Asociación entre la Arquitectura Muscular y el Índice de Calidad Muscular en Adultos Sedentarios / Association Between Muscle Architecture and Muscle Quality Index in Sedentary Adults

La evaluación de la calidad y la arquitectura muscular son importantes para comprender y cuantificar los cambios musculares asociados con el envejecimiento y el estilo de vida sedentario, además nos facilita información de la capacidad del músculo para generar fuerza, potencia o funcionalidad. los objetivos del estudio fueron (I) determinar la asociación entre los parámetros de la arquitectura muscular y el índice de calidad muscular (MQI) y (II) determinar la asociación entre los parámetros de la arquitectura muscular y la potencia media relativa del sit to stand test (STS). Únicamente el grosor muscular (MT) mostró una asociación moderada con el MQI (r = 0,545). En contraste, tanto la longitud del fascículo (FL) como el ángulo de penación (PA) exhibieron asociaciones "muy bajas", las cuales no resultaron significativas con el MQI. Al examinar la relación de los parámetros de la arquitectura muscular con la potencia media relativa de STS, MT presentó una asociación "moderada" (r = 0,444). Sin embargo, tanto FL como PA mostraron asociaciones "muy bajas" y "bajas", respectivamente, con la potencia media relativa al STS. En conclusión, estos hallazgos refuerzan la idea de que MT puede ser un indicador relevante de la calidad muscular y la capacidad de generar potencia en la prueba de STS. Específicamente, se observó que un aumento en MT estaba asociado con una mejora en MQI y la potencia media relativa de STS.

SUMMARY: Assessment of muscle quality and architecture is important for understanding and quantifying muscle changes associated with aging and a sedentary lifestyle and provides information on the muscle's ability to generate strength, power, or function. The aims of the study were (I) to determine the association between muscle architecture parameters and muscle quality index (MQI) and (II) to determine the association between muscle architecture parameters and mean relative power in the sit-to-stand test (STS). Only muscle thickness (MT) showed a moderate association with MQI (r = 0.545). In contrast, both fascicle length (FL) and penile angle (PA) exhibited "very low" associations, which were not significant with the MQI. When examining the relationship between muscle architecture parameters and mean relative STS power, MT presented a "moderate" association (r = 0.444). However, both LF and PA showed "very low" and "low" associations, respectively, with a mean power relative to STS. In conclusion, these findings reinforce the idea that MT may be a relevant indicator of muscle quality and ability to generate power in the STS test. Specifically, an increase in MT was associated with an improvement in MQI and mean power relative to STS.

Influence of probe position in the measurement of muscle thickness and its association with lean mass: an ultrasound study / Influencia de la posición de la sonda en la medición del grosor muscular y su asociación con la masa magra: un estudio ecográfico

SUMMARY: Skeletal muscles play a fundamental role in people's lives and their evaluation provides significant information on health. Different tools have been used to evaluate muscle mass, and the evaluation of muscle thickness (MT) using ultrasound has been included as an alternative, which can be performed with the probe in different positions; however, these could present differences. The objectives of this study were to determine whether there are differences in the measurement of MT in the vastus lateralis (VL) muscle using the probe in the longitudinal or transverse position, and to determine its association with the lean mass of the lower limbs. The results indicated no significant differences between MT measurements with the probe in the longitudinal and transverse positions (p =0.084). However, when associating these measurements with lower limb lean mass, it was found that transverse measurements had a strong association (r =0.547; p < 0.001), while longitudinal measurements had a moderate association (r =0.351; p =0.007). This suggests that measurements with the probe positioned transversely to measure the MT would be the best option. Therefore, it could be useful as an indicator of lower limb lean mass in the absence of tools, such as bioelectrical bioimpedance or magnetic nuclear resonance.

