Individual Responses to Different Vibration Frequencies Identified by Electromyography and Dynamometry in Different Types of Vibration Application.

ABSTRACT: Oliveira, MP, Menzel, H-JK, Cochrane, DJ, Drummond, MD, Demicheli, C, Lage, G, and Couto, BP. Individual responses to different vibration frequencies identified by electromyography and dynamometry in different types of vibration application. J Strength Cond Res 35(6): 1748-1759, 2021-The application of mechanical vibration is a common neuromuscular training technique used in sports training programs to generate acute increases in muscle strength. The principal aim of the study was to compare the individual optimal vibration frequency (IOVF) identified by electromyography (EMG) activity and force production in strength training. Twenty well-trained male volunteers (age: 23.8 ± 3.3 years) performed a familiarization and 2 interventions sessions, which included 5 maximal voluntary contractions (MVCs) of the elbow flexors with a duration of 10 seconds and 5-minute intervals between each MVC. The first MVC was performed without vibration followed by 4 randomized MVCs with application of vibration in the direction of the resultant muscle forces' vector (VDF) or whole-body vibration (WBV) at frequencies of 10, 20, 30, or 40 Hz. The mechanical vibration stimulus was superimposed during the MVC. Individual optimal vibration frequency, as identified by EMG, did not coincide with IOVF identified by force production; low agreement was observed between the vibration frequencies in generating the higher EMG activity, maximal force, and root mean square of force. These findings suggest that the magnitude of the vibratory stimulus response is individualized. Therefore, if the aim is to use acute vibration in conjunction with strength training, a preliminary vibration exposure should be conducted to determine the individualized vibratory stimulus of the subject, so that training effects can be optimized.

Understanding Player Load: Meanings and Limitations.

We present a critical reflection on the mechanical variable Player Load, which is based on acceleration data and commonly used in sports. Our motivation to write this paper came from the difficulties that we encountered in the calculation and interpretation of Player Load using our own data, since we did not use the Catapult Sports equipment, which is a merchandise of the company that proposed this variable. We reviewed existing literature in order to understand Player Load better; we found many inconsistencies in PL calculation methods and in the meanings attached to it. Accordingly, this paper presents a brief discussion on the meanings that have been assigned to Player Load, its limitations, and the lack of clear and complete information about Player Load calculation methods. Moreover, the use of arbitrary units and different practical meanings in the literature has associated Player Load with many physical quantities, thereby resulting in difficulties in determining what Player Load measures within the context of sports. It seems that Player Load is related to the magnitude of changes in acceleration, but not the magnitude of acceleration itself. Therefore, coaches and sports scientists should take this information into account when they use Player Load to prescribe and monitor external loads. We concluded that a deeper discussion of Player Load as a descriptor of external load is warranted in the sports sciences literature.

Spike jump biomechanics in male versus female elite volleyball players.

There are well-known biological differences between women and men, especially in technical-coordinative variations that contribute to sex differences in performance of complex movements like the most important offensive action in volleyball, the spike jump. The aim of this study was to investigate sex-dependent performance and biomechanical characteristics in the volleyball spike jump. Thirty female and male sub-elite volleyball players were analysed while striking a stationary ball with maximal spike jump height. Twelve MX13 Vicon cameras with a cluster marker set, two AMTI force plates, surface EMG, and a Full-Body 3D model in Visual3D were used. Main findings include sex differences (P< .05) in jump height (pη2 = .73), approach [speed (pη2 = .61), step length], transition strategy [plant angle, neuromuscular activation (pη2 = .91), horizontal force maxima and impulses], acceleration distances [centre of mass displacement (pη2 = .21), minimal knee and hip angles], use of torso and arms [incline, angular velocity (pη2 = .23)]. Correlations support that the results cannot be explained fully by strength and power differences between sexes but represent the product of technical-coordinative variations. Their relevance is acknowledged for both sexes and numerous performance determinants displayed sex differences. The integration of such attributes into sex-specific training seems promising but its effect requires further investigation.

TEST-retest reliability of kinetic variables measured on campus board in sport climbers.

Sport climbers frequently use campus board (CB) to improve their upper limb strength under similar conditions of high-difficulty sport climbing routes. The objective of this study was to assess the test-retest reliability of peak force and impulse measured using a CB instrumented with two load cells on starting holds. The same evaluator examined 22 climbers on two days with 48 h between the assessments. The participants performed five concentric lunges (CL) and five lunges with stretch-shortening cycle with 1 min intervals between repetitions and 10 min between exercises. All variables were associated with significant intraclass correlation coefficient (ICC) values (p = 0.001), and none variable showed systematic errors (p > 0.05). Peak force ICC was higher than 0.88, and the standard error of measurement (SEM%) was less than 5%. Impulse ICC for the CL was greater than 0.90, and the SEM% was less than 14%. We conclude that the kinetic variables measured using the CB were reliable. The ability of the hands to maintain contact with the holds (peak force) and the abilities of the arms and shoulders vertically move the centre of mass (impulse) should be taken into account by coaches on CB training prescription as well for further research.

