Evaluation of muscular and functional inter-limb asymmetries during mid-season in young male soccer athletes.

BACKGROUND: To identify inter-limb asymmetries through the knee's muscular and lower limb functional performance in young male soccer athletes. METHODS: Twenty male soccer athletes aged 17 to 19 from an under-20 team performed isokinetic tests at 60°/s., 120°/s., 180°/s., and 240°/s. To assess the knee extensors and flexors muscles and functional tests (hop tests and Y-balance test). RESULTS: There were no significant differences between the dominant limb (DL) and non-dominant limb (NDL) in the knee extensors and flexors peak torque and hamstrings (H)/quadriceps(Q) conventional ratio. Moreover, no angular velocities observed inter-limb asymmetries seen by values higher than 10% in the isokinetic parameters. However, the H/Q conventional ratio shows borderline values in low angular velocities (60°/s. and 120°/s.). No significant changes were observed in the functional test performance between the DL and NDL. Furthermore, we did not see inter-limb asymmetries in both hop and Y-balance tests. On the contrary, the anterior distance reached was lower than found in the literature, and the composite score of the Y-balance test demonstrated values below the normative (>94%). CONCLUSION: The data demonstrated that soccer athletes have muscular and functional inter-limb symmetry. However, they tend to have knee muscle imbalance in low velocities and dynamic balance deficits that might increase the risk of musculoskeletal injury.

Avaliação muscular do joelho e funcional de membros inferiores de jovens atletas de voleibol do sexo feminino / Knee muscle evaluation and lower limbs' functional evaluation of young female volleyball athletes

Os desequilíbrios musculares e funcionais são analisados na tentativa de prevenir lesões e melhorar os desempenhos de atletas. Objetivo: Analisar o desempenho muscular de extensores e flexores de joelho e o desempenho funcional dos membros inferiores de atletas de voleibol. Métodos: Quinze atletas da categoria sub-16 de voleibol feminino da Universidade de Caxias do Sul foram avaliadas. Para análise do desempenho muscular, as variáveis pico de torque de extensores e flexores de joelho, e razão convencional de extensores/flexores, foi utilizado o dinamômetro isocinético. Já para a análise funcional dos membros inferiores, foram utilizados os testes Hop tests e Y balance test (YBT). Resultados: Na comparação entre membro dominante (MD) e não dominante (MND), não houve diferenças estatisticamente significativas na análise do pico de torque; já na razão flexores/extensores foi encontrada diferença significativa apenas à 240°/s. Entretanto, os valores médios da razão flexores/extensores encontrarem-se abaixo dos valores sugeridos pela literatura. As avaliações funcionais também não mostraram assimetrias entre os membros; no entanto, a pontuação composta do YBT apresentou-se abaixo dos valores normativos. Conclusão: A excelente simetria entre os membros pode ser justificada pela especificidade do esporte, pois os gestos esportivos do voleibol apresentam carácter simétrico durante as exigências físicas dos membros inferiores. No entanto, os baixos valores da razão flexores/extensores e da pontuação composta do YBT talvez não estejam diretamente relacionados a um risco maior de lesões já que os valores de referência utilizados são de atletas adultos.

Muscle and functional imbalances are analyzed in order to try prevent injuries and improve athletes' performance. Objective: To analyze knee's muscular performance of the knee extensors and flexors and lower limbs' functional performance of volleyball athletes. Methods: Fifteen female volleyball, athletes under the age of 16 from the University of Caxias do Sul, were analyzed. For analysis of muscle performance, the variables peak torque of knee extensors and flexors, and conventional flexor/extensor ratio, the isokinetic dynamometer was used. For the functional analysis of the lower limbs, the Hop tests and Y balance test (YBT) were used. Results: In the comparison between dominant (MD) and non-dