Déficits no equilíbrio muscular em jovens atletas de ginástica feminina / Muscle deficits in young female gymnastics / Déficit muscular en jóvenes gimnastas de sexo femenino

Resumo Objetivo: Avaliar os desequilíbrios musculares em atletas de ginástica feminina e correlacionar com a idade. Metodologia: 24 ginastas femininas de 9 a 15 anos tiveram os desequilíbrios musculares do joelho avaliados por meio de dinamômetro isocinético. Resultados: A razão I/Q demonstrou que 87,5% das ginastas apresentaram risco de lesão nos membros dominante e 91% no não dominante. Os desequilíbrios bilaterais revelaram 25% das ginastas com desequilíbrio bilateral superior a 10% no quadríceps e 30% nos isquiotibiais. Não foram encontradas correlações entre os desequilíbrios musculares e a idade das ginastas. Conclusão: Jovens ginastas apresentam desequilíbrios musculares que podem estar relacionados a possíveis lesões nos membros inferiores.

Abstract The purpose of this study was to evaluate muscle imbalances in female gymnasts correlate with age. 24 female gymnasts 9 to 15 years old had their muscle imbalances of the knee evaluated by Isokinetic Dynamometer. The H/Q ratio showed that 87.5% and 91% of the gymnasts were at risk of injury in the dominant and non-dominant limbs respectively. Bilateral imbalances revealed that 25% of the gymnasts had bilateral imbalance exceeding 10% in the quadriceps and 30% in hamstrings. No correlations were found between muscle imbalances and age of the gymnasts. Young gymnasts have muscle imbalances that might be related to possible lower limb injuries.

Resumen El propósito de este estudio fue evaluar los desequilibrios musculares en gimnastas femeninas y correlacionarlos con la edad. Metodología: se evaluaron los desequilibrios musculares de la rodilla de 24 gimnastas de 9 a 15 años mediante dinamómetro isocinético. La relación I/Q mostró que el 87,5 y el 91% de las gimnastas corrían el riesgo de sufrir lesiones en las extremidades dominantes y no dominantes, respectivamente. Los desequilibrios bilaterales revelaron que el 25% de las gimnastas presentaban desequilibrio bilateral superior al 10% en el cuádriceps y al 30% en los isquiotibiales. No se encontraron correlaciones entre los desequilibrios musculares y la edad de las gimnastas. Las gimnastas jóvenes presentaban desequilibrios musculares que podrían estar relacionados con posibles lesiones en los miembros inferiores.

Validity analysis of one-repetition maximum strength test for determining the hamstrings-to-quadriceps ratio

One of the approaches to evaluate injury prediction is the hamstrings-to-quadriceps peak torque conventional ratio (H:Q ratio). The gold standard for assessment of muscle strength in vivo is by isokinetic dynamometry; however, the one-repetition maximum strength test (1-RM) presents high correlation with isokinetic data. This study aimed to compare measures of H:Q ratio in young adults obtained by dynamometry and 1-RM testing. No significant differences were observed in the H:Q ratio when comparing 1-RM and dynamometry testing. However, there was a significant and strong correlation between the measurements obtained in the two tests. Despite this correlation, data from both tests are not equal as the H:Q ratio obtained from 1-RM test presents a systematic error. Nonetheless, the results can enhance the applicability of 1-RM test in clinical settings

O fortalecimento do complexo lombo pélvico core e sua importância na reabilitação e no esporte / The strengthening of the core and its importance in rehabilitation and sport

Introdução: O complexo lombo-pélvico, também conhecido pelos pesquisadores como core, tem como função manter o alinhamento postural e o equilíbrio postural dinâmico durante as atividades funcionais e esportivas. Desta forma, este estudo tem como objetivo analisar a influência do fortalecimento da musculatura do core na prevenção de lesões, na reabilitação e no processo de preparação física do atleta. Material e métodos: Foi realizada uma revisão de literatura não-sistemática nas bases de dados Lilacs, Medline, Scielo e Pubmed, desde o ano de 2000 até 2015, além de consultas ao acervo pessoal de livros e dissertações. A estratégia de busca correlacionava às seguintes palavras-chave: complexo lombo-pélvico, estabilização central, desequilíbrio muscular, treinamento do core, reabilitação lombar. Resultados: O conceito de estabilidade do core e de como esta característica pode ser treinada para melhorar funcionalidade dos movimentos e o desempenho esportivo tem sido muito utilizado, porém interpretado de maneira diferente entre os profissionais. Conclusão: O programa de fortalecimento deve ser planejado de acordo com o objetivo desejado, para a reabilitação, prevenção de lesões ou o aprimoramento do desempenho esportivo. (AU)