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

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

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

Impact of competitive level and age on the strength and asymmetry of young soccer players / Impacto do nível competitivo e da faixa etária sobre força e assimetria de futebolistas jovens / Impacto del nivel competitivo y franja etaria en la fuerza y asimetría de los futbolistas jóvenes

INTRODUCTION: Muscular strength is an essential capacity for soccer players; however, the profile of this capacity has not yet been clearly established in young players. OBJECTIVE: To compare muscular strength performance in the countermovement jump (CMJ) task and the presence of lower limb asymmetry among soccer athletes of the under 15 (U15), under 17 (U17) and under 20 (U20) categories, and between two teams of different competitive levels. METHODS: One hundred and fifty one young soccer players of three different categories (U15, U17 and U20) from two teams in the Brazilian first and second divisions performed six vertical jumps in a system of two force plates. Ground reaction force (GRF) was used to calculate jump height and to obtain the variables Peak force (FMAX), Impulse (I) and Peak power (PMAX) with regard to body mass and the respective asymmetry values. RESULTS: No differences were found in the performance and asymmetry variable between the categories (Jump height: p=0.23; FMAX: p=0.15; I: p=0.11; PMAX: p=0.32; FMAX asymmetry: p=0.21; I asymmetry: p=0.58; PMAX asymmetry: p=0.58). The first division club had higher muscle strength and asymmetry values than the second division club (Jump height: p<0.01; I: p<0.01; PMAX: p<0.01; FMAX asymmetry: p<0.01; I asymmetry: p<0.01; PMAX asymmetry: p<0.01), except for FMAX (p=0.63). No variable had an interaction effect (club x category). CONCLUSION: As categories progress, jump height, relative I, PMAX and FMAX values and their respective asymmetries are stable. The asymmetry and strength performance of the first division club were higher than that of the second division club, except for FMAX, indicating that the competitive level may influence strength performance and the development of asymmetry. Level of Evidence II; Diagnostic study ­ Investigating a diagnostic test.

INTRODUÇÃO: A força muscular é uma capacidade fundamental para futebolistas; entretanto, o perfil dessa capacidade ainda não está bem estabelecido em jogadores jovens. OBJETIVO: Comparar o desempenho de força muscular na tarefa de salto com contramovimento e a presença de assimetria entre membros inferiores entre atletas de futebol das categorias Sub 15, Sub 17 e Sub 20 e entre dois clubes de níveis competitivos diferentes. MÉTODOS: Cento e cinquenta e um jogadores de futebol jovens de dois clubes da primeira e segunda divisão e de três categorias diferentes (Sub 15, Sub 17 e Sub 20) realizaram seis saltos verticais em um sistema de duas plataformas de força. A partir da força de reação de solo, calculou-se a altura do salto e foram obtidas as variáveis Força máxima (FMÁX), Impulso (I) e Potência máxima (PMÁX) com relação à massa corporal e aos respectivos valores de assimetria. RESULTADOS: Nenhuma variável de desempenho e assimetria foi diferente entre as categorias (Altura do salto: p = 0,23; FMÁX: p = 0,15; I: p = 0,11; PMÁX: p = 0,32; Assimetria de FMÁX: p = 0,21; Assimetria de I: p = 0,58; Assimetria de PMÁX: p = 0,58). O clube de primeira divisão apresentou maior desempenho de força e maior assimetria do que o clube de segunda divisão (Altura do salto: p < 0,01; I: p < 0,01; PMÁX: p < 0,01; Assimetria de FMÁX: p < 0,01; Assimetria de I: p < 0,01; Assimetria de PMÁX: p < 0,01), exceto para FMÁX: (p = 0,63). Nenhuma variável teve efeito de interação (clube x categoria). CONCLUSÃO: À medida que as categorias progridem, a altura do salto e os valores de I, PMÁX e FMÁX relativos e as respectivas assimetrias são estáveis. A assimetria e o desempenho de força do clube da primeira divisão foram maiores do que a do clube da segunda divisão, exceto para FMÁX, mostrando que o nível competitivo pode influenciar o desempenho de força e o desenvolvimento de assimetria. Nível de evidência II; Estudo diagnóstico ­ Investigação de um exame para diagnóstico.

