Efeito imediato e crônico do treinamento de equilíbrio nas variáveis biomecânicas de atletas
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2018-09-05
Autores
Eltz, Giovana, Duarte
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Universidade Estadual Paulista (Unesp)
Resumo
O equilíbrio é um pré-requisito importante para o aprendizado de habilidades motoras complexas e estão relacionadas ao esporte, desde a juventude até a idade adulta. O desempenho do equilíbrio vem sendo associado a melhora do desempenho atlético (ou seja, saltos verticais, sprints, tarefas de mudança de direção) e até mesmo está sendo considerado uma condição importante para o atleta tornar-se de alto nível. Atualmente equipes e atletas estão utilizando o treino de equilíbrio como uma modalidade de exercício para melhorar o equilíbrio, prevenir lesões nas extremidades inferiores, reabilitar a propriocepção e função neuromuscular. Este treinamento, tem como objetivo gerar instabilidade ao atleta e com isso gerar melhora do controle postural, propriocepção e alguns casos força. A melhora controle postural se dá através dos mecanismos neuronais, envolvendo redes espinhais e supraespinhais. No nível da coluna vertebral, o treino de equilíbrio inibe a excitabilidade reflexa espinhal devido a um aumento na inibição pré-sináptica. Melhorias no desempenho do equilíbrio estão associadas a redução da excitabilidade córticoespinal e cortical (nível supraespinhal), gerando regulações no reflexo. Além disso, adaptações favoráveis após treinamento de equilíbrio podem estar associadas as mudanças estruturais na massa cinzenta e substância branca no lobo pré-frontal em indivíduos jovens saudáveis. Portanto, mudanças geradas no Sistema Nervoso Central (SNC) podem contribuir na melhora do desempenho do equilíbrio e nos efeitos que tendem a prevenir as lesões. Apesar do treinamento equilíbrio ser uma ferramenta efetiva para a melhoria do controle postural e variáveis neuromusculares, ainda há contradição na literatura em relação aos seus efeitos no desempenho de atletas e pouco se sabe sobre o efeito imediato deste treinamento. Preparadores físicos e fisioterapeutas devem considerar que os indivíduos submetidos a treinos de equilíbrio possam apresentar déficit imediato. O objetivo desta pesquisa é determinar quais parâmetros biomecânicos são influenciados após o treinamento equilíbrio em atletas de forma imediata e crônica. As coletas foram realizadas em 45 participantes do sexo feminino e 15 do masculino com idade entre 18 e 35 anos, sendo que para o experimento 1 e 2 foram avaliadas trinta jogadoras de basquete, no experimento 3 atletas de diversas modalidades, quinze mulheres e quinze homens. No experimento 1 e 3 foram realizadas avaliações imediatamente após o treinamento de equilíbrio, 15 minutos e 30 minutos. No experimento 1 foram avaliadas as variáveis de equilíbrio (área, comprimento e velocidade do centro de pressão - COP) e do salto contramovimento (altura e força de reação do solo na aterrissagem), já no experimento 3 foram realizados testes isométricos e isocinético para verificação do torque e com eletromiografia nos músculos reto femoral, vasto lateral e vasto medial para cálculos da eficiência neuromuscular. No experimento 2 foi realizado treinamento equilíbrio com jogadoras de basquete por oito semanas. Foram divididas em dois grupos (controle e treinamento), realizaram avaliações pré e pós treinamento. As avaliações realizadas foram senso de posição ativa, cinestesia, teste isométrico e teste isocinético de joelho dominante, equilíbrio unipodal e salto contramovimento. Após a verificação da normalidade (ShapiroWilk) e homogeneidade (Levene), foi utilizado o teste T independente para comparar as variáveis dependentes entre grupos. Para verificar o efeito do treinamento de equilíbrio, foi aplicada a análise de variância (ANOVA) two-way. Na sequência utilizou-se a ANOVA one way, com correção de Bonferroni para análises par a par quando encontradas interações ou quando encontrados somente efeitos principais. Para todas as variáveis foram adotados o nível de significância de α < 0.05. Após 8 semanas de treino, o grupo treinamento melhorou o desempenho do salto, do equilíbrio olhos fechado e olhos aberto membro não dominante, do senso de posição, torque isométrico e isocinético, mas não apresentou melhora no equilíbrio olhos abertos membro dominante e cinestesia. Já no efeito imediato apenas a altura do salto contramovimento não apresentou déficit imediatamente pós o treino de equilíbrio. As demais variáveis, força de reação do solo, equilíbrio unipodal, torque isométrico, torque isocinético e eficiência neuromuscular apresentaram déficit imediatos ao treino e algumas delas levando não retornaram ao valor basal após 30 minutos de treino.