El músculo esquelético cumple un rol fundamental en la vida de las personas, y su evaluación entrega mucha información de la salud. Se han utilizado diferentes herramientas para evaluar la masa muscular, y el último tiempo se ha incluido la evaluación del grosor muscular (MT) a través de la ecografía como una alternativa para estimarla, las cuales se pueden realizar con la sonda en distintas posiciones, sin embargo, estas podrían presentar diferencias. Los objetivos del estudio fueron determinar si existen diferencias en la medición de MT en el músculo vasto lateral (VL) utilizando la sonda en posición longitudinal o transversal y determinar su asociación con la masa magra de los miembros inferiores. Los resultados indican que no existen diferencias significativas entre las mediciones de MT con la sonda en posición longitudinal y transversal (valor p: 0.084). Sin embargo, al asociar estas mediciones con la masa magra de los miembros inferiores, se encontró que las mediciones transversales poseen una asociación fuerte (r: 0.547; valor p < 0.001), mientras que las mediciones longitudinales presentan una asociación moderada (r: 0.351; valor p: 0.007). Esto sugiere que las mediciones con la sonda posicionada transversal para medir MT serían la mejor opción. Por lo tanto, podría ser de utilidad como un indicador de masa magra de los miembros inferiores en caso de no contar con herramientas como la bioimpedancia bioeléctrica o resonancia nuclear magnética.

Influence of maximal isometric strength on 20-meter sprint time / Influência da força isométrica máxima sobre o tempo em sprints de 20 metros / Influencia de la fuerza isométrica máxima sobre el tiempo en sprints de 20 metros

ABSTRACT Introduction The squat is an exercise that is widely used for the development of strength in sports. However, considering that not all sports gestures are vertical, it is important to investigate the effectiveness of propulsive force stimuli applied in different planes. Objective The main purpose of this study was to determine the influence of maximum isometric force (MIF) exerted on starting blocks over performance in 5, 10 and 20-meter sprints. Methods Seven high-level male sprinters (mean age ± SD = 28 ± 5.77 years) participated in this study. The variables were: a) MIF in squats and on starting blocks (measured using a functional electromechanical dynamometer [FEMD]), b) time in 5, 10 and 20-m sprints and c) jump height (measured by the squat jump test). For data analysis, a Pearson correlation was performed between the different variables. The criteria for interpreting the strength of the r coefficients were as follows: trivial (<0.1), small (0.1−0.3), moderate (0.3−0.5), high (0.5−0.7), very high (0.7−0.9), or practically perfect (>0.9). The level of significance was p < 0.05. Results There was very high correlation between MIF exerted on starting blocks and performance in the first meters of the sprint (5-m: r = -0.84, p = 0.01). However, there was small correlation between MIF in squats and performance in the first meters of the sprint (5-m: r = -0.22, p < 0.62). Conclusion The MIF applied on starting blocks correlates very high with time in the first meters of the sprint in high-level athletes. In addition, the use of the FEMD provides a wide range of possibilities for evaluation and development of strength with a controlled natural movement. Level of evidence IV; Prognostic Studies - Case series.

RESUMO Introdução O agachamento é um exercício amplamente utilizado para o desenvolvimento de força nos esportes. No entanto, considerando que nem todos os gestos esportivos são verticais, é importante investigar a eficácia dos estímulos de força propulsiva em diferentes planos. Objetivo O principal objetivo deste estudo foi determinar a influência da força isométrica máxima (FIM) exercida em os blocos de largada sobre o desempenho em sprints de 5, 10 e 20 metros. Métodos Sete velocistas de alto nível do sexo masculino (média ± DP = 28,0 ± 5,77 anos) fizeram parte deste estudo. As variáveis foram: a) FIM no agachamento e nos blocos de largada (avaliados com um dinamômetro eletromecânico funcional (DEF)), b) tempo de sprints de 5, 10 e 20 metros e c) altura do salto (medida pelo teste de squat jump). Para análise dos dados, foi usada a correlação de Pearson entre as diferentes variáveis. Os critérios para interpretar o coeficiente r foi: nulo (< 0,1), pequeno (0,1 a 0,3), moderado (0,3 a 0,5), alto (0,5 a 0,7), muito alto (0,7 a 0,9) ou praticamente perfeito (> 0,9). O nível de significância foi p < 0,05. Resultados Houve correlação muito alta entre a FIM exercida nos blocos de largada e o desempenho nos primeiros metros do sprint (5-m: r = -0,84, p = 0,01). No entanto, a correlação entre o agachamento da FIM e os primeiros metros de sprint foi pequena (5-m: r = -0,22, p < 0,62). Conclusão A FIM aplicada aos blocos de largada teve uma correlação muito alto com o tempo nos primeiros metros de sprint em atletas de alto nível. Além disso, o uso de um DEF oferece uma ampla gama de possibilidades para avaliar e desenvolver força com um movimento natural controlado. Nível de evidência IV; Estudos Prognósticos - Série de casos.