INTRODUCCIÓN: La fuerza muscular es una capacidad fundamental para los futbolistas, sin embargo, aún no está bien establecido el perfil de esa capacidad en jugadores jóvenes. OBJETIVO: Comparar el desempeño de fuerza muscular en la tarea de salto con contramovimiento y la presencia de asimetría entre miembros inferiores de atletas de fútbol de las categorías Sub15, Sub17 y Sub20, y entre dos clubes de fútbol de diferente nivel competitivo. MÉTODO: 151 futbolistas de dos clubes de primera y segunda división y tres categorías diferentes (Sub15, Sub17 y Sub20) realizaron seis saltos verticales en un sistema de plataformas de fuerza. A partir de la fuerza de reacción de suelo, se calculó altura del salto y variables Fuerza máxima (FMÀX), Impulso (I) y Potencia máxima (PMÁX) relativas a la masa corporal y los respectivos valores de asimetría. RESULTADOS: Ninguna variable de rendimiento y asimetría fue diferente entre las categorías (Altura: p=0,23; FMÀX: p=0,15; I: p=0,11; PMÁX: p=0,32; FMÀX: p=0,21; Asimetría de I: p=0,58; Asimetría de PMÁX: p=0,58). El club de la primera división ha presentado mayor rendimiento de fuerza y mayor asimetría que el club de la segunda división (Altura del salto: p<0,01; I: p<0,01; PMÁX: p<0,01; Asimetría de FMÀX: p<0,01, asimetría de I: p<0,01, asimetría de PMÁX: p<0,01), excepto para FMÀX: (p=0,63). Ninguna variable ha presentado efecto de interacción (club x categoría). CONCLUSIÓN: A medida que las categorías progresan, la altura del salto y los valores de IMP, PMAX y FMAX relativos y las respectivas asimetrías se mantienen estables. La asimetría y el desempeño de fuerza del club de la primera división fueron mayores que del club de segunda división, excepto para FMAX, mostrando que el nivel competitivo puede influir en el desempeño de fuerza y en el desarrollo de asimetría. Nivel de evidencia II; Estudio diagnóstico ­ Investigación de un examen para diagnóstico.

Quality of life and associated characteristics: application of WHOQOL-BREF in the context of Primary Health Care. / Qualidade de vida e características associadas: aplicação do WHOQOL-BREF no contexto da Atenção Primária à Saúde.

This study aimed to identify the characteristics associated to quality of life (QOL) in users of four Basic Health Units (Unidades Básicas de Saúde, UBS) in Belo Horizonte, Minas Gerais. We conducted a cross-sectional study with 930 adult users enrolled in the selected UBS, using a questionnaire containing the WHOQOL-bref instrument and questions about sociodemographic characteristics, lifestyle and health conditions. Following descriptive analysis, we performed simple and multiple linear regression to evaluate the association between the exposure variables and the QOL domains. The highest mean values of QOL were observed in the social relationships domain. The lowest means were observed in the environment domain, with a statistically significant difference between some of the UBS. The worst perceptions of QOL were related to worse health, housing, education and income conditions, as well as problems in social relationships and psychological conditions. Actions are needed to improve QOL in Primary Health Care users through actions promoted by both health professionals and public managers.

Qualidade de vida e características associadas: aplicação do WHOQOL-BREF no contexto da Atenção Primária à Saúde / Quality of life and associated characteristics: application of WHOQOL-BREF in the context of Primary Health Care

Resumo O objetivo deste estudo foi identificar as características associadas à qualidade de vida (QV) em usuários de quatro Unidades Básicas de Saúde (UBS) de Belo Horizonte, Minas Gerais. Delineou-se um estudo transversal com 930 usuários adultos e cadastrados nas UBS selecionadas. Utilizou-se o um questionário contendo o instrumento WHOQOL-bref e perguntas sobre características sociodemográficas, estilo de vida e condições de saúde. Após análise descritiva, realizou-se regressão linear simples e múltipla para avaliar a associação entre as variáveis de exposição e os domínios da QV. As maiores médias de QV foram observadas no domínio relações sociais. No domínio ambiente foram observadas as menores médias, com diferença estatisticamente significante entre algumas das UBS. As piores percepções de QV relacionaram-se com piores condições de saúde, habitação, educação e renda, além de problemas nas relações sociais e condições psicológicas. São necessários esforços para a melhoria da QV em usuários da Atenção Primária, por meio de ações promovidas tanto por profissionais de saúde quanto por gestores públicos.

Abstract This study aimed to identify the characteristics associated to quality of life (QOL) in users of four Basic Health Units (Unidades Básicas de Saúde, UBS) in Belo Horizonte, Minas Gerais. We conducted a cross-sectional study with 930 adult users enrolled in the selected UBS, using a questionnaire containing the WHOQOL-bref instrument and questions about sociodemographic characteristics, lifestyle and health conditions. Following descriptive analysis, we performed simple and multiple linear regression to evaluate the association between the exposure variables and the QOL domains. The highest mean values of QOL were observed in the social relationships domain. The lowest means were observed in the environment domain, with a statistically significant difference between some of the UBS. The worst perceptions of QOL were related to worse health, housing, education and income conditions, as well as problems in social relationships and psychological conditions. Actions are needed to improve QOL in Primary Health Care users through actions promoted by both health professionals and public managers.

Exploratory factor analysis for differentiating sensory and mechanical variables related to muscle-tendon unit elongation.

