Formato: 390-398
Português
Relevância na Pesquisa
66.46%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); One of the problems that most concerns the elderly population is the falling, which can be caused by muscle fatigue. The objective of this study was to compare median electromyographic frequency values for the vastus lateralis muscle and the lateral portion of the gastrocnemius muscle (as parameters of electromyographic fatigue) in elderly people with and without a history of falls. A total of 20 healthy, physically active, elderly women who had or had not suffered falls were enrolled on the study. Median electromyographic signal frequencies were analyzed for the vastus lateralis muscle and the lateral portion of the gastrocnemius muscle in isometric contraction. ANOVA and Student’s t test were used for comparisons, to a cutoff of p ≤ 0.05. Median frequencies for the gastrocnemius and vastus lateralis muscles were both higher in the group with a history of falling, but without statistical significance. It was also observed that the rate of decline in median frequency was greater in the group with a history of falling. It can be concluded that elderly people with a history of falling have a greater tendency to fatigue of the gastrocnemius and vastus lateralis muscles than their peers with no history of falling.; Um dos problemas que mais preocupam a população idosa são as quedas...

Effect of peripheral muscle fatigue during the testing of handgrip strength

Fernandes,Alex de Andrade; Brito,Ciro José; Vieira,Breno Cesar; Marins,João Carlos Bouzas
Fonte: Pontifícia Universidade Católica do Paraná Publicador: Pontifícia Universidade Católica do Paraná
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2014 Português
Relevância na Pesquisa
66.5%
Introduction Muscle fatigue is a phenomenon associated with physical work. It is common in endurance sports, physical fitness tests and daily activities. Some tests can be directly affected by the effect of peripheral muscle fatigue, including the handgrip strength (HGS) test, which is considered baseline measure for assessing the functionality of the hand. Objectives a) verify the effect of peripheral muscle fatigue (between trials) during the testing of HGS, with a 60-second recovery interval; b) to analyze whether there is a difference in considering the mean value obtained in three trials or the best result as the final result. Materials and methods The final sample comprised 1,279 men. We followed the standard methodology and used a hydraulic hand dynamometer. Results There were statistically significant differences (P < 0.05) in the dominant hand among all the trials: first (46.5 ± 8.6 Kgf), second (46.4 ± 8.5 Kgf) and third (46.1 ± 8.6 Kgf); and also in the non-dominant hand: first (44.9 ± 8.4 Kgf), second (44.5 ± 8.3 Kgf) and third (44.0 ± 8.3 Kgf). We also found statistically significant differences (P < 0.05) between the two ways of considering the final result. For the dominant hand...

Effects of the infrared lamp illumination during the process of muscle fatigue in rats

Abou-Hala,Andréia Zarzour; Barbosa,Daniella Galvão; Marcos,Rodrigo Labat; Pacheco-Soares,Cristina; Silva,Newton Soares da
Fonte: Instituto de Tecnologia do Paraná - Tecpar Publicador: Instituto de Tecnologia do Paraná - Tecpar
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/05/2007 Português
Relevância na Pesquisa
66.41%
In this study the effects of infrared lamp illumination during the muscle fatigue process was studied. Three different groups (n=5) were used: one control group and two treated (Infrared Lamp 780-1400nm), with the energy densities of 0.5 and 1.0 J/cm² and time of illumination of 300 seconds. The treated animals were illuminated in one point directly in the tibialis muscle, after the first tetanic contraction out of six, with an interval between each tetany. The results were registered in an electrophysiograph and the intensity of the force of contraction in grams was analysed. It was observed that the control group presented a reduction in the intensity of the force of contraction, while the treated group managed to maintain it, which was clearly evident in the energy density of 0.5 J/cm². It was concluded that the use of the infrared lamp illumination was efficient concerning resistance to muscle fatigue.

