Las fuerzas con efecto transiente durante la marcha militar

Introdução: O padrão vertical anormal da força de reação do solo (FRS) apresenta a assimetria ou mais de dois picos como marcha patológica típica. Uma força típica e assimétrica é a força transiente. Será que a marcha militar é uma espécie de marcha patológica? Objetivo: Descrever e analisar a força de reação do solo vertical durante a fase de apoio da marcha militar. Método: Os participantes foram 20 soldados do Exército \ud Brasileiro que tiveram anteriormente uma lesão nos membros inferiores relacionada com a marcha militar. Duas plataformas de força foram usadas para medir as componentes da FRS (mediolateral, anteroposterior e vertical) durante a marcha. Para cada lado e condição (andar e marcha), cinco amostras para cada pé foram registradas. A análise de variância foi utilizada para comparar os parâmetros da FRS durante o andar e marcha. \ud Resultado: O primeiro pico de força foi o mais alto durante a condição de marcha. O pico de força transiente durante a marcha foi maior que o primeiro pico durante o andar. A força mínima foi a maior durante a marcha. Conclusão: A análise das forças de reação do solo marcha militar mostra uma força vertical transiente que não está normalmente presente no padrão de marcha normal.INTRODUCTION: The abnormal vertical ground reaction force (GRF) pattern presents the asymmetry or the presence of more than two peaks as typical pathological gait. The typical asymmetric force is the transient force. Is the military marching a kind of pathological gait? OBJECTIVE: To describe and analyze the vertical ground reaction forces during the stance phase of the military marching. METHOD: Participants were 20 Brazilian Army soldiers who previously had an injury in the lower limbs related to the military marching. Two strain-gauge force platforms measured the GRF components (mediolateral, anterior posterior; and vertical components) during gait. To each side and condition (gait and marching) five samples for each foot were recorded. One-way analysis of variance (ANOVA) was used to compare the GRF parameters during gait and marching. RESULTS: The first force peak was the highest during the marching condition. The first force peak was the highest during marching condition. The peak transient force during marching was higher than the first peak during gait. The minimum force was higher during marching. CONCLUSION: The analysis of ground reaction forces in military marching shows a transient vertical force that is not usually present in normal gait patternINTRODUCCIÓN: El estándar vertical anormal de la fuerza de reacción del suelo (FRS) presenta la asimetría, o más de dos picos, como marcha patológica típica. Una fuerza típica y asimétrica es la fuerza con efecto transiente. ¿Será que la marcha militar es un tipo de marcha patológica? Objetivo: Describir y analizar la fuerza vertical de reacción del suelo durante la fase de apoyo de la marcha militar. MÉTODO: Los participantes fueron 20 soldados del Ejército Brasileño, quienes tuvieron antes una lesión en los miembros inferiores relacionada con la marcha militar. Se usaron dos plataformas de fuerza para medir los componentes de la FRS (mediolateral, anteroposterior y vertical) durante la marcha. Para cada lado y condición (andar y marcha), se registraron cinco muestras para cada pie. El análisis de la variación fue utilizado para comparar los parámetros de la FRS durante el andar y la marcha. RESULTADO: El primer pico de fuerza fue el más alto durante la condición de marcha. El pico de fuerza, con efecto transiente durante la marcha, fue mayor que el primer pico durante el andar. La fuerza mínima fue mayor durante la marcha. CONCLUSIÓN: El análisis de las fuerzas de reacción del suelo, en la marcha militar, muestra una fuerza vertical, con efecto transiente, que normalmente no está presente en el estándar de marcha normal.Autoria: No documento, leia-se Julio Cerca Serrão (onde se lê "Julio Cerca Amadio"

Motor physical therapy affects muscle collagen type I and decreases gait speed in dystrophin-deficient dogs

