Association between anthropometric and physical data of university soccer players from different positions / Associação entre dados antropométricos e físicos de jogadores universitários de futebol de diferentes posições

ABSTRACT The present study aimed to check if there is an association between fitness performance variables and to analyze the variation of fitness levels between playing positions university soccer players. Twenty university soccer players were selected (20.95 ± 1.84 years; 71.60 ± 11.65 kg; 176.85 ± 7.28 m) divided into defenders, midfielders and attackers. Body composition was assessed in a cross-sectional analysis that correlated fat mass, lean mass and fat-free mass by DXA with the physical capacity tests. The main results of the present study revealed that both 10-m and 20-m accelerations had moderate-to-large correlations with agility tests across the playing positions, however these accelerations were largely inversely correlated with YoYo intermittent recovery test in defenders and largely positively in midfielders. The agility test was moderately correlated with YoYo intermittent recovery test across the different playing positions. In conclusion, there the acceleration and the agility had a positive association with the different positions of the soccer players.

RESUMO O objetivo do presente estudo foi verificar se existe associção entre as variáveis de desempenho físico e analisar a variação dos níveis de aptidão física entre as posições de jogador de futebol universitário. Foram selecionados 20 jogadores de futebol universitário (20,95 ± 1,84 anos; 71,60 ± 11,65 kg; 176,85 ± 7,28 m) divididos em zagueiros, meio-campistas e atacantes. Mensurou-se a composição corporal em uma análise transversal e correlacionou-se a massa gorda, massa magra e massa livre de gordura por meio do DXA com os testes de capacidade física. As principais evidências do presente estudo revelaram que as acelerações de 10 e 20 m tiveram correlações de moderada a grande com o teste de agilidade nas posições de jogo, porém essas acelerações foram inversamente correlacionadas com o teste de recuperação intermitente nos defensores e amplamente positiva nos meio-campistas. O teste de agilidade foi moderadamente correlacionado com o teste de recuperação intermitente YoYo nas diferentes posições de jogo. Em conclusão, a aceleração e a agilidade tiveram uma associação positiva com as diferentes posições dos jogadores de futebol.

Comparison of drop jump force-time profiles of team sport athletes and active controls

Abstract Aim: Lower-body non-contact injuries in team sport athletes (TSAs) are associated when absorbing force, during cutting and landing movements due to a lack of eccentric strength and decreased neuromuscular control leading to excessively higher joint forces. Thus, this project aimed to identify if TSAs had different acceleration and deceleration force profiles compared to a control group (non-TSA) when performing drop jumps (DJs). Methods: University TSAs (n = 15) and non-TSAs (n = 10) performed a series of DJs from a 39 cm box onto a force-plate. All data were normalized to the individual's body mass. Between-group differences in ground reaction force (GRF), rate of force development (RFD), and propulsive and breaking impulses were compared via t-tests and standardized differences. Results: TSAs had significantly, and meaningfully greater RFD than the non-TSAs (p < 0.01, Hedges' g (ES) = 1.24, 53%). While not statistically significant, the non-TSA group produced practically larger mean GRFs than TSAs (p = .09, ES = 0.72, 12.1%). No significant or meaningful between-group differences were detected for propulsive impulse (p = 0.08, ES = 0.41, 9.1%), braking impulse (p = 0.85, ES = 0.25, 4.6%), or impulse ratio (p = 0.35, ES = 0.21, 6.7%). Conclusions: This study shows the presence of significant RFD differences during the DJ in TSAs compared to non-TSAs. Furthermore, this investigation also showed there was no difference between TSA and students in GRF and impulse metrics. Implications from these findings suggest that TSAs can produce force rapidly, but deceleration metrics were not different from untrained students.

Valoración de ecuaciones derivadas del flujo pulmonar y regurgitación tricuspídea: utilidad en el test de vasoreactividad pulmonar / Valuation of equations derived from Pulmonary Flow and Tricuspid Regurgitation: usefulness in Pulmonary Vasoreactivity Testing

RESUMEN: Antecedentes: La presión media arterial pulmonar (PMAP) es una variable hemodinámica indispensable para el diagnóstico, clasificación y pronóstico de la Hipertensión Pulmonar (HP). Su cuantificación se realiza en forma invasiva por cateterismo cardíaco derecho (CCD) y no invasivamente por ecocardiografía Doppler. Masuyama propuso su medición mediante el gradiente transvalvular pulmonar diastólico derivado de la velocidad máxima inicial de la regurgitación pulmonar (∆RPi2) correspondiendo cercanamente a la medición invasiva. Objetivos: Revalidar 3 métodos ecocardiográficos que estiman la PMAP y valorar la utilidad del método de Chemla en el Test de Reactividad Vascular Pulmonar (TRVP). Métodos: Estudio prospectivo, observacional, doble ciego divido en dos etapas. A) o I) 30 pacientes se realizó ecocardiografía Doppler diagnóstica en nuestro centro. Se midieron regurgitación tricuspídea (RT) y tiempo de aceleración pulmonar (TAP) para derivar las siguientes ecuaciones: 1) 0.61xPSAP+1.95 (Chemla) 2) Gradiente presión media RT (∆PmRT) +PAD (presión-aurícula derecha) (Aduen) y 3) 79-0.45xTAP o 90-0.60xTAP, según sea el valor del TAP. B) o II) 10 pacientes enrolados para realizar el TRVP comparando la medición ecocardiográfica (Chemla) con CCD. Resultados: En la primera parte del estudio se encontró alta correlación entre las 3 ecuaciones: ChemlaAduen, R2=0.91; Chemla-Kitabatake, R2=0.87; Aduen-Kitabatake, R2=0,91. En la segunda parte comparando la PMAP-Chemla y Cateterismo derecho (CD) obtuvimos alta correlación: en tiempo 0, 30 min y recuperación:(R2=0.87, 0.99, 0.98, respectivamente). Ambas partes del estudio mostraron límites de concordancia satisfactoria con valor medio de la diferencia entre los métodos cercano a 1 en el t30 y tR del TRVP. Conclusión: los métodos dependientes de la medición de la RT son efectivos y confiables para estimar la PMAP. El método de Chemla es útil en el TRVP.

ABSTRACTS: Background: Mean Pulmonary arterial pressure (PMAP)is an indispensable hemodynamic variable for the diagnosis, classification and prognosis of Pulmonary Hypertension (PH). Its quantification is performed invasively by cardiac catheterization and non-invasively by Doppler echocardiography. Masuyama proposed its measurement by the transvalvular diastolic pulmonary gradient derived from the initial maximum velocity of pulmonary regurgitation(ΔPRi2) corresponding closely to the invasive measurement. Objectives: to compare 3 known echocardiographic methods to estimate MPAP and demonstrate the usefulness of the Chemla method in the Pulmonary Vascular Reactivity Test (PVRT). Methods: prospective, observational, double-blind study divided into two stages. A) 30 patients underwent diagnostic Doppler echocardiography. Tricuspid regurgitation (TR) and pulmonary acceleration time (PAT) were measured to derive the equations: 1) 0.61xSPAP + 1.95 (Chemla) 2) Gradient mean pressure TR (ΔPmTR) + RAP (right atrium pressure) (Aduen).3) 79-0.45xPAT o 90-0.60xPAT depending on the value of PAT. B) 10 patients enrolled to PVRT comparing the echocardiographic measurement (Chemla) with right catheterization. Results: in the first part of the study a high correlation between the 3 equations was found : ChemlaAduen, R2 = 0.91; Chemla-Kitabatake, R2=0.87; Aduen-Kitabatake, R2=0.91. In the second part comparing the MPAP-Chemla and RHC we obtained a high correlation in time 0, 30 min and recovery: (R2=0.87,0,99,0.98, respectively). Both parts of the study showed satisfactory limits concordance with mean value of the difference between the methods close to 1 in the t30 and tR of the TRVP. Conclusion: the methods dependent on the measurement of the TR are effective and reliable for estimating MPAP. The Chemla method is useful in the PVRT.