Introduction: The lumbar-pelvic complex, also known by researchers as core, has as function to maintain postural alignment and dynamic postural balance during functional activities and sports. Thus, this study aims to analyze the influence of the strengthening of core muscles in injury prevention, rehabilitation and physical athlete preparation process. Methods: A non-systematic literature review was conducted in Lilacs, Medline, Pubmed and Scielo databases, from 2000 until 2015, as well as in personal collection of books and dissertations. The search strategy correlated with the following key-words: lumbar-pelvic complex, central stabilization, muscle imbalance, core training, and low back rehabilitation. Results: The concept of core stability and how this feature can be trained to improve functionality of movement and sports performance has been widely used, however interpreted differently among professionals. Conclusion: The strengthening program should be planned according to the desired aim, for rehabilitation, injury prevention or improvement of sports performance. (AU)

Bilateral asymmetry of knee and ankle isokinetic torque in soccer players u20 category / Assimetria bilateral no torque isocinético do joelho e tornozelo em jogadores de futebol da categoria sub 20

Abstract Bilateral asymmetries and muscle imbalances are associated with increased risk for lower limb injuries and still seem to imply in athletes performance. This study aimed to analyze bilateral asymmetry of soccer players in age category below 20 years old (peak torque and conventional and functional reason in extensor/flexors of knee and inverter/ eversion of ankle) and to compare these variables between defending, midfield and attacker players. The study included 22 athletes in age category below 20, which underwent a five maximal isokinetic testing with repetitions at 180°/s for knee and 120°/s for ankle, both concentric and eccentric actions. T test for dependent data was used to compare values of torque between dominant and non-dominant limbs and one-way ANOVA was used to compare neuromuscular variables between players of different positions, both at p <0.05. No significant differences were observed in any neuromuscular variable (peak torque and functional and conventional ratio) between dominant and non-dominant sides (p> 0.05). It was found that defensive players had eccentric torque values of extensors knee higher than midfield players (p <0.05). Defensive players exhibit greater eccentric torque of knee extensor muscles compared to midfield players. It can be concluded that the analyzed soccer players did not present bilateral asymmetries in flexor/extensor knee muscles neither in inverter/eversion ankle muscles.

Resumo As assimetrias bilaterais e os desequilíbrios musculares estão associados com o risco aumentado para lesões nos membros inferiores e ainda parecem implicar o desempenho dos atletas. Assim, este estudo objetivou analisar a assimetria bilateral de jogadores de futebol da categoria sub 20 (pico de torque e razão convencional e funcional dos extensores/flexores do joelho e inversores/eversores do tornozelo), além de comparar tais variáveis entre jogadores defensores, meias e atacantes. Participaram deste estudo 22 atletas da categoria sub 20, que foram submetidos a um teste isocinético com cinco repetições máximas a 180º/s para o joelho e 120º/s para o tornozelo, ambos com ações concêntricas e excêntricas. Utilizou-se o teste t para dados dependentes para comparar os valores de torque entre os membros dominante e não-dominante e ANOVA one way para comparar as variáveis neuromusculares entre jogadores de diferentes posições, ambos a p < 0,05. Não foram observadas diferenças significativas em nenhuma variável neuromuscular (pico de torque e razão funcional e convencional) entre os lados dominante e não-dominante (p > 0,05). Foi verificado que os jogadores defensores apresentavam valores de torque excêntrico nos extensores do joelho, superiores aos meias (p < 0,05). Os jogadores que atuam na defesa apresentam maior torque excêntrico nos extensores do joelho, quando comparados aos jogadores de meio-campo. Pode-se concluir que os jogadores analisados não apresentaram assimetrias bilaterais nos músculos flexores/extensores do joelho, bem como nos inversores/eversores do tornozelo.