BACKGROUND: Stretching exercises are able to promote adaptations in the muscle-tendon unit (MTU), which can be tested through physiological and biomechanical variables. Identifying the key variables in MTU adaptations is crucial to improvements in training. OBJECTIVE: To perform an exploratory factor analysis (EFA) involving the variables often used to evaluate the response of the MTU to stretching exercises. METHOD: Maximum joint range of motion (ROMMAX), ROM at first sensation of stretching (FSTROM), peak torque (torqueMAX), passive stiffness, normalized stiffness, passive energy, and normalized energy were investigated in 36 participants during passive knee extension on an isokinetic dynamometer. Stiffness and energy values were normalized by the muscle cross-sectional area and their passive mode assured by monitoring the EMG activity. RESULTS: EFA revealed two major factors that explained 89.68% of the total variance: 53.13% was explained by the variables torqueMAX, passive stiffness, normalized stiffness, passive energy, and normalized energy, whereas the remaining 36.55% was explained by the variables ROMMAX and FSTROM. CONCLUSION: This result supports the literature wherein two main hypotheses (mechanical and sensory theories) have been suggested to describe the adaptations of the MTU to stretching exercises. Contrary to some studies, in the present investigation torqueMAX was significantly correlated with the variables of the mechanical theory rather than those of the sensory theory. Therefore, a new approach was proposed to explain the behavior of the torqueMAX during stretching exercises.

Exploratory factor analysis for differentiating sensory and mechanical variables related to muscle-tendon unit elongation

ABSTRACT Background Stretching exercises are able to promote adaptations in the muscle-tendon unit (MTU), which can be tested through physiological and biomechanical variables. Identifying the key variables in MTU adaptations is crucial to improvements in training. Objective To perform an exploratory factor analysis (EFA) involving the variables often used to evaluate the response of the MTU to stretching exercises. Method Maximum joint range of motion (ROMMAX), ROM at first sensation of stretching (FSTROM), peak torque (torqueMAX), passive stiffness, normalized stiffness, passive energy, and normalized energy were investigated in 36 participants during passive knee extension on an isokinetic dynamometer. Stiffness and energy values were normalized by the muscle cross-sectional area and their passive mode assured by monitoring the EMG activity. Results EFA revealed two major factors that explained 89.68% of the total variance: 53.13% was explained by the variables torqueMAX, passive stiffness, normalized stiffness, passive energy, and normalized energy, whereas the remaining 36.55% was explained by the variables ROMMAX and FSTROM. Conclusion This result supports the literature wherein two main hypotheses (mechanical and sensory theories) have been suggested to describe the adaptations of the MTU to stretching exercises. Contrary to some studies, in the present investigation torqueMAX was significantly correlated with the variables of the mechanical theory rather than those of the sensory theory. Therefore, a new approach was proposed to explain the behavior of the torqueMAX during stretching exercises.

Consumo de frutas e hortaliças e as condições de saúde de homens e mulheres atendidos na atenção primária à saúde / Consumption of fruit and vegetables and the health conditions of men and women attended in the primary healthcare network

Resumo Estudo transversal com o objetivo de analisar as associações entre as condições de saúde e a inadequação do consumo de frutas e hortaliças (FH) de 1.255 homens e mulheres atendidos em Unidades Básicas de Saúde de Belo Horizonte (MG). A coleta de dados contemplou o consumo de FH, a situação socioeconômica e as condições de saúde. Os resultados foram apresentados em razão de prevalência (RP) e intervalo de confiança de 95% (IC 95%). Verificou-se 77,5% (IC 95%: 75,1%-79,8%) de inadequação do consumo de FH (< 5 porções diárias) e esta foi superior entre os homens (83,8%, IC 95%: 79,0%-88,5% vs. mulheres: 76%, IC 95%: 73,4%-78,6%). Para as mulheres, o consumo inadequado de FH foi maior entre aquelas com percepção muito ruim da qualidade de sua saúde (RP: 1,37; IC 95%: 1,19-1,59) e entre as que consideraram a sua alimentação não saudável (RP: 1,15; IC 95%: 1,07-1,24). Para os homens, o consumo inadequado de FH foi superior entre os que referiram de 2 a 4 visitas ao médico no ano anterior à entrevista (RP: 1,21; IC 95%: 1,06-1,37). Concluiu-se que o consumo de FH na amostra encontra-se aquém das recomendações e que as condições de saúde se associaram de maneira distinta entre os sexos.

