The development of hand, foot, trunk, hearing, and visual lateral preference throughout the lifespan.

This research investigated the developmental process of five lateral preference dimensions (hand, foot, trunk, hearing, and visual preference). A total of 1236 volunteers participated in this study, divided into five age groups: 07-12 (n = 247); 13-17 (n = 234); 18-30 (n = 227); 31-60 (n = 225); and 61-90 years old (n = 303). Lateral preference was assessed via questionnaire with the Global Lateral Preference Inventory. By assessing the degree and direction of lateral preference in different ages, our results revealed a pattern of lateralization strengthening with aging in all the analyzed dimensions. We also verified significant correlation between hand preference and the other dimensions for all age groups, but correlation was stronger in the 7-12 group for all correlation pairs. Our results lead to the suggestion of an underlying general lateralization process in early ages (7-12 years old) followed by specific developmental trajectories of each preference dimension (13 years forward), likely startled by hemisphere and functional specialization related to innate developmental patterns of neural structures and social/environmental influences.

Cultural and environmental aspects influence lateral preferences.

Transcultural approaches comparing the distribution of lateral preference between countries focused primarily on handedness. However, other laterality dimensions may also be susceptible to cultural variations. The present study compared lateral preference in five dimensions (hand, foot, trunk, hearing, and visual) of young adults from Brazil and Mozambique. Two hundred and two undergraduate students participated in the study, of which 101 were Brazilian (21.7 ± 1.66 years old) and 101 Mozambican (25.6 ± 6.2 years old). The participants' lateral preference direction and degree were assessed using the global lateral preference inventory. Most Brazilians were classified in the moderate preference category, while Mozambicans had a higher frequency of individuals with strong preferences. Hence, Mozambicans presented a higher lateralization degree for all dimensions. A subsequent analysis considering only preference direction (right, left or indifferent), and not degree, did not show the same outcomes, revealing similarities in preference distribution between the two groups. This finding highlights the necessity to incorporate preference degrees in future analysis to not overlook potential differences. We also conclude lateral preference investigations with transcultural approaches should analyse beyond handedness, as other dimensions can also be modulated by cultural characteristics.

How Positional Constraints Affect Footedness in Football: A Notational Analysis of Five Leagues in Europe.

In elite-level soccer, the ability to take shots with both limbs from different positions in the pitch may be key to success. This research aimed to: 1) analyze footedness of elite-football players in European leagues during shooting by computing frequency of right- and left-foot use and accuracy; and 2) investigate whether an athlete's distance from the target (goal, penalty, and outside penalty area) and pitch zone (center, left, or right from the goal) can constrain foot selection during shooting. We analyzed 1826 games from the 2017/18 season, divided between: Spanish LaLiga (380 matches); Italian Serie A (380 matches); English Premier League (380 matches); German Bundesliga (306 matches); and French Ligue 1 (380 matches). Results revealed asymmetrical proportions of foot selection, favoring the preferred foot for right- and left-footed athletes. Frequency of preferred foot selection increased as a function of distance from the target (i.e., the farther the athlete, higher the percentage of preferred foot selection). Shots taken from the left side were more often performed with the right foot and vice-versa, for both left- and right-footed athletes. Interestingly, asymmetries were observed only in foot selection, but not in performance, as success rate did not vary between limbs in any position.

Are the Predictions of the Dynamic Dominance Model of Laterality Applicable to Children?

According to the dynamic dominance model, the left cerebral hemisphere is specialized for the control of intersegmental dynamics and the right hemisphere for impedance control. Our aim was to test predictions from the dynamic dominance model in children by comparing performance between the right (preferred) and left hands in aiming. Three groups were compared: 4-7, 8-11, and 18-38 years old. Results showed higher movement linearity in the performance with the right hand in all age groups (P < .01), while initial directional error and endpoint accuracy were equivalent between hands. These results provided partial support for the dynamic dominance model.

Are the predictions of the dynamic dominance model of laterality applicable to the lower limbs?

