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Mauro Goncalves - One of the best experts on this subject based on the ideXlab platform.
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Antagonist coactivation of trunk stabilizer muscles during Pilates exercises
Journal of Bodywork and Movement Therapies, 2013Co-Authors: Denise Martineli Rossi, Mary Hellen Morcelli, Nise Ribeiro Marques, Camilla Zamfolini Hallal, Dain P. Laroche, Mauro Goncalves, Marcelo Tavella NavegaAbstract:Summary The purpose of this study was to compare the antagonist coactivation of the local and global trunk muscles during mat-based exercises of Skilled Modern Pilates. Twelve women performed five exercises and concurrently, surface EMG from internal oblique (OI), multifidus (MU), rectus abdominis (RA) and Iliocostalis lumborum (IL) muscles was recorded bilaterally. The percentage of antagonist coactivation between local (OI/MU) and global muscles (RA/IL) was calculated. Individuals new to the practice of these exercises showed differences in coactivation of the trunk muscles between the exercises and these results were not similar bilaterally. Thus, in clinical practice, the therapist should be aware of factors such as compensation and undesirable rotation movements of the trunk. Moreover, the coactivation of global muscles was higher bilaterally in all exercises analyzed. This suggests that the exercises of Skilled Modern Pilates only should be performed after appropriate learning and correct execution of all principles, mainly the Centering Principle.
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emg activity of trunk stabilizer muscles during centering principle of pilates method
Journal of Bodywork and Movement Therapies, 2013Co-Authors: Nise Ribeiro Marques, Mary Hellen Morcelli, Camilla Zamfolini Hallal, Mauro GoncalvesAbstract:Summary This study aimed to analyze the electromyographic (EMG) activity of Iliocostalis lumborum (IL), internal oblique (IO) and multifidus (MU) and the antagonist cocontraction (IO/MU and IO/IL) during the performance of Centering Principle of Pilates Method. Participating in this study were eighteen young and physically fit volunteers, without experience in Pilates Method, divided in two groups: low back pain group (LBPG, n = 8) and control group (CG, n = 10). Two isometric contractions of IO muscles (Centering Principle) were performed in upright sitting posture. EMG signal amplitude was calculated by Root Mean Square (RMS), which was normalized by RMS maximum value. The common area method to calculate the antagonist cocontraction index was used. MU and IO activation and IO/MU cocontraction ( p
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Comparação do sinal EMG e das características da passada em diferentes protocolos de corrida incremental Comparación de la actividad EMG y características del pasado en los diferentes protocolos de raza incrementales Comparison of EMG activity and step characteristics of different running incremental protocols
Escola de Educação Física e Esporte da Universidade de São Paulo (EEFEUSP), 2012Co-Authors: Carina Helena Wasem Fraga, Roberto Bianco, Mauro GoncalvesAbstract:O objetivo do presente estudo foi comparar o sinal eletromiográfi co, a frequência e a amplitude de passada entre diferentes intensidades de corrida: 60%, 80% e 100% da velocidade máxima em dois protocolos incrementais. Participaram deste estudo 11 corredores do sexo masculino. Os protocolos de corrida foram realizados com velocidades iniciais de 10 km.hr-1, com incrementos de 1 km.hr-1 a cada três minutos até a exaustão, que diferiram em relação ao intervalo entre cada estágio incremental: 30 e 120 segundos. Foram analisados valores RMS dos músculos iliocostal lombar, reto femoral, vasto lateral, vasto medial, bíceps femoral, tibial anterior, e gastrocnêmio, e a amplitude e frequência de passada. Os valores RMS mostraram aumento entre as intensidades para quase todos os músculos, e não foram influenciados pelo tipo de protocolo utilizado para maioria dos músculos. A frequência e amplitude de passada apresentaram contribuições percentuais diferenciadas para o aumento da velocidade de corrida.El objetivo de este estudio es comparar la actividad electromiográfica, la amplitud y la frecuencia del pasado entre las diferentes intensidades de carrera: 60%, 80% y 100% de la velocidad máxima en dos protocolos adicionales. En el estudio participaron 11 corredores. Los protocolos se realizaron con velocidades de carrera iniciales de 10 km.hr-1, con incrementos de 1 km.hr-1 cada tres minutos hasta que se agoten, que diferían en el intervalo entre cada etapa incremental: 30 a 120 segundos. Se analizaron los valores RMS de las Iliocostalis lumbar, rectus femoris, vastus lateralis, vastus medialis, biceps femoris, tibialis anterior, gastrocnemius, la amplitud y la frecuencia del pasado. Los valores de RMS mostró un aumento entre las intensidades para casi todos los músculos, y no fueron influenciadas por el tipo de protocolo utilizado. Las contribuciones de frecuencia y amplitud de pasado presentaran porcentaje diferenciado para aumentar la velocidad de funcionamiento.The aim of this study was to compare the electromyographic signal and the stride frequency and length among different intensities of running: 60%, 80% and 100% of maximum speed in two incremental protocols. The study included 11 male runners. The protocols were performed with initial running speed of 10 km.hr-1, with increments of 1 km.hr-1 at every three minutes until exhaustion. The two protocols differed in the interval between each incremental stage: 30 to 120 seconds. We analyzed RMS values of the Iliocostalis lumbar, rectus femoris, vastus lateralis, vastus medialis, biceps femoris, tibialis anterior, gastrocnemius lateralis, and the stride length and frequency. The RMS values showed an increase among intensities for almost all muscles, and were not influenced by the type of protocol used for most muscles. The contribution of stride length and frequency were percentile different as the running speed increased
