Educação (física) infantil: território de relações comunicativas

Com base na Semiótica de C. S. Peirce, o objetivo deste estudo é refletir sobre as temáticas do modo específico de ser criança, das suas singularidades/alteridades e da produção de linguagem/signos como condições fundantes que configuram a prática pedagógica com crianças, compreendida como experiência vívida e relações comunicativas no fluxo das semioses. O método utilizado é o abdutivo/indutivo proposto por Peirce, pelo qual pudemos estabelecer relações específicas com a Concepção Dialógica do Movimento Humano - Se-Movimentar.

Effects of exercise training on the cardiovascular system: Pharmacological approaches

Physical exercise promotes beneficial health effects by preventing or reducing the deleterious effects of pathological conditions, such as arterial hypertension, coronary artery disease, atherosclerosis, diabetes mellitus, osteoporosis, Parkinson's disease, and Alzheimer disease. Human movement studies are becoming an emerging science in the epidemiological area and public health. A great number of studies have shown that exercise training, in general, reduces sympathetic activity and/or increases parasympathetic tonus either in human or laboratory animals. Alterations in autonomic nervous system have been correlated with reduction in heart rate (resting bradycardia) and blood pressure, either in normotensive or hypertensive subjects. However, the underlying mechanisms by which physical exercise produce bradycardia and reduces blood pressure has not been fully understood. Pharmacological studies have particularly contributed to the comprehension of the role of receptor and transduction signaling pathways on the heart and blood vessels in response to exercise training. This review summarizes and examines the data from studies using animal models and human to determine the effect of exercise training on the cardiovascular system. (c) 2007 Elsevier B.V. All rights reserved.

Motor perseveration during an A not B task in children with intellectual disabilities

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Educação Física e a Cultura da Prática

physical education with a discipline or field has reached the status and scope in all spheres of contemporary culture. Not by chance that issues relating to body and human movement in recent years have been the focus of studies, especially understanding of the need to reflect on new concepts in physical education. Science in the traditional sense, as a method of analysis supports the idea of scientific rigor, but is fundamental reflection. This essay seeks the interface between science and philosophy, on which discussions can take other visibilities in physical education as an activity of the culture. With interdisciplinary approaches and thinking about body movement, focus on scientific concepts and philosophical traverse historically a possible way to rethink the design physical education.

Análise cinemática tridimensional do movimento de eqüinos em esteira rolante

Adaptou-se uma metodologia utilizada no estudo do movimento humano para analisar o movimento de eqüinos em esteira rolante de alto desempenho, construindo-se um sistema de calibração utilizando-se um teodolito eletrônico de alta precisão e calibradores que demarcavam o espaço ocupado pelo animal. Dessa forma, foram obtidas as coordenadas espaciais dos marcadores presentes nos calibradores, compondo o arquivo de calibração. Duas câmeras de vídeo (60Hz) foram posicionadas em vista lateral esquerda, distantes 5m da manta de rolagem da esteira a 1,8m de altura. As imagens foram enquadradas utilizando-se um monitor de vídeo. Para a validação do método, um membro da equipe movimentou, no espaço calibrado, uma haste rígida com marcadores fixados nas suas extremidades, distantes um do outro 43,8cm. Para a análise das imagens, utilizou-se o programa Dvideow, desenvolvido pelo Laboratório de Instrumentação para Biomecânica - UNICAMP. Após a reconstrução tridimensional das imagens utilizou-se um programa matemático para o cálculo do valor médio da distância entre os marcadores. Obteve-se, após a mensuração em 100 quadros, o valor médio de 43,7cm com coeficiente de variação de 0,8%. Estes resultados mostram que a metodologia desenvolvida é precisa e adequada para o estudo da locomoção de eqüinos.

Representation and analysis of soccer players' actions using principal components

This paper proposes the use of the Principal Components Analysis (PCA) method to represent and to analyse soccer players' actions distribution in the pitch. The seven games of the Brazilian National Team during the 2002 World Cup were analysed. The player's position actions were measured from videotapes in a computer interface. The results were: a) the graphical representation, given by two orthogonal segments in the two directions of maximal variability and centred at the mean of each player's actions position; b) the eccentricity measurement, given by the variability ratio and c) the actions zone area, given by variability product. The results showed that the individual characteristics of acting were well represented by the PCA, allowing comparisons among games and providing insights related to the tactical organisation of the team.