RESUMEN Introducción La sentadilla es un ejercicio ampliamente usado para el desarrollo de fuerza en los deportes. Sin embargo, considerando que no todos los gestos deportivos son verticales, es importante investigar la eficacia de los estímulos de fuerza propulsiva en diferentes planos. Objetivo El principal objetivo de este estudio fue determinar la influencia de la fuerza isométrica máxima (FIM) ejercida en los bloques de salida sobre el rendimiento en sprints de 5, 10 y 20 metros. Métodos Siete velocistas de alto nivel del sexo masculino (promedio ± SD = 28,0 ± 5,7 años) formaron parte de este estudio. Las variables fueron: a) FIM en la sentadilla y en los bloques de salida (evaluados con un dinamómetro electromecánico funcional [DEF]) b) tiempo de sprints de 5, 10 y 20-metros y c) altura del salto (medida a través del test de squat jump). Para el análisis de los datos se usó la correlación de Pearson entre las diferentes variables. Los criterios para interpretar el coeficiente r fueron: nulo (<0,1), pequeño (0,1 a 0,3), moderado (0,3 a 0,5), alto (0,5 a 0,7), muy alto (0,7 a 0,9) o prácticamente perfecto (>0,9). El nivel de significancia fue p < 0,05. Resultados Hubo correlación muy alta entre la FIM ejercida en los bloques de salida y el rendimiento en los primeros metros del sprint (5-m: r = -0,84, p = 0,01). Sin embargo, la correlación entre la FIM en sentadilla y los primeros metros de sprint fue pequeña (5-m: r = -0,22, p < 0,62). Conclusión La FIM aplicada a los bloques de salida tuvo una correlación muy alta con el tiempo en los primeros metros de sprint en atletas de alto nivel. Además, el uso de un DEF ofrece una amplia gama de posibilidades para evaluar y desarrollar fuerza con un movimiento natural controlado. Nivel de evidencia IV; Estudios pronósticos: Serie de casos.

Catéter de Swan Ganz con marcapasos en la cirugía mini-invasiva mitral / Pacing Swan-Ganz Catheter in Minimally Invasive Mitral Valve Surgery

RESUMEN Introducción: La cirugía mediante mini-toracotomía lateral presenta ventajas comparativas sobre el acceso convencional como menor trauma quirúrgico, reducida morbimortalidad y un resultado estético superior, pero plantea dificultades en caso de necesitar estimulación eléctrica temporal. Objetivo: Valorar el empleo terapéutico del catéter de Swan-Ganz con marcapasos incorporado como solución a dicho problema y analizar sus complicaciones. Material y métodos: Se incluyeron pacientes programados para cirugía mini-invasiva mitral mediante mini-toracotomía lateral. Se definió empleo terapéutico del catéter al uso debido a bradiarritmias o trastornos de conducción o necesidad de incrementar la frecuencia cardíaca con fines hemodinámicos. Pacientes intervenidos de urgencia o emergencia, fueron excluidos del estudio. Resultados: Fueron incluidos 517 pacientes (289 de sexo masculino, con edad promedio de 68,3 ± 10,4 años); se efectuaron 115 (22,2%) reemplazos y 402 (77,7%) plásticas mitrales. Simultáneamente, se realizaron 294 (56,9%) procedimientos de Maze, 182 (35,2%) cierres de orejuela izquierda, 9 (1,7%) cierres de defectos septales y 14 (2,7%) plásticas tricuspídeas. Ciento sesenta y dos (313%) pacientes necesitaron ser marcapaseados; debido a bradiarritmias, 85 (52,47%) pacientes; por trastornos de conducción, 50 (30,86%) pacientes; mientras que otros 27 (16,66%) requirieron incrementar su frecuencia debido a bajo volumen minuto. La mortalidad resultó de 12 (2,32%) casos. Catorce (2,7%) pacientes presentaron pérdida de captura y se resolvieron con el reposicionamiento del catéter, mientras que 2 (0,6%) pacientes presentaron atrapamiento y requirieron reintervención. Conclusiones: Casi un tercio de los pacientes intervenidos mediante mini-toracotomía lateral requirieron del empleo terapéutico del catéter de Swan-Ganz con marcapasos. Dos pacientes presentaron atrapamiento y requirieron resolución quirúrgica.