Investigation of manual actions has supported the proposition that the right and left cerebral hemispheres have complementary specializations relevant for movement control. To test the extent to which hemisphere specialization affect lower limb control, we compared performance between the legs in two motor tasks. A pedal aiming task was employed to test the notion of left hemisphere specialization for dynamic control, and unipedal balance was employed to test the notion of right hemisphere specialization for impedance control. Evaluation was conducted on young adults, in the contexts of separate (Experiment 1) and integrated (Experiment 2) performance of the probing tasks. Results from the aiming task showed equivalent movement linearity toward the target between the right and left feet across experiments. Analysis of unipedal balance revealed that increased stance stability when supported on the left leg was observed when performing simultaneously the aiming task with the contralateral foot, but not in the context of isolated task performance. These results are inconsistent with the proposition of left hemisphere specialization for dynamic control in the lower limbs, and suggest that specialization of the right hemisphere for impedance control can be observed in balance control when stance is associated with voluntary movements of the contralateral lower limb.

Controlling Degrees of Freedom in Learning a Taekwondo Kick.

To test Bernstein's degrees of freedom (DF) hypothesis, the authors analyzed the effect of practice on the DF control and interjoint coordination of a Taekwondo kick. Thirteen inexperienced and 11 expert Taekwondo practitioners were evaluated. Contrary to Bernstein's hypothesis, the inexperienced group froze the DF at the end of learning, reducing the joint range of motion of the knee. Moderate and strong cross-correlations between joints did not change, demonstrating that the interjoint coordination was maintained. The inexperienced group's movement pattern was similar to that of the group of experts, from the beginning of the learning process. Thus, even after years of practice, experts continue to explore the strategy of freezing DF. The DF freeing/freezing sequence strategy was explored during the learning process, suggesting that DF-freezing/freeing strategies are task dependent.

Freezing Degrees of Freedom During Motor Learning: A Systematic Review.

According to Bernstein, the central nervous system solution to the human body's enormous variation in movement choice and control when directing movement-the problem of degrees of freedom (DF)-is to freeze the number of possibilities at the beginning of motor learning. However, different strategies of freezing DF are observed in literature, and the means of selection of the control strategy during learning is not totally clear. This review investigated the possible effects of the class and objectives of the skill practiced on DF control strategies. The results of this review suggest that freezing or releasing the DF at the beginning of learning does not depend on the class (e.g., discrete skill class: football kick, dart throwing; continuous skill class: athletic march, handwriting) or objective of the skill (e.g., balance, velocity, and accuracy), in isolation. However, an interaction between these two skill elements seems to exist and influences the selection of the DF control strategy.

A historical, systematic review of handedness origins.

Handedness ontogenesis is still under debate in science. This systematic review analyzed articles regarding the theories and basis of handedness formation, highlighting the historical knowledge path that this literature underwent. Cochrane Library, LILACS, Web of Sciences, Science Direct and PubMed databases were searched. This review included review studies with handedness as the main topic. Only papers written in English with analyses exclusively in neurotypical humans (any age range) were included. Different approaches (genetic, neural, social, and behavioural) were reviewed in light of growing evidence, summarizing the current state of the art. Genetic and environmental/social impacts are common points in most of the reviews, each given more or less importance, depending on the author and theory proposed. Multifactorial, developmental approaches to handedness formation seem to be the most up to date view of the phenomenon. Different control mechanisms between hemisphere and neural asymmetries are also contributing factors to handedness formation.

Changing handedness: What can we learn from preference shift studies?

Handedness is a dynamic and complex aspect of human behavior. Changing it through practice, either willingly or obliged by some reason, requires a considerable amount of effort. Analyzing studies that presented handedness shifts may expand our comprehension of this phenomenon, since knowing how to change it might provide insights into how it develops. Therefore, we reviewed the outcomes of handedness shifts. The results suggest that neural asymmetries related to handedness are likely a consequence of lateralized practice since they correlate with modifications in the behavioral patterns. Clearly, practice is not the only factor influencing handedness development, but it seems to play a significant role in the formation and consolidation of neural and behavioral asymmetries. Another key finding of our review is the suggestion of a ceiling effect for the capacity to change handedness direction and degree, considering none of the reviewed studies reported complete shifts in behavioral measures and brain activation patterns.

Motor repertoire and gray matter plasticity: Is there a link?