Golden Retriever Muscular Dystrophy (GRMD) is a dystrophin-deficient canine model genetically homologous to Duchenne Muscular Dystrophy (DMD) in humans. Muscular fibrosis secondary to cycles of degeneration/regeneration of dystrophic muscle tissue and muscular weakness leads to biomechanical adaptation that impairs the quality of gait. Physical therapy (PT) is one of the supportive therapies available for DMD, however, motor PT approaches have controversial recommendations and there is no consensus regarding the type and intensity of physical therapy. In this study we investigated the effect of physical therapy on gait biomechanics and muscular collagen deposition types I and III in dystrophin-deficient dogs. Two dystrophic dogs (treated dogs-TD) underwent a PT protocol of active walking exercise, 36/week, 40 minutes/day, 12 weeks. Two dystrophic control dogs (CD) maintained their routine of activities of daily living. At t0 (pre) and t1 (post-physical therapy), collagen type I and III were assessed by immunohistochemistry and gait biomechanics were analyzed. Angular displacement of shoulder, elbow, carpal, hip, stifle and tarsal joint and vertical (Fy), mediolateral (Fz) and craniocaudal (Fx) ground reaction forces (GRF) were assessed. Wilcoxon test was used to verify the difference of biomechanical variables between t0 and t1, considering p<.05. Type I collagen of endomysium suffered the influence of PT, as well as gait speed that had decreased from t0 to t1 (p<.000). The PT protocol employed accelerates morphological alterations on dystrophic muscle and promotes a slower velocity of gait. Control dogs which maintained their routine of activities of daily living seem to have found a better balance between movement and preservation of motor functionFAPESP, 06/61561-

Eight steps’ paradigm shift in men’s 110 metres hurdles: an 89 years retrospective study

Men’s 110 metres hurdles is one of the oldest disciplines in the Olympic Games and yet scarce anecdotal reports are found to pinpoint technical elements indicators of success. The approach technique to the hurdles has been raised by coaches as a potential element of success however it seems that the approach strategies undertaken to the first hurdle have not been investigated to the current date. Therefore, this study aimed to examine the employment of the seven and eight steps strategy until the first hurdle in the 110 m discipline among the Olympic Games and World Championships in Athletics’ finalists. Public domain videos of the events in the period between 1924 and 2013 were assessed. An international level sprint and hurdles’ coach, using the Dartfish software, assessed the number of steps taken until the first hurdle. A left-tailed one sample sign test showed that although the seven steps strategy adoption seems to have begun in 1960 it was only in 2011 that it was considered a dominant tactic. Due to determination of factors that influence the choice of strategy or their respective influence on performance falling outside the scope of this study, future research is needed in this area. Notwithstanding, the success by the hurdlers that adopt the seven steps strategy, evidenced by the number of medals won, allowed to pinpoint the approach strategy to the first hurdle as a potential performance variable to be investigated

Força de reação do solo e atividade eletromiográfica da marcha de amputados transfemorais: uma série de casos

Ground reaction forces (GRF) and electromyographic activity form a part of the descriptive data that characterise the biomechanics of gait. The research of these parameters is important in establishing gait training and understanding the impact of amputation and prosthetic components on movement during the act of walking. Therefore, this case series describes the GRF and electromyographic activity in the gait of transfemoral amputees. A force plate was used to measure GRF, and an electromyographic system monitored the vastus lateralis, biceps femoris, tibialis anterior, and gastrocnemius lateralis muscles of the non-amputated leg. The average vertical and anteroposterior GRF time-curves, average electromyographic activity, and descriptor variables were then analysed. We observed decreases in vertical and anteroposterior GRF magnitudes as well as in anteroposterior GRF descriptor variables during the propulsive phase in the amputated leg. There were increases in phasic muscle activity and co-activation in the non-amputated leg. We concluded that, during walking, the unilateral transfemoral amputees (who were analysed in this case series) developed lower GRF in the amputated limb and a longer period of electromyographic activity in the non-amputated limb.O comportamento da Força de Reação do Solo (FRS) e a atividade eletromiográfica\ud formam uma parte dos dados que caracterizam a biomecânica da marcha. O estudo\ud destes parâmetros é importante para a recuperação da locomoção e para compreensão do impacto da amputação e dos componentes protéticos nos movimentos desenvolvidos no andar. Portanto, esta série de casos tem como objetivo descrever a atividade eletromiográfica e a FRS de amputados transfemorais. Para mensurar a FRS, foi utilizada uma plataforma de força e um sistema de eletromiografia monitorou os músculos vasto lateral, bíceps femoral, tibial anterior e gastrocnêmio lateral da perna não-amputada. As médias das componentes vertical e ânteroposterior da FRS, a atividade eletromiográfica e variáveis descritivas foram analisadas. Foi observado uma diminuição da magnitude da FRS vertical e ânteroposterior e das variáveis descritivas da componente ânteroposterior da FRS durante a fase de propulsão na perna amputada. Houve aumento na atividade fásica muscular e co-ativação na perna não-amputada. Pode-se concluir que os amputados transfemorais unilaterais analisados nesta série de casos desenvolveram menor FRS na perna amputada e longos períodos de atividade eletromiográfica na perna não amputada durante a marcha