Habilidades motoras fundamentais e nível de atividade física de crianças: um estudo com escolares do ensino fundamental / Fundamental motor skills and level of physical activity in children: a study with elementary school students

Habilidades Motoras Fundamentais (HMFS) são movimentos básicos como correr e arremessar, cujo desenvolvimento ocorre na infância e deve ser mantida por toda vida. A proficiência nessas habilidades é desejável para a execução adequada das atividades diárias, recreativas e competitivas. A literatura relata uma associação entre as HMFS com um aumento do nível de atividade física (NAF), indicando que as pessoas mais habilidosas são mais confiantes para executar suas atividades e consequentemente, são mais ativas fisicamente. No entanto, não se conhece bem a relação e impacto das HMFS sobre o NAF. Quando se considera os benefícios conhecidos da atividade física (AF) e a natureza do desenvolvimento motor, é racional reconhecer que o professor de Educação Física (EF) é o principal responsável pelo desenvolvimento das HMFS com importante impacto no futuro estilo de vida dos seus alunos. Assim, o objetivo deste estudo foi descrever e investigar os níveis de HMFS e sua associação com NAF em escolares do ensino fundamental. Método: Participaram deste estudo 148 crianças saudáveis (70 meninos; 78 meninas) com idades entre seis e 10 anos. O teste TGMD-2 foi usado para classificar os níveis das HMFS (em sete escalas) nos subtestes (locomoção e controle de objetos) e no quociente do desenvolvimento motor grosso (QDMG). O NAF foi determinado por acelerometria (Actigraph wGT3X-BT) por meio de "counts", considerando o Vetor Magnitude (VM) Semanal de AF Moderada/Vigorosa (Total Semanal MV), para classificar o NAF Total Semanal MV como sedentário ou ativo, de acordo com as classificações de Chandler et al. (2015). A associação entre os escores padrões das HMFS com o QDMG e com o NAF foi verificada (Pearson). A influência das HMFS sobre o NAF Total Semanal MV foi estabelecida por regressão linear simples explicativa, considerando o NAF como variável dependente e os escores padronizados dos subtestes e o QDMG como variáveis independentes. Para todas as análises realizadas (SPSS 20.0) considerou-se ?=0,05. Resultados: Para o NAF Total Semanal MV foram identificadas baixas correlações estatisticamente significantes com QDMG (r=0,33: p<0,001), escore padrão da locomoção (r = 0,24; p=0,004) e escore padrão controle de objetos (r=0,32: p<0,001). A regressão linear (?) mostrou que o QDMG explica 33.3% da variância do NAF Total Semanal MV [FANOVA = 18,216, p=0.001; r2ajustado=0.105]. De modo semelhante, a variância do NAF Total Semanal MV é explicada em diferentes magnitudes pelo escore padrão da locomoção (?=23.8%; [FANOVA = 8.738, p=0.004; r2=0.050]) e pelo controle de objetos (?=32,3%; [FANOVA = 16,991, p=0.001; r2=0.098]). As HMFS apresentaram um impacto de 33% no NAF Total Semanal MV. Crianças com níveis mais altos de HMFS foram as mais ativas fisicamente. Conclusão: Assim, pode-se considerar que os níveis de proficiência das HMFS têm importante influência no NAF Total Semanal MV das crianças. Diante disso, as crianças das séries iniciais necessitam de planos de ensino enfatizando o desenvolvimento das HMFS, pois são prioritariamente desenvolvidas nessa fase da infância

Fundamental Motor Skills (FMS) are basic movements, such as running and throwing, whose development occurs in childhood and must be maintained throughout life. Proficiency in these skills is desirable for proper performance of daily, recreational and competitive activities. The literature reports an association between FMS with an increase in the level of physical activity (LPA), indicating that people who are more skilled are more confident to perform activities and consequently, are more physically active. However, it is not well understood the relationship and impact of FMS on LPA. When considering the known benefits of physical activity (PA) and the nature of motor development, it is rational to recognize that the Physical Education (PE) teacher is the most responsible for the development of FMS with important impact on the future lifestyle of his/her students. Thus, the objective of this study was to describe and investigate levels of FMS and their association with LPA in elementary school students. Method: A total of 148 healthy children (70 boys, 78 girls) with ages between six and 10 years participated in this study. The TGMD-2 test was used to classify FMS levels (on seven scales) in the subtests (locomotor and object control) and in the Gross Motor Quotient (GMQ). The LPA was determined by accelerometry (Actigraph wGT3X-BT) by means of "counts", considering the Magnitude Vector (MV) Weekly of Moderate/Vigorous PA (Total Weekly MV), to classify the LPA Total Weekly VM as sedentary or active, according to the classifications of Chandler et al. (2015). The association between FMS standard scores with GMQ and LPA was verified (Pearson). The influence of the FMS on the LPA Total Weekly MV was established by simple linear regression, considering the LPA as the dependent variable and the standardized scores of the subtests and the GMQ as independent variables. All analyzes were performed considering ? = 0.05. Results: For the LPA Total Weekly MV, low statistically significant correlations were identified with GMQ (r = 0.33: p <0.001), standard locomotor score (r = 0.24, p = 0.004) p <0.001) and standard object control score (r = 0.32: p <0.001). The linear regression (?) showed that the GMQ explains 33.3% of the variance of the LPA Total Weekly MV [FANOVA = 18,216, p = 0.001; r2 set = 0.105]. Similarly, the variance of the LPA Total Weekly MV is explained in different magnitudes by the standard locomotor score (? = 23.8%, [FANOVA = 8.738, p = 0.004, r2 = 0.050]) and object control (?=32, 3%; [FANOVA = 16,991, p=0.001; r2=0.098]). FMS had a 33% impact on LPA Total Weekly MV. Children with higher levels of FMS were the most physically active. Conclusion: Thus, it can be considered that FMS proficiency levels have an important influence on children's LPA Total Weekly MV. Faced with this, children in early grade need teaching plans emphasizing the development FMS, as they are primarily developed at this stage of childhood

Analysis of acceleration time of ankle in long-distance runners and triathletes / Análise de tempo de aceleração do tornozelo em corredores de longa distância e triatletas

INTRODUCTION: Adequate muscle reaction time is essential for protecting the joints against injuries during sports activities. This phenomenon of time of acceleration has been investigated through methodologies such as trapdoor experiments and electromyography. However, isokinetic analysis is an assessment method that is more dynamic and shows behavior closer to the functionality of the sport. Sports that involve running, such as long distance running and triathlon, have high lower-limb injury rates, particularly in relation to the ankle joint. The objective of this study was to evaluate and compare isokinetic acceleration and deceleration times of the dorsiflexor and plantar flexor musculature of the ankle in long-distance runners, triathletes and non-athletic individuals. METHOD: The sample comprised 75 individuals (men aged 18-42 years), divided into three groups: triathlete group, long-distance runner group and control group. The individuals were tested bilaterally on an isokinetic dynamometer. The evaluation modes used were (i) concentric/eccentric for plantar flexion and dorsiflexion, and (ii) eccentric/concentric for plantar flexion and dorsiflexion. We used (a) analysis of variance and Tukey's post hoc test; (b) Kruskal-Wallis and Müller-Dunn post hoc tsts; (c) Chi-square tests. RESULTS: The acceleration time during concentric contraction was statistically different only between the control group and the long-distance runner group, such that the controls presented faster acceleraton. CONCLUSION: This may signify a deficiency in their motor sensory control during concentric activity of the dorsiflexors.

