Asociación entre variables de empuje Isométrico de media pierna (EIMP) con variables antropométricas y cualidades físicas en jugadores varones de Rugby Amateurs / Relationships between Isometric Mid-Thigh pull with anthropometric variables and physical qualities in Amateur Rugby players / Relações entre a puxada isométrica do meio da coxa com variáveis antropométricas e qualidades físicas em jogadores amadores de rugby

Objetivo: el objetivo de este estudio es describir el perfil de las variables del EIMP entre las dos posiciones de juego y determinar las posibles asociaciones con las características antropométricas y las cualidades físicas de un grupo de jugadores Rugby amateurs chilenos. Hipótesis: es por eso por lo que podemos plantear como hipótesis la existencia de asociaciones entre las variables de EIMP y las cualidades físicas de los jugadores de RU. Diseño metodológico: este estudio tiene un diseño de cohorte observacional, descriptivo y correlacional. Se investigó la asociación existente entre las variables de EIMP con las pruebas físicas y las variables antropométricas. Fueron evaluados treinta y dos jugadores de rugby varones de nivel amateurs chilenos (promedio ( DE, edad, 23,3 ( 5,4 años). Resultados: para la variable Masa Muscular se encontraron asociaciones grandes (r = 0.53) (p = 0.001) con la FM y asociaciones moderadas (r = 0,48) (r = 0,47) (r = 0,44) (r = 0,46) con F50, F100, F150 y F200 respectivamente. También se pueden observar las asociaciones grandes (R2 = 0,305) (R2 = 0,297) (R2 = 0,267) entre 1RM PB y F200, F100 y F150, respectivamente. Conclusión: en conclusión, este estudio puede demostrar la existencia de asociaciones estadísticamente significativas entre algunas de las variables antropométricas y físicos con las variables de Fuerza de EIMP en jugadores de RU amateurs chilenos.

OBJECTIVE: The objective of this study is to describe the profile of the EIMP variables between two playing positions and to determine its possible associations with anthropometric characteristics and physical qualities of a group of Chilean amateur rugby players. HYPOTHESIS: There are associations between the EIMP variables and the physical qualities of UR players. METHODOLOGICAL DESIGN: This study has an observational, descriptive and correlational cohort design. The association between the EIMP variables, from the physical tests, and the anthropometric variables was investigated. Thirty-two Chilean amateur-level male rugby players were evaluated (mean ( SD, age, 23.3 ( 5.4 years). RESULTS: For the Muscle Mass variable, large associations were found (r=0.53) (p=0.001) to FM, and moderate associations (r=0.48) (r=0.47) (r=0.44) (r =0.46) to F50, F100, F150, and F200 respectively. Large associations (R2=0.305) (R2=0.297) (R2=0.267) between 1RM PB and F200, F100, and F150, respectively, can also be observed. CONCLUSION: In conclusion, this study can demonstrate the existence of statistically significant associations between some of the anthropometric and physical variables and the EIMP Strength variables in Chilean amateur UR players.

OBJETIVO: O objetivo deste estudo é descrever o perfil das variáveis EIMP entre as duas posições de jogo e determinar as possíveis associações com as características antropométricas e qualidades físicas de um grupo de jogadores amadores de rugby chilenos. HIPÓTESE: É por isso que podemos hipotetizar a existência de associações entre as variáveis do EIMP e as qualidades físicas dos jogadores do RU. DESENHO METODOLÓGICO: Este estudo tem um desenho de coorte observacional, descritivo e correlacional. Investigou-se a associação entre as variáveis do EIMP com os testes físicos e as variáveis antropométricas. Trinta e dois jogadores de rugby masculinos de nível amador chileno foram avaliados (média ( DP, idade, 23,3 ( 5,4 anos). RESULTADOS: Para a variável Massa Muscular foram encontradas grandes associações (r=0,53ejercicio y cualidades físicos) (r=0,47) (r=0,44) (r=0,46) com F50, F100, F150 e F200 respectivamente. Grandes associações (R2=0,305) (R2=0,297) (R2=0,267) entre 1RM PB e F200, F100 e F150 respebaloncestotambém podem ser observadas. CONCLUSÃO: Em conclusão, este estudo pode demonstrar a existência de associações estatisticamente significativas entre algumas das variáveis antropométricas e físicas com as variáveis EIMP Força em jogadores amadores do RU chilenos.

Isometric resistance training effects on lower limb muscle activity / Efeitos do treino isométrico resistido sobre a atividade muscular dos membros inferiores / Efectos del entrenamiento de resistencia isométrica en la actividad muscular de los miembros inferiores

ABSTRACT Introduction The high muscular strength in the hip joint is the foundation of jumping ability. Isometric resistance training includes the process of takeoff and landing, recruiting a more extensive set of muscle groups. Objective Analyze the isometric resistance training effects on lower limb muscle activity, including the coactivation of the antagonist's muscles. Methods By mathematical statistics, weight-bearing isometric resistance training effects on lower extremity maximal muscle strength and explosive power were observed. Changes in coactivation and preactivation levels of lower extremity antagonist muscles data are evaluated and compared before and after isometric resistance training. Results The peak angular velocity of the joints at the hip and ankle in the isometric resistance training group is significantly higher than the control group. There was no significant difference in the peak angular velocity of the knee between the groups (P<0.05). Conclusion Isometric resistance training can shorten the return period, shorten the amortization period, and increase the energy conversion capacity in the muscle-tendon complex. Evidence level II; Therapeutic Studies - Investigating the results.