ABSTRACT Background: The use of a lateral mini-thoracotomy presents several advantages over the standard access, such as less surgical trauma, reduced morbidity and mortality, shorter recovery time and better cosmetic results, but presents difficulties if temporary pacing is required. Objective: The aim of this study was to evaluate the therapeutic use of a Swan-Ganz catheter with pacing capabilities and analyze its complications. Methods: Patients undergoing scheduled minimally invasive mitral valve surgery through lateral mini-thoracotomy were included in the study. Therapeutic use of the pacing catheter was defined as the need for pacing due to bradyarrhythmias or conduction disorders or need of increasing heart rate in case of hemodynamic instability. Patients undergoing urgent or emergency surgery were excluded from the study. Results: A total of 517 patients were included in the study; mean age was 68.3 ± 10.4 years and 289 (55.9%) were men; 115 patients (22.2%) underwent mitral valve replacement and 402 (77.7%) mitral valve repair. The following concomitant procedures were carried out: 294 (56.9%) Maze procedures, 182 (35.2%) left atrial appendage closures, 9 (1.7%) atrial septal defect closures and 14 (2.7%) tricuspid valve repair surgeries. In the postoperative period 162 (31.3%) patients required pacing due to bradyarrhythmias in 85 cases (52.47%), conduction disorders in 50 (30.86%), and need to increase heart rate in 27 (16.66%) patients with low cardiac output syndrome. Postoperative mortality was 2.32% (n=12). Fourteen (2.7%) patients presented loss of capture that was resolved with catheter repositioning, while 2 (0.6%) patients presented catheter entrapment requiring reintervention. Conclusion: Almost one-third of the patients undergoing lateral mini-thoracotomy required therapeutic use of the pacing Swan-Ganz catheter. Two patients presented catheter entrapment and required surgical reintervention.

Comparison of two incremental protocols for evaluation of hip extension / Comparação de dois protocolos progressivos na avaliação da extensão de quadril

Abstract Introduction: The hip muscles play an important role in controlling the transverse and frontal plane of the femur during displacement. The hip extension and abduction/adduction exercises are among the most widely evaluated protocols both clinically and in research. Objective: To compare which assessment protocol in an isokinetic strength regime (distal grip-ankle vs. proximal grip-knee) best represents the action of hip extension and to analyze the test-retest reliability in the variables peak force (PF) and work (W). Methods: A total of 20 subjects participated in this research. All participants were female. The mean and standard deviations of age, weight and height were 21 ± 3.9 years, 65 ± 11 kg, 166 ± 3.4 cm, respectively. Results: Significant differences were found in both variables (PF and W) between protocols 1 and 2 (p < 0.05) on assessment days 1 and 2. No differences between days 1 and day 2 in either protocol (p < 0.05) were found. Index values of interclass correlation (ICC) of protocol 1 ranged between 0.38 and 0.86. In protocol 2 the ICC range was between 0.33 and 0.87. Conclusions: In light of these results, the hip extension exercise with a proximal grip best represents the strength of the muscle groups involved in this action.

Resumo Introdução: Os músculos do quadril desempenham um papel importante no controle do plano transverso e frontal do fêmur durante o deslocamento. Os exercícios de extensão e abdução/adução do quadril estão entre os protocolos mais amplamente avaliados tanto na clínica como na pesquisa. Objetivo: Comparar qual protocolo de avaliação em um regime de força isocinética (aperto distal no tornozelo versus aperto proximal no joelho) melhor representa a ação de extensão de quadril e analisar a confiabilidade teste-reteste nas variáveis de força máxima de (FM) e trabalho (T). Métodos: Um total de 20 indivíduos participou desta pesquisa. Todos os participantes eram do sexo feminino. A média e desvios-padrão de idade, peso e altura foram 21 ± 3.9 anos, 65± 11 kg e 166 ± 3.4 cm, respectivamente. Resultados: Foram encontradas diferenças significativas em ambas as variáveis (FM e T) entre protocolos 1 e 2 (p < 0,05) nos dias 1 e 2 de avaliação. Não houve diferenças entre os dias 1 e dia 2 em qualquer protocolo (p < 0,05). O índice de valores de correlação interclasse (ICC) do protocolo 1 variou entre 0,38 e 0.86. No protocolo 2 a faixa do ICC foi entre 0,33 e 0,87. Conclusões: Tendo em conta estes resultados, o exercício de extensão de quadril com uma fixação proximal é quem melhor representa a força dos grupos musculares envolvidos nesta ação.

