Surf Biomechanics and Bioenergetics.

O surf moderno vem sendo descrito como uma atividade física intermitente, que varia em duração e intensidade, seguida de períodos de recuperação consideráveis. Atualmente, a análise e avaliação das sessões de surf são baseadas em conhecimento empírico, experiência e observação. Em outras palavras, procedimentos que envolvem grandes erros de medição. No entanto, é extremamente difícil obter informações analíticas sobre os parâmetros de desempenho. As primeiras investigações científicas no mundo do surf enfrentam uma dificuldade clássica do mundo da ciência, que é medir sem interferir. Além disso, o ambiente marítimo, particularmente devido à água salgada, é extremamente hostil aos componentes eletrônicos, que atualmente são a nossa maior fonte de informações quantitativas.O objetivo desta pesquisa foi investigar a fase horizontal do surf, especificamente a remada de potência, a remada de longa duração e a técnica de transição para ficar de pé na prancha de surf. Todo este pacote sob a perspetiva da biomecânica, associado a alguns parâmetros bioenergéticos. A abordagem geral foi apoiada por um processo de desconstrução dos movimentos e técnicas em partes didáticas, a fim de reconstruir um conhecimento global e uma melhor compreensão do surf. Olhando para o futuro, agregámos a este projeto o desenvolvimento de recursos tecnológicos que possibilitam explorar o surf diretamente no oceano. Tudo isso ganha ainda muito mais peso, desde que o Surf foi selecionado como novo desporto olímpico para os Jogos de Tóquio, em 2020. Os Jogos Olímpicos passam a ser uma excelente oportunidade, onde o surf se tornará mais profissionalizado e organizado. Neste contexto, as métricas para avaliação de desempenho são importantes para ajudar a validação de metodologias de ensino-aprendizagem, treinamento e julgamentos competitivos.Palavras-chave: biomecânica do surf, surfing, remadas do surf, ficar de pé, medições.Modern surfing has been described as an intermittent physical activity, which varies in duration and intensity, followed by considerable recovery periods. Currently, the analysis and judgment of surf sessions are based on empirical knowledge, experience, and observation. In other words, procedures that involve great measurement errors. However, it is extremely difficult to obtain analytical information on performance parameters. The first scientific investigations in the surf world faced a classic difficulty of the world of science, which is to measure without interfering. In addition, the maritime environment, particularly due to salt water, is extremely hostile to electronic components, which are currently our largest source of quantitative information.This research aimed to investigate the horizontal phase of surfing, specifically the sprint paddling, endurance paddling and the transition pop-up - standing technique. The whole pack under a biomechanics perspective, associated with bioenergetic parameters. The general approach was supported by process of deconstruction of movements and techniques in didactic parts, in order to reconstruct a global knowledge, and a better understanding of surfing. Looking to the future, we aggregate to this project the development of technological resources that make it possible to explore surf directly in the ocean. All this gained even more relevance since Surf has been selected as the new Olympic sport for the next Games of Tokyo 2020. The Olympic Games are an excellent opportunity where surfing will become more professional and organised. In this context, the metrics for performance evaluation are important to help validating teaching-learning methodologies, support training and competitive judgments