INTRODUÇÃO: O tempo adequado de reação muscular é essencial para proteger as articulações contra lesões durante atividades esportivas. Este fenômeno de tempo de aceleração tem sido investigado por meio de metodologias como experimentos com trampolim e eletromiografia. No entanto, a análise isocinética é um método de avaliação que é mais dinâmico e mostra comportamento mais próximo da funcionalidade do esporte. Corrida de longa distância e triatlo têm altas taxas de lesão de membros inferiores, particularmente em relação à articulação do tornozelo. O objetivo deste estudo foi avaliar e comparar os tempos de aceleração e desaceleração isocinética do dorsiflexor e da musculatura flexora plantar do tornozelo em corredores de longa distância, triatletas e indivíduos não atléticos. MÉTODO: A amostra incluiu 75 indivíduos (homens com idade entre 18-42 anos), divididos em três grupos: triatletas, corredores de longa distância e grupo controle. Os indivíduos foram testados bilateralmente em um dinamômetro isocinético. Os modos de avaliação utilizados foram: 1. concêntricos/excêntricos para flexão plantar e dorsiflexão; 2. excêntricos/concêntricos para flexão plantar e dorsiflexão. A análise estatística utilizou análise de variância e teste post hoc de Tukey; Testes post hoc de Kruskal-Wallis e Müller-Dunn e testes Qui-quadrado. RESULTADOS: O tempo de aceleração durante a contração excêntrica foi estatisticamente diferente apenas entre o grupo controle e o grupo corredor de longa distância: os controles apresentaram aceleração mais rápida. CONCLUSÃO: Este resultado pode indicar uma deficiência no controle sensorial do seu motor durante a atividade concêntrica dos dorsiflexores.

Reevaluation of the Strain Pressure Theory: Toward a Better Understanding the Biology of Tooth Movement / Reevaluación de la Teoría Presión - Tensión: Hacia una Mejor Comprensión de la Biología del Movimiento Dental

The aim of this report was to analyze the majority of publications referred to orthodontic movement Biological basis, principally strain- pressure theory taking account contemporaneous methodological study designs. The literature published in Pubmed from 1967 to 2014 was reviewed, in addition to well-known scientific reports that were not classified under this database like classical manuscripts since 1839. The comment items are: Limitations of animal models, Histological slices, what to watch for, Rats as an experimental model in orthodontics, Strain­pressure, the force used in these studies that fundament this theory, Reevaluation studies about strain-pressure theory in biology movement using contemporaneous models, Up to date concepts, Theory reevaluation the first step to understanding new acceleration concepts and Movement biology research, present and future. After analyzing those items we concluded: A 3D perspective is essential for a complete understanding of events in tooth movement involves two interrelated processes: the bending of alveolar bone and remodeling of the periodontal tissues. It's important to start, and acknowledge that the PDL cannot be divided into two different areas that react independently to an applied force. It´s a continuous periodontal compartment in OTM, rather than a pressure side and a tension side. When an orthodontic force is applied there are two simultaneous effects that correlate. Alveolar bone flexion and remodeling of the periodontal tissues. Alveolar Bone deformation compromising the main structures (PDL, bone and cement), compression and tension can coexist in different directions. The magnitudes of compression and tension are typically different in different directions. As the majority of research and studies indicate that fundamental movement biology are made on animal models, it is important to know that their results and conclusions, under the actual evidenced based practice guidelines do not allow to make clinical decisions even if they are included on systematic reviews.

El objetivo de esta revisión es analizar la mayoría de las publicaciones relacionadas a la fundamentación sobre el movimiento de ortodoncia, principalmente la teoría presión-tensión, teniendo en cuenta los diseños de estudios metodológicos contemporáneos. Se revisó la literatura publicada en la base de datos de MEDLINE, 1967-2013 , además de los informes conocidos que no fueron clasificados en esta base de datos como manuscritos clásicos desde 1839. Los temas principales en los que se divide el artículo son: Limitaciones de los modelos animales, cortes histológicos, las ratas como modelo experimental en ortodoncia, la fuerza utilizada en los estudios que fundamentan esta teoría, reevaluación sobre los estudios de la teoría presión ­tensión en modelos contemporáneos, conceptos actuales en biología del movimiento, reevaluación de la teoría: el primer paso para entender los nuevos métodos en aceleración del movimiento, conceptos e investigaciones en biología del movimiento: presente y futuro. Una perspectiva 3D es esencial para una comprensión completa de los acontecimientos. El movimiento dental implica dos procesos interrelacionados: la curvatura del hueso alveolar y la remodelación de los tejidos periodontales. Es importante empezar, y reconocer que el PDL no puede ser dividido en dos áreas diferentes que reaccionan de forma independiente a una fuerza aplicada. Está en un compartimiento continuo periodontal , en lugar de un lado de presión y un lado de tensión. Al aplicar una fuerza de ortodoncia hay dos efectos simultáneos: la flexión del hueso Alveolar y la remodelación de los tejidos periodontales. La deformación del hueso compromete las estructuras principales (PDL, hueso y cemento) y la compresión y la tensión pueden coexistir en diferentes direcciones.

Do speed cameras reduce speeding in urban areas? / ¿Los radares modifican comportamientos de velocidad excesiva en áreas urbanas? / Os radares fixos modificam o comportamento relacionado à velocidade excessiva dos condutores em áreas urbanas?

Abstract This observational study aimed to estimate the prevalence of speeding on urban roadways and to analyze associated factors. The sample consisted of 8,565 vehicles circulating in areas with and without fixed speed cameras in operation. We found that 40% of vehicles 200 meters after the fixed cameras and 33.6% of vehicles observed on roadways without speed cameras were moving over the speed limit (p < 0.001). Motorcycles showed the highest recorded speed (126km/h). Most drivers were men (87.6%), 3.3% of all drivers were using their cell phones, and 74.6% of drivers (not counting motorcyclists) were wearing their seatbelts. On roadway stretches without fixed speed cameras, more women drivers were talking on their cell phones and wearing seatbelts when compared to men (p < 0.05 for both comparisons), independently of speed limits. The results suggest that compliance with speed limits requires more than structural interventions.