Fatigue Alters in Vivo Function Within and Between Limb Muscles During Locomotion

Biewener, Andrew A.; Higham, Timothy E.
Fonte: Royal Society, The Publicador: Royal Society, The
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
56.55%
Muscle fatigue, a reduction in force as a consequence of exercise, is an important factor for any animal that moves, and can result from both peripheral and/or central mechanisms. Although much is known about whole-limb force generation and activation patterns in fatigued muscles under sustained isometric contractions, little is known about the in vivo dynamics of limb muscle function in relation to whole-body fatigue. Here we show that limb kinematics and contractile function in the lateral (LG) and medial (MG) gastrocnemius of helmeted guineafowl (Numida meleagris) are significantly altered following fatiguing exercise at 2 m sK1 on an inclined treadmill. The two most significant findings were that the variation in muscle force generation, measured directly from the muscles’ tendons, increased significantly with fatigue, and fascicle shortening in the proximal MG, but not the distal MG, decreased significantly with fatigue. We suggest that the former is a potential mechanism for decreased stability associated with fatigue. The region-specific alteration of fascicle behaviour within the MG as a result of fatigue suggests a complex response to fatigue that probably depends on muscle–aponeurosis and tendon architecture not previously explored. These findings highlight the importance of studying the integrative in vivo dynamics of muscle function in response to fatigue.; Organismic and Evolutionary Biology

Does motoneuron adaptation contribute to muscle fatigue?

Nordstrom, M.; Gorman, R.; Laouris, Y.; Spielmann, J.; Stuart, D.
Fonte: John Wiley & Sons Inc Publicador: John Wiley & Sons Inc
Tipo: Artigo de Revista Científica
Publicado em //2007 Português
Relevância na Pesquisa
66.39%
To help reduce the gap between the cellular physiology of motoneurons (MNs) as studied "bottom-up" in animal preparations and the "top-down" study of the firing patterns of human motor units (MUs), this article addresses the question of whether motoneuron adaptation contributes to muscle fatigue. Findings are reviewed on the intracellularly recorded electrophysiology of spinal MNs as studied in vivo and in vitro using animal preparations, and the extracellularly recorded discharge of MUs as studied in conscious humans. The latter "top-down" approach, combined with kinetic measurements, has provided most of what is currently known about the neurobiology of muscle fatigue, including its task and context dependencies. It is argued that although the question addressed is still open, it should now be possible to design new "bottom-up" research paradigms using animal preparations that take advantage of what has been learned with the use of relatively noninvasive quantitative procedures in conscious humans.; Michael A. Nordstrom, Robert B. Gorman, Yiannis Laouris, John M. Spielmann and Douglas G. Stuart; Published in Muscle & Nerve, 2007; 35 (2):135-158 at www.interscience.wiley.com

Stabilometric response during single-leg stance after lower limb muscle fatigue

Bruniera,Carlos A. V.; Rogerio,Fernando R. P. G.; Rodacki,Andre L. F.
Fonte: Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia Publicador: Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2013 Português
Relevância na Pesquisa
66.49%
OBJECTIVE: This study sought to analyze the effect of muscle fatigue induced by active isotonic resistance training at a moderate intensity by measuring the knee extension motion during the stabilometric response in a single-leg stance among healthy university students who perform resistance training on a regular basis. METHOD: Eleven healthy university students were subjected to a one-repetition maximum (1RM) test. In addition, stabilometric assessment was performed before and after the intervention and consisted of a muscle fatiguing protocol, in which knee extension was selected as the fatiguing task. The Shapiro-Wilk test was used to investigate the normality of the data, and the Wilcoxon test was used to compare the stabilometric parameters before and after induction of muscle fatigue, at a significance level of p≤0.05. Descriptive statistics were used in the analysis of the volunteers' age, height, body mass, and body mass index (BMI). RESULTS: The sample population was 23.1±2.7 years of age, averaged 1.79.2±0.07 m in height and 75.6±8.0 Kg in weight, and had a BMI of 23.27±3.71 Kg.m-2. The volunteers performed exercises 3.36±1.12 days/week and achieved a load of 124.54±22.07 Kg on 1RM and 74.72±13.24 Kg on 60% 1RM. The center of pressure (CoP) oscillation on the mediolateral plane before and after fatigue induction was 2.89±0.89 mm and 4.09±0.59 mm...

Analysis of localized muscle fatigue in elderly women with and without a history of falls using electromyographic signal frequency parameters

Silva,Lissara Ellen; Pedroni,Cristiane Rodrigues; Navega,Marcelo Tavella; Scheicher,Marcos Eduardo
Fonte: Universidade Federal de Santa Catarina Publicador: Universidade Federal de Santa Catarina
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2014 Português
Relevância na Pesquisa
66.46%
One of the problems that most concerns the elderly population is the falling, which can be caused by muscle fatigue. The objective of this study was to compare median electromyographic frequency values for the vastus lateralis muscle and the lateral portion of the gastrocnemius muscle (as parameters of electromyographic fatigue) in elderly people with and without a history of falls. A total of 20 healthy, physically active, elderly women who had or had not suffered falls were enrolled on the study. Median electromyographic signal frequencies were analyzed for the vastus lateralis muscle and the lateral portion of the gastrocnemius muscle in isometric contraction. ANOVA and Student's t test were used for comparisons, to a cutoff of p ≤ 0.05. Median frequencies for the gastrocnemius and vastus lateralis muscles were both higher in the group with a history of falling, but without statistical significance. It was also observed that the rate of decline in median frequency was greater in the group with a history of falling. It can be concluded that elderly people with a history of falling have a greater tendency to fatigue of the gastrocnemius and vastus lateralis muscles than their peers with no history of falling.