ABSTRACT This cross-sectional study sought to analyze the associations between health conditions and the inadequate consumption of fruit and vegetables (FV) of 1,255 men and women attended in Primary Healthcare Units in Belo Horizonte (State of Minas Gerais). Data collection included FV consumption, socioeconomic status and health conditions. Results are presented by prevalence ratio (PR) with a confidence interval of 95% (CI 95%). A 77.5% (CI 95%: 75.1%-79.8%) of inadequacy of consumption (< 5 daily servings) was found and it was more prevalent among men (83.8%, CI 95%: 79.0%-88.5% than among women: 76.0%, CI 95%: 73.4%-78.6%). For women, the inadequate consumption of FV was higher among those with poor perception of health quality (PR: 1.37; CI 95%: 1.19-1.59) and among those who consider their dietary habits as being unhealthy (PR: 1.15; CI 95%: 1.07-1.24). For men, the inadequate consumption was higher between individuals that reported 2 to 4 visits to the doctor in the year prior to the interview (PR: 1.21; CI 95%: 1.06-1.21). The conclusions showed that the consumption of FV among the population under study is below the recommendations and the health conditions are associated differently for each gender.

[Consumption of fruit and vegetables and the health conditions of men and women attended in the primary healthcare network]. / Consumo de frutas e hortaliças e as condições de saúde de homens e mulheres atendidos na atenção primária à saúde.

This cross-sectional study sought to analyze the associations between health conditions and the inadequate consumption of fruit and vegetables (FV) of 1,255 men and women attended in Primary Healthcare Units in Belo Horizonte (State of Minas Gerais). Data collection included FV consumption, socioeconomic status and health conditions. Results are presented by prevalence ratio (PR) with a confidence interval of 95% (CI 95%). A 77.5% (CI 95%: 75.1%-79.8%) of inadequacy of consumption (< 5 daily servings) was found and it was more prevalent among men (83.8%, CI 95%: 79.0%-88.5% than among women: 76.0%, CI 95%: 73.4%-78.6%). For women, the inadequate consumption of FV was higher among those with poor perception of health quality (PR: 1.37; CI 95%: 1.19-1.59) and among those who consider their dietary habits as being unhealthy (PR: 1.15; CI 95%: 1.07-1.24). For men, the inadequate consumption was higher between individuals that reported 2 to 4 visits to the doctor in the year prior to the interview (PR: 1.21; CI 95%: 1.06-1.21). The conclusions showed that the consumption of FV among the population under study is below the recommendations and the health conditions are associated differently for each gender.

ANÁLISE DO PERFIL DA FLEXIBILIDADE DE CRIANÇAS E ADOLESCENTES MENSURADA POR MEIO DE DOIS TESTES / ANALYSIS OF THE FLEXIBILITY PROFILE OF CHILDREN AND ADOLESCENTS MEASURED BY TWO TESTS

RESUMOO objetivo do presente estudo foi mensurar a flexibilidade de crianças e adolescentes de ambos os sexos (7 aos 15 anos de idade), utilizando o teste de Sentar-e-Alcançar (TSA) e outro teste (Banco para a Avaliação da Flexibilidade - BAFLEX) que possibilite controlar as influências das características antropométricas individuais. Participaram do estudo 250 escolares do sexo masculino e feminino, agrupados em cinco faixas etárias: 7, 9, 11, 13, 15 anos. Quando testados pelo TSA, foi verificado um comportamento similar entre os sexos, destacando-se uma diminuição da flexibilidade até os 13 anos e estabilização aos 15 anos de idade. Em relação ao BAFLEX, não foi detectada redução do desempenho, mas sim um aumento da flexibilidade com o avanço da idade. Adicionalmente, as voluntárias apresentaram maiores níveis de flexibilidade que os indivíduos do sexo masculino na faixa etária de 13 anos. O comportamento da flexibilidade foi diferente entre os testes utilizados, reforçando a expectativa de que os resultados do TSA são influenciados por características antropométricas.

ABSTRACTThe aim of this study was to measure the flexibility of children and adolescents of both sexes (7 to 15 years old), using the Sit-and-Reach (SRT) and other test (Bench for Flexibility Assessment - BFA) that allows controlling the influences of individual anthropometric characteristics. The study included 250 male and female students, grouped into five age groups: 7, 9, 11, 13, and 15 years old. When tested by the SRT, there was similar pattern between the sexes, especially a reduction in the flexibility up to 13 years and then stabilizing the performance at 15 years old. With regard to BFA, this test did not detect a reduction in performance, but an increase in the flexibility with advancing age. Additionally, the female volunteers had higher levels of flexibility than males aged 13 years old. The flexibility behavior was different between the tests used, supporting the expectation that SRT results are influenced by anthropometric characteristics.

A new training algorithm using artificial neural networks to classify gender-specific dynamic gait patterns.

The aim of this study was to present a new training algorithm using artificial neural networks called multi-objective least absolute shrinkage and selection operator (MOBJ-LASSO) applied to the classification of dynamic gait patterns. The movement pattern is identified by 20 characteristics from the three components of the ground reaction force which are used as input information for the neural networks in gender-specific gait classification. The classification performance between MOBJ-LASSO (97.4%) and multi-objective algorithm (MOBJ) (97.1%) is similar, but the MOBJ-LASSO algorithm achieved more improved results than the MOBJ because it is able to eliminate the inputs and automatically select the parameters of the neural network. Thus, it is an effective tool for data mining using neural networks. From 20 inputs used for training, MOBJ-LASSO selected the first and second peaks of the vertical force and the force peak in the antero-posterior direction as the variables that classify the gait patterns of the different genders.