Isokinetic muscle assessment after treatment of pectoralis major muscle rupture using surgical or non-surgical procedures

INTRODUCTION: Rupture of the pectoralis major muscle appears to be increasing in athletes. However, the optimal treatment strategy has not yet been established. OBJECTIVES: To compare the isokinetic shoulder performance after surgical treatment to that after non-surgical treatment for pectoralis major muscle rupture. METHODS: We assessed 33 pectoralis major muscle ruptures (18 treated non-surgically and 15 treated surgically). Horizontal abduction and adduction as well as external and internal rotation at 60 and 120 degrees/s were tested in both upper limbs. Peak torque, total work, contralateral deficiency, and the peak torque agonist-to-antagonist ratio were measured. RESULTS: Contralateral muscular deficiency did not differ between the surgical and non-surgical treatment modalities. However, the surgical group presented twice the number of athletes with clinically acceptable contralateral deficiency (<20 percent) for internal rotators compared to the non-surgical group. The peak torque ratio between the external and internal rotator muscles revealed a similar deficit of the external rotation in both groups and on both sides (surgical, 61.60 percent and 57.80 percent and non-surgical, 62.06 percent and 54.06 percent, for the dominant and non-dominant sides, respectively). The peak torque ratio revealed that the horizontal adduction muscles on the injured side showed similar weakness in both groups (surgical, 86.27 percent; non-surgical, 98.61 percent). CONCLUSIONS: This study included the largest single series of athletes reported to date for this type of injury. A comparative analysis of muscular strength and balance showed no differences between the treatment modalities for pectoralis major muscle rupture. However, the number of significant clinical deficiencies was lower in the surgical group than in the non-surgical group, and both treatment modalities require greater attention to the rehabilitation process, especially for the recovery of muscle strength and balance.

Análise da relação entre dor lombar e desequilíbrio de força muscular em bailarinas / Analysis of the relationship between low back pain and muscle strength imbalance in ballet dancers

Objetivo: Investigar a relação entre dor lombar e desequilíbrio de força muscular na região lombopélvica em bailarinas clássicas. Métodos: O estudo foi do tipo exploratório transversal e desenvolvidonas academias de dança das cidades de Divinópolis e Oliveira, MG. Foram selecionadas 42 bailarinas,divididas em dois grupos (Grupos Dor e Sem Dor) de acordo com a presença ou não de queixas de dor na região lombar. Inicialmente, as bailarinas foram submetidas, por um único examinador, a quatro de força muscular na região lombopélvica: músculos glúteo máximo × isquiossurais e glúteo máximo × paravertebrais no movimento de extensão de quadril; glúteos máximo e médio × tensor da fáscia lata no movimento de abdução de quadril; abdominais e flexores de quadril no movimento de flexão de quadril. Em seguida, um segundo examinador aplicou os testes de força muscular para os músculos abdominais e paravertebrais. Para verificar a associação entre a queixa de dor lombar e a presença de desequilíbrios musculares foi utilizado o teste qui-quadrado. O nível de significância estabelecido foi de α = 0,05. Resultados: A maioria das bailarinas, independente do grupo do qual participavam, apresentou desequilíbrios de força muscular na região lombopélvica,porém apenas o desequilíbrio entre abdominais × flexores de quadril teve associação significativa coma dor lombar (p = 0,043). Conclusão: Desequilíbrios musculares lombopélvicos são frequentes em bailarinas clássicas. Entretanto, não é possível afirmar se tais desequilíbrios são adaptações específicas do balé clássico ou disfunções associadas a quadros álgicos resultantes de falhas no treinamento.

Objective: To investigate the relationship between low back pain and muscle strength imbalance in the lumbopelvic region of classical ballet dancers. Methods: This cross-sectional exploratory study was developed in the ballet academies of Divinópolis and Oliveira, Minas Gerais State. Forty-two ballet dancers were selected and then divided into two groups (Pain and Painless Groups), according to the presence or absence of pain complaints in the low back. Firstly, the ballet dancers were submitted, by one examiner, to four tests of muscle strength imbalance in the lumbopelvic region: gluteus maximus × hamstrings muscles and gluteus maximus × paraspinal muscles in the hip extension movement; gluteus maximus and medius × tensor fascia latae muscles in the hip abduction movement; abdominal × hip flexors in the hip flexion movement. After that, a second examiner applied the muscular strength tests for the abdominal and paraspinal muscles. Chi-square tests were used to verify the association between low back pain and muscle imbalances. The level of significance was set at α = 0.05. Results: Most of the ballet dancers, independently of the group, showed muscle strength imbalances in the lumbopelvic region. The abdominal × hip flexors test demonstrated a significant association with low back pain (p = 0.043). Conclusion: Muscle imbalances in the lumbopelvic region are common in classical ballet dancers. However, it is not possible to assure that these muscle imbalances are specific adaptations to the classical ballet or dysfunctions associated to algic symptoms resulted from training faults.