Resumen Este estudio observacional fue realizado para estimar la prevalencia de los conductores que no respetan el límite de velocidad en vías urbanas y estudiar los factores relacionados con este comportamiento. La muestra consistió en 8.565 vehículos circulando en zonas con y sin radares fijos en funcionamiento. Se encontró que 40% de los vehículos a 200 metros mas allá del radar estacionario y 33,6% de los observados en las zonas sin radar exceden los límites legales (p < 0,001). Las motos registran una velocidad máxima más elevada (126km/h). Los hombres fueron mayoría (87,6%), el uso de celular mientras se conduce representó un 3.3% de todas las observaciones y el 74,6% de los conductores estaban usando cinturones de seguridad entre los automobilistas. En sitios donde no había presencia de radar estacionario, se observó una mayor proporción de mujeres que usan el teléfono y el cinturón de seguridad (p < 0,05 para ambas comparaciones), independientemente de los límites de velocidad. Se sugiere que la adherencia a las normas referidas a velocidades máximas va más allá de las intervenciones estructurales.

Resumo Este estudo observacional teve como objetivo estimar a prevalência de condutores que transitam com excesso de velocidade em vias urbanas e estudar fatores relacionados a este comportamento. A amostra consistiu de 8.565 veículos que circulavam em áreas com e sem radares fixos em operação. Verificamos que 40% dos veículos observados em locais a 200m de radar fixo e 33,6% daqueles observados nos locais sem radar excedem os limites legais (p < 0,001). Motocicletas tiveram maior velocidade máxima registrada (126km/h). Os homens mostraram ser maioria entre os condutores (87,6%), o uso do celular durante a direção foi verificado em 3,3% de todas as observações e 74,6% dos condutores, exceto motociclistas, faziam uso do cinto de segurança. Nos locais onde não havia a presença do radar fixo, maior proporção de mulheres foi observada utilizando mais o celular e o cinto de segurança em relação aos homens (p < 0,05, para ambas comparações), independente dos limites de velocidade. Sugere-se que adesão ao cumprimento dos limites de velocidade vai além de intervenções estruturais.

Cambios cinemáticos de la marcha en pacientes con artrosis de rodilla con diferentes descargas de peso / Kinematic Changes of Gait in Patients with Knee Osteoarthritis by Different Weight bearings / Mudanças cinemáticas da marcha em pacientes com artrose de joelho com diferentes descargas de peso

Objetivo: Describir las diferencias en las variables cinemáticas de la marcha en mujeres mayores de 60 años con artrosis de rodilla con diferentes descargas de peso. Materiales y métodos: Diseño investigativo longitudinal Phanel con un muestreo no probabilístico a conveniencia en mujeres n = 16, con edad > 60 años, sobrepeso y artrosis de rodilla; el control de la descarga de peso se realizó por medio de una plataforma de rehabilitación locomotora midiéndose la marcha en tres momentos con el 100%, 90% y 80% del peso. Resultados: Los rangos de movimiento para algunas fases de la marcha fueron diferentes para la descarga de peso utilizadas p < 0,05; para la velocidad y aceleración angular no se encontraron diferencias estadísticamente significativas. Conclusiones: Las diferentes descargas de peso no representaron para la presente investigación una variable que modificara de forma significativa las variables cinemáticas de la marcha.

Objective: To describe the differences in kinematic gait variables in women over sixty years of age with knee osteoarthritis by different weight bearings. Material and Methods: Phanel longitudinal research design with convenience sampling probabilistic n = 16 women, aged > 60 years, obesity and knee osteoarthritis, control weight bearing was performed by a locomotive rehabilitation platform that measured gait three times with weights of 100%, 90% and 80%. Results: The movement ranges in certain gait phases were different for bearings of used weight p < 0.05; for angular speed and acceleration no statistically significant differences were found. Conclusions: The different weight bearings for this research represented a variable that significantly change the kinematic gait variables.

Objetivo: descrever as diferenças nas variáveis cinemáticas da marcha em mulheres maiores de sessenta anos com artrose de joelho com diferentes descargas de peso. Materiais e métodos: concepção investigativa longitudinal Phanel com uma amostragem não probabilística a conveniência em mulheres n=16 com idade >60 anos, sobrepeso e artrose de joelho, o controle da descarga de peso se realizou por meio de uma plataforma de reabilitação locomotora medindo-se a marcha em três momentos com o 100% do peso, 90 e 80. Resultados: Os rangos de movimento para algumas fases da marcha foram diferentes para a descarga de peso utilizada p<0.05, para a velocidade e aceleração angular não se encontraram diferenças estatisticamente significativas. Conclusões: As diferentes descargas de peso não representaram para a presente pesquisa uma variável que modificará de forma significativa as variáveis cinemáticas da marcha.

Diseño e implementación de sistema de plantilla para medición de presiones y cinemática del pie / Design and implementation of system for measurement pressures and foot kinematics

Este es un trabajo donde se desarrolló e implementó un sistema integrado que combina una plan-tilla instrumentada con sensores de presión y un módulo de sensores inerciales compuesto por un acelerómetro y un giroscopio, los cuales permitio la medición de variables baropodométricas (presiones plantares) y variables cinemáticas (aceleración, velocidad angular y desplazamiento angular) del pie. El sistema resultante le deja al especialista realizar un estudio biomecánico del pie a través del análisis estático y/o dinámico del movimiento y la visualización en pantalla de da-tos cuantitativos e información cualitativa, para la evaluación e intervención de los deportistas.

This paper presents the development and implementation of an integrated system that combi-nesan insole instrumented with pressure sensors and an inertial sensor module consists of an accelerometer and a gyroscope, which allows measurement of baropodometric variables (plantar pressures) and kinematic variables (acceleration, angular rate, and angular displacement) of the foot. The resulting system allows the specialist to conduct a foot biomechanical study through static and/or dynamic analysis and screen display of quantitative data and qualitative informa-tion, whose analysis allows prevention and intervention programs for musculoskeletal disorders that may affect the performance of athletes.

Experiencia en el uso video-Impulso Cefálico (vHIT) en la evaluación del reflejo vestíbulo-ocular para el canal semicircular horizontal / Assesing vestibulo-ocular reflex of the horizontal semicircular canal with video Head Impulse Testing (vHIT)

Introducción: La prueba de impulso cefálico consiste en una herramienta sencilla y rápida para evaluar la función del reflejo vestíbulo ocular. La implementación de un acelerómetro y una cámara de alta velocidad, permiten registrar alteraciones sutiles de este fenómeno, optimizando esta prueba. Objetivo: Describir la experiencia inicial y relevancia clínica de la prueba de impulso cefálico asistida por video y acelerómetro (vHIT). Material y método: Se realizó prueba vHIT a pacientes con indicación de estudio funcional de VIII par. Resultados: Utilizando prueba calórica como patrón de oro se evaluaron 60 pacientes. vHIT presentó una especificidad de 93% y una sensibilidad de 74%. En un paciente con colesteatoma bilateral con vértigo agudo, el examen contribuyó en la identificación del lado complicado, además de registrar fenómenos de compensación vestibular. Discusión y conclusión: vHIT demostró ser altamente específico. Los supuestos falsos positivos presentaban sintomatología vestibular, por lo que consideramos que podrían representar casos donde vHIT es más sensible que la prueba calórica. vHIT presenta además una buena sensibilidad. Los casos de falsos negativos podrían explicarse en relación a la diferencia de velocidad angular usada en la estimulación entre vHIT y la prueba calórica. vHIT podría representar un importante complemento al estudio del paciente con patología vestibular.