RESUMO Introdução A elevada força muscular na articulação do quadril é o que fundamenta a habilidade do salto. O treino resistido isométrico inclui o processo de decolagem e aterrissagem, recrutando um conjunto maior de grupos musculares. Objetivo Analisar os efeitos do treino isométrico resistido sobre a atividade muscular dos membros inferiores, incluindo a coativação dos músculos antagonistas. Métodos Por meio de estatísticas matemáticas, observa-se o efeito do treino isométrico resistido com sustentação de peso na força muscular máxima das extremidades inferiores e sua potência explosiva. Os dados das mudanças nos níveis de coativação e pré-ativação dos músculos antagonistas dos membros inferiores são avaliados e comparados antes e após o treino isométrico resistido. Resultados O pico de velocidade angular das articulações no quadril e tornozelo do grupo de treino isométrico resistido é significativamente maior do que no grupo controle. Não houve diferença significativa no pico de velocidade angular do joelho entre os dois grupos (P<0,05). Conclusão O treino isométrico resistido pode encurtar o período de retorno, encurtar o período de amortização e aumentar a capacidade de conversão de energia no complexo músculo-tendíneo. Nível de evidência II; Estudos terapêuticos - Investigação de resultados.

RESUMEN Introducción La elevada fuerza muscular en la articulación de la cadera es lo que fundamenta la capacidad de saltar. El entrenamiento de resistencia isométrica incluye el proceso de despegue y aterrizaje, reclutando un conjunto mayor de grupos musculares. Objetivo Analizar los efectos del entrenamiento de resistencia isométrica en la actividad muscular de las extremidades inferiores, incluyendo la coactivación de los músculos antagonistas. Métodos Mediante la estadística matemática, se observó el efecto del entrenamiento de resistencia isométrica con carga de peso sobre la fuerza muscular máxima de las extremidades inferiores y su potencia explosiva. Los datos de los cambios en los niveles de coactivación y preactivación de los músculos antagonistas de las extremidades inferiores se evalúan y comparan antes y después del entrenamiento de resistencia isométrica. Resultados La velocidad angular máxima de las articulaciones en la cadera y el tobillo en el grupo de entrenamiento de resistencia isométrica es significativamente mayor que en el grupo de control. No hubo diferencias significativas en la velocidad angular máxima de la rodilla entre los dos grupos (P<0,05). Conclusión El entrenamiento de resistencia isométrica puede acortar el periodo de retorno, reducir el periodo de amortización y aumentar la capacidad de conversión de energía en el complejo músculo-tendón. Nivel de evidencia II; Estudios terapéuticos - Investigación de resultados.

Strength of scapular elevation in women with TMD and asymptomatic women - a cross-sectional study

Temporomandibular disorder (TMD) is recognized for its high prevalence, presenting characteristic signs and symptoms. Cervical spine pain is present in 70% of diagnosed TMD cases. Aim To verify if women with TMD present changes in isometric muscle strength in the scapula elevation. Methods This is an observational, cross-sectional study. Thirty-five women, aged 22.89±2.04 years, were divided into the TMD group (TMDG), diagnosed with TMD according to the DC/TMD, and control group (CG), with asymptomatic individuals. The volunteers accessed a online link by the smartphone in order to answer questions on personal data, the Fonseca Anamnestic Index (FAI), Neck Disability Index (NDI), and Masticatory preference. In all participants, evaluation of the force of the scapula elevation muscles was performed, using a load cell model MM-100 (Kratos® SP, Brazil). Data were analyzed descriptively using the maximum, mean, and standard deviation and a two-way ANCOVA test was applied for all variables. A significance level of 5% was considered. Results There were no statistically significant differences between the TMDG and CG for the maximal and mean muscle strength of scapular elevation. There were statistically significant differences in FAI (p <0.001*) between the CG and the TMDG. Conclusion Based on the results, it was not possible to confirm the hypothesis that women diagnosed with TMD present lower isometric strength during scapular elevation (right/left).

Gender-based Variations in Trunk Motion and Isometric Strength in Young Adults with Low Back Pain: A Prospective Case-control Study / Variações baseadas em gênero no movimento e na força isométrica do tronco em jovens adultos com dor lombar: Um estudo de caso-controle prospectivo

Abstract Objective To determine gender-based variations in trunk range of motion (RoM) and isometric strength (IS) in symptomatic and asymptomatic young adults. Methods In this prospective case-control study, 73 subjects with low back pain (LBP) and 80 asymptomatic subjects were analyzed. Dynamometer-based device trunk RoM and IS measurements in extension, flexion, and rotation were compared in both groups and gender-based subgroups. Multivariate analysis was used to determine factors influencing trunk RoM and IS. Results Symptomatic males had significantly less extension RoM and extension, flexion, and rotation isometric trunk strength (ITS) (p < 0.0001) compared with asymptomatic males, whereas no significant difference was found between asymptomatic and symptomatic females. However, the mean extension-flexion RoM and mean extension-flexion ITS ratios were significantly lower (p = 0.04) in asymptomatic females compared with symptomatic females. Female gender was significantly associated with less extension and flexion ITS in both asymptomatic and symptomatic subjects. Conclusion Males with LBP had significant global ITS weakness when compared with asymptomatic males. Despite no significant ITS difference in symptomatic versus asymptomatic females, LBP caused significant extension-flexion RoM and ITS imbalance in females. These gender-based variations in trunk RoM and IS, especially the extensor-flexor IS imbalance in females, must be considered while designing rehabilitation treatment protocols for LBP.