Condições de saúde e aconselhamento sobre alimentação e atividade física na atenção primária à aaúde de Belo Horizonte-MG / Health conditions and counseling on diet and physical activity in primary care in Belo Horizonte, Minas Gerais state, Brazil / Condiciones de salud y consejos sobre alimentación y actividad física en la atención primaria de salud de Belo Horizonte-MG

Objetivo: investigar fatores associados ao recebimento de aconselhamento sobre alimentação e atividade física. Métodos: estudo transversal, realizado de outubro de 2009 a janeiro de 2010, com amostra de usuários de Unidades Básicas de Saúde (UBS) de Belo Horizonte, Minas Gerais, Brasil. Foram coletados dados sociodemográficos, antropométricos, sobre consumo alimentar, uso de serviços e condições de saúde e relato de recebimento de aconselhamento. Resultados: a frequência média de aconselhamento foi de 51,1 por cento, com variação de 16,5 por cento a 36,0 por cento entre as UBS. Foram variáveis associadas ao recebimento de aconselhamento (p<0,05): ter hipertensão arterial, hipercolesterolemia, diabetes, excesso de peso; usar medicamentos e participar do Programa Academia da Saúde (PAS). Conclusão: a presença de agravos e a participação do PAS foram as condições de saúde associadas ao recebimento do aconselhamento, evidenciando-se a importância deste programa e a necessidade de reforçar a prática do aconselhamento com caráter preventivo e promotor da saúde na Atenção Primária.

Objective: to investigate health factors associated with receiving counseling on diet and physical activity. Methods: cross-sectional study with a sample of Primary Health Care Centers service users in Belo Horizonte-MG. Sociodemographic, anthropometric and dietary intake data were collected, as were data on use of services, health conditions and reported receipt of counseling. Results: on average 51.1 percent received counseling, varying between 16.5 percent at Center A and 36.0 percent at Center D. After adjusting for Primary Health Care Center, variables associated with receiving counseling (p<0.05) were: having hypertension, hypercholesterolemia, diabetes, overweight, taking medication and taking part in the Health Fitness Academy Program (HFAP). Conclusion: health factors associated with counseling were the presence of disease and taking part in HFAP. These findings highlight the importance of HFAP and the need to strengthen preventive health promotion counseling in Primary Care.

Objetivo: investigar factores asociados a la recepción de consejos sobre alimentación y actividad física. Métoodos: estudio transversal, realizado de octubre de 2009 a enero de 2010, con muestra de usuarios de Unidades Básicas de Salud (UBS) de Belo Horizonte, Minas Gerais, Brasil. Se recolectaron datos sociodemográficos, antropométricos, sobre consumo alimentario, uso de servicios y condiciones de salud y relato de recibimiento de consejos.Resultados: la frecuencia media de ofrecimiento de consejos fue de 51,1%, con variación de 16,5% a 36,0% entre las UBS. Fueron variables asociadas para recibir consejos (p<0,05): sufrir de hipertensión arterial, hipercolesterolemia, diabetes, exceso de peso; usar medicamentos y participar del Programa Academia de Salud (PAS).Conclusion: la presencia de agravamientos y la participación del PAS fueron las condiciones de salud asociadas a la recepción de consejos, evidenciando la importancia de este programa y la necesidad de reforzar la práctica de los consejos con carácter preventivo y como promotor de salud en la Atención Primaria.

Functional data analyses for the assessment of joint power profiles during gait of stroke subjects.

Lower extremity kinetic data during walking of 12 people with chronic poststroke were reanalyzed, using functional analysis of variance (FANOVA). To perform the FANOVA, the whole curve is represented by a mathematical function, which spans the whole gait cycle and avoids the need to identify isolated points, as required for traditional parametric analyses of variance (ANOVA). The power variables at the ankle, knee, and hip joints, in the sagittal plane, were compared between two conditions: With and without walking sticks at comfortable and fast speeds. For the ankle joint, FANOVA demonstrated increases in plantar flexion power generation during 60-80% of the gait cycle between fast and comfortable speeds with the use of walking sticks. For the knee joint, the use of walking sticks resulted in increases in the knee extension power generation during 10-30% of the gait cycle. During both speeds, the use of walking sticks resulted in increased power generation by the hip extensors and flexors during 10-30% and 40-70% of the gait cycle, respectively. These findings demonstrated the benefits of applying the FANOVA approach to improve the knowledge regarding the effects of walking sticks on gait biomechanics and encourage its use within other clinical contexts.