Introduction: The head impulse test is a simple and quick tool for assessing the vestibulo-ocular reflex. The implementation of an accelerometer and a high-speed camera, allows the recording of subtle, priorly unaccessible alterations, thus optimazing the test. Aim: To describe an initial experience and clinical relevance of a video and accelerometer assisted head impulse test (vHIT). Material and method: We performed vHITon patients with indication of vestibular testing due to vertigo or balance related symptoms. Results: Regarding caloric testing as gold standard, 60 patients were evaluated. vHIT had a specificity of 93% and a sensitivity of 74%. In a patient with bilateral cholesteatoma with acute vertigo, vHIT examination contributed in identifying the complicated side, in addition to recording previously undetectable vestibular compensation phenomena. Discussion and conclusion: vHIT proved to be highly specific. Every supposed false positive cases had vestibular symptoms, so we consider these cases to represent a scenario where vHIT is actually more sensitive than caloric testing. vHIT showed also good sensitivity. False negative cases could be explained in relation to the test's angular velocity stimuli difference existing between VHIT and caloric test. VHIT could represent an important contribution to patients with vestibular disorders.

Evaluación del gasto energético y actividad física en escolares eutróficos, con sobrepeso u obesidad / Assessment of energy expenditure and physical activity in eutrophic, overweight or obese school students using Actihearts monitors

Physical inactivity has been identified as a major cause of overweight and obesity in children. Objective: To determine and compare the intensity of physical activity and energy expenditure in eutrophic (E) and overweight/obese (OW) children. Patients Method: 37 school children 6 to 9 years old, 15 overweight (OW) and 22 eutrophic (E) were studied with Actihearts™ monitors. Nutritional status was classified according to body mass index (BMI). Resting metabolic rate (RMR), total energy expenditure (TEE) and physical activity level (PAL) was calculated. Actihearts™ monitors were used to record heart rate (HR), physical activity energy expenditure (PAEE), time spent in physical activity (TPA) and accelerometry (AC). Results: OW children reported a RMR = 1,275 kcal/d +/- 164,2; TEE = 2,316 kcal/d +/- 358,7; PAEE = 985 kcal/d +/- 223,1; PAL = 1,82 +/- 0,13; significantly higher (p < 0.05) than those recorded by the eutrophic: RMR = 1066 kcal/d +/- 78,8; TEE = 1821 kcal/d +/- 241,8; PAlEE = 713 kcal/d +/- 168,1; PAlL = 1,70 +/- 0,12. The TPA and the AC did not show significant difference (p < 0.05) between both groups. Conclusions: This study concluded that OW and E children in the early years in elementary school spend, on average, the same time in physical activity and the same PAEE in activities of moderate to vigorous intensity. Both groups present similar physical activity behavior, which suggests that a hypothesis other than physical inactivity might be looked for regarding the origin of obesity, or perhaps look at origins at an earlier age.

La inactividad física ha sido identificada como una causa del sobrepeso y obesidad en niños. Objetivo: Determinar y comparar la intensidad de la actividad física y el gasto energético entre niños eutróficos (E) y con sobrepeso/obesidad (S/O). Pacientes Método: 37 varones de 6 a 9 años, 15 (S/O) y 22 (E) fueron estudiados utilizando monitores Actihearts™ como instrumento de medición. El estado nutricional se clasificó de acuerdo al índice de masa corporal (IMC). Se calculó la tasa metabólica basal (TMB), gasto energético total (GET) y el nivel de actividad física (NAF). El monitor Actihearts™ registró frecuencia cardíaca (FC), gasto energético en actividad física (GEAF), tiempo dedicado a la actividad física (TAF) y la acelerometría (AC). Resultados: Los Escolares S/O registraron: TMB = 1 275 kcal/d +/- 164,2; GET = 2 316 kcal/d +/- 358,7; GEAF = 985 kcal/d +/- 223,1; NAF = 1,82 +/- 0,13; significativamente mayores (p < 0,05) que los registrados por los eutróficos: TMB = 1066 kcal/d +/- 78,8; GET = 1 821 kcal/d +/- 241,8; GEAF = 713 kcal/d +/- 168,1 y NAF = 1,70 +/- 0,12. El TAF y la AC no mostraron diferencia significativa (p < 0,05) entre ambos grupos. Conclusiones: El presente estudio concluyó que los escolares S/O y E del primer ciclo de educación básica dedican en promedio el mismo tiempo a la actividad física y el mismo GEAF en actividades de moderada a vigorosa intensidad, identificando que ambos grupos tuvieron un similar comportamiento en el nivel de actividad física, lo que permite plantear una nueva hipótesis que el S/O es promovido entre otras variables por la inactividad física pero quizá a edades más tempranas.

The physical activity level of Mexican children decreases upon entry to elementary school / El nivel de actividad física disminuye en niños mexicanos al ingresar a la escuela primaria

OBJECTIVE: To compare the physical activity patterns of a cohort of Mexican children in kindergarten (K), first (1ES) and second grade (2ES) of elementary school. MATERIAL AND METHODS: The physical activity of 217 children (123 girls and 94 boys) aged 5-6 years was measured (five full-day triaxial accelerometry) annually.Weekday and weekend moderate/ vigorous physical activity (MVPA) and school and off-school MVPA was calculated. Comparisons between surveys were made using longitudinal multilevel generalized linear models. RESULTS: Weekday MVPA was 22 and 37 min/d lower for 1ES (p=0.06) and 2ES (p<0.01), respectively, compared to K. School MVPA for 1ES and 2ES was 37 (-5.0 min/h) and 40 percent (-5.5 min/h) (p<0.001) lower, respectively, compared to K. No differences were found between weekend and off-school MVPA among school stages (p>0.5). CONCLUSION: MVPA was significantly reduced from K to ES,in part because of a decline in MVPA during school activities. Interventions targeted to school environment modifications should be promoted.

OBJETIVO: Comparar los patrones de actividad física (AF) en una cohorte de niños mexicanos en el jardín de niños, primer y segundo grado de primaria. MATERIAL Y MÉTODOS: Se midió anualmente la AF (acelerometría triaxial de cinco días completos) en 217 niños (123 niñas y 94 niños) de 5 a 6 años de edad. Se calculó la AF moderada/vigorosa (AFMV) entre semana y de fin de semana, dentro y fuera del horario escolar. Se realizaron comparaciones mediante modelos lineales generalizados multinivel longitudinales. RESULTADOS: La AFMV entre semana fue 22 (p=0.06) y 37 min/d (p<0.01) menor, y la AFMV durante el horario escolar disminuyó 37 (-5.0 min/h) y 40 por cento (-5.5 min/h) (p<0.001), en 1º y 2º de primaria,respectivamente,comparado con el jardín de niños.No se encontraron diferencias en la AFMV de fin de semana o fuera del horario escolar entre los grados escolares (p>0.05). CONCLUSIONES: La AFMV disminuyó de manera significativa del jardín de niños a 2º de primaria en parte debido a una reducción de AFMV durante las actividades escolares. Es necesaria la promoción de intervenciones enfocadas a la modificación del ambiente escolar.