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analysis of strength and resistance parameters of the lumbar spinae erector muscles during isometric exercise at different effort levels
Revista Brasileira De Medicina Do Esporte, 2005Co-Authors: Mauro Goncalves, Fernando ArbosaAbstract:The low-back pain has demonstrated to be a common finding among athletes and particularly the overload in the lumbar column resulting from a strength or isometric resistance involvement of muscles of this segment as result of the muscular fatigue has been considered as important etiological factor for its development. In this context, tests used for the training evaluation of the lumbar spinae erector muscles are emphasized. In the present study, the analysis of the strength and isometric resistance parameters was used with the objective of evaluating responses of these muscles during maximal and sub-maximal voluntary isometric contractions (MVIC) in two situations: with fatigue and without fatigue induced by isometric exercise performed until exhaustion. Nine male healthy volunteers performed MVIC before and after vertebral column extension exercises supporting 5%, 10%, 15% and 20% of the MVIC. In each one of these situations, the electromyographic signal (EMG) of the Iliocostalis and multifidus muscles as well as the strength level generated in the MVIC were recorded. Muscular fatigue was identified through the MVIC values decrease verification and median frequency (MF) of the EMG signals obtained after isometric exercise. The results demonstrated that while the strength was able to evidence muscular fatigue, the MF demonstrated in a statistically significant way the Iliocostalis and multifidus muscles fatigue, and the multifidus muscles presented a higher muscular fatigue level. Interestingly, loads between 5% and 20% of the MVIC induced the same level of muscular fatigue. Thus, although the strength generated during vertebral column extension after isometric exercise-induced exhaustion remains unchanged, probably due to the action of accessory muscles, the overload on the vertebral column is developed as result of the vertebral column stability involvement resulting from the muscular fatigue identified after isometric exercise.
Gijsbertus Jacob Verkerke - One of the best experts on this subject based on the ideXlab platform.
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development and evaluation of a passive trunk support system for duchenne muscular dystrophy patients
Journal of Neuroengineering and Rehabilitation, 2018Co-Authors: Mohammad Nauzef Mahmood, Laura H C Peeters, Micha I Paalman, Gijsbertus Jacob Verkerke, Idsart Kingma, Jaap H Van DieenAbstract:Patients with Duchenne muscular dystrophy gradually lose the ability to use different muscles of their body. Consequently, they lose the ability to stabilize their trunk against gravity. This hinders them to effectively perform different daily activities. In this paper, we describe the design, realization and evaluation of a trunk orthosis for these patients that should allow them to move their trunk and maintain stability. This study aimed to primarily assess the effectiveness of the trunk support system in terms of unloading of trunk muscles, so only healthy participants were recruited for this phase of the study. Measurements were done on 10 healthy participants (23.4±2.07 [M±SD] years old, average body weight 68.42±24.22 [M±SD] kg). The experiment comprised maintaining a constant trunk posture in three different device conditions (control without orthosis and two conditions with different configurations of the orthosis), at four different flexion angles (10°, 20°, 30°, 40°) for each device condition and for two load conditions (with and without stretching the arms). Electromyography (EMG) signals from the trunk muscles were measured to estimate activation levels of the trunk muscles (Iliocostalis, longissimus, external oblique and rectus abdominis) and a motion capture system was used to record the movement of the participants during the experiment. Wearing the orthosis caused reductions in longissimus and Iliocostalis activity. The average muscle activity level was 5%–10% of maximum voluntary contraction in the unsupported conditions for those particular muscles. This level was reduced to 3%–9% of maximal voluntary contraction for the supported conditions. No effect on external oblique and rectus abdominis activity was observed. Moreover, no pain or discomfort was reported by any of the participants during the experiment. The results from the current experiment also suggests the necessity of lumber stabilizing systems while using trunk orthosis. The developed orthosis reduces trunk muscle activation level and provides a solid step for further development of support systems for Duchenne muscular dystrophy patients. The current study was approved by the medical ethics committee Arnhem-Nijmegen (study number: NL53143.091.15 ), The Netherlands.