Mudança no foco de atenção ao longo da prática de uma habilidade motora / Change in attentional focus through the practice of a motor skill

Este experimento investigou os efeitos da mudança do foco de atenção durante o processo de aprendizagem de uma habilidade motora. Quatro grupos experimentais (foco interno, foco externo, foco interno-externo e foco externo-interno) e um grupo controle praticaram uma tarefa de arremesso de dardo. Durante a fase de aquisição, dois grupos experimentais tiveram uma forma de focalizar a atenção (foco interno ou externo) e os outros dois grupos tiveram o foco de atenção mudado na metade da prática (foco interno-externo ou externo-interno). Os resultados do teste de retenção mostraram que o foco interno-externo resultou em um desempenho mais consistente. Esses resultados sugerem a existência de relação entre os efeitos do foco de atenção e o nível de aprendizagem.

This experiment investigated the effects of changing the attentional focus during the process of learning a motor skill. Four experimental groups (internal, external, internal-external and external-internal focus) and one control group practiced a dart throwing task. During the acquisition phase, two experimental groups had only one focusing attention (internal or external focus), and other two experimental groups had focus of attention changed half way through the amount of practice (internal-external or external-internal focus). The results of the retention test showed that the internal-external focus resulted in a more consistent performance. These results suggest the existence of a relationship between the effects of attentional focus and level of learning.

Analysis of lower limb asymmetries by isokinetic and vertical jump tests in soccer players.

Assessment of lower extremity bilateral asymmetries in soccer players is important for both injury prevention and performance. The purpose of this investigation was to compare isokinetic knee extensor assessment of asymmetry with a more specific countermovement jump (CMJ). Forty-six Brazilian male professional soccer players participated in this study. The maximal power, maximal force and impulse were determined during CMJ and the total work and peak torque at 60, 180, and 300°·s during isokinetic leg extension, separately for each leg. Factor analysis was performed for all investigated variables, and the diagnostic concordance between different criteria was analyzed by McNemar's χ test. The factor analysis showed that the isokinetic and CMJ tests were widely independent methods for the assessment of bilateral differences. Concordance of the diagnostic information could only be found between the maximal force during CMJ and the total work and peak torque at 180 and 300°·s during isokinetic leg extension. Impulse and maximal power during CMJ on a double force platform appear to be appropriate additional variables for the identification of bilateral differences. Therefore, it might be pertinent to perform, in addition to isokinetic assessment, a vertical jump test on a force platform to assure widespread and reliable diagnostic information.

Variação e índice de simetria de variáveis cinéticasem cães normais no trote / Variations and Symmetric Index of Kinetic Variables of Normal Canines during Running

Os índices de simetria na marcha de caninos foram pouco relatados, existindo falta de consensoe desconhecimento do efeito da normalização nos resultados, sobretudo na ortogonalcraniocaudal. A cinética da marcha no ciclo de trote de quinze cachorros mestiços foi analisadamediante plataforma de força amplificada procurando determinar a simetria na marchadeterminando-se o índice de simetria (IS), sob dois sistemas de normalização dos dadosem caninos normais, normalização pelo peso corporal e normalização pelas característicasmorfométricas bidimensionais dos membros. Foram obtidos desta forma variáveis dinâmicasprimárias de estudo como o IS no tempo e impulso até o pico de força e outras variáveissecundárias como resultado da amplificação da plataforma de força. Os valores para cadaensaio foram utilizados para calcular a média, desvio padrão e coeficiente de variação entreindivíduos e entre os animais. As variáveis na ortogonal craniocaudal foram mais irregularese assimétricas que na ortogonal vertical e tiveram uma menor correlação com a normalizaçãopela massa corporal. A normalização pelo peso corporal mostrou uma maior eficácia que anormalização pelas características morfométricas bidimensionais dos membros ratificandoseu uso em estudos de cinética em caninos. Determinou-se que os índices de simetria nãodevem ser inferiores a 0,90 e 0,75 nas ortogonais vertical e craniocaudal respectivamente.Valores superiores aos descritos são valores aceitáveis para caninos normais e sem alteraçõesortopédicas...

Los índices de simetría en la marcha de caninos han sido escasamente reportados. Falta consenso y se desconoce el efecto de la normalización en los resultados, sobre todo en la ortogonal craneocaudal. La cinética de la marcha en el ciclo de trote de quince perros mestizos se analizó mediante una plataforma de fuerza amplificada buscando determinar la simetría en la marcha. Se determinó el índice de simetría (IS) bajo dos sistemas de normalización de los datos en caninos entonces: normalización por el peso corporal y normalización por las características morfométricas bidimensionales de los miembros. Se obtuvieron variables dinámicas primarias de estudio como el IS en el tiempo e impulso hasta el pico de fuerza y otras variables secundarias como resultado de la amplificación de la plataforma de fuerza. Los valores para cada ensayo se utilizaron para calcular media, desviación estándar y coeficiente de variación entre individuos y entre los animales. Las variables en la ortogonal craneocaudal fueron más irregulares y asimétricas que en la ortogonal vertical y tuvieron una menor correlación con la normalización por la masa corporal. La normalización por el peso corporal mostró una mayor eficacia que la normalización por las características morfométricas bidimensionales de los miembros ratificándose su uso en estudios de cinética en caninos. Se determinó que los índices de simetría no deben ser inferiores a 0,90 y 0,75 en las ortogonales vertical y craneocaudal respectivamente. Valores superiores a los descritos son valores aceptables para caninos normales y sin alteraciones ortopédicas...