Efecto agudo de Complex Training en press banca sobre la distancia del lanzamiento de la granada / Acute effect of a Complex Training over grenade throwing distance

Objetivo: determinar el efecto agudo de un Complex Training en press banca sobre el lanzamiento de la granada en pentatletas militares profesionales y aficionados. Métodos: diecinueve pentatletas militares divididos en dos grupos fueron parte del estudio. Las variables medidas fueron: distancia máxima del lanzamiento de la granada y potencias máximas en press banca. El protocolo consistió en: 4 series de 5 repeticiones al 30 por ciento de una repetición máxima, más 4 repeticiones al 60 por ciento de una repetición máxima, más 3 lanzamientos de granada con pausa de 15 segundos. Para el análisis estadístico se utilizó ANOVA de medias. Resultados: la distancia máxima del lanzamiento de la granada presentó un aumento significativo entre la Serie Control y las cuatro series experimentales para el Grupo Profesional (p= 0,0019, tamaño del efecto= 0,370) y un descenso significativo en el Grupo Aficionado (p= 0,0128, tamaño del efecto = 0,305); las potencias máximas en press banca no sufrieron modificaciones significativas en ambos grupo (Grupo Profesional p= 0,15, tamaño del efecto= 0,166; Grupo Aficionado p= 0,17, tamaño del efecto= 0,199). Conclusión: el efecto agudo positivo del Complex Training fue atribuido a la Potenciación Posactivación de la musculatura involucrada en el lanzamiento. El descenso significativo en el lanzamiento de la granada observado en el Grupo Aficionado fue atribuido a la imposibilidad de sintetizar ATP posesfuerzo, lo que indujo una fatiga muscular(AU)

Purpose: Determining the acute effect of a Complex Training in bench press over grenade throwing in professional and amateur military pentathletes. Methods: Nineteen military pentathletes divided into two groups were part of the study (Professional Group = 10 and Amateur Group = 9). Variables measured were: Distance maximum in grenade throwing and peak power in bench press. Complex Training protocol consisted of: 4 sets of 5 repetitions at 30 percent of one repetition maximum + 4 repetitions at 60 percent of one repetition maximum + 3 grenade throws with a 15-second rest. For the statistical analysis, repeated measures ANOVA was used, the effect size was estimated with Eta Partial Squared. Results: Distance maximum of grenade throwing showed a significant increase between the Control Set and the four experimental sets for the Professional Group (p = 0.0019, effect size = 0.370) and a significant decrease in the Amateur Group (p = 0.0128, effect size = 0.305); peak power in bench press did not suffer significant modifications in both groups (Professional Groupp = 0.15, effect size = 0.166; Amateur Group p = 0.17, effect size = 0.199). Conclusions: The results of the study showed a positive acute effect from Complex Training on the distance of grenade throwing only for professional military pentathletes, such effect was attributed to a Post-Activation Potentiation of the muscles involved in throwing. The significant decline in grenade throwing observed in the amateur military pentathletes was attributed to the impossibility of synthetizing ATP post-workout(AU)

Efecto de los juegos reducidos en la composición corporal y la condición física aeróbica en un grupo de adolescentes escolares / Effects of small-sided exercises on body composition and maximal oxygen uptake in adolescents

Background: The regular practice of physical activity contributes to weight control and improves maximal oxygen uptake (VO2max), socialization and quality of life. Aim: To determine the effect of moderate-to-vigorous physical activity on body composition and VO2max in a group of overweight school-age males. Material and Methods: We studied fifty-five overweight males aged 15.6 ± 0.7 years. Participants were divided in two groups (experimental and control groups). The intervention in the experimental group was the practice of small-sided games during 60 minutes, two days per week and during 11 weeks. At baseline and the end of the intervention, body composition was measured using bioimpedance and VO2max was calculated using the Course Navette test. Results: A 7% reduction in the percentage of body fat and a 9% increase in VO2max were observed in the experimental group (p < 0.01). No changes were recorded in the control group. Conclusions: Eleven weeks of small-sided exercises performed twice per week increased VO2max and reduced fat mass in overweight adolescents.