There is a considerable amount of evidence sustaining that aerobic exercise causes positive modifications in gray matter density (GMD), especially in the hippocampus and anterior cingulate cortex. However, recent experimental researches with motor learning paradigms are consistently showing that increasing cardiorespiratory capacity is not the only mechanism able to promote positive outcomes in GMD with exercise. In the present study, we present a theoretical suggestion that expanding one's motor repertoire is another primary mechanism related to the increases in GMD. Motor repertoire can be understood as the number of movement possibilities and motor skills that can be performed by a person. Supporting our suggestion, professional athletes present higher GMD than controls, and experimental protocols repeatedly observes positive changes in GMD following motor learning. The relationship between physical inactivity, amputation, and lower GMD values also gives further support for the hypothesis. Follow-up studies monitoring GMD before and after training programs that stimulate new motor skill learning are essential to confirm this proposition. The brain regions related to sensory processing of the motor tasks and the cortical areas related to motor control (e.g., primary motor cortex, supplementary motor area) are probably the ones most affected by plastic changes. If the hypothesis turns out to be reliable, dancing, gymnastics, and other movement-rich activities are thoroughly encouraged for this purpose. Therefore, this approach might be used to attenuate GMD loss related to aging or another condition, such as Parkinson's and Alzheimer's.

Beyond handedness: assessing younger adults and older people lateral preference in six laterality dimensions.

Lateral preference is influenced by many different factors. Although studies that assessed handedness contributed greatly to our understanding of the phenomenon, looking to other dimensions of motor laterality, such as lower limbs, trunk, visual and hearing preference, may be an interesting strategy to further advance in the field. Comparing different age groups with a complete inventory also contributes to understanding the ageing impact on these variables. Our aim, therefore, was to assess six motor laterality dimensions in younger adults and older people. Two hundred subjects participated in this study (102 adults, 30.6 ± 11.2 years old, and 98 elders, 70.4 ± 7.22 years old) and lateral preference was assessed by the Global Lateral Preference Inventory. We verified significant differences between groups in all dimensions, except the visual one, with proportionally stronger right preference in the older group. Compared to other dimensions, higher frequency of ambidexterity was observed in trunk, hearing and visual preference for both groups. These results might indicate that lateral preference is, indeed, multifactorial, being affected by ageing, task complexity and other possible related aspects.

Effect of visual occlusion and light touch on dynamic postural balance on an unstable platform in elderly and young adult women / Efeito da oclusão visual e do toque suave no equilíbrio postural dinâmico em plataforma instável de idosas e de adultas jovens

ABSTRACT Aging causes the detriment of sensory information that reflects the quality of postural control. The use of light touch has been suggested as a strategy to reduce postural sway even in the absence of vision. However, the effects of this strategy in unstable situations on the support base are unclear. The aim of this study was to analyze the effects of visual occlusion and light touch on the balance of elderly and young adult women on an unstable platform. Twenty elderly women (69.4±6.7 years) and twenty young adult women (20.6±3.2years) performed three attempts at the task which consisted of maintaining balance on an unstable platform on a bipedal base for twenty seconds, with medial-lateral perturbation, in four conditions. The Mann-Whitney U test showed that the elderly women presented worse balance compared to the young adult women in all conditions (p<0.05). The Friedman and Wilcoxon tests demonstrated worse balance with visual occlusion in both groups (p<0.05). On the other hand, there was an improvement in balance using light touch for both vision and no vision conditions (p<0.05). Both groups were able to use the haptic sensory information through light touch to assist in balance maintenance.

RESUMO O envelhecimento causa detrimento nas informações sensoriais que refletem na qualidade do controle postural. O uso do toque suave tem sido sugerido como estratégia para diminuir a oscilação postural mesmo na ausência de visão. Porém, ainda não está claro este efeito em situação de instabilidade da base de suporte. O objetivo do presente estudo foi analisar o efeito da oclusão visual e do toque suave no equilíbrio em plataforma instável de idosas e adultas jovens. Vinte idosas (69,4±6,7 anos) e vinte adultas jovens (20,6±3,2 anos) realizaram três tentativas da tarefa que consistiu em manter o equilíbrio postural dinâmico em plataforma instável, em base bipodal durante vinte segundos, com perturbação médio-lateral em 4 condições. O teste de Mann-Whitney U demonstrou que as idosas apresentaram pior desempenho no equilíbrio em comparação às adultas jovens em todas as condições (p<0,05). Os testes de Friedman e Wilcoxon demonstraram pior desempenho no equilíbrio com a oclusão visual em ambos os grupos (p<0,05). Por outro lado, houve melhora no equilíbrio com o toque tanto na condição com visão quanto sem visão (p<0,05). Ambos os grupos foram capazes de utilizar as informações sensoriais hápticas por meio do toque suave para auxiliar na manutenção do equilíbrio.