The role of veracity on the load monitoring of professional soccer players: a systematic review in the face of the big data era

Big Data has real value when the veracity of the collected data has been previously identified. However, data veracity for load monitoring in professional soccer players has not been analyzed yet. This systematic review aims to evaluate the current evidence from the scientific literature related to data veracity for load monitoring in professional soccer. Systematic searches through the PubMed, Scopus, and Web of Science databases were conducted for reports onthe data veracity of diverse load monitoring tools and the associated parameters used in professional soccer. Ninety-four studies were finally included in the review, with 39 different tools used and 578 associated parameters identified. The pooled sample consisted of 2066 footballers (95% male: 24 ± 3 years and 5% female: 24 ± 1 years). Seventy-three percent of these studies did not report veracity metrics for anyof the parameters from these tools. Thus, data veracity was found for 54% of tools and 23% of parameters. The current information will assist in the selection of the most appropriate tools and parameters to be used for load monitoring with traditional and Big Data approaches while identifying those still requiring the analysis of their veracity metrics or their improvement to acceptable veracity levels

RELAÇÃO DA CARGA SUBJETIVA DURANTE O TESTE DE REPETIÇÃO MÁXIMA PARA O MEMBRO INFERIOR EM INDIVÍDUOS TREINADOS

O objetivo do estudo foi verificar as diferenças entre a carga subjetiva (1T) com as alcançadas nas tentativas posteriores (2T e 3T) no teste de 10 RM em indivíduos treinados para exercícios do membro inferior. O grupo experimental foi composto de 16 indivíduos do sexo masculino (24,4 À 6,7 anos, 78,6 À 9,42 kg, 171À 6,14 cm). Foram realizadas três tentativas com o intervalo de 5 minutos entre as mesmas e de 20 minutos entre os exercícios cadeira extensora (EXT) e agachamento (AGA). A análise de variância apresentou diferença significativa quando da comparação entre os resultados apresentados para EXT e AGA. O coeficiente de correlação intraclasse (ICC) foi de 0,91 e 0,85 para os exercícios EXT e AGA, respectivamente. Parece que a determinação da carga inicial de forma subjetiva pode não ser um parâmetro confiável para a prescrição do treinamento de força, sendo necessária a aplicação do teste para a obtenção deste parâmetro