Resumo Objetivo Determinar as variações na amplitude de movimento (ADM) do tronco e na força isométrica do tronco (FIT) em jovens adultos sintomáticos e assintomáticos baseadas no gênero dos indivíduos. Métodos Neste estudo caso-controle prospectivo, 73 indivíduos com dor lombar (DL) e 80 indivíduos assintomáticos foram analisados. As medidas de ADM do tronco e FIT de extensão, flexão e rotação foram comparadas em ambos os grupos e em subgrupos organizados por gênero. A análise multivariada foi usada para determinar os fatores que influenciam a ADM do tronco e a FIT. Results Symptomatic males had significantly less extension RoM and extension, flexion, and rotation isometric trunk strength (ITS) (p < 0.0001) compared with asymptomatic males, whereas no significant difference was found between asymptomatic and symptomatic females. However, the mean extension-flexion RoM and mean extension-flexion ITS ratios were significantly lower (p = 0.04) in asymptomatic females compared with symptomatic females. Female gender was significantly associated with less extension and flexion ITS in both asymptomatic and symptomatic subjects. Conclusão Indivíduos do sexo masculino com DL apresentaram significativa fraqueza global relacionada à FIT quando comparados com indivíduos do sexo masculino assintomáticos. Apesar de não haver diferença significativa de FIT em indivíduos do sexo feminino sintomáticos versus assintomáticos, a DL impactou a ADM e a FIT de extensão-flexão em indivíduos do sexo feminino. Essas variações de ADM do tronco e FIT baseadas no sexo, especialmente o desequilíbrio extensor-flexor de força isométrica em indivíduos do sexo feminino, devem ser consideradas ao projetar-se protocolos de tratamento de reabilitação para lombalgia.

High frequency transcutaneous electrical stimulation in the immediate postoperative period of anterior cruciate ligament reconstruction: a randomized clinical trial / Estimulação elétrica transcutânea de alta frequência no pós operatório imediato de reconstrução do ligamento cruzado anterior: um ensaio clínico randomizado

INTRODUCTION: The anterior cruciate ligament (ACL) is an important structure for knee stability. Transcutaneous electrical nerve stimulation (TENS) is an electrical current applied for significant pain relief. OBJECTIVE: To evaluate the effects of high-frequency TENS on the immediate postoperative period of ACL reconstruction. METHODS: 46 patients in the postoperative period of ACL reconstruction were randomly assigned to a control group (CG=23) and a TENS group (TG=23). Knee range of motion (ROM), pain, muscle strength, and drug intake were assessed before surgery and 24 and 48 hours after surgery. The TENS intervention protocol started in the recovery room, shortly after surgery, and was maintained continuously for the first 48 hours after surgery. RESULTS: The TENS group (TG) significantly controlled the increased level of postoperative pain (p<0.05) and significantly increased flexion ROM (p<0.05). When compared to the Control group (CG), the TENS group had a lower intake of ketoprofen (48.27%), diazepam (256.98%), and dipyrone (121.21%), morphine (320.77%), and tramadol (437.46%). CONCLUSION: Continuous high-frequency TENS significantly reduced pain intensity and significantly improved ROM, muscle strength, and drug intake in the postoperative period of ACL reconstruction.

Different types of mechanical vibration application on EMG response and strength performance

Abstract Aim: The present study aimed to compare the strength performance and the neuromuscular activity during one maximum repetition test (1RM), and the maximum voluntary isometric contractions (MVIC) performed with whole-body vibration (WBV), local vibration (LV), and no vibration (NV). Methods: The sample consisted of 15 males, experienced in strength training for at least 6 months, which performed all strength tests in the barbell curl exercise across randomized trials on the following conditions: NV, WBV, and LV. During all tests, the normalized root means square values of the electromyographic signals (EMGRMS) of the biceps brachii and brachioradialis were recorded and compared between the conditions. The one-way ANOVAs with repeated measures were used to compare the results of 1RM and MVIC tests and the normalized EMGRMS between the conditions. When necessary, a post hoc Scott-Knott test was used to identify the differences reported in the ANOVAs. The significance level adopted was α < 0.05. Results: The EMGRMS response of the biceps brachii and brachioradialis muscles during the 1RM and MVIC tests presented significantly higher values at LV compared to WBV, and NV (p < 0.001). The 1RM tests, and the MVIC results were similar between conditions (p = 0.9803; p = 0.061, respectively). Conclusion: These results indicate that the application of MV was not sufficient to increase strength performance.

Evaluación de un programa kinésico de fortalecimiento muscular en adultos mayores con alteración del equilibrio / Assessment of a Kinesthetic Program for Muscle Strengthening in Older Adults with Balance Impartment

Introducción: El aumento de la población adulta mayor es uno de los grandes cambios demográficos en Chile, por lo que resulta necesario establecer abordajes terapéuticos eficaces para prevenir caídas y, consecuentemente, la dependencia funcional en este grupo etario. Objetivo: Evaluar la eficacia de un programa kinésico de prevención de caídas mediante fortalecimiento muscular de extremidad inferior en adultos mayores de 65 años con alteración del equilibrio, en comparación con el programa kinésico convencional. Métodos: Ensayo clínico aleatorizado no farmacológico, incluyó un grupo experimental y un grupo control con 25 participantes en cada grupo. La modalidad del tratamiento experimental es más educativa y participativa que el convencional. La eficacia de cada tratamiento fue evaluada mediante la variación de parámetros de equilibrio estático y dinámico al segundo y tercer mes de tratamiento (resultados principales). Resultados: Los resultados secundarios fueron: fuerza, potencia y diámetro pierna - muslo. Se evaluó la eficacia de ambos programas por el modelo multinivel, se consideraron las variables tiempo y tratamiento. Resultados: Hubo mejorías significativas en parámetros de equilibrio estático y dinámico con ambos tratamientos. La eficacia del tratamiento experimental fue superior a la del convencional en parámetros de potencia muscular y aumento de diámetros de ambos muslos y pierna izquierda. El factor tiempo de tratamiento aportó significativamente a la eficacia. Conclusiones: Ambos tratamientos mejoran los parámetros de equilibrio, pero el tratamiento experimental es más eficaz sobre parámetros de potencia muscular. Con su modalidad educativa y participativa este tratamiento podría optimizar resultados para prevenir caídas del adulto mayor en el nivel primario de atención(AU)