Procedures of assessment on the quantification of thoracic kyphosis and lumbar lordosis by radiography and photogrammetry: A literature review.

The quantification of thoracic kyphosis and lumbar lordosis can be assessed in different ways; among them radiography and photogrammetry. However, the assessment procedures are not consistent in the literature for either method. The objective of this study was to conduct a literature review about postural assessment through radiography and photogrammetry, for delineating the procedures for both methods. In total 38 studies were selected by an online search in the MEDLINE and LILACS databases with the keywords: radiograph and posture, postural alignment, photogrammetry or photometry or biophotogrammetry. For the radiographic method, the results showed divergences in arm positioning and in the calculation of thoracic and lumbar angles. The photogrammetry demonstrated differences in relation to the camera, tripod, plumb line and feet positioning, angle calculation, software utilization, and the use of footwear. Standardization is proposed for both methods to help establish normative values and comparisons between diagnoses.

Efeito da potencialização pós-ativação no torque isométrico do tríceps braquial em adultos / Effect of postactivation potentiation on isometric torque of the brachii triceps in adults

Objetivo: Analisar o efeito de contrações voluntárias isométricas máximas e da eletroestimulação no torque isométrico e na ativação muscular do tríceps braquial em adultos fisicamente ativos. Métodos: Dezenove homens foram submetidos a testes de força isométrica (FI) como pré-teste, por meio de contração voluntária isométrica máxima durante 10 segundos e atividades condicionantes (ACs) randomizadas: isometrias durante 7, 10 e 12 segundos e eletroestimulação em 70 e 120Hz por 10 segundos cada. Após as ACs, foram realizadas duas contrações voluntárias isométricas máximas de 10 segundos com intervalo de 4 e 8 minutos, respectivamente. A atividade elétrica do tríceps braquial (porções medial e lateral) foi registrada. Resultados: Não foi verificado efeito em nenhuma das condições para o torque máximo ou médio, bem como para atividade elétrica do tríceps braquial (P>0,05). Conclusão: O intervalo adotado entre as ACs e o teste de FI não foi suficiente para induzir a melhoria do torque isométrico. (AU)

Objective: To analyze the effect of maximal voluntary isometric contractions and of electroestimulation on isometric torque and muscle activation of the brachii triceps in physically active adult males. Methods: Nineteen men underwent isometric force tests as pre-test, through 10-second long maximal voluntary isometric contractions and conditioning activities randomized: isometric contraction during 7, 10 and 12 seconds and electric stimulation in 70 and 120 Hz for 10 seconds each. After the conditioning activities, two voluntary isometric contractions were performed for 10 seconds with interval of 4 and 8 minutes, respectively. The muscle electrical activity of brachii triceps (medial and lateral portion's) was measured. Results: It was not verified effect in any conditions to maximal or mean torque (P>0.05), likewise to muscle electrical activity of brachii triceps (P>0.05). Conclusion: The interval adopted among the conditioning activities and the isometric force test was not enough to induce the isometric torque improvement. (AU)

Preferência lateral percebida e diagnosticada em adolescentes / Lateral perceived and diagnosed preference in teenagers / Preferencia lateral percibida en adolescentes diagnosticados

Resumo O estudo analisou a percepção e a preferência lateral global de adolescentes (11-15 anos). Para tal, 153 adolescentes foram submetidos ao inventário de preferência lateral global (Iplag). Os participantes foram classificados como "moderadamente destros" na preferência lateral global percebida. A preferência lateral diagnosticada classificou os participantes como fortemente destros para membros superiores, membros inferiores, audição e visão e como moderadamente destros para tronco. Portanto, os adolescentes apresentaram-se como fortemente destros para preferência lateral global. Os escores de coerência entre a preferência lateral percebida e a preferência lateral diagnosticada demonstraram que os participantes têm grande conhecimento sobre sua preferência lateral.