Desenvolvimento e validação de um recordatório de 24 horas de avaliação da atividade física / Development and validation of a 24-hour recall for the evaluation of physical activity

O objetivo deste estudo foi desenvolver e verificar a validade de um recordatório de 24 horas de atividade física (R24AF). A amostra foi composta por 98 adultos com idade entre 18 e 59 anos matriculados no Centro de Saúde Escola Geraldo de Paula Souza, localizado na região central do município de São Paulo. O estudo foi realizado entre outubro de 2005 a dezembro de 2006. Os participantes foram orientados a utilizar o acelerômetro Biotrainer II em dois dias da semana e um dia do final de semana e o R24AF foi aplicado no dia posterior ao uso. Os dados obtidos no R24AF foram digitados em um software elaborado especificamente para este estudo, obtendo-se os minutos por dia e o gasto energético em atividades leves, moderadas e vigorosas. Para verificar a relação entre as variáveis de estudo utilizou-se a correlação de Spearman e correlação ajustada por idade, índice de massa corporal (IMC) e perímetro da cintura. O índice Kappa foi calculado para avaliar o grau de concordância entre o R24AF e o acelerômetro. Foram encontrados coeficientes de correlação que variaram de 0,23 para homens e de 0,53 para mulheres na contagem de movimento do acelerômetro com o total de atividade física do R24AF. Os melhores coeficientes foram obtidos para atividade moderada e vigorosa obtida pelo R24AF com o acelerômetro (0,43 para homens e 0,54 para as mulheres). Nas análises ajustadas, verificou-se melhora nos coeficientes obtidos para os homens, enquanto que para as mulheres os resultados mantiveram-se os mesmos. Verificou-se concordância moderada entre o R24AF e o acelerômetro. Conclui-se que os resultados encontrados neste estudo mostraram que o R24AF apresentou evidências de validade adequadas e pode ser um instrumento interessante para uma avaliação detalhada da atividade física.

The aim of this study was to develop and verify the validity of a 24 hours physical activity recordatory (24PAR). Sample was composed by 98 adults aged 18 to 59 years registered in the Health School Center Geraldo de Paula Souza, located in the center region of the city of São Paulo. The study was realized between October 2005 to December 2006. Participants were guided to utilize the Biotrainer II (IM Systems) accelerometer in two week days and one weekend day. Data from 24PAR were typed in specific software elaborated for this study, which obtains minutes for day and the energy expenditure in physical activity of low, moderate and vigorous intensity. To verify the correlation between the study variables it was utilized the Spearman's correlation and correlation adjusted by age, body mass index (BMI) and waist circumference. Kappa index was calculated to evaluate the level of concordance between 24PAR and accelerometer. It was found correlations ranged between 0.23 for men and 0.53 for women in the comparisons of the activity counts measured by the accelerometer and the 24PAR total physical activity. The best coefficients were presented for moderate and vigorous physical activity obtained by 24PAR with the accelerometer (0.43 for men and 0.54 for women). In adjusted analyses, it was verified an increase in the coefficients obtained by men, while to women the results maintained unchanged. It was verified moderate concordance between 24PAR and accelerometer. It was concluded that the results found in this study demonstrated that the 24PAR presented validated evidences and it is an appropriate instrument to a physical activity detailed evaluation

Correlação entre o desempenho de jogadores de futebol no teste de sprint de 30m e no teste de salto vertical / Correlation between performance of soccer players in the 30-meter sprint test and in the vertical jump test

O objetivo do estudo foi determinar o nível de correlação entre o desempenho nos 10m iniciais, dos 20m finais e no tempo total do teste de sprint de 30m, com o do salto vertical com contra-movimento (CMJ) entre jogadores de futebol. Participaram do estudo 167 jogadores das categorias profissional (N. 94) e júnior (N. 73). Foram determinadas as velocidades dos jogadores em 10m (V10), 20m (V20) e no total de 30m (V30). A habilidade de salto foi avaliada através do CMJ. Para correlacionar os dados, foi utilizado o coeficiente de correlação de Pearson com nível de significância de p<0,05. A categoria júnior apresentou maiores valores de V10 e menores valores de V20 em comparação com a categoria profissional (p<0,05). Os valores de correlação entre o CMJ e os parâmetros de velocidade para a categoria júnior foram; r= 0,239, 0,370, 0,408 para V10, V20 e V30 respectivamente e para a categoria profissional foram; r= 0,381, 0,381 e 0,470 para V10, V20 e V30 respectivamente. Quando as duas categorias foram avaliadas em conjunto os valores de correlação foram; r= 0,293, 0,386 e 0,441 para V10, V20 e V30 respectivamente. Foi encontrada uma fraca correlação entre o CMJ e o V10 da categoria júnior sendo a mesma moderada para os demais parâmetros. A categoria profissional apresentou valores de correlação moderada entre o CMJ e todos os outros parâmetros. Maiores valores de correlação do V10 para a categoria profissional pode ser devido a efeitos específicos do treinamento.

The aim of the present study was to determine the association between the results in the counter movement jump (CMJ) and the results in the first 10 meters, in the final 20 meters and the in the total 30 meters of a 30-meter sprint. One-hundred and sixty seven Soccer players from the professional (N. 93) and under twenty (N. 74) categories, from a Brazilian first division Soccer club participated in the study. The sprint test consisted of a 30-meter run timed at the 10-meter and at the 30-meter marks. The jump capacity was assessed through the CMJ. Pearson’s correlation (r) was used to determine the association between these variables. The significance level adopted was p<.05. The U-20 players presented faster V10 and slower V20 than the professionals (p<.05). The correlation (r) between CMJ and V10, V20 and V30 were .239, .370 and .408, respectively, for the U20 group and .381, .381 and .470, respectively, for the professional group. Evaluating the two categories together the correlation were; r= 0,293, 0,386 and 0,441 to V10, V20 and V30 respectively. The correlation between CMJ and V10 was weak and moderate for V20 and V30. In the professional category the correlation between CMJ and all the other parameters was moderate. It is probable that higher correlation values for CMJ and V10 for the professionals could be attributed to specific training effects.

Modelo conceptual para identificar factores relevantes en la seguridad de los niños en los autobuses escolares / Conceptual model for identifying factors relevant to the safety of children in school buses

OBJETIVO: Elaborar un modelo conceptual que permita comprender las relaciones entre las variables que llevan a los niños a adoptar posturas en los vehículos de transporte escolar que incrementan los efectos lesivos en caso de accidentes de tránsito. MÉTODOS: Para la identificación de las variables se recolectó información directa de la actividad del transporte escolar por medio de grupos de enfoque, con asistentes de ruta y conductores de estos vehículos, la filmación interior de autobuses durante el transporte de los niños, y el registro de dimensiones de componentes en diferentes tipos de autobuses escolares. El análisis de la información recolectada se hizo mediante el software Atlas ti v6 y, la construcción del modelo, por medio de un proceso deductivo. RESULTADOS: Se encontraron relaciones importantes entre la adopción de posturas potencialmente riesgosas por parte de los niños durante el transporte escolar y las características dimensionales de los asientos y cinturones de seguridad, las características del servicio de transporte y el rol del asistente de ruta. CONCLUSIONES: Para llevar a cabo intervenciones coherentes y específicas en el ámbito de la seguridad en el transporte escolar, se deben considerar no solo aspectos técnicos concernientes al vehículo o condiciones posturales controladas en pruebas de choque en laboratorio, sino también las variables específicas de la actividad que llevan a los niños a adoptar posturas que incrementan el riesgo de lesiones.