Influences of sport shoes in biomechanics of human locomotion

Esta tese tem por objetivo analisar a influência do calçado esportivo no movimento humano. O experimento 1, objetivou a análise biomecânica do calçado de corrida durante seu ciclo de utilização, o experimento 2 estendeu essa análise para os calçados de Futsal, e experimento 3 objetivou a análise da locomoção sem o uso do calçado esportivo. Para tanto, foram utilizadas uma plataforma de força piezoelétrica, um eletrogoniômetro, e um eletromiógrafo, segundo procedimentos e protocolos metodológicos de controle experimental que permitiram análise e interpretação das variáveis. Para os resultados dos experimentos 1 e 2, as alterações mais expressiva e consistentes foram observadas na corrida com os calçados de Futsal, dentre as quais se destacaram o aumento do primeiro pico da força vertical (17,26%), do gradiente de crescimento 1 (56,25%), do segundo pico da força vertical (3,43%), do incremento da força vertical (14,81%), do gradiente de crescimento 2 (25,00%), e a redução do tempo para o primeiro pico da força vertical (22,50%). No entanto, a análise intra-sujeitos, mostrou que alguns sujeitos mantiveram condições biomecânicas satisfatórias à realização do movimento apesar do desgaste do calçado. Dentre as alterações observadas no experimento 3, destacam-se a significativa redução do tempo para o primeiro pico da força vertical do calçado para o descalço e o surgimento de novos picos de força na locomoção na última condição. Observou-se ainda a antecipação do pico de atividade do m. vastus lateralis (de 11,85 ± 5,27% para 7,69 ± 5,50%) e do m. gastrocnemius (de 69,44 ± 2,93% para 50,65 ± 27,67%) na marcha, e também na corrida (de 29,23 ± 9,21% para 19,00 ± 9,84%, e de 32,63 ± 12,49% para 28,81 ± 11,41%, para o m. vastus lateralis e o m. gastrocnemius , respectivamente). Concluí-se que a influência exercida pelo calçado esportivo sobre o movimento humano não parece ser mais expressiva do que a exercida pelo aparelho locomotor, que se mostrou capaz de garantir condições biomecânicas favoráveis à boa manutenção do movimento mesmo em situações adversas. Tais fatos sugerem que os esforços na busca da execução segura e eficiente do movimento humano, devem estar voltados primordialmente para o desenvolvimento das estruturas e funções do aparelho locomotor, e não apenas para a seleção e desenvolvimento do calçado esportivo. Destaca-se ainda a necessidade da utilização de ferramentas que facilitem a diferenciação da variabilidade do movimento da variabilidade induzida pelo calçado, sempre que a análise do movimento for a estratégia escolhida para analisar a influência do calçado no movimento humanoThis thesis analyzed sport shoes influence in human movement. In the experiment 1 we run the analysis of the running shoes until their full wastage. In experiment 2, it was analyzed the Futsal shoes wastage. And in the experiment 3, it was studied the unshod. For those experiments, we have used different experimental devices: a piezoelectric force platform, an electrogoniometer, and electromyographer, according to procedures and methodological protocols experimental control that allowed analysis and interpretation of the variables. results, for experiments 1 and 2, the most expressive and consistent alterations were observed for running with Futsal shoes. We highlight the increase for the following variables: vertical force first peak (17.26%), loading rate 1 (56.25%), vertical force second peak (3.43%), vertical force increment (14.81%), loading rate 2 (25.00%), and the decrease of time to first peak of vertical force (22.50%). However, the intrasubject analysis have shown that some subjects kept satisfactory biomechanical conditions during movement tasks to overcome the shoe wastage. In experiment 3, e pointed out the significant reduction of time to first peak of vertical force for the hod condition comparing to the unshod condition and the new force peaks during locomotion during the second condition. We also observed m. vastus lateralis and m. gastrocnemius anticipatory peak (from 11.85 ± 5,27% to 7.69 ± 5.50%, and from 69.44 ± 2.93% to 50.65 ± 27.67%, respectively) during walking. The same results were found for running: m. vastus lateralis anticipatory peak from 29.23±9.21% to 19.00 ± 9.84%, and m. gastrocnemius anticipatory peak from 32.63 ± 12.49% to 28.81 ± 11.41%. As conclusion, we have verified that sport shoes influence in human movement is not more expressive than the locomotor system itself. The locomotor system provides to the movement stability biomechanical conditions to master unexpected and adverse situations. Such facts suggest us that the search for safeness and efficiency during human movement should be addressed to the development of structures and functions of locomotor apparatus, not only for the selection and development of the sport shoes. We also suggest the need for developing tools to discriminate the movement variability and the variability induced by the sport shoes, when movement analysis was the chosen tool to investigate the influence of sports shoes in human movemen

Correction: 16 Weeks of Progressive Barefoot Running Training Changes Impact Force and Muscle Activation in Habitual Shod Runners.

[This corrects the article DOI: 10.1371/journal.pone.0167234.]