Balance is an important prerequisite for learning complex, life-related motor skills. Balance performance has been associated with improved athletic performance (ie, vertical jumps, sprints, change-of-direction tasks) and is even considered to be an important condition for the athlete to become a high-level athlete. Currently teams and athletes are using balance training as an exercise modality to improve balance, prevent injury to the lower extremities, rehabilitate proprioception and neuromuscular function. This training aims to generate instability to the athlete and with that improves athletes’ postural control through neuronal mechanisms, involving spinal and supraspinal networks. At the spinal level, balance training apears to inhibit spinal reflex excitability due to an increase in presynaptic inhibition. Improvements in balance performance can be associated with substantially reduce corticospinal and cortical excitability so that the traininginduced reflex down-regulation is associated with improvements in balance performance (supraspinal level). In addition, favorable adaptations after balance training may be associated with structural changes in gray matter and white matter in the prefrontal lobe in healthy young subjects. Therefore, changes generated in the Central Nervous System (CNS) may contribute to improved balance performance and to effects that tend to prevent injury. Although balance training is an effective tool for the improvement of postural control and neuromuscular variables, there is still contradiction in the literature regarding its effects on the performance of athletes and little is known about the immediate effect of this training. Physical trainers and physiotherapists should consider that individuals submitted to balance training may present immediate deficit. The aim of this research is to determine which biomechanical parameters are influenced after the balance training in athletes immediately and chronically. The samples were collected in 45 female participants and 15 male participants aged 18 to 35 years. For the experiment 1 and 2, thirty basketball players were evaluated, in the experiment 3 athletes of various modalities, fifteen women and fifteen men. In experiments 1 and 3, evaluations were performed immediately after the balance training, 15 minutes and 30 minutes. In the experiment 1, were evaluated the variables of balance and countermovement jump, and in the experiment 3, was performed isometric and isokinetic tests with electromyography in the rectus femoris, vastus lateralis and vastus medialis muscles. In experiment 2, balance training was performed with basketball players for eight weeks. They were divided into two groups (control and training), performed pre and post training assessments. The evaluations performed were a sense of active position, kinesthesia, isometric test and isokinetic test of dominant knee, unipodal balance and countermovement jump. After verification of normality (Shapiro-Wilk) and homogeneity (Levene), the independent T-test was used to compare the dependent variables between groups. To verify the effect of the balance training, the ANOVA two-way was applied. An ANOVA one way, with Bonferroni correction, was used for parity analyzes when interactions were found or when only main effects were found. For all variables, the level of significance of α <0.05 was adopted. After 8 weeks of training, the training group improved the performance of the jump, the closed eyes balance and open eyes non-dominant limb, the sense of position, isometric and isokinetic torque, but did not show improvement in the open eyes limb dominant balance and kinesthesia. Already in the immediate effect only the height of the countermovement jump did not present deficit immediately after the balance training. The other variables, ground reaction force, unipodal balance, isometric torque, isokinetic torque and neuromuscular efficiency presented immediate training deficit, and some of them did not return to baseline after 30 minutes of training.
Balance is an important prerequisite for learning complex, life-related motor skills. Balance performance has been associated with improved athletic performance (ie, vertical jumps, sprints, change-of-direction tasks) and is even considered to be an important condition for the athlete to become a high-level athlete. Currently teams and athletes are using balance training as an exercise modality to improve balance, prevent injury to the lower extremities, rehabilitate proprioception and neuromuscular function. This training aims to generate instability to the athlete and with that improves athletes’ postural control through neuronal mechanisms, involving spinal and supraspinal networks. At the spinal level, balance training apears to inhibit spinal reflex excitability due to an increase in presynaptic inhibition. Improvements in balance performance can be associated with substantially reduce corticospinal and cortical excitability so that the traininginduced reflex down-regulation is associated with improvements in balance performance (supraspinal level). In addition, favorable adaptations after balance training may be associated with structural changes in gray matter and white matter in the prefrontal lobe in healthy young subjects. Therefore, changes generated in the Central Nervous System (CNS) may contribute to improved balance performance and to effects that tend to prevent injury. Although balance training is an effective tool for the improvement of postural control and neuromuscular variables, there is still contradiction in the literature regarding its effects on the performance of athletes and little is known about the immediate effect of this training. Physical trainers and physiotherapists should consider that individuals submitted to balance training may present immediate deficit. The aim of this research is to determine which biomechanical parameters are influenced after the balance training in athletes immediately and chronically. The samples were collected in 45 female participants and 15 male participants aged 18 to 35 years. For the experiment 1 and 2, thirty basketball players were evaluated, in the experiment 3 athletes of various modalities, fifteen women and fifteen men. In experiments 1 and 3, evaluations were performed immediately after the balance training, 15 minutes and 30 minutes. In the experiment 1, were evaluated the variables of balance and countermovement jump, and in the experiment 3, was performed isometric and isokinetic tests with electromyography in the rectus femoris, vastus lateralis and vastus medialis muscles. In experiment 2, balance training was performed with basketball players for eight weeks. They were divided into two groups (control and training), performed pre and post training assessments. The evaluations performed were a sense of active position, kinesthesia, isometric test and isokinetic test of dominant knee, unipodal balance and countermovement jump. After verification of normality (Shapiro-Wilk) and homogeneity (Levene), the independent T-test was used to compare the dependent variables between groups. To verify the effect of the balance training, the ANOVA two-way was applied. An ANOVA one way, with Bonferroni correction, was used for parity analyzes when interactions were found or when only main effects were found. For all variables, the level of significance of α <0.05 was adopted. After 8 weeks of training, the training group improved the performance of the jump, the closed eyes balance and open eyes non-dominant limb, the sense of position, isometric and isokinetic torque, but did not show improvement in the open eyes limb dominant balance and kinesthesia. Already in the immediate effect only the height of the countermovement jump did not present deficit immediately after the balance training. The other variables, ground reaction force, unipodal balance, isometric torque, isokinetic torque and neuromuscular efficiency presented immediate training deficit, and some of them did not return to baseline after 30 minutes of training.
Descrição
Palavras-chave
Treinamento sensório-motor, Efeito imediato, Instabilidade, Propriocepção, Sensorimotor training, Immediate effect, Instability, Proprioception