Attending to the non-preferred hand improves bimanual coordination in children

The effect of attentional focus in bimanual coordination was investigated from a developmental perspective by examining performance of right- and left-handed children, 5-8-years and 9-12-years old, on bimanual reciprocal tapping tasks. Attentional focus was either specified, by asking the children to attend to the preferred or to the non-preferred hand, or unspecified for the execution of the tasks. When attention was oriented to the non-preferred hand we found a reduced movement time and a lower frequency of errors. Performance differences for handedness and age-groups were observed when the children were oriented to attend to the preferred hand or when there was no instruction regarding attention. These differences in performance were eliminated when attention was oriented to the non-preferred hand. (C) 2004 Elsevier B.V. All rights reserved.

Task demand effects on postural control in older adults

The literature shows conflicting results regarding older adults' (OA) postural control performance. Differing task demands amongst scientific studies may contribute to such ambiguous results. Therefore, the purpose of this study was to examine the performance of postural control in older adults and the relationship between visual information and body sway as a function of task demands. Old and young adults (YA) maintained an upright stance on different bases of support (normal, tandem and reduced), both with and without vision, and both with and without room movement. In the more demanding tasks, the older adults displayed greater body sway than the younger adults and older adults were more influenced by the manipulation of the visual information due to the room movement. However, in the normal support condition, the influence of the moving room was similar for the two groups. These results suggest that task demand is an important aspect to consider when examining postural control in older adults. (c) 2006 Elsevier B.V. All rights reserved.

An examination of constraints affecting the intralimb coordination of hemiparetic gait

A dynamical systems approach to the study of locomotor intralimb coordination in those with hemiparesis led to an examination of the utility of the shank-thigh relative phase (RP) as a collective variable and the identification of potential constraints that may shape this coordination. Eighteen non-disabled individuals formed three groups matched to the age and gender of six participants with chronic right hemiparesis. The three groups differed in the constraints imposed on their walking: (1) walking at their preferred walking speed; (2) walking as slowly as those with hemiparesis; and, (3) walking slowly with a right ankle-foot orthosis (AFO). The results revealed an asymmetry in intralimb coordination between the unaffected and affected leg of those with hemiparesis localized to the latter third of the gait cycle when the limb is advanced from the end of stance to the reestablishment of a new stance. Walking slowly with or without an AFO resulted in no measureable effect in the non-disabled, but accounts for 22% of the variance in the intralimb coordination of the hemiplegic's affected limb and 16% in the unaffected limb. The AFO offered little additional contribution. These results derive from shank-thigh RP that is shown to provide more information about intralimb coordination than knee angle displacement. Implications for these results and the use of RP for rehabilitation are discussed. (C) 2000 Elsevier B.V. B.V. All rights reserved. PsycINFO classification. 3297. 2330.

Interference of high-heeled shoes in static balance among young women

The aim of the present study was to assess the effect of the use of high-heeled shoes on static balance in young adult women. Fifty-three women between 18 and 30 years of age and accustomed to wearing high-heeled shoes participated in the study. None of the participants had any orthopedic or neurologic alterations. Static balance was assessed using a force plate. Oscillations from the center of pressure in the mediolateral and anteroposterior directions were measured both when barefoot and when wearing high-heeled shoes [7 centimeters (cm) in height and 1 cm in diameter] under the conditions of eyes open and eyes closed. Two-way analysis of variance was employed for the statistical analysis, with the level of significance set at 5% (p < .05). The results revealed statistically significant differences between tests when barefoot and when wearing high-heeled shoes as well as with eyes open and eyes closed (p < .01). With the use of high-heeled shoes, there was a significant increase in mediolateral oscillation with eyes closed (p < .01). The present study demonstrates that the use of seven-cm high heels altered static balance in the healthy young women analyzed, increasing the oscillation of the center of pressure, regardless of visual restriction. (C) 2012 Elsevier B.V. All rights reserved.

Do men and women use similar adaptive locomotion to clear static and dynamic obstacles?

Purpose. The purpose of this study was to analyze the influence of gender on the adaptive locomotion in the clearance of obstacles. Specifically, it was evaluated if there are differences in the space-temporal parameters between male and female in the clearance of and dynamic obstacles moving at both slow and fast speeds. Basic procedures. Five young male adults and five young female adults took part in this study. The task was performed in three conditions: static obstacle and dynamic obstacle - clearance perpendicular to the participant's trajectory at slow speed (1.07 m/s) and at fast speed (1.71 m/s). The trials were recorded by two digital cameras and spatial-temporal information was obtained. Main findings. The dynamic obstacle conditions required more visual inspection. The results showed different adaptive locomotion between the sexes. The distinct gait patterns were evidenced for the spatial and temporal variables and cadence in the three conditions. Conclusions. The women presented a more conservative behavior, which was evidenced by the increase of the length in the penultimate step and in the toe clearance.