OBJECTIVE: Prepare a conceptual model that facilitates understanding of the relationships between the variables that lead children to adopt postures in school transportation vehicles that increase injuries in traffic accidents. METHODS: For identification of the variables, direct information on school transportation was collected through focus groups, with bus aides and bus drivers, on-board filming during the transport of children, and recording of the dimensions of components in different types of school buses. The information collected was analyzed using the Atlas.ti v6 software and the construction of a model through deduction. RESULTS: Important relationships were found between adoption of potentially hazardous postures by children during transport to and from school and the seat and seat belt dimensions, the characteristics of the transportation service, and the role of bus aides. CONCLUSIONS: In order to adopt coherent interventions in school transportation safety, it is necessary to consider not only the technical aspects of the vehicle or posture that are controlled in crash tests but the specific variables of the activities that lead children to adopt postures that put them at greater risk of injury.

Acelerometría: una nueva herramienta para incluir en la práctica clínica / Accelerometry: a new techinique in a clinical practice

El propósito del presente trabajo es mostrar un primer acercamiento al estudio del movimiento humano a través de acelerometria. Se describe el funcionamiento de los sensores involucrados y se revisan algunas investigaciones que han aplicado esta tecnología bajo distintas configuraciones. Mediante el análisis del comportamiento de las señales obtenidas a través de registros acelerométricos se analizó la marcha automática sobre una cinta caminadora a velocidad constante durante treinta segundos en un sujeto sin disfunción del movimiento. Se analizó la respuesta para las direcciones vertical, medio-lateral y antero-posterior observándose un patrón característico, tanto en el dominio del tiempo como de la frecuencia. Los resultados presentados en este reporte muestran concordancia con Los hallazgos obtenidos por otros autores, lo que evidencia un aporte significativo desde el punto de vista de la tecnología empleada en Los registros, tanto por las proyecciones que esta herramienta ofrece, como por los reducidos costos involucrados. En Chile, este tipo de herramientas es poco conocida, sin embargo esta línea de investigación y desarrollo puede constituir una real alternativa a los sistemas de análisis de movimiento convencionales. En el Laboratorio de Análisis de Movimiento Humano de la Universidad Metropolitana de Ciencias de la Educación, se está abriendo esta línea de investigación, que puede significar una alternativa a los sistemas convencionales de análisis de movimiento y un aumento del trabajo investigativo en Kinesiología, al situarse como una técnica barata, con el potencial de ser aplicada en cualquier lugar, sin necesidad de un Laboratorio, lo que además abre la posibilidad de realizar mediciones de forma ambulatoria, por ejemplo en un consultorio o en la casa de un paciente.

The purpose of this work is to show a first approach to the study of the human motion through accelerometry. The functioning of the involucrate sensors is described and some investigations that applied this technology under different configurations were checked. By means of the analysis of the signal behaviour obtained through accelerometric records examined the automatic walk on a treadmill at constant velocity during thirty seconds in a patient without dysfunction of movement. The answer was examined for vertical, half lateral and antero posterior directions observing a similar pattern, as much as in the domain of the time as in frequency. The results given in this report show concordance with obtained findings by other authors, what evidences a significant contribution from a technology point of view used in the records, as much as projections this tool offers, as implicated costs reduced. In Chile, this kind of tool is not well known, however this line of research and development can constitute a real alternative to conventional systems of analysis of movement. In the Laboratory of Human Movement Analysis of The Universidad Metropolitana de Ciencias de la Educación university, this line of investigation is starting to open, this can mean an alternative to the conventional systems of analysis of movement and an increase of the investigating work in Kinesiology, been placed like a cheap technique, with the potential to be used everywhere, without the need of a Laboratory, giving also the possibility to take records in a outpatient clinic, at a primary healthcare or at patient’s house, for instance. Therefore, the challenge is to include this tool within the routine of the national healthcare, either to describe a patient’s movement quantitatively, compare the results of a therapy or training objectively, determine principles of a treatment or evaluate data with other records to understand the causes that determine the condition to study.

Predição do desempenho aeróbio na canoagem a partir da aplicação de diferentes modelos matemáticos de velocidade crítica / Aerobic performance prediction in canoeing from the application of different mathematical models of critical velocity

O modelo de velocidade crítica com dois parâmetros vem sendo utilizado para a determinação do desempenho aeróbio e anaeróbio. No entanto, o modelo com três parâmetros prevê um parâmetro adicional correspondente à velocidade instantânea máxima (Vmáx) ao modelo original, tendo impacto sobre a estimativa dos outros dois parâmetros. Sendo assim, o objetivo deste trabalho foi verificar e comparar a relação da velocidade crítica (VCrit), fornecida pelos modelos com dois (VCrit-2parâmetros) e três (VCrit-3parâmetros) parâmetros, com a velocidade média mantida em esforço máximo de 6.000m (V6000m) na canoagem. Nove canoístas (17,4 ± 2,4 anos) competitivos do sexo masculino realizaram, em dias diferentes, testes máximos de 200, 500, 1.000, 1.800 e 6.000m. A VCrit foi calculada para todos os sujeitos, a partir das distâncias de 200 a 1.800m, utilizando-se as equações hiperbólicas com dois e três parâmetros. As durações dos percursos ficaram no intervalo entre 46,1 ± 2,5s e 513,9 ± 25,6s. Para comparação entre as velocidades (VCrit-2parâmetros, VCrit-3parâmetros e V6000m) foi utilizada ANOVA one way para medidas repetidas, seguida pelo teste post hoc de Newman-Keuls. A associação entre as variáveis foi feita a partir de correlação de Pearson. Para análise de concordância foi aplicada a plotagem de Bland-Altman entre os valores de VCrit-2parâmetros, VCrit-3parâmetros e V6000m . Em média, o tiro de 6.000m teve duração de 29,9 ± 1,0 min. Houve diferença significante da VCrit-3parâmetros (2,93 ± 0,36m/s) em relação à VCrit-2parâmetros (3,31 ± 0,22m.s-1) e V6000m (3,35 ± 0,11m.s-1). VCrit-2parâmetros e V6000m não diferiram entre si. A correlação entre VCrit-2parâmetros e V6000m foi de 0,72 (p = 0,03), enquanto que a entre VCrit-3parâmetros e V6000m não foi significante. Os resultados deste estudo sugerem que o modelo de velocidade crítica de dois parâmetros fornece valor de VCrit mais adequado para a avaliação aeróbia de canoístas. A VCrit-3parâmetros...