Introduction: The increase in the older adult population is one of the great demographic changes in Chile, a reason why it is necessary to establish effective therapeutic approaches to prevent falls and, consequently, functional dependence in this age group. Objective: To assess the efficacy of a kinesthetic program for the prevention of falls through lower limb muscle strengthening in adults over 65 years of age with impaired balance, in comparison with the conventional kinesthetic program. Methods: Nonpharmacological randomized clinical trial including an experimental group and a control group, with 25 participants each. The modality of experimental treatment is more educational and participatory than the conventional one. The efficacy of each treatment was assessed based on the variation of static and dynamic balance parameters at the second and third months of treatment (main results). Secondary outcomes included strength, power, and leg-thigh diameter. The efficacy of both programs was assessed using the multilevel model; the variables time and treatment were considered. Results: There were significant improvements in static and dynamic balance parameters with both treatments. The efficacy of the experimental treatment was higher than the conventional one in parameters of muscular power and increase in diameters of both thighs and the left leg. The factor time of treatment contributed significantly to efficacy. Conclusions: Both treatments improve balance parameters, but the experimental treatment is more effective regarding muscle power parameters. With its educational and participatory modality, this treatment could optimize results to prevent falls in the older adult at the primary level of care(AU).

Teste de força prancha em crianças: reprodutibilidade, confiabilidade e relação com o teste sit-up / Plank strength test in children: reproducibility, reliability and relationship with the sit-up test

: Os objetivos deste estudo são verificar a reprodutibilidade e confiabilidade do teste "Prancha" em escolares de 6 a 12 anos; e identificar a associação entre a medida de força isométrica no teste prancha com força/resistência abdominal no teste sit-up. Tratase de um estudo transversal com abordagem quantitativa, realizado com 221 escolares, 58,8% do sexo masculino, selecionados por conveniência em uma escola do Sul de Santa Catarina, Brasil. Avaliou-se a força isométrica abdominal por meio do teste prancha, adaptado de Mckenzie. O Teste sit-up foi avaliado seguindo o protocolo do PROESP-BR. Mensurou-se a reprodutibilidade e confiabilidade com teste de correlação intraclasse (CI) e gráfico de Bland e Altman. A correlação da força no teste prancha com o teste abdominais sit-up foi mensurada de acordo com o coeficiente de determinação (R2), Alfa de Cronbach e estimativa de Ômega de McDonald. A CI entre medidas do teste prancha apresentou concordância elevada (>0,70; p=0,001). Houve moderada relação entre teste, re-teste, prancha com o número de abdominais sit-up em um minuto (R2=0,43 masculino; R2=0,33 feminino). Os alfas de Cronbach e Ômega de McDonald foram elevados entre as três medidas (>0,80). Conclui-se que o teste prancha isométrica apresenta um elevado nível de reprodutibilidade, confiabilidade e elevada relação com a força abdominal sit-up. O teste prancha pôde ser utilizado como medida alternativa para a força isométrica abdominal nos escolares do presente estudo.(AU)

The objectives of this study are to verify the reproducibility and reliability of the "Plank" test in schoolchildren aged 6 to 12 years and to identify the association between isometric strength measurement in the plank test and abdominal resistance strength in the sit-up test. That is a cross-sectional study with a quantitative approach, performed with 221 students, 58.8% of the male gender, selected by convenience at a school in southern Santa Catarina, Brazil. Abdominal isometric strength was assessed by the plank test, it adapted from the Mckenzie. The sit-up test was evaluated following the PROESP-BR protocol. Reproducibility and reliability were measured with intraclass correlation test (IC) and Bland and Altmann graph. The correlation of the strength in the plank test with the sit-up abdominal test was measured according to the determination coefficient (R2), Cronbach's Alpha and McDonald Omega estimate. The IC between plank test measurements showed high agreement (> 0.70; p = 0.001). There was a moderate relationship between test, retest plank with the number of sit-ups in one minute (R2 = 0.43 male; R2 = 0.33 female). The Cronbach's alpha and McDonald's Omega are elevated between the three measures (> 0.80). It concluded that the proposed isometric plank test presents a high level of reproducibility, reliability, and a high relationship with sit-up abdominal strength. It indicates that Plank can be used as an alternative measure for isometric abdominal strength in schoolchildren of present study.(AU)

Delayed onset muscle soreness intensity affects muscular performance / El Dolor muscular de aparición tardía afecta el desempeño muscular

Abstract Background: The study of functional impact of delayed onset muscle soreness has been limited to describe the decline on maximal isometric contraction, but muscular work and time to peak torque has not been examined yet. Purpose: To describe the changes induced by a session of lengthening contractions on muscle performance and delayed onset muscle soreness (DOMS). Methods: A quasi-experimental study was conducted in the Institutional laboratory; Twenty healthy men; mean age 21 SD 0.34 were recruited, all subjects performed 200 lengthening contractions of the quadriceps at 120°/s. Isometric and isokinetic peak torque, muscular work, time to peak torque, DOMS and creatine kinase activity were assessed at baseline, 48 h and 96 h post-exercise. The muscle performance was assessed with an isokinetic dynamometer and DOMS with a visual analog scale (VAS). Results: Relative to baseline, isometric and isokinetic peak torque and muscular work decreased in ~30% at 48 h post-exercise; delayed onset muscle soreness increased ~300%, which remained at 96 h post-exercise. Conclusions: These reflect that the decline in muscular performance is due to the changes in peak torque and muscular work, which has greater implications on muscle function. No changes were detected in time to peak torque. The alterations in muscular performance variables are accompanied by delayed onset muscle soreness which has also a negative impact on force production (29% of the drop on peak torque is explain by soreness intensity).