Abstract The study analyzed the global lateral perception and preference of teenagers (11-15 years old). Within this scope, the study involved 153 teenagers, which were submitted to answer the Global Lateral Preference Inventory (Iplag). The participants were classified as "moderate right-handed" for perceived global lateral preference. In relation to lateral preference, they were classified as "strong right-handed" for the upper limbs, lower limbs, hearing and vision, and "moderate right-handed" for the trunk. Thus, the teenagers were classified as "strong right-handed" for the global lateral preference. The scores of consistency between lateral preference and perceived lateral preference showed that participants had great knowledge about their lateral preference.

Resumen El estudio analizó la percepción global lateral y la preferencia de los adolescentes (11-15 años). En este ámbito, en el estudio participaron 153 adolescentes, los cuales respondieron el Inventario Global de Preferencia Lateral (IPLAG). Los participantes se clasificaron como "moderadamente diestros" en la preferencia global lateral percibida. En relación con la preferencia lateral, se los clasificó como "fuertemente diestros" de los miembros superiores, miembros inferiores, audición y visión, y "moderado diestros" del tronco. Por lo tanto, a los adolescentes se los clasificó como "fuertemente diestros" de la preferencia lateral global. Las puntuaciones de la coherencia entre la preferencia lateral y la preferencia lateral percibida mostró que los participantes conocían muy bien su preferencia lateral.

Five-week sensory motor training program improves functional performance and postural control in young male soccer players - A blind randomized clinical trial.

Sensory motor training programs are used in the rehabilitation and prevention of injuries among soccer players. Inconsistencies are found in the literature regarding the duration of the protocols and the exercises and equipment used. OBJECTIVE: To evaluate the benefits of a five-week sensory motor training program on the functional performance and postural control of young soccer players. METHODS: The study sample comprised 22 young male soccer players who were evaluated using: the Figure-of-Eight Test (F8), Side Hop Test (SHT), Star Excursion Balance Test (SEBT), and a force platform. The players were randomly divided into a control group (N = 10), who continued their soccer practice sessions and an intervention group (N = 12), who continued their soccer practice sessions and were also enrolled in a supervised five-week sensory motor training program. RESULTS: After the five-week training program, the intervention group obtained significant results in the F8, SHT and SEBT, as well as in the following parameters: area of pressure of sway center (COP), mean velocity and mean frequency of COP. CONCLUSION: The five-week sensory motor training program, carried out with easily available and low cost equipment, was effective at improving functional performance and postural control in young soccer players.

Efeito da restrição espacial do ambiente na preferência manual em tarefa de alcance em adultos jovens / Effect of spatial constraint of the environment on the hand preference in reaching task in young adults / Efecto de la restricción espacial del entorno en la preferencia manual en una tarea de alcance en adultos jóvenes

Resumo A preferência manual (direção e magnitude) na tarefa de alcançar em adultos foi analisada em função da localização espacial de um objeto no ambiente. Trinta participantes fizeram a tarefa de alcançar um cilindro, devendo-se escolher apenas uma das mãos para fazer a tarefa, a 50 cm de distância em cinco posições diferentes em relação ao plano sagital do participante. Duas condições foram cumpridas: conforto (sem restrição da velocidade) e velocidade (movimento feito o mais rapidamente possível). Anova de Friedman apontou diferença (X230,9 = 122,17; p < 0,001) e o teste de Wilcoxon apontou maiores escores nas posições de 90°, 120° e 150° em comparação com 30° e 60° para ambas as condições (p < 0,01) demonstrando alcances ipsilaterais. Tais resultados foram explicados pela restrição biomecânica para fazer a tarefa, modulando a preferência manual, de acordo com a localização espacial dos objetos no ambiente.

Abstract The manual preference in a reaching task in adults was analyzed according to the spatial location of an object in the environment. Thirty participants performed the task of reaching a cylinder, with one hand, at 50 cm distance in five different positions in relation to the sagittal plane of the participant. Two conditions were performed: comfort and speed. Friedman' s ANOVA showed difference (X230,9 = 122.17; p < 0.001) and the Wilcoxon' s test showed higher scores at positions 90°, 120° and 150° in comparison 30° and 60°, for both conditions (p < 0.01) showing ipsilateral reaches. These results were explained by the biomechanics restriction to perform the task, modulating the manual preference, according to the spatial location of objects in the environment.