CARACTERIZAÇÃO DE ELÉCTRODOS TÊXTEIS PARA MEDIÇÕES EMG: IMPEDÂNCIA E MORFOLOGIA DO SINAL

Textile electrodes are an alternative to conventional silver-chloride electrodes in wearable systems. Their easy integration in garments and comfort provided to the user make them an interesting development of textile engineering. The potential of such electrodes to allow more unobtrusive data collection in health and sports context may enable the development of biosensing garments to be used in biomechanics. However, proper validation of the recorded signals is paramount, and few studies have yet presented consistent methodologies for textile-based electromyographic recordings. This study presents the validation of the electrical and morphological properties of electromyographic signals recorded with textile electrode, in comparison to conventional silver-chloride electrodes. Results indicate that both sets of electrodes have identical signal-to-noise ratios, but with distinct impedance frequency responses. Electromyographic envelope morphologies are also identical, although textile electrodes usually have lower amplitudes.Los electrodos textiles son una alternativa a los electrodos de cloruro de plata convencionales en los sistemas portátiles. Su fácil integración en las vestimentas y la comodidad que brinda al usuario las convierten en un interesante desarrollo de la ingeniería textil. El potencial de tales electrodos para permitir una recopilación de datos más discreta en el contexto de la salud y el deporte puede permitir el desarrollo de vestimentas biosensibles para su uso en biomecánica. Sin embargo, la validación adecuada de los señales registradas es primordial y pocos estudios han presentado metodologías consistentes para registros electromiográficos basados en textiles. Este estudio presenta la validación de las propiedades eléctricas y morfológicas de señales electromiográficas registradas con electrodo textil, en comparación con electrodos convencionales de cloruro de plata. Los resultados indican que ambos los electrodos tienen relaciones señal-ruido idénticas, pero con una respuesta de frecuencia de impedancia distinta. La morfología de la envoltura electromiográfica también se identifica entre electrodos, aunque generalmente de menor amplitud en el electrodo textil.Eléctrodos têxteis são uma alternativa aos convencionais eléctrodos de cloreto de prata em sistemas vestiveis. A sua fácil integração em vestuário e o conforto que providenciam tornam-nos um interessante desenvolvimento da engenharia têxtil. O potencial destes eléctrodos para permitir a discreta recolha de dados em contexto de saúde e desporto poderá permitir o desenvolvimento de vestuário biossensivel com aplicação em biomecânica. No entanto, uma adequada validação dos sinais registados é fundamental, e poucos estudos apresentaram metodologias consistentes para registos electromiográficos baseados em elétrodos têxteis. Este estudo apresenta a validação das propriedades eléctricas e morfológicas de sinais electromiográficos registados com eléctrodos têxteis, em comparação com os convencionais eléctrodos de cloreto de prata. Os resultados indicam que ambos os eléctrodos apresentam razões sinal-ruído identicos, mas com uma resposta em frequência de impedância distincta. A morfologia do envelope electromiográfico é também identifca entre electrodos, ainda que geralmente de menor amplitude no eléctrodo têxtil

LABORATÓRIO DE BIOMECÂNICA DO PORTO: ENSINO, INVESTIGAÇÃO E SERVIÇOS À COMUNIDADE

Porto Biomechanics Laboratory is a technological centre of the University of Porto dedicated to teaching, scientific and technological research, innovation, to provide specialized technical services and transference of knowledge and technology (product development) in Biomechanics (human and animal) of ergonomic, clinical, sports or biomimetic interest (e.g. design, computer animation and model development). LABIOMEP-UP mission is to catalyse the growth potential and competitive edge of University of Porto in all domains directly or indirectly related to Biomechanics, including the interaction with industry.El Laboratorio de Biomecánica de Porto es un centro tecnológico de la Universidad de Porto dedicado a la docencia, la investigación científica y tecnológica, la innovación, proporcionar servicios técnicos especializados y transferencia de conocimiento y tecnología (desarrollo de productos) en Biomecánica (humana y animal) de ergonomía, clínica, deportiva, o interés biomimético (por ejemplo, diseño, animación por computadora y desarrollo de modelos). La misión de LABIOMEP-UP es catalizar el potencial de crecimiento y la ventaja competitiva de la Universidad de Oporto en todos los dominios relacionados directa o indirectamente con la biomecánica, incluida la interacción con la industria.O Laboratório de Biomecânica do Porto (LABIOMEP-UP) é um centro de competências da Universidade do Porto dedicado ao ensino, investigação científica e tecnológica, inovação, prestação de serviços técnicos especializados e transferência de conhecimento e tecnologia em Biomecânica (humana e animal) de interesse ergonómico, clínico, desportivo ou biomimético (ex: design, animação computacional e desenvolvimento de modelos). A missão do LABIOMEP-UP é catalisar o potencial de crescimento e vantagem competitiva da Universidade do Porto em todos os domínios direta ou indiretamente relacionados com a Biomecânica, incluindo a interação com o tecido industrial e comercial