Resumen Introducción: Los estudios de impacto funcional del dolor muscular de aparición tardía (DMAT) se han limitado a describir la disminución de la contracción isométrica máxima, pero aún no se ha examinado el trabajo muscular y el tiempo del torque máximo. Objetivo: Describir los cambios inducidos por una sesión de ejercicio excéntrico sobre el rendimiento muscular y DMAT. Método: se realizó un estudio cuasi-experimental, los participantes fueron veinte hombres sanos; edad media 21 DE 0,34, todos los sujetos realizaron 200 contracciones excéntricas del cuádriceps a 120°/s. Se evaluó el torque pico isométrico e isocinético, el trabajo muscular, el tiempo hasta el torque máximo, DMAT y la actividad de la creatina quinasa al inicio, 48 h y 96 h después del ejercicio, el rendimiento muscular se evaluó con un dinamómetro isocinético y DOMS con una escala análoga visual (EAV). Resultados: en relación con la línea de base, el torque pico isométrico e isocinético y el trabajo muscular disminuyeron en ~ 30 % a las 48 h post-ejercicio; El dolor muscular de aparición tardía aumentó ~300 %, que permaneció 96 h después del ejercicio. Conclusiones: los resultados reflejan que la disminución del rendimiento muscular se debe a los cambios en el torque pico y trabajo muscular, lo que tiene mayores implicaciones en la función muscular. No se detectaron cambios en el tiempo hasta el torque máximo. Las alteraciones en las variables de rendimiento muscular se acompañan de DMAT que también tiene un impacto negativo en la producción de fuerza (el 29 % de la caída en el torque máximo se explica por la intensidad del dolor).

Análise de diferentes tarefas para normalização do sinal elétrico do músculo orbicular da boca pela contração voluntária máxima: estudo piloto / Analysis of different tasks to normalize the electrical signal of the orbicularis oris muscle by maximum voluntary contraction: pilot study

RESUMO Objetivo pesquisar a atividade elétrica do músculo orbicular da boca em quatro diferentes tarefas isométricas e indicar a mais apropriada para utilização como referência na normalização do sinal elétrico do músculo orbicular da boca pela contração voluntária máxima. Métodos participaram do estudo 22 indivíduos, sendo dez do sexo masculino e 12 do feminino, com idades entre 20 e 33 anos. A atividade elétrica das porções superior e inferior do músculo orbicular da boca foi registrada durante a realização das seguintes tarefas isométricas: protrusão labial com fechamento, protrusão labial sem fechamento, contrarresistência com a placa de resistência labial e preensão de lábios. A ordem de realização das tarefas foi randomizada entre os participantes. Os dados foram comparados entre as tarefas, para cada seguimento labial. Resultados no segmento marginal superior, a tarefa com maior média e mediana de amplitude foi preensão labial, embora sem diferença significativa entre tarefas. O menor coeficiente de variação foi obtido na tarefa de contrarresistência com a placa de resistência labial. No segmento marginal inferior, a tarefa com maior média e mediana de amplitude foi protrusão labial com fechamento, que também teve o menor coeficiente de variação e diferença significativa entre as tarefas protrusão labial com fechamento e preensão, sendo os maiores valores obtidos na primeira. Conclusão indica-se como referência para a normalização do sinal elétrico do músculo orbicular da boca, pela contração voluntária máxima, a tarefa de protrusão labial com fechamento.

ABSTRACT Purpose To verify the electrical activity of the orbicularis oris in four different isometric tasks and to indicate the most appropriate task for use as a reference in the normalization of the electrical signal of the orbicularis oris muscle by maximum voluntary contraction. Methods Twenty-two individuals participated in the study, of which 10 were male and 12 were female, with ages ranging from 20 to 33 years. The electrical activity of the upper and lower parts of orbicularis oris muscle was recorded during the following isometric tasks: lip protrusion with bilabial closure; lip protrusion without bilabial closure; the counter resistance using the plate of labial resistance and lips prehension. The order of the tasks was randomized among participants. Data were compared between tasks for each lip part. Results in the upper marginal segment, the task with the highest mean and median amplitude was lip prehension, although there was no significant difference between tasks. The lowest coefficient of variation was obtained in the counter resistance task with the plate of labial resistance. In the lower marginal segment, the task with the highest mean and median amplitude was labial protrusion with lips closure, which also had the lowest coefficient of variation. In this segment, there was a significant difference between labial protrusion with lips closure and prehension, with the highest values obtained in the first task. Conclusion lip protrusion with bilabial closure is suggested as reference for the normalization of the electrical signal of the orbicularis oris muscle, by maximum voluntary contraction.

Isometric exercises have high responsiveness to lower limbs / Exercícios isométricos possuem alta responsividade para membros inferiores

INTRODUCTION: For post-surgical rehabilitation of the anterior cruciate ligament, the medialis and the lateralis vastus need to be worked on for good recovery. There is the discussion about the isometric and isotonic exercises to be used in the rehabilitation phase, and their results diverge in the literature. OBJECTIVE: This study aims to compare the activation of the medialis and the lateralis vastus in isometric and isotonic exercises. METHODS: Eleven subjects (seven men and four women) physically active and experienced in resistance training participated in the study. Anamnesis, anthropometric assessment, 10 Repetition maximum (RM) load test, maximum voluntary isometric contraction test and squat test were performed. RESULTS: For the vastus lateralis of the right leg, the electromyographic activity was significantly higher in the maximal isometric voluntary contraction compared to the dynamic squatting (p<0.05). The same was observed for the left leg (p<0.05). CONCLUSION: Recruitment of the medial and the lateral vastus in isometric exercises is higher in relation to isotonic exercises.

INTRODUÇÃO: Para a reabilitação pós-cirúrgica do ligamento cruzado anterior, os vastos medial e lateral precisam ser trabalhados visando uma boa recuperação. Discute-se a respeito dos exercícios isométricos e isotônicos a serem utilizados na fase de reabilitação, tendo seus resultados divergentes na literatura. OBJETIVO: Assim, o objetivo do presente estudo é comparar a ativação dos vastos medial e lateral em exercícios isométricos e isotônicos. MÉTODOS: Participaram deste estudo 11 sujeitos (sete homens e quatro mulheres), fisicamente ativos e com experiência em musculação. Foi realizada a anamnese, a avaliação antropométrica, o teste de carga de 10 repetições máximas (RM), o teste de contração voluntária isométrica máxima e o teste de agachamento. RESULTADOS: No vasto lateral da coxa direita, a atividade eletromiográfica foi significativamente maior na contração voluntária isométrica máxima em relação ao agachamento dinâmico (p<0,05). O mesmo foi observado na coxa esquerda (p<0,05). CONCLUSÃO: O recrutamento dos vastos medial e lateral em exercícios isométricos é maior em relação a exercícios isotônicos.