Resumen Se analizó la preferencia manual en una tarea de alcance en adultos en función de la ubicación espacial de un objeto en el entorno. Treinta participantes realizaron la tarea de alcanzar un cilindro, con una sola mano, a una distancia de 50 cm en cinco posiciones diferentes en relación con el plano sagital del participante. Dos condiciones se cumplieron: comodidad y velocidad. La prueba ANOVA de Friedman mostró una diferencia (χ230,9 = 122,17; p < 0,001) y la prueba de Wilcoxon mostró puntuaciones más altas en las posiciones de 90̊, 120̊ y 150̊ en comparación con las de 30̊ y 60̊, en ambas condiciones (p < 0,01), lo que demostró alcances ipsilaterales. Estos resultados se debieron a la biomecánica de restricción para realizar la tarea mediante la modulación de la preferencia manual, de acuerdo con la ubicación espacial de los objetos en el entorno.

Reprodutibilidade intra avaliador e interavaliadores na identificação digital da posição dos marcadores de referência na avaliação postural de fotogrametria / Intra and inter-rater reproducibility in digital identification of the position of the reference markers on postural evaluation by photogrammetry

O processo de identificação dos referenciais anatômicos em imagens (digitalização) na avaliação postural por fotogrametria, pode ser fonte de erro e, assim, influenciar a reprodutibilidade das medidas. O presente estudo analisou a reprodutibilidade inter e intra-avaliadores na identificação da posição dos marcadores no processo de digitalização na avaliação postural por fotogrametria. Trinta voluntários participaram do estudo, sendo 15 homens e 15 mulheres com idade média de 25 anos (DP=5,8). Foram identificados por um avaliador previamente treinado os processos das vértebras C7, T12 e L5 de cada participante por meio do método de palpação e colocação de marcadores externos seguido da realização de sessões de fotos. Os ângulos torácicos e lombares foram calculados pela identificação destes marcadores externos nas imagens por meio do software SAPO. Para a análise intraavaliadores, a identificação dos processos foi realizada por 2 avaliadores previamente treinados que avaliaram uma foto de cada participante e a análise interavaliadores for realizada por um avaliador que analisou as mesmas fotos duas vezes com 24 horas de intervalo entre as análises. Foi utilizado o coeficiente de correlação intraclasse (CCI) para análise da reprodutibilidade inter e intravaliadores e o teste proposto por Bland e Altman para análise de concordância. Os resultados demonstraram forte reprodutibilidade para os ângulos torácicos para a análise inter e intra-avaliadores (CCI=0,99 e CCI=0,90, espectivamente) com viés de 0,280 entre as sessões do avaliador 1 e 2,490 entre os dois avaliadores. Para os ângulos lombares foi demonstrado forte reprodutibilidade interavaliadores (CCI=0,99) com viés de 0,320 . No entanto, as análises intra-avaliadores demonstraram boa reprodutibilidade (CCI=0,79) com viés de 4,60 . Dessa maneira, o processo de identificação dos referenciais anatômicos na foto (digitalização) não demonstrou ser fonte de erro capaz de comprometer a avaliação postural por meio de fotogrametria.(AU)

The identification process of anatomic references in images (scanning) on the postural assessment by photogrammetry, may be mistaken and influence the measures. This present study analyzed the inter and intra examiner reproducibility on the markers positions identification in the scanning process on the postural assessment by photogrammetry. Thirty volunteers participated in the study, mean age 25 years old (SD=5.8). The vertebrae processes (C7, T12 and L5) were identified by an examiner previously trained using the palpation method; markers were attached to the participant´s skin followed by the photo section. The thoracic and lumbar angles were calculated by those markers identification on the images by SAPO software. For the intra examiner analysis, the process identification were realized by 2 examiners previously trained, who assessed a photo from each participant and the inter examiner reproducibility were realized by an examiner who analyzed the same picture twice with 24 hours interval between them. The intraclass correlation coeficient (ICC) were used to analyze the inter and intra examiner´s reproducibility and the Bland &Altman test to the concordance analyses. The results showed strong reproducibility for thoracic for intra and inter examiners analyses (ICC=0.99 e ICC=0.9, respectively) with 0.280 bias between the examiner 1 sections and 2.490 bias between both examiners. For lumbar angles, the inter examiner reproducibility were strong (ICC=0.99) with 0.320 bias. However, the intra examiner reproducibility showed good reproducibility (ICC=0.79) with 4.60 bias. The identification process of anatomic references on the image (scanning) did not show to be an error font able to influence the postural assessment by photogrammetry.(AU)