Fadiga dos músculos eretores da espinha: um estudo eletromiográfico; Erector spime muscle fatigue: an electromyographic study

Barbosa, Fernando Sérgio Silva; Gonçalves, Mauro
Fonte: Universidade de São Paulo. Faculdade de Medicina Publicador: Universidade de São Paulo. Faculdade de Medicina
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; ; ; ; Formato: application/pdf
Publicado em 31/08/2005 Português
Relevância na Pesquisa
66.49%
Os músculos eretores da espinha são importantes responsáveis pela integridade física e funcional da coluna vertebral. Justifica-se o estudo da fadiga desses músculos, associada à dor lombar, pelas constantes demandas advindas das atividades da vida diária. Este estudo visou verificar a ocorrência e o comportamento da fadiga muscular, analisandoo sinal eletromiográfico dos músculos ileocostais e multífidos em um teste isométrico. Participaram do estudo nove voluntários do sexo masculino com média de idade de 20,4±1,3 anos, que foram submetidos a um teste de contração isométrica dos músculos eretores da espinha contra cargas de 5%, 10%, 15% e 20% da carga máxima. Para a captação dos sinais eletromiográficos foi utilizado um módulo de aquisição de sinais biológicos de quatro canais, aos quais foram conectados cabos e eletrodos, uma placa conversora analógica-digital e eletrodos de superfície posicionados bilateralmente sobre os músculos ileocostal emultífido. A fadiga muscular foi identificada pela verificação do aumento da amplitude do sinal eletromiográfico em função do tempo. O protocoloproposto revela-se eficaz para a verificação da ocorrência de fadiga emcontrações isométricas mantidas até a exaustão. Os resultados demonstraram que o músculo ileocostal evidenciou em geral maior fadigaque o músculo multífido. A comparação bilateral evidenciou que os músculos eretores da espinha do lado direito sofreram predominantemente maior fadiga.; The erector spinae muscles are important antigravity muscles...

Análise da fadiga dos músculos paraespinhais em indivíduos saudáveis na posição sentada; Analysis of erector spinae muscle fatigue in healthy subjects in the sitting position

Kawano, Marcio Massao; Universidade Estadual de Londrina. Londrina, PR. Brasil; Menacho, Maryela de Oliveira; Universidade Estadual de Londrina; Oliveira, Beatriz Ito Ramos; Boer, Marcela Carrilho; Souza, Roger Burgo; Cardoso, Jefferson Rosa; Universidade
Fonte: Universidade Federal de Santa Catarina. Florianópolis, SC. Brasil Publicador: Universidade Federal de Santa Catarina. Florianópolis, SC. Brasil
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; "Avaliado por Pares",; ; Avaliado por Pares; Experimental Formato: application/pdf; application/pdf
Publicado em 06/12/2008 Português
Relevância na Pesquisa
66.46%
http://dx.doi.org/10.5007/1980-0037.2009v11n1p30O objetivo deste estudo foi avaliar os parâmetros de freqüência e amplitude da eletromiografia de superfície durante a fadiga dos músculos paraespinhais em indivíduos saudáveis na posição sentada. Participaram do estudo 11 indivíduos do gênero masculino, saudáveis e livres de sintomas de dor lombar. Um eletromiógrafo de superfície foi utilizado para obtenção dos parâmetros eletromiográficos. Foram posicionados quatro eletrodos lateralmente aos processos espinhosos da primeira e quinta vértebras lombares. Os sinais foram registrados mediante a extensão de tronco na posição sentada contra a resistência de uma célula de carga. Foram utilizadas as cargas de 50% e 75% da contração isométrica voluntária máxima, por 25 segundos, para induzir os sujeitos à fadiga muscular. Os sinais eletromiográficos processados pelo algoritmo da Transformada Rápida de Fourier e pela raiz quadrática média foram submetidos à regressão linear para se determinar o índice de fadiga. A freqüência mediana do espectro de potência apresentou valores negativos, assim como a amplitude eletromiográfica valores positivos, o que representa a fadiga muscular. Quando se comparou a altura e o lado...