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Development and evaluation of a passive trunk support system for Duchenne muscular dystrophy patients
Journal of NeuroEngineering and Rehabilitation, 2018Co-Authors: Mohammad Nauzef Mahmood, Laura H C Peeters, Micha I Paalman, Gijsbertus Jacob Verkerke, Idsart Kingma, Jaap H. Van DieënAbstract:Background Patients with Duchenne muscular dystrophy gradually lose the ability to use different muscles of their body. Consequently, they lose the ability to stabilize their trunk against gravity. This hinders them to effectively perform different daily activities. In this paper, we describe the design, realization and evaluation of a trunk orthosis for these patients that should allow them to move their trunk and maintain stability. Method This study aimed to primarily assess the effectiveness of the trunk support system in terms of unloading of trunk muscles, so only healthy participants were recruited for this phase of the study. Measurements were done on 10 healthy participants (23.4±2.07 [M±SD] years old, average body weight 68.42±24.22 [M±SD] kg). The experiment comprised maintaining a constant trunk posture in three different device conditions (control without orthosis and two conditions with different configurations of the orthosis), at four different flexion angles (10°, 20°, 30°, 40°) for each device condition and for two load conditions (with and without stretching the arms). Electromyography (EMG) signals from the trunk muscles were measured to estimate activation levels of the trunk muscles (Iliocostalis, longissimus, external oblique and rectus abdominis) and a motion capture system was used to record the movement of the participants during the experiment. Results Wearing the orthosis caused reductions in longissimus and Iliocostalis activity. The average muscle activity level was 5%–10% of maximum voluntary contraction in the unsupported conditions for those particular muscles. This level was reduced to 3%–9% of maximal voluntary contraction for the supported conditions. No effect on external oblique and rectus abdominis activity was observed. Moreover, no pain or discomfort was reported by any of the participants during the experiment. The results from the current experiment also suggests the necessity of lumber stabilizing systems while using trunk orthosis. Conclusion The developed orthosis reduces trunk muscle activation level and provides a solid step for further development of support systems for Duchenne muscular dystrophy patients. Trial registration The current study was approved by the medical ethics committee Arnhem-Nijmegen (study number: NL53143.091.15 ), The Netherlands.
Mohammad Nauzef Mahmood - One of the best experts on this subject based on the ideXlab platform.
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development and evaluation of a passive trunk support system for duchenne muscular dystrophy patients
Journal of Neuroengineering and Rehabilitation, 2018Co-Authors: Mohammad Nauzef Mahmood, Laura H C Peeters, Micha I Paalman, Gijsbertus Jacob Verkerke, Idsart Kingma, Jaap H Van DieenAbstract:Patients with Duchenne muscular dystrophy gradually lose the ability to use different muscles of their body. Consequently, they lose the ability to stabilize their trunk against gravity. This hinders them to effectively perform different daily activities. In this paper, we describe the design, realization and evaluation of a trunk orthosis for these patients that should allow them to move their trunk and maintain stability. This study aimed to primarily assess the effectiveness of the trunk support system in terms of unloading of trunk muscles, so only healthy participants were recruited for this phase of the study. Measurements were done on 10 healthy participants (23.4±2.07 [M±SD] years old, average body weight 68.42±24.22 [M±SD] kg). The experiment comprised maintaining a constant trunk posture in three different device conditions (control without orthosis and two conditions with different configurations of the orthosis), at four different flexion angles (10°, 20°, 30°, 40°) for each device condition and for two load conditions (with and without stretching the arms). Electromyography (EMG) signals from the trunk muscles were measured to estimate activation levels of the trunk muscles (Iliocostalis, longissimus, external oblique and rectus abdominis) and a motion capture system was used to record the movement of the participants during the experiment. Wearing the orthosis caused reductions in longissimus and Iliocostalis activity. The average muscle activity level was 5%–10% of maximum voluntary contraction in the unsupported conditions for those particular muscles. This level was reduced to 3%–9% of maximal voluntary contraction for the supported conditions. No effect on external oblique and rectus abdominis activity was observed. Moreover, no pain or discomfort was reported by any of the participants during the experiment. The results from the current experiment also suggests the necessity of lumber stabilizing systems while using trunk orthosis. The developed orthosis reduces trunk muscle activation level and provides a solid step for further development of support systems for Duchenne muscular dystrophy patients. The current study was approved by the medical ethics committee Arnhem-Nijmegen (study number: NL53143.091.15 ), The Netherlands.