The 2-parameter critical velocity model has been used for determination of aerobic and anaerobic performance. Nevertheless, the 3-parameter model previews an additional parameter corresponding to the maximal instantaneous velocity (Vmax) to the original model, having an impact on the estimation of the other two parameters. Thus, the aim of this work was to verify and compare the relationship of the critical velocity (Ccrit), provided by the 2-parameter (Ccrit-2parameters) and 3-parameter (Vcrit-3parameters) models, with the mean velocity kept in a maximal effort of 6,000m (V6000m) in canoeing. Nine competitive, male canoers (17.4± 2.4 years) performed at different days, maximal tests of 200, 500, 1,000, 1,800 and 6,000m. The Vcrit was calculated for all subjects, from the 200 to 1,800 distances, using the hyperbolic equations with two and three parameters. The distance durations were in the interval between 46.1 ± 3.5 s to 513.9 ± 25.6 s. One-way ANOVA for repeated measures was used for comparison between velocities (Vcrit-2parameters, Vcrit-3parameters and V6000m), followed by the Newman-Keuls post hoc. The association between variables was performed with the Pearson correlation. The Bland-Altman Plot among the Vcrit-2parameters, V Crit-3parameters and V6000m was applied for concordance analysis. The 6,000m sprint had an average of 29.9 ± 1.0 min duration. There was significant difference of the Vcrit-3parameters (2.93 ± 0.36 m/s) in comparison with the Vcrit-2parameters (3.31 ± 0.22 m.s-1) and V6000m (3.35 ± 0.11 m.s-1). Vcrit-2parameters and V6000m did not differ between each other. The correlation between Vcrit-2parameters and V6000m was of 0.72 (p= 0.03), while the correlation between Vcrit-3parameters and V6000m was not significant. The outcomes of this study suggest that the 2-parameter critical velocity model provides Vcrit values more suitable for the aerobic assessment of canoers. The Vcrit-3parameters underestimates the velocity...

Valor de un test clínico para evaluar actividad física en niños / Value of a clinical test for assessing physical activity in children

Background: An appropriate measurement of physical activity (PA) in children is useful, since inactivity is associated to obesity, cardiovascular and metabolic risk. Aim: To assess the reliability of the INTA questionnaire of PA, to compare the derived PA score with accelerometry and to assess its ability to identify excessively inactive children. Material and methods: One hundred eighty children aged 8 to 13 years answered an interviewer-administered questionnaire about their usual PA, consisting in 5 items (recumbent, seated, walking, playing outdoor, sports). The answers were converted to a PA score with a 0-10 points scale. Reliability was tested in 87 children by test/retest conducted 3-5 days apart. The PA score was compared with 3-day accelerometry in 77 of 93 children (35 obese and 42 non obese). Receiver operating characteristic (ROC) curves were used to determine the optimal cut-point for identify an excessively sedentary child. Results: The test/retest reliability of the questionnaire was 0.69 to 0.93 (Lin coefficient). Accelerometry was significantly associated with PA score (RHO: 0.60, p =0.008), outdoor plays (RHO: 0.37, p =0.0009) and practicing of sports (RHO: 0.33, p =0.003). Obese children were less active than non obese children, according both to PA score and to accelerometry. The optimal cut-point for classifying a child as too sedentary was a score of 5 (sensitivity =0.89). Conclusions: The INTA-test is a valuable instrument for measuring usual PA in clinical practice and is easy to administer.

Synergistic control of forearm based on accelerometer data and artificial neural networks

In the present study, we modeled a reaching task as a two-link mechanism. The upper arm and forearm motion trajectories during vertical arm movements were estimated from the measured angular accelerations with dual-axis accelerometers. A data set of reaching synergies from able-bodied individuals was used to train a radial basis function artificial neural network with upper arm/forearm tangential angular accelerations. The trained radial basis function artificial neural network for the specific movements predicted forearm motion from new upper arm trajectories with high correlation (mean, 0.9149-0.941). For all other movements, prediction was low (range, 0.0316-0.8302). Results suggest that the proposed algorithm is successful in generalization over similar motions and subjects. Such networks may be used as a high-level controller that could predict forearm kinematics from voluntary movements of the upper arm. This methodology is suitable for restoring the upper limb functions of individuals with motor disabilities of the forearm, but not of the upper arm. The developed control paradigm is applicable to upper-limb orthotic systems employing functional electrical stimulation. The proposed approach is of great significance particularly for humans with spinal cord injuries in a free-living environment. The implication of a measurement system with dual-axis accelerometers, developed for this study, is further seen in the evaluation of movement during the course of rehabilitation. For this purpose, training-related changes in synergies apparent from movement kinematics during rehabilitation would characterize the extent and the course of recovery. As such, a simple system using this methodology is of particular importance for stroke patients. The results underlie the important issue of upper-limb coordination.

Suplementação de creatina potencializa o desempenho de sprints consecutivos em jogadores de basquetebol / Creatine supplementation maximizes repeated-sprint capacity of basketball players

Objetivos: o presente estudo teve como objetivo verificar o efeito da suplementação de creatina sobre o tempo de execução de 6 sprints consecutivos em jogadores de basquetebol. Materiais e métodos: a amostra foi constituída de 16 atletas de basquetebol do sexo masculino, com idade média de 18 ± 0,5 anos, da categoria juvenil. Os atletas foram divididos aleatoriamente, por posição, em Grupo Placebo (n=8) e Grupo Creatina (n=8). O protocolo desuplementação foi conduzido segundo o modelo duplo-cego. Na fase de sobrecarga foram administrados25 gramas de creatina (ou placebo) por dia durante 5 dias. Posteriormente, foram oferecidos 5 gramas por dia, nos 5 dias subseqüentes. Para aferir a capacidade de realização desprints repetidos foi realizado um teste, no qual deveriam ser percorridos 30 metros no menor tempo possível. O teste foi constituído de 6 sprints consecutivos, com pausas de 120 segundos. Resultados: foi observado aumento significativo da massa corporal após a suplementação decreatina (p<0,05). Também foi verificada alteração significativa no tempo de execução dos sprints repetidos no Grupo Creatina. O quarto, quinto e o sexto sprints tiveram seu tempo de execução reduzido em 8,5%, 10% e 9%, respectivamente (pré vs. pós-suplementação - p<0,05). Conclusão: A suplementação de creatina potencializou o desempenho em sprints consecutivos de 30 metros em atletas de basquetebol.

Aim: The aim of the present study was to verify the effect of creatine supplementation upon repeated-sprint capacity of basketball players. Materials and Methods: Sixteen young basketball players (18 ± 0.5 yrs) were randomically divided in Creatine (n=8) and Placebo (n=8) groups. The supplementation protocol was conducted as double-blind design.It was administrated 25g.day-1 of creatine (or placebo) in the loading phase for 5 days and 5g.day-1 in the subsequent 5 days. In order to access repeated-sprint capacity, the athletes were submitted to 30 m sprint test which should be realized as fast as possible. Six consecutives sprints were realized with 120 seconds of recovery. Results: It was observed a weight gain in Creatine-supplemented group (p<0.05). It was noted a decrease in the time of consecutives sprints performed by Creatine-supplemented group. The time of the 4th, 5th and 6th sprints were reduced by 8.5%, 10% and 9%, respectively, in post-supplementation as compared to pre-supplementation condition (p<0.05). Conclusion: Creatine supplementation maximized repeated-sprint capacity (6x30m) of basketball players.