Entrenamiento de handgrip isométrico de alta intensidad en adultos mayores pre-hipertensos y con diagnóstico de hipertensión arterial sistémica etapa I / Effects high intensity isometric handgrip training on blood pressure of hypertensive older people

Background: Moderate isometric handgrip exercise is an effective tool in the management of systemic hypertension. Aim: To evaluate the effectiveness of a high intensity isometric handgrip exercise protocol for the reduction of blood pressure in older people with pre or stage-1 hypertension. Material and Methods: Twenty-three participants aged 73.8 ± 6.6 years (range 61-90) completed eight weeks of high intensity isometric handgrip training 2 times per week, performing 32 contractions maintained for 5 seconds, with breaks of 5 seconds. Blood pressure (BP) was measured at baseline and at the end of the intervention. Results: Systolic blood pressure decreased from 141 ± 11 to 127 ± 10 mmHg (p < 0.01). The decrease in diastolic blood pressure was from 79 ± 7 to 74 ± 6 mmHg (p < 0.01). Conclusions: A blood pressure reduction was recorded in these participants after a period of high intensity isometric handgrip exercise.

What is the best method to assess the abdominal wall? Restoring strength does not mean functional recovery / Qual é o melhor método para avaliação da parede abdominal? Restabelecer força não significa recuperação funcional

ABSTRACT Background: Restoring the contractile function to the abdominal wall is a major goal in hernia repair. However, the core understanding is required when choosing the method for outcome assessment. Aim: To assess the role of the anterolateral abdominal muscles on abdominal wall function in patients undergoing hernia repair by analysis of correlation between the surface electromyography activation signal of these muscles and torque produced during validated strength tests. Methods: Activation of the rectus abdominis, external oblique, and internal oblique/transverse abdominis muscles was evaluated by surface electromyography during two validated tests: Step: 1-A, isometric contraction in dorsal decubitus; 1-B, isometric contraction in lateral decubitus; 2-A, isokinetic Biodex testing; and 2-B, isometric Biodex testing. Results: Twenty healthy volunteers were evaluated. The linear correlation coefficient between root mean square/peak data obtained from surface electromyography signal analysis for each muscle and the peak torque variable was always <0.2 and statistically non-significant (p<0.05). The agonist/antagonist ratio showed a positive, significant, weak-to-moderate correlation in the external oblique (Peak, p=0.027; root mean square, 0.564). Surface electromyography results correlated positively among different abdominal contraction protocols, as well as with a daily physical activity questionnaire. Conclusions: There was no correlation between surface electromyography examination of the anterolateral abdominal wall muscles and torque measured by a validated instrument, except in a variable that does not directly represent torque generation.

RESUMO Racional: A devolução da funcionalidade contrátil da parede abdominal é uma das metas no reparo das hérnias abdominais. Contudo, o entendimento do core deve necessariamente fazer parte na escolha do método de avaliação desse desfecho. Objetivo: Avaliar o papel dos músculos da parede anterolateral na função da parede abdominal com base na correlação entre o sinal de ativação muscular obtido na eletromiografia de superfície e torque produzido durante testes de força validados. Métodos: A ativação dos músculos reto abdominal, oblíquo externo, e oblíquo interno e transverso foi avaliada por eletromiografia de superfície durante dois testes validados. Etapa: 1-A, contração isométrica em decúbito dorsal; 1-B, contração isométrica em decúbito lateral; 2-A, teste isocinético no Biodex; e 2-B, teste isométrico no Biodex. Resultados: Foram avaliados 20 voluntários saudáveis. O coeficiente de correlação linear entre os dados de valor quadrático médio/Pico obtidos análise do sinal da eletromiografia de superfície para cada músculo e o Pico de torque foram sempre <0,2 e estatisticamente insignificantes (p<0.05). A relação agonista/antagonista demonstrou correlação positiva, significativa e de fraca a moderada no músculo externo oblíquo (Pico, p=0,027; valor quadrático médio, 0,564). Os resultados eletromiografia de superfície estiveram positivamente correlacionados nos diferentes protocolos de contração abdominal e também com um questionário de atividade física diária. Conclusões: Não houve correlação entre o exame de eletromiografia de superfície e o torque mensurado por um instrumento validado, exceto em uma variável que não representa diretamente a geração de torque.

Muscle Activities of the Brachioradialis and Extensor Carpi Radialis Longus According to the Type of Backhand Stroke in Badminton / 대한스포츠의학회지

PURPOSE: The purpose of this study was to investigate the muscle activities of the brachioradialis and extensor carpi radialis longus according to the type of backhand stroke in badminton.METHODS: To measure the muscle activities, we used electromyography (EMG) equipment to measure EMG values by performing maximal voluntary contraction (MVC) of the forearm muscles, which depends on the type of backhand stroke. With these values, the %maximum voluntary isometric contraction values were obtained. The data were calculated using SPSS ver. 21.0 and one-way repeated measures analysis of variance with a post-hoc least significant difference test.RESULTS: In this study, the backhand clear achieved higher maximum muscle activity values than those by the backhand push, under clear, and drive in the brachioradialis. The backhand smash achieved higher maximum muscle activity values than those by the backhand push in the extensor carpi radialis longus.CONCLUSION: The backhand clear is associated with a higher injury rate than those associated with the backhand push, under clear, and drive. The backhand smash is associated with a higher rate of the occurrence of tennis elbow than that associated with the backhand push. To prevent injuries, it is considered that the forearm's strength, stretching before and after exercise, and sufficient time to rest are important.