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Development and evaluation of a passive trunk support system for Duchenne muscular dystrophy patients
Journal of NeuroEngineering and Rehabilitation, 2018Co-Authors: Mohammad Nauzef Mahmood, Laura H C Peeters, Micha I Paalman, Gijsbertus Jacob Verkerke, Idsart Kingma, Jaap H. Van DieënAbstract:Background Patients with Duchenne muscular dystrophy gradually lose the ability to use different muscles of their body. Consequently, they lose the ability to stabilize their trunk against gravity. This hinders them to effectively perform different daily activities. In this paper, we describe the design, realization and evaluation of a trunk orthosis for these patients that should allow them to move their trunk and maintain stability. Method This study aimed to primarily assess the effectiveness of the trunk support system in terms of unloading of trunk muscles, so only healthy participants were recruited for this phase of the study. Measurements were done on 10 healthy participants (23.4±2.07 [M±SD] years old, average body weight 68.42±24.22 [M±SD] kg). The experiment comprised maintaining a constant trunk posture in three different device conditions (control without orthosis and two conditions with different configurations of the orthosis), at four different flexion angles (10°, 20°, 30°, 40°) for each device condition and for two load conditions (with and without stretching the arms). Electromyography (EMG) signals from the trunk muscles were measured to estimate activation levels of the trunk muscles (Iliocostalis, longissimus, external oblique and rectus abdominis) and a motion capture system was used to record the movement of the participants during the experiment. Results Wearing the orthosis caused reductions in longissimus and Iliocostalis activity. The average muscle activity level was 5%–10% of maximum voluntary contraction in the unsupported conditions for those particular muscles. This level was reduced to 3%–9% of maximal voluntary contraction for the supported conditions. No effect on external oblique and rectus abdominis activity was observed. Moreover, no pain or discomfort was reported by any of the participants during the experiment. The results from the current experiment also suggests the necessity of lumber stabilizing systems while using trunk orthosis. Conclusion The developed orthosis reduces trunk muscle activation level and provides a solid step for further development of support systems for Duchenne muscular dystrophy patients. Trial registration The current study was approved by the medical ethics committee Arnhem-Nijmegen (study number: NL53143.091.15 ), The Netherlands.
Cesar Fernandezdelaspenas - One of the best experts on this subject based on the ideXlab platform.
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myofascial trigger points pain disability and sleep quality in patients with chronic nonspecific low back pain
Pain Medicine, 2013Co-Authors: Juan J Iglesiasgonzalez, Maria T Munozgarcia, Daiana Priscila Rodriguesdesouza, Francisco Alburquerquesendin, Cesar FernandezdelaspenasAbstract:Objective To investigate the difference in the presence of trigger points (TrPs) between patients with chronic nonspecific low back pain (LBP) and healthy people, and to determine the relationship of TrPs with the intensity of ongoing pain, disability, and sleep quality. Design A cross-sectional study. Setting The role of TrPs in LBP has not been determined. Patients Forty-two patients with nonspecific LBP (50% women), aged 23–55 years old, and 42 age- and sex-matched controls participated. Outcome Measures TrPs were bilaterally explored within the quadratus lumborum, Iliocostalis lumborum, psoas, piriformis, gluteus minimus, and gluteus medius muscles in a blinded design. TrPs were considered active if the subject recognized the local and referred pain as familiar symptoms, and TrPs were considered latent if the pain was not recognized as a familiar symptom. Pain measures were collected with a numerical pain rate scale, disability was assessed with the Roland–Morris questionnaire, and sleep quality was determined with the Pittsburgh Sleep Quality Index. Results Patients with nonspecific LBP exhibited a greater disability and worse sleep quality than healthy controls ( P < 0.001). Patients with nonspecific LBP exhibited a mean of 3.5 ± 2.3 active TrPs. Further, patients with nonspecific LBP showed a greater ( P < 0.001) number of latent TrPs (mean: 2.0 ± 1.5) than healthy controls (mean: 1.0 ± 1.5). Active TrPs in the quadratus lumborum, Iliocostalis lumborum, and gluteus medius muscles were the most prevalent in patients with nonspecific LBP. A greater number of active TrPs was associated with higher pain intensity (rs = 0.602; P < 0.001) and worse sleep quality (rs = 0.338; P = 0.03). Conclusions The local and referred pain elicited by active TrPs in the back and hip muscles contributes to pain symptoms in nonspecific LBP. Patients had higher disability and worse sleep quality than controls. The number of active TrPs was associated with pain intensity and sleep quality. It is possible that a complex interaction among these factors is present in patients with nonspecific LBP.