Symmetry indexes in canine gait have been scarcely reported, and there is a lack of consensusand knowledge on the effect of normalization in the results, especially in the craniocaudalorthogonal. The kinetics of running was analyzed in the running cycle of fifteen mongreldogs through an amplified force plate, in order to determine the symmetry of gait and symmetryindex (SI) under two data standardization systems in normal dogs: normalization bybody weight and normalization by the two-dimensional morphometric characteristics of thelimbs. Thus, primary dynamic variables of study were obtained, such as the SI in time andmomentum to peak force, as well as other secondary variables as a result of the force plateamplification. The values used for each test were used to calculate the mean, standard deviationand coefficient of variation between individuals and among the animals. Variablesin the craniocaudal orthogonal were more irregular and asymmetrical than in the verticalorthogonal, and had a lower correlation with body mass normalization. Normalization bybody weight showed greater efficacy than that given by the two-dimensional morphometriccharacteristics of the limbs, ratifying its use in kinetics studies in dogs. It was determined thatsymmetric indexes should not be inferior to 0.95 and 0.75 in vertical and craniocaudalorthogonal, respectively. Values higher than those described are acceptable for normal canineswithout orthopedic alterations...

Validade de testes utilizados para medir a flexibilidade dos músculos posteriores da coxa em estudantes universitários / Validity of tests used to measure the flexibility of hamstring muscles in university students

Apesar do teste Sentar-e-Alcançar (TSA) ser frequentemente utilizado na mensuração da flexibilidade dos músculos posteriores da coxa (PC), este teste ainda apresenta validade questionável para esta finalidade. Os objetivos desse estudo foram: a) verificar o nível de correlação entre o desempenho no Banco para a Avaliação da Flexibilidade (BAFLEX) e o desempenho em um teste específico para a medida da flexibilidade dos músculos PC (Teste de Extensão de Joelho modificado – TEJ-mod); b) verificar se o nível de correlação das medidas no TSA modificado (TSA-mod) é aumentada quando correlacionado com uma medida de critério (TEJ-mod) realizada de forma ativa. Participaram deste estudo 26 voluntários (13 indivíduos de cada sexo) com idade média de 22,2 ± 3,4 anos. Os voluntários realizaram aleatoriamente a mensuração da flexibilidade utilizando diferentes testes (BAFLEX, TSA-mod, TEJ-mod). Os coeficientes de correlação de Pearson indicaram níveis de associação significativos e moderados (BAFLEX x TEJ-mod: r = 0,57; TSA-mod x TEJ-mod: r = 0,52; poder > 0,8 em todas as análises). Embora o BAFLEX objetive minimizar problemas presentes no TSA, como diferenças antropométricas entre os indivíduos e a participação de movimentos compensatórios, tal teste não resultou numa alta correlação com o TEJ-mod. Além disso, a realização ativa da medida da flexibilidade dos músculos PC também não permitiu alcançar níveis de correlação altos entre TSA-mod e TEJ-mod. Baseado na baixa variância comum entre BAFLEX e TEJ-mod (32,4%), bem como entre TSA e TEJ-mod (27,3%), conclui-se que os desempenhos nos testes TSA-mod e BAFLEX não são determinados suficientemente pela flexibilidade dos músculos PC.

Although the Sit-and-Reach Test (SRT) is often used to measure the flexibility of the hamstring muscles, this test still shows questionable validity for this purpose. The aims of this study were to (a) verify the level of correlation between performance on Bench for Flexibility Assessment (BFA) and performance on a specific test for the measurement of hamstring flexibility (modified Knee Extension Test – mKET), and (b) verify whether the level of correlation between performance on modified SRT (mSRT) is increased when correlated with a criterion measurement (mKET) executed actively. The study included 26 volunteers (13 males and 13 females) with an average age of 22,2 ± 3,4 years. The subjects were randomly tested for each of three assessments of hamstring flexibility (BFA, mSRT, mKET). The Pearson correlation coefficients indicated significant and moderate levels of association among tests (BAF x mKET: r = 0,57; mSRT x mKET: r = 0,52; power > 0,8 in all analyses). Although BFA aims to minimize problems found in the TSA, as anthropometric differences among the individuals and the participation of compensatory movements, the BFA did not provide a high correlation with the mKET. Furthermore, the active measurement of hamstring flexibility also failed to achieve high levels of correlation between mSRT and mKET. Based on the low common variance between BFA and mKET (32.4%), and between mSRT and mKET (27.3%), we concluded that performances on mSRT and BFA are not sufficiently determined by the flexibility of the hamstring muscles.