Effects of fatigue induced by prolonged gait when walking on the elderly

Purpose. Fatigue has been pointed as a fall risk in the elderly; however, the effects of prolonged gait on neuromuscular recruitment and on its pattern remain unknown. The aim of this study was to evaluate the effects of prolonged gait on neuromuscular recruitment levels and spatial-temporal gait variables. Methods. Eight healthy older women (age: 72.63 ± 6.55 years) walked at their preferred walking speed for twenty minutes on a treadmill. The Root Mean Square (RMS) from the vastus-lateralis, femoral biceps, tibialis anterior and lateral gastrocnemius muscles were determined at the first and last minute of the test during the moments of Heel Strike (HS), Terminal Stance and Terminal Swing (TS). In addition, coactivation in the knee and ankle as well as the stride cadence and length were measured in the test. The two RMS data (taken at the first and last minute) were compared by means of a Student's t-test. Results. Twenty minutes of walking induced fatigue in the subjects, as observed through an increase in RMS, notably during the HS and TS. Coactivation was also influenced by the prolonged gait test. The only gait phase where a risk of falling was enhanced was the HS. Nonetheless, subjects developed strategies to maintain a safe motor pattern, which was evidenced by an increase in stride length and a decrease in stride cadence. Conclusion. Tests lasting just twenty minutes on a treadmill were enough to induce fatigue in older adults. However, the level of fatigue was not enough to present a danger or fall risk to elderly individuals.

Maximal isokinetic peak torque and EMG activity determined by shorter ranges of motion

Purpose. Isokinetic tests are often applied to assess muscular strength and EMG activity, however the specific ranges of motion used in testing (fully flexed or extended positions) might be constrictive and/or be painful for patients with injuries or under-going rehabilitation. The aim of this study was to examine the effects of different ranges of motion (RoM) when determining maximal EMG during isokinetic knee flexion and extension with different types of contractions and velocities. Methods. Eighteen males had EMG activity recorded on the vastus lateralis, vastus medialis, semitendinosus and biceps femoris muscles during five maximal isokinetic concentric and eccentric contractions for the knee flexors and extensors at 60° • s -1 and 180° • s -1. The root mean square of EMG was calculated at three different ranges of motion: (1) a full range of motion (90°-20° [0° = full knee extension]); (2) a range of motion of 20° (between 60°-80° and 40°-60° for knee extension and flexion, respectively) and (3) at a 10° interval around the angle where peak torque is produced. EMG measurements were statistically analyzed (ANOVA) to test for the range of motion, contraction velocity and contraction speed effects. Coefficients of variation and Pearson's correlation coefficients were also calculated among the ranges of motion. Results. Predominantly similar (p > 0.05) and well-correlated EMG results (r > 0.7, p ≤ 0.001) were found among the ranges of motion. However, a lower coefficient of variation was found for the full range of motion, while the 10° interval around peak torque at 180° • s -1 had the highest coefficient, regardless of the type of contraction. Conclusions. Shorter ranges of motion at around the peak torque angle provides a reliable indicator when recording EMG activity during maximal isokinetic parameters. It may provide a safer alternative when testing patients with injuries or undergoing rehabilitation.

Effects of elbow flexor muscle resistance training on strength, endurance and perceived exertion

Purpose. To verify the effects of resistance training at the electromyographic fatigue threshold (EMGFT) based on one-repetition maximum strength (1RM), heart rate (HR), rate of perceived exertion (PE) and endurance time (EndT). Methods. Nineteen subjects (training group [TG]: n = 10; control group [CG]: n = 9), performed 1-min bicep curl exercises sets at 25%, 30%, 35% and 40% 1RM. Electromyography (biceps brachii and brachiorradialis), HR and PE were registered. Biceps brachii EMGFT was used to create a load index for an eight-week resistance training programme (three sets until exhaustion/session, two sessions/week) for the TG. The CG only attended one session in the first week and another session in the last week of the eight-week training period for EndT measurement. EndT was determined from the number of repetitions of each of the three sets performed in the first and last training sessions. After training, 1RM, EMGFT, EndT, HR and PE at the different bicep curl load intensities were again measured for both groups. Results. Increases in 1RM (5.9%, p < 0.05) and EndT (> 60%, p < 0.001) after training were found. In addition, PE was reduced at all load intensities (p < 0.05), while no changes were found for HR and EMGFT after training. Conclusions. Strength-endurance training based on the EMGFT improved muscular endurance and also, to a lesser extent, muscular strength. Moreover, the reduced levels of physical exertion after training at the same intensity suggest that endurance training exercises may improve comfort while performing strength exercises.

Padrão de coordenação do pular corda: um estudo desenvolvimental

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)