Balance autonómico basal y durante el ejercicio isométrico en jóvenes con diferente reactividad cardiovascular / Basal autonomic balance and during the isometric exercise in young people with different cardiovascular reactivity

RESUMEN Introducción: El sistema nervioso autónomo desempeña un papel importante en los reajustes cardiovasculares al ejercicio. En la hiperreactividad cardiovascular existe una mayor sensibilidad del sistema simpático ante diferentes estímulos estresantes. Objetivo: Determinar las características del control autonómico cardíaco en adultos jóvenes con diferentes grados de reactividad cardiovascular en condiciones basales y durante el ejercicio isométrico. Método: La muestra estuvo constituida por 97 individuos de ambos sexos, y se dividió en tres grupos: normorreactivos, hiperreactivos y con respuesta hipertensiva, de acuerdo a la respuesta presora a la prueba del peso sostenido. A todos los individuos se les realizó un estudio de variabilidad de la frecuencia cardíaca en reposo y durante la prueba isométrica. Se estudiaron las variables en el dominio de la frecuencia: baja, alta, relación baja/alta en reposo, y los parámetros del diagrama de Poincaré en reposo y durante el ejercicio (valores de desviación estándar 1 [SD1], 2 [SD2], y la razón entre ambos). Resultados: En estado basal los individuos hiperreactivos y con respuesta hipertensiva presentaron un predominio simpático sobre la función cardíaca y una menor variabilidad de la frecuencia cardíaca. Durante el ejercicio isométrico disminuyeron los valores de los ejes SD1 y SD2 en todos los grupos y la razón SD1/SD2 decreció en individuos normorreactivos y con respuesta hipertensiva; pero apenas se modificó en los hiperreactivos. Conclusiones: En los individuos con hiperreactividad cardiovascular ya está presente un desbalance autonómico en estado basal y existe una reducción de la modulación autonómica vagal durante el ejercicio, que puede favorecer el desarrollo de la hipertensión arterial.

ABSTRACT Introduction: The autonomic nervous system plays an important role in cardiovascular readjustments to exercise. In cardiovascular hyperreactivity there is a greater sensitivity of the sympathetic system to different stressors. Objective: To determine the characteristics of cardiac autonomic control in young adults with different degrees of cardiovascular reactivity under basal conditions and during isometric exercise. Method: The sample consisted of 97 individuals of both sexes, and was divided into three groups: normoreactive, hyperreactive and with hypertensive response, according to the pressor response to weight-bearing tests. The individuals underwent a complete study of heart rate variability at rest and during isometric test. The frequency domain for the variables was: low, high, low/high resting ratio, and the parameters of Poincaré plots at rest and during exercise (values of standard deviation 1 [SD1], 2 [SD2], and the reason between them). Results: Under basal conditions, hyperreactive individuals with a hypertensive response had a sympathetic predominance over cardiac function and lower heart rate variability. During the isometric exercise SD1 and SD2 axes values decreased in all groups and SD1/SD2 ratio decreased in normoreactive individuals with hypertensive response; but it was hardly modified in those hyper-reactive. Conclusions: Individuals with cardiovascular hyperreactivity have a prior autonomic imbalance under basal conditions and a reduction of autonomic vagal modulation during exercise that may favor the development of arterial hypertension.

Efeito agudo da aplicação de vibração de corpo inteiro na força muscular de membros superiores / Acute effect of whole body vibration in the upper limbs strength

RESUMO O objetivo desse estudo foi verificar o efeito agudo da aplicação de vibração de corpo inteiro (VCI) sobre o impulso e sobre a força máxima de membros superiores. Vinte voluntários do sexo masculino, treinados, com idade: 23,8 ± 3,3 anos, foram submetidos a 3 sessões (uma sessão de familiarização e duas sessões de intervenção). Em cada uma das sessões de intervenção os voluntários realizaram uma contração voluntária máxima (CVM) de flexores do cotovelo sem aplicação de vibração e duas CVM com adição de vibração. Foram utilizadas 4 frequências de VCI (10, 20, 30 e 40Hz) distribuídas de maneira aleatória nas 4 CVM realizadas com vibração nas duas sessões de coleta. Os resultados encontrados mostraram que a força máxima e o impulso gerados na contração sem vibração foram significativamente maiores do que a força máxima e o impulso gerados durante a contração realizada com aplicação de VCI. Para o treinamento de força, a aplicação de VCI, nas frequências testadas na presente investigação, representou um menor estímulo de treinamento para os membros superiores, uma vez que gerou uma redução na força máxima e no impulso dos músculos flexores do cotovelo.

ABSTRACT The aim of this study was to investigate, from a protocol of maximal isometric contractions of the elbow flexors, the effect of WBV in the maximal force and of impulse in strength-trained individuals. Twenty male volunteers, age: 23.8 ± 3.3 years, performed 3 sessions (one familiarization session and two intervention session). The sessions were composed by 3 MVC of the elbows flexor muscles with 5 minute of rest between them. The first CVM was performed without vibration and the others, applying aleatory WBV with 10, 20, 30, 40Hz, and amplitude of 6mm. The results showed that the maximal force and of impulse obtained during the MVC without vibration was significantly higher than the maximal force and of impulse recorded during the application of WBV. For strength training, the application of WBV, in the adopted frequencies, was not able to generate sufficient stimulus to induce acute adaptations in muscle strength of upper limbs.