Análise do equilíbrio dinâmico em praticantes de balé clássico, de dança de salão e de não praticantes de dança / Analysis of dynamic balance in practitioners of classical ballet, of ballroom and non-practitioners of dance

O presente estudo analisou o equilíbrio dinâmico de praticantes de balé clássico, de dança de salão e de não praticantes de dança. Participaram do estudo 48 indivíduos entre 16 e 30 anos, divididos em 3 grupos: Balé (GB), Dança de Salão (GS) e Controle (GC). Os participantes realizaram a tarefa de manter-se em equilíbrio sobre uma plataforma instável, em 3 tentativas, durante 10 segundos, em cada uma das bases de apoio: pés paralelos (PP), semi-tandem (ST), unipodal com o pé direito (UD) e unipodal com o pé esquerdo (UE). Houve melhor desempenho no equilíbrio dinâmico para GS, em comparação ao GB e ao GC. Ademais, o GS e GC demonstraram piores desempenhos em bases de apoio mais restritas, enquanto, o GB não demonstrou efeito da redução na base de apoio. Tais resultados foram explicados pelas características específicas das práticas fornecidas pelas modalidades de dança de salão e balé.

The present study analyzed the dynamic balance of practitioners of classical ballet, of ballroom dancing and non-practitioners of dance. The study included 48 subjects, age between 16 and 30 years old, divided into three groups: Ballet (GB), Ballroom Dancing (GS) and Control (GC). The subjects performed a task which consisted to remain in balance on an unstable platform in three attempts for 10 seconds in each of the following conditions: feet parallel (PP), semi-tandem (ST), unipedal on the right foot (UD) and unipedal on the left foot (UE). Data demonstrated better dynamic equilibrium for GS, compared to GB and GC. Moreover, GS and GC showed worse balancing in constrained bases of supports. While the GB showed no effect on balance with the decrease on support base. These results were explained by the specific characteristics of the practices provided by the modalities of dance and ballet.

Efeito da oclusão de informações espaciais na cortada do voleibol sobre a tomada de decisão defensiva em atletas com diferentes níveis de experiência / The effect of spatial information occlusion in volleyball spike on defensive decision-making in athletes with different levels of experience

O presente estudo analisou o efeito da oclusão de informações espaciais na cortada do voleibol sobre a tomada de decisão defensiva em atletas com diferentes níveis de experiência. Os participantes foram divididos em grupo adulto (GAD; n=16), infanto/mirim (GIM; n=16) e adulto novato (GNO; n=16). Foram ocluídas 5 informações espaciais: bola (OE1), braço e mão (OE2), cabeça (OE3), tronco (OE4) e MMII como condição controle (OE5). Foi mensurada a precisão na predição da trajetória da bola e a confiança da resposta. O GAD foi mais preciso que os demais grupos na condição OE2 (P's<0,008), que proporcionou o pior desempenho dos grupos (P's<0,001). O GAD apresentou maior confiança que o GNO em todas as condições (P's<0,003), mas sem diferença em relação ao GIM (Bonferroni P's>0,036). O GIM apenas foi mais confiante que GNO em OE4 (P=0,01). Assim, as informações OE1 e OE2 demonstraram afetar mais o melhor desempenho dos participantes.

The aim of this study was to analyze the effect of the occlusion of spatial information in volleyball spike on defensive decision-making in athletes with different levels of experience. Participants were divided into adult (GAD; n=16), juvenile (GIM; n=16) and novice (GNO; n=16) groups. Five types of spatial information were occluded: ball (OE1), arm and hand (OE2), head (OE3), trunk (OE4), and lower limbs as a control condition (OE5). We measured the accuracy in predicting the ball's trajectory prediction and the confidence of the response. GAD was more precise than the other groups in the OE2 condition (P's<0.008), which provided the worst performance of the groups (P's<0.001). GAD showed more confidence than GNO in all conditions (P's<0.003), but with no difference compared to GIM (P's>0,036). GIM was only more confident than GNO in OE4 (P=0.01). Therefore, the OE1 and OE2 proved to have greater effect on the performance of the best participants.