Gonçalves Mauro - One of the best experts on this subject based on the ideXlab platform.
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Antagonist coactivation of trunk stabilizer muscles during Pilates exercises
2013Co-Authors: Rossi, Denise Martineli, Marques, Nise Ribeiro, Morcelli, Mary Hellen, Hallal, Camilla Zamfolini, Gonçalves Mauro, Laroche, Dain P., Navega, Marcelo TavellaAbstract:The purpose of this study was to compare the antagonist coactivation of the local and global trunk muscles during mat-based exercises of Skilled Modern Pilates. Twelve women performed five exercises and concurrently, surface EMG from internal oblique (OI), multifidus (MU), rectus abdominis (RA) and Iliocostalis lumborum (IL) muscles was recorded bilaterally. The percentage of antagonist coactivation between local (OI/MU) and global muscles (RA/IL) was calculated. Individuals new to the practice of these exercises showed differences in coactivation of the trunk muscles between the exercises and these results were not similar bilaterally. Thus, in clinical practice, the therapist should be aware of factors such as compensation and undesirable rotation movements of the trunk. Moreover, the coactivation of global muscles was higher bilaterally in all exercises analyzed. This suggests that the exercises of Skilled Modern Pilates only should be performed after appropriate learning and correct execution of all principles, mainly the Centering Principle. © 2013 Elsevier Ltd. All rights reserved
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EMG activity of trunk stabilizer muscles during Centering Principle of Pilates Method
2013Co-Authors: Marques, Nise Ribeiro, Morcelli, Mary Hellen, Hallal, Camilla Zamfolini, Gonçalves MauroAbstract:This study aimed to analyze the electromyographic (EMG) activity of Iliocostalis lumborum (IL), internal oblique (IO) and multifidus (MU) and the antagonist cocontraction (IO/MU and IO/IL) during the performance of Centering Principle of Pilates Method. Participating in this study were eighteen young and physically fit volunteers, without experience in Pilates Method, divided in two groups: low back pain group (LBPG, n = 8) and control group (CG, n = 10). Two isometric contractions of IO muscles (Centering Principle) were performed in upright sitting posture. EMG signal amplitude was calculated by Root Mean Square (RMS), which was normalized by RMS maximum value. The common area method to calculate the antagonist cocontraction index was used. MU and IO activation and IO/MU cocontraction (. p < 0.05) were higher in CG. The CG therefore showed a higher stabilizer muscles recruitment than LBPG during the performance of Centering Principle of Pilates Method. © 2012 Elsevier Ltd
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Comparação do sinal EMG e das características da passada em diferentes protocolos de corrida incremental
Universidade de São Paulo. Escola de Educação Física e Esporte, 2012Co-Authors: Fraga, Carina Helena Wasem, Bianco Roberto, Gonçalves MauroAbstract:The aim of this study was to compare the electromyographic signal and the stride frequency and length among different intensities of running: 60%, 80% and 100% of maximum speed in two incremental protocols. The study included 11 male runners. The protocols were performed with initial running speed of 10 km.hr-1, with increments of 1 km.hr-1 at every three minutes until exhaustion. The two protocols differed in the interval between each incremental stage: 30 to 120 seconds. We analyzed RMS values of the Iliocostalis lumbar, rectus femoris, vastus lateralis, vastus medialis, biceps femoris, tibialis anterior, gastrocnemius lateralis, and the stride length and frequency. The RMS values showed an increase among intensities for almost all muscles, and were not influenced by the type of protocol used for most muscles. The contribution of stride length and frequency were percentile different as the running speed increased.El objetivo de este estudio es comparar la actividad electromiográfica, la amplitud y la frecuencia del pasado entre las diferentes intensidades de carrera: 60%, 80% y 100% de la velocidad máxima en dos protocolos adicionales. En el estudio participaron 11 corredores. Los protocolos se realizaron con velocidades de carrera iniciales de 10 km.hr-1, con incrementos de 1 km.hr-1 cada tres minutos hasta que se agoten, que diferían en el intervalo entre cada etapa incremental: 30 a 120 segundos. Se analizaron los valores RMS de las Iliocostalis lumbar, rectus femoris, vastus lateralis, vastus medialis, biceps femoris, tibialis anterior, gastrocnemius, la amplitud y la frecuencia del pasado. Los valores de RMS mostró un aumento entre las intensidades para casi todos los músculos, y no fueron influenciadas por el tipo de protocolo utilizado. Las contribuciones de frecuencia y amplitud de pasado presentaran porcentaje diferenciado para aumentar la velocidad de funcionamiento.O objetivo do presente estudo foi comparar o sinal eletromiográfi co, a frequência e a amplitude de passada entre diferentes intensidades de corrida: 60%, 80% e 100% da velocidade máxima em dois protocolos incrementais. Participaram deste estudo 11 corredores do sexo masculino. Os protocolos de corrida foram realizados com velocidades iniciais de 10 km.hr-1, com incrementos de 1 km.hr-1 a cada três minutos até a exaustão, que diferiram em relação ao intervalo entre cada estágio incremental: 30 e 120 segundos. Foram analisados valores RMS dos músculos iliocostal lombar, reto femoral, vasto lateral, vasto medial, bíceps femoral, tibial anterior, e gastrocnêmio, e a amplitude e frequência de passada. Os valores RMS mostraram aumento entre as intensidades para quase todos os músculos, e não foram influenciados pelo tipo de protocolo utilizado para maioria dos músculos. A frequência e amplitude de passada apresentaram contribuições percentuais diferenciadas para o aumento da velocidade de corrida
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Electromyographic activity of trunk muscles during exercises with flexible and non-flexible poles
IOS Press, 2011Co-Authors: Gonçalves Mauro, Hallal, Camilla Zamfolini, Marques, Nise R., Van Dieen, Jaap H.Abstract:Objective: Hand-held flexible poles which are brought into oscillation to cause alternating forces on trunk, are advocated as training devices that are supposed to solicit increased levels of stabilizing trunk muscle activity. The aim of this study was to verify this claim by comparing electromyographic (EMG) activity of trunk muscles during exercises performed with a flexible pole and a rigid pole.Methods: Twelve healthy females performed three different exercises with flexible and rigid poles. EMG activity of Iliocostalis lumborum (IL), multifidus (MU), rectus abdominis (RA), external oblique (EO) and internal oblique (IO), and was continuously measured. The EMG signals were analyzed in time domain by calculation of the Root Mean Square (RMS) amplitudes over 250 ms windows. The mean RMS-values over time were normalized by the maximum RMS obtained for each muscle.Results: The IO showed a 72% greater EMG activity during the exercises performed with the flexible pole than with the rigid pole (p = 0.035). In exercises performed in standing, the IO was significantly more active than when sitting (p = 0.006).Conclusion: As intended, the cyclic forces induced by the oscillating pole did increase trunk muscle activation. However, the effect was limited and significant for the IO muscle only
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Lumbar muscles recruitment during resistance exercise for upper limbs
Elsevier B.V., 2009Co-Authors: Castelo Oliveira, Anderson De Souza, Gonçalves MauroAbstract:The aim of this study was to evaluate the EMG activity of lumbar multifidus (MU), longissimus thoracis (LT) and Iliocostalis (IC) muscles during an upper limb resistance exercise (biceps curl). Ten healthy males performed maximal voluntary isometric contraction (MVC) of the trunk extensors, after this, the biceps curl exercise was executed at 25%, 30%, 35% and 40% one repetition maximum during 1 min, with 10 min rest between them. EMG root mean square (RMS) and median frequency (MFreq) were calculated for each lifting and lowering of the bar during the exercise bouts, to calculate slopes and intercepts. The results showed increases in the RMS and decreases in the MFreq slopes. RMS slopes were no different between muscles, indicating similar fatigue process along the exercise irrespective of the load level. MU and LT presented higher RMS irrespective of the load level, which can be related to the specific function during the standing position. on the other hand, IC and MU presented higher MFreq intercepts compared to LT, demonstrating possible differences in the muscle fiber conduction velocity of these muscles. These findings suggest that trunk muscles are differently activate during upper limb exercises, and the fatigue process affects the lumbar muscles similarly. (C) 2008 Elsevier Ltd. All rights reserved