LABORATÓRIO DE BIOMECÂNICA DO PORTO: ENSINO, INVESTIGAÇÃO E SERVIÇOS À COMUNIDADE

Porto Biomechanics Laboratory is a technological centre of the University of Porto dedicated to teaching, scientific and technological research, innovation, to provide specialized technical services and transference of knowledge and technology (product development) in Biomechanics (human and animal) of ergonomic, clinical, sports or biomimetic interest (e.g. design, computer animation and model development). LABIOMEP-UP mission is to catalyse the growth potential and competitive edge of University of Porto in all domains directly or indirectly related to Biomechanics, including the interaction with industry.El Laboratorio de Biomecánica de Porto es un centro tecnológico de la Universidad de Porto dedicado a la docencia, la investigación científica y tecnológica, la innovación, proporcionar servicios técnicos especializados y transferencia de conocimiento y tecnología (desarrollo de productos) en Biomecánica (humana y animal) de ergonomía, clínica, deportiva, o interés biomimético (por ejemplo, diseño, animación por computadora y desarrollo de modelos). La misión de LABIOMEP-UP es catalizar el potencial de crecimiento y la ventaja competitiva de la Universidad de Oporto en todos los dominios relacionados directa o indirectamente con la biomecánica, incluida la interacción con la industria.O Laboratório de Biomecânica do Porto (LABIOMEP-UP) é um centro de competências da Universidade do Porto dedicado ao ensino, investigação científica e tecnológica, inovação, prestação de serviços técnicos especializados e transferência de conhecimento e tecnologia em Biomecânica (humana e animal) de interesse ergonómico, clínico, desportivo ou biomimético (ex: design, animação computacional e desenvolvimento de modelos). A missão do LABIOMEP-UP é catalisar o potencial de crescimento e vantagem competitiva da Universidade do Porto em todos os domínios direta ou indiretamente relacionados com a Biomecânica, incluindo a interação com o tecido industrial e comercial

Impact of a motor intervention program on performance of schoolchildren in implementing the agility s test of upper limbs Plate Tapping

The aim of this study was to investigate the impact of a motor intervention program on performance of schoolchildren in implementing the agility s test of upper limbs by the Plate Tapping Test that is a part of the Eurofit Testing Battery. A group of 108 schoolchildren with ages between 12 to 15 years of both sexes participated of this study. According to the experimental design the individuals were evaluated firstly by the Plate Tapping Test, called pre-test, and after this they were organized by performance, age and sex. The Kolmogorov-Smirnov (p=0.20) and Shapiro-Wilk (p=0.063) normality tests were applied and both resulted in a normal distribution. By means of a stochastic selection algorithm, the individuals were randomly assigned to three groups: Experimental Group 1 (GE1), Experimental Group 2 (GE2) and Control Group (GC), each one of them comprising 36 schoolchildren. A one-way analysis of variance (ANOVA) was performed to verify if the division of groups was homogeneous and equivalent with relation to the individuals performance and it resulted in a value of p=0.317 at a confidence level of 95%, that means no significant differences between groups. The intervention motor procedures with 5 sets of 20 repetitions per day were then conducted to each group. The GC not received any intervention while GE1 and GE2 received respectively 3 days and 1 day of motor intervention. The Plate Tapping Test was applied in each group before (pre-test) and after (post-test) of the motor intervention procedures and the results were analyzed between groups through an ANOVA 2x3. No significant differences were found in the pre-tests, whereas all groups presented significant differences in the post-test. The results of the post-test indicated no differences between 1 and 3 days of intervention, nevertheless the application of motor intervention resulted in a superior performance of the experimental groups (GE1 and GE2) compared to CG. The groups presented respectively the following results for pre-test, post-test and the difference between of them: GE1 (41.11 sd 32.12 | 84.06 sd 24.26 | 42.95), GE2 (24.86 sd 23.83 | 73.61 sd 24.47 | 48.75) and GC (32.75 sd 28.75 | 57.56 sd 28.94 | 24.81). In the test execution were observed three distinct phases by the analysis of the performance curve, which were called of adaptation phase, optimized phase and fatigue phase, since those phases indicated the progression's behavior and allowed to observe the conduct of the intervention in each phase. In conclusion, the intervention showed to have an important role in the learning of a task and this suggested that for the evaluation protocols should exist adaptation periods to recognition and learning of the tasks to be performed, aiming to verify more faithfully the performance.O objetivo desse estudo foi investigar o impacto de um programa de intervenção motora no desempenho de escolares, na execução do teste de agilidade de membros superiores Golpeio de Placas, da Bateria Eurofit. Participaram do estudo 108 escolares, com idades de 12 a 15 anos de ambos os sexos. De acordo com o delineamento experimental os sujeitos foram inicialmente avaliados com o teste Golpeio de Placas (pré-teste) os resultados foram ordenados por idade, sexo e desempenho. O teste de normalidade de Kolmogorov-Smirnov apresentou distribuição normal p=0,20. Por meio de um algoritmo de seleção estocástica, os sujeitos foram distribuídos aleatoriamente em três diferentes grupos: Grupo Experimental 1 (GE1), Grupo Experimental 2 (GE2) e Grupo Controle (GC), cada um composto por 36 escolares. A análise de variância one way, foi realizada para verificar a homogeneidade dos grupos quanto ao desempenho dos sujeitos, o resultado p=0,317 indicou que, a um nível de confiança de 95%, não verificou-se diferenças significativas entre os grupos. Conduziu-se então, para cada grupo, os procedimentos de intervenção motora, estes eram estruturados com 5 séries de 20 repetições por dia. O GC não recebeu intervenção motora, GE1 e GE2 receberam, respectivamente, 3 dias e 1 dia de intervenção motora. O teste de Golpeio de Placas foi aplicado em cada grupo antes (pré-teste) e depois (pós-teste) dos procedimentos de intervenção motora. Os resultados foram analisados entre os grupos através de uma ANOVA 2X3. No pré-teste não foram encontradas diferenças significativas, já em relação ao pós-teste, todos os grupos apresentaram diferenças significativas. Os resultados do pós-teste mostraram que não ocorreram diferenças entre 1 e 3 dias de intervenção, mas que a intervenção fez com que os grupos experimentais obtivessem um desempenho superior ao GC. Os grupos apresentaram os seguintes resultados para pré-teste, pós-teste, e a diferença entre ambos, respectivamente: GE1 (41,11 dp 32,12 | 84,06 dp 24,26 | 42,95), GE2 (24,86 dp 23,83 | 73,61 dp 24,47 | 48,75) e GC (32,75 dp 28,75 | 57,56 dp 28,94 | 24,81). Na análise da curva de desempenho foram observadas fases distintas durante a execução do teste, as quais foram chamadas de fase de adaptação, fase otimizada e fase de fadiga, pois indicaram o comportamento da progressão do teste e possibilitaram observar como a intervenção se comportou em cada fase. Concluiu-se que a intervenção tem um papel importante na aprendizagem de uma tarefa, portanto sugere-se que nos protocolos de avaliação deveriam existir períodos de adaptação para reconhecimento e aprendizagem das tarefas a serem realizadas, com o objetivo de verificar mais fidedignamente o desempenho.Coordenação de Aperfeiçoamento de Pessoal de Nível Superio

Monitoring of plantar forces and surfboard’s movement: alternative to understand the injuries mechanism

The concern about injuries in sport are evident due to the implications it carries. To have the knowledge of the mechanisms of injuries is important either to prevent and recovery. This context generates the appropriate scenario to develop an electronic solution to measure dynamically the Center of Pressure (CoP) and surfboard’s movement and support the understanding of the mechanisms responsible for the occurrence of injuries. Two matrices composed by 24 force sensors and Inertial Measurement Unit (IMU) controlled by ATEMEGA1280 microcontroller were developed. This system was tested using a dynamic protocol using one unstable structure at the bottom of the surfboard. The results have shown that the CoP displacement was largest during the tests that presented great rotation changes. Furthermore, the power oscillations were greater during transition moments. The proposed system is able to measure biomechanical variables dynamically, i.e., force, and surfboard’s angle pitch and roll. This report reviews the surf injuries in literature and describes the electronic device used beyond to present the results of the tests performed.info:eu-repo/semantics/publishedVersio

Correlates between physical fitness and sexual activity in elderly

INTRODUCTION: With increasing life expectancy, interest is growing in the elderly remain independent and quality of life. In this context, sexual activity is an important part and the exercise has shown protective effect on the sexual health in aging. OBJECTIVE: The objective of this study was to explore the relationship between physical fitness and sexual activity in men 55 to 72 years. METHODS: The participants underwent an exercise test and were interviewed about risk factors and cardiovascular aspects of life such as sexual satisfaction, desire and frequency. The data collected was used Spearman correlation tests for nonparametric variables and chi-square for categorical variables. RESULTS:: The physical fitness and aspects of sexual activity were lower in older subjects. Adjusted for age, seniors with higher functional ability had better scores for sexual desire and frequency, but with no correlation to satisfaction. The lowest satisfaction scores were justified by the difficulty in maintaining an erection during the sexual act, and was associated with the high cholesterol risk factors. CONCLUSION: Although physical fitness is associated with better scores for sexual desire and frequency, the use of medications for erection and sexual counseling with a therapist can help the elderly increase in sexual satisfaction.</p

Comparative study of physical growth and nutritional status of schoolchildren (1997 and 2009).

Physical growth and nutritional status are excellent health indicators since they permit the establishment of growth monitoring charts, especially for schoolchildren. The objective of this study was to compare the growth profile and nutritional status of schoolchildren between two samples (1997 and 2009). The data of physical growth and nutritional status obtained for the present sample of 645 schoolchildren (270 boys and 375 girls). The children were classified according to the body mass index (BMI)-for-age reference values of the WHO child growth standards. Although no significant differences in height or body weight were observed between the children studied, these variables tended to increase from the first to the second sample and in the two genders. With respect to the adequacy of BMI in boys, there was an increase in the percentage of children with low BMI-for-age, doubling of the percentage of obese children, and a reduction in the percentage of children with overweight. An increase in the number of subjects with low body weight, overweight and obesity and a decrease in the number of subjects with adequate BMI-for-age were noted among girls. In conclusion, there were no significant changes in the physical growth indicators (weight, height and BMI) over the period comprising the two samples (1997 and 2009). However, height, body weight and the number of subjects with risk of obesity and obesity tended to increase, especially among girls

<b>Comparative study of physical growth and nutritional status of schoolchildren (1997 and 2009)</b>. DOI: 10.5007/1980-0037.2011v13n3p216

Physical growth and nutritional status are excellent health indicators since they permit the establishment of growth monitoring charts, especially for schoolchildren. The objective of this study was to compare the growth profile and nutritional status of schoolchildren between two samples (1997 and 2009). The data of physical growth and nutritional status obtained for the present sample of 645 schoolchildren (270 boys and 375 girls). The children were classified according to the body mass index (BMI)-for-age reference values of the WHO child growth standards. Although no significant differences in height or body weight were observed between the children studied, these variables tended to increase from the first to the second sample and in the two genders. With respect to the adequacy of BMI in boys, there was an increase in the percentage of children with low BMI-for-age, doubling of the percentage of obese children, and a reduction in the percentage of children with overweight. An increase in the number of subjects with low body weight, overweight and obesity and a decrease in the number of subjects with adequate BMI-for-age were noted among girls. In conclusion, there were no significant changes in the physical growth indicators (weight, height and BMI) over the period comprising the two samples (1997 and 2009). However, height, body weight and the number of subjects with risk of obesity and obesity tended to increase, especially among girls

Comparison of upper limb kinematics in two activities of daily living with different handling requirements

Recently, kinematic analysis of the drinking task (DRINK) has been recommended to assess the quality of upper limb (UL) movement after stroke, but the accomplishment of this task may become difficult for poststroke patients with hand impairment. Therefore, it is necessary to study ADLs that involve a simpler interaction with a daily life target, such as the turning on a light task (LIGHT). As the knowledge of movement performed by healthy adults becomes essential to assess the quality of movement of poststroke patients, the main goal of this article was to compare the kinematic strategies used by healthy adults in LIGHT with those that are used in DRINK. 63 adults, aged 30 to 69 years old, drank water and turned on a light, using both ULs separately, while seated. The movements of both tasks were captured by a 3D motion capture system. End-point and joint kinematics of reaching and returning phases were analysed. A multifactorial analysis of variance with repeated measures was applied to the kinematic metrics, using age, sex, body mass index and dominance as main factors. Mean and peak velocities, index of curvature, shoulder flexion and elbow extension were lower in LIGHT, which suggests that the real hand trajectory was smaller in this task. In LIGHT, reaching was less smooth and returning was smoother than DRINK. The instant of peak velocity was similar in both tasks. There was a minimal anterior trunk displacement in LIGHT, and a greater anterior trunk displacement in DRINK. Age and sex were the main factors which exerted effect on some of the kinematics, especially in LIGHT. The different target formats and hand contact in DRINK and LIGHT seem to be responsible for differences in velocity profile, efficiency, smoothness, joint angles and trunk displacement. Results suggest that the real hand trajectory was smaller in LIGHT and that interaction with the switch seems to be less demanding than with the glass. Accordingly, LIGHT could be a good option for the assessment of poststroke patients without grasping ability. Age and sex seem to be the main factors to be considered in future studies for a better match between healthy and poststroke adults.info:eu-repo/semantics/publishedVersio