The Changes of Contraction Patterns in Trunk Muscles with Multidirectional Tilting Motion on the Dynamic Posturography / 대한스포츠의학회지

PURPOSE: The aim of this study was to investigate the changes of contraction patterns and the differences of activities in trunk muscles during dynamic balance (multidirectional tilting exercise). METHODS: Eight physically active male subjects participated in the study. Tilting exercises were included by four directions (i.e., forward, backward, left, and right side), and were undertaken at three different tilting degrees (i.e., 10°, 20°, and 30°). They performed two occasions of tilting exercise, separated by 6-week time interval. Surface electromyography system was used for record of any signals produced by muscles which normalized as percentage of maximum voluntary isometric contraction. RESULTS: There were no statistically significant different interactive effects in any of muscles between two factors (time vs. degree). However, we identified significant main effects of degrees (among 10°, 20°, and 30°) in muscle activations during maintaining with forward tilting (left and right longissimus, multifidus), backward tilting (left and right rectus abdominis, external oblique), left side tilting (right rectus abdominis, external oblique, longissimus, multifidus), right side tilting (left rectus abdominis, external oblique, longissimus, multifidus). CONCLUSION: Findings from this study allow the multidirectional tilting exercise to be considered as suitable for ameliorate muscle balance by inducing co-contraction in trunk muscles.

Effects of the Short Foot Exercise With Neuromuscular Electrical Stimulation on Navicular Height in Flexible Flatfoot in Thailand: A Randomized Controlled Trial / 예방의학회지

OBJECTIVES: Flatfoot, or low medial longitudinal arch, contributes to back and lower extremity injuries and is caused by weak abductor hallucis (AbdH) muscles. The purpose of this study was to investigate the effects of short foot exercise (SFE) alone or with neuromuscular electrical stimulation (NMES) on navicular height, the cross-sectional area (CSA) of the AbdH muscle, and AbdH muscle activity in flexible flatfoot. METHODS: Thirty-six otherwise healthy people with flexible flatfoot were randomly assigned to a group that received SFE with placebo NMES treatment (the control group) or a group that received both SFE and NMES treatment (the experimental group). Each group received 4 weeks of treatment (SFE alone or SFE with NMES). Navicular height, the CSA of the AbdH muscle, and AbdH muscle activity were assessed before and after the intervention. RESULTS: No significant differences were found in navicular height or the CSA of the AbdH muscle between the control and experimental groups, while AbdH muscle activity showed a statistically significant difference between the groups (SFE=73.9±11.0% of maximal voluntary isometric contraction [MVIC]; SFE with NMES=81.4±8.3% of MVIC; p<0.05). Moreover, the CSA of the AbdH muscle showed a statistically significant increase after treatment in the SFE with NMES group (pre-treatment=218.6±53.2 mm²; post-treatment=256.9±70.5 mm²; p<0.05). CONCLUSIONS: SFE with NMES was more effective than SFE alone in increasing AbdH muscle activity. Therefore, SFE with NMES should be recommended to correct or prevent abnormalities in people with flexible flatfoot by a physiotherapist or medical care team.

Effects of Isometric Handgrip Exercise versus Aerobic Exercise on Arterial Stiffness and Brachial Artery Flow-Mediated Dilation in Older Hypertensive Patients / 대한스포츠의학회지

PURPOSE: Isometric handgrip exercise (IHE) is an easy and accessible form of exercise that has beneficial effects on blood pressure (BP). However, it remains unclear whether IHE is similar benefits on arterial stiffness and endothelial function compared with aerobic exercise (AE) in elderly hypertensive patients. The aim of this study was to compare the effects of IHE versus AE on arterial stiffness and endothelial function in elderly hypertensive patients.METHODS: We conducted a randomized controlled trial with a three-arm design. Fifty-four elderly hypertensive patients (15 men; mean age, 69±6 years; systolic blood pressure, 131.2±14.7; diastolic blood pressure, 80.2±7.9 mm Hg) were randomized to IHE training (n=18), AE training (n=21), or non-exercise control group (n=21) for 12 weeks. Bilateral IHE training was performed four times of 2 minutes at 30% of maximal voluntary contraction with three times per week. AE training was performed brisk walking for 30 minutes at moderate intensity with three times per week. Carotid-femoral pulse wave velocity (PWV), augmentation index heart rate corrected (AIx@75 bpm) and brachial artery flow-mediated vasodilation (FMD) as indices of arterial stiffness and endothelial function were measured at baseline and after the intervention.RESULTS: Following 12-week intervention, resting BP was significantly decreased in both IHE (p=0.001) and AE groups (p=0.002). AIx@75 bpm and FMD were unchanged in the all groups. However, PWV was significantly decreased in both IHE and AE groups (IHE, 10.9±2.3 to 9.9±2.1 m/s [p<0.001]; AE, 10.5±2.0 to 9.4±1.6 m/s [p=0.001]), without any change in the control group.CONCLUSION: These findings suggest that both IHE and AE trainings were comparable effect in improving arterial stiffness in elderly hypertensive patients.

Vesicular Glutamate Transporter 1 (VGLUT1)- and VGLUT2-containing Terminals on the Rat Jaw-closing γ-Motoneurons

Currently, compared to jaw-closing (JC) α-motoneurons, the information on the distribution and morphology of glutamatergic synapses on the jaw-closing (JC) γ-motoneurons, which may help elucidate the mechanism of isometric contraction of the JC muscle, is very limited. This study investigated the distribution and ultrastructural features of vesicular glutamate transporter 1 (VGLUT1)- and VGLUT2-immunopositive (+) axon terminals (boutons) on JC γ-motoneurons by retrograde tracing with horseradish peroxidase, electron microscopic immunocytochemistry, and quantitative analysis. About 35% of the boutons on identified JC γ-motoneurons were VGLUT+, and of those, 99% were VGLUT2+. The fraction of VGLUT1+ boutons of all boutons and the percentage of membrane of JC γ-motoneurons covered by these boutons were significantly lower than those for the JC α-motoneurons, revealed in our previous work. The bouton volume, mitochondrial volume, and active zone area of the VGLUT2+ boutons on the JC γ-motoneurons were uniformly small. These findings suggest that the JC γ-motoneurons, in contrast to the JC α-motoneurons, receive generally weak glutamatergic synaptic input almost exclusively from VGLUT2+ premotoneurons that form direct synapse with motoneurons.