Analysis of localized muscle fatigue in elderly women with and without a history of falls using electromyographic signal frequency parameters; Análise da fadiga muscular localizada em idosas caidoras e não caidoras através de parâmetros de frequência do sinal eletromiográfico

Silva, Lissara Ellen; Universidade Estadual Paulista. Faculdade de Filosofia e Ciências. Departamento de Fisioterapia e Terapia Ocupacional. Marília, SP. Brasil.; Pedroni, Cristiane Rodrigues; Universidade Estadual Paulista. Faculdade de Filosofia e Ci
Fonte: Universidade Federal de Santa Catarina. Florianópolis, SC. Brasil Publicador: Universidade Federal de Santa Catarina. Florianópolis, SC. Brasil
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; "Avaliado por Pares",; Comparative studies; Avaliado por Pares; Estudo comparativo Formato: application/pdf
Publicado em 27/05/2014 Português
Relevância na Pesquisa
66.46%
DOI: http://dx.doi.org/10.5007/1980-0037.2014v16n4p390One of the problems that most concerns the elderly population is the falling, which can be caused by muscle fatigue. The objective of this study was to compare median electromyographic frequency values for the vastus lateralis muscle and the lateral portion of the gastrocnemius muscle (as parameters of electromyographic fatigue) in elderly people with and without a history of falls. A total of 20 healthy, physically active, elderly women who had or had not suffered falls were enrolled on the study. Median electromyographic signal frequencies were analyzed for the vastus lateralis muscle and the lateral portion of the gastrocnemius muscle in isometric contraction. ANOVA and Student’s t test were used for comparisons, to a cutoff of p ≤ 0.05. Median frequencies for the gastrocnemius and vastus lateralis muscles were both higher in the group with a history of falling, but without statistical significance. It was also observed that the rate of decline in median frequency was greater in the group with a history of falling. It can be concluded that elderly people with a history of falling have a greater tendency to fatigue of the gastrocnemius and vastus lateralis muscles than their peers with no history of falling.; DOI: http://dx.doi.org/10.5007/1980-0037.2014v16n4p390Um dos problemas que mais preocupam a população idosa são as quedas...

Effect of muscle fatigue on posture control in soccer players during the short-pass movement. DOI: 10.5007/1980-0037.2011v13n5p348; Efeito da fadiga muscular sobre o controle postural durante o movimento do passe em atletas de futebol. DOI: 10.5007/1980-0037.2011v13n5p348

Baroni, Bruno Manfredini; Universidade Federal do Rio Grande do Sul. Laboratório de Pesquisa do Exercício. Porto Alegre, RS. Brasil; Wiest, Matheus Joner; Universidade Federal do Rio Grande do Sul. Laboratório de Pesquisa do Exercício. Porto Alegre, R
Fonte: Universidade Federal de Santa Catarina. Florianópolis, SC. Brasil Publicador: Universidade Federal de Santa Catarina. Florianópolis, SC. Brasil
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; "Avaliado por Pares",; Descriptive; Avaliado por Pares; Descritiva Formato: application/pdf; application/pdf
Publicado em 26/08/2011 Português
Relevância na Pesquisa
66.47%
Muscle fatigue is characterized by the inability to generate or maintain an expected effort or force level and negatively affects sports performance. One of the functional consequences of fatigue is a decrease in static and dynamic postural stability. The objective of this study was to evaluate the effect of muscle fatigue induced by high-intensity exercise on the dynamic postural stability of soccer players during the characteristic motor action of the sport: the short-pass. Twenty-seven male soccer players aged 14 to 16 years performed the short-pass movement on a stabilometric platform before and after a high-intensity exercise protocol performed on a cycle ergometer. After the fatigue protocol, the athletes presented a 31% increase in the mean velocity of the center of pressure displacement. Moreover, although the difference in the center of pressure displacement amplitude in the medial-lateral direction (15%) was not significant, displacement increased by 22% in the anterior-posterior direction. It was concluded that muscle fatigue promotes a decrease of postural stability during the short-pass movement in soccer players, probably compromising the sports performance of the athletes. ; A fadiga muscular é caracterizada pela incapacidade na geração ou manutenção de um nível de força...