ABSTRACT
: A educação cruzada corresponde a uma adaptação neural em que ocorre melhoria de desempenho do membro não treinado após um período de prática unilateral do membro contralateral. A co-ativação da musculatura antagonista também corresponde a um fenômeno neural que pode limitar a produção de força e estratégias de como a pré-ativação procuram melhorar o desempenho. A combinação de ambos pode resultar em aumento de desempenho n o treinamento de força. O objetivo do estudo foi investigar os efeitos de diferentes protocolos de pré-ativação antagonista contralateral sobre o desempenho de repetições múltiplas. Quinze mulheres treinadas realizaram a pré-ativação da musculatura antagonista contralateral de forma unilateral em quatro protocolos distintos: no protocolo preferido e não preferido flexor-extensor era realizado a CF do membro preferido ou não e em seguida a CE do membro contralateral. No protocolo p referido e não preferido extensor-flexor era realizado a CE do membro preferido ou não preferido e em seguida a CF do membro contralateral. Eram realizadas t rês séries usando cargas máximas de dez repetições com intervalo de dois minutos. Em relação à CE, verificou-se volume de treinamento (VTT) significativamente maior no protocolo flexor-extensor (23,5s). Quanto a CF, verificou-se resultado significativamente maior no protocolo extensor-flexor (10,6%; 22,2%). Em relação ao TST, foi significativamente maior no protocolo extensor-flexor para ambos os membros (23,2s.; 23,9s.). Não houve diferença significativa para percepção subjetiva de esforço. A pré-ativação antagonista contralateral permitiu um aumento no VTT e no TST em ambos os protocolos na CE e CF sendo um a possível alternativa para tal objetivo....(AU)
: The cross education corresponds a neural adaptation in which the performance improvement of the utrained limb o ccurs aft er a period of unilateral practice by the contralateral limb. The co-activation of the antagonistic also corresponds a neural phenomenon t hat can limit the muscle strength and strategies like as pre-activation seek to improve performance. The combination of both can result in increased resistance training performance. The aim of the study was to investigate the effects of diferente protoco ls o s p re- activation antago nist contralateral on the performance of repetitions. Fifteen trained women performed pre-activation of thecontralateral antagonist musculature unilateral in four diferente protocols: in the preferred and not preferred flexor-extensor protocol, the LC of the preferred or non-preferred lim was performed and then the LE of the contralaterals limb. In the preferred and not preferred extensor-flexor protocol, the LE of preferredor non-preferred limb was performed and then the LC of the contralateral limb. Three sets were performed usin g m ax imum lo ads of tem repetitions with and interval of two minutes. In the LE, there was a significantly higher training v o lume (VTT) in th e flex or -extensor protocol (14,9%; 16,9%). About time under tension (TST), LE a significant increase in TST was identified in the non-preferred m em ber of the flexor extensor protocol (23,5s.). As for LG, there was a significantly higher result in the extensor-flexor protocol (10,6%; 2 2,2%). In relation to TST, it was significantly higher in the extensor-flexor protocol for both members (23,2s; 2 3,9s). There was no significant difference for subjective perception of effort. The controlateral antagonista pre-activation provided na increase in the VTT and the TST in both protocols in LE and LC, being a possible alternative for this objective....(AU)
Subject(s)
Humans , Female , Adult , Women , Education , Muscle Strength , Resistance Training , Health Strategies , Adaptation to Disasters , EfficiencyABSTRACT
PURPOSE: The purpose of the current study was to examine the effects of exercise-induced fatigue of the plantar flexor muscle in the dominant ankle on the plantar flexor strength and postural control function of the contra-lateral side. METHODS: Twenty-one young adults (male: 10, female: 11) volunteered to participate in this study. An exercise-induced fatigue protocol to induce fatigue was performed in the plantar flexor of the dominant ankle. For the fatigue protocol, the participants were instructed to raise their heels as high as possible in the position with one leg stance of the dominant lower limb, and the heel was then downed after holding for 1 second. The muscle strength of the contra-lateral plantar flexor was measured using a digital muscle strength test device, and the static and dynamic postural control were tested by acquiring the center of gravity velocity while performing one leg standing. A paired t-test was used to identify the differences between the pre- and post, and the data were analyzed using SPSS 12.0 software. RESULTS: Comparison of the pre- and post-test data revealed a significant difference in the plantar flexor strength and dynamic postural control after exercise-induced muscle fatigue in the dominant side. On the other hand, there was no significant difference in the static postural control. CONCLUSION: These findings have practical implications, suggesting that unilateral muscle fatigue affects the ankle muscle strength and postural ability of the contralateral side.
Subject(s)
Female , Humans , Young Adult , Ankle , Fatigue , Gravitation , Hand , Heel , Leg , Lower Extremity , Muscle Fatigue , Muscle StrengthABSTRACT
O treinamento de força gera adaptações no sistema neuromuscular. Nesta perspectiva, o "cross-education" surge como um fenômeno caracterizado por adaptações neurais e pelo aumento da capacidade de geração de força voluntária do membro oposto ao não treinado, que ocorre como resultado do treinamento de força unilateral. Sendo assim, o presente estudo tem como objetivo fornecer informações sobre o fenômeno cross-education, apresentando suas evidências, mecanismos, implicações para a reabilitação e aplicações práticas. Neste trabalho, foi realizado um levantamento bibliográfico sobre o cross-education nas bases de dados disponíveis na Internet. As fontes de informações eletrônicas foram acessadas nas bases de dados do Pubmed, periódicos da CAPES e Lilacs. Para a busca de informações foram utilizadas as seguintes expressões: muscle strength, unilateral exercise, cross-education. A pesquisa inclui trabalhos publicados entre os anos de 1997 a 2015. Os estudos mostraram que o cross-education é caracterizado por adaptações neurais assim como por alterações no SNC que possibilitam a transferência de força para o membro contralateral, imobilizado ou não imobilizado. Conforme os resultados, este fenômeno parece ser importante para a reabilitação, à medida que ao realizarmos o treinamento de um membro isolado, podemos obter repercussões no membro contralateral. No entanto, mais pesquisas são necessárias para investigar as evidências e os mecanismos relacionados ao cross-education, assim como seus efeitos crônicos. Consequentemente, estudos complementares sobre esse fenômeno serão importantes para analisar a reabilitação de indivíduos com alguma lesão dos membros e as suas diversas aplicações práticas.
Strength Training generates adaptations in neuromuscular system. Within this perspective "cross-education" emerges as a phenomenon featured by neural adaptations and by the increase of the capacity to generate volunteer strength of the opposite member to the non-trained one that occurs as a result of the unilateral strength training. Hence, the present study has as its objective provide information about the cross-education phenomenon, presenting its evidences, mechanisms, implications for practical rehabilitation and applications. In this paper a bibliographic survey about the cross-education has been made with data available on the internet. The electronic sources of information were accessed in the data base from Pubmed, from CAPES journals and Lilacs. For the search of information the following expressions were used: muscle strength, unilateral exercise, cross-education. The research includes papers published between the years of 1997 to 2015. Studies showed that cross-education is featured by neural adaptations so as by alterations at the SNC that enable the transference of strength to the contralateral limb, fixed or not fixed. According to its results, this phenomenon seems to be essential to rehabilitation, because as we train the static member we can obtain repercussions in the subordinate member. However, more research is necessary to investigate evidences and the mechanisms related to cross-education, as well as its chronic effects. As a result, complementary studies about this phenomenon will be important to analyze the rehabilitation of people with any member injuries and its many practical applications.
Subject(s)
Rehabilitation , Education , Muscle StrengthABSTRACT
Objective To investigate the extent of cross-education between the pronation and supination muscles of the right and left forearms after unilateral isometric training.Methods Twenty healthy young girls were randomized into a training group and a control group using a random number table.The training group underwent isometric training of their right forearms for six weeks,while the control group continued ordinary life without exercises.Pronation peak torque (PPT) and supination peak torque (SPT) were assessed before and after the training for both groups.Results The differences in PPT or SPT between the training group and the control group were not significant before the training program.When the training had been completed,however,the average PPT and SPT on right side of those trained of course had increased significantly compared to before training or to the control group.More significantly,the average PPT and SPT on the left side in the training group were also significantly better than before training or in the control group after training.Conclusion Unilateral isometric training of the forearm pronation and supination muscles for six weeks can significantly increase muscle strength bilaterally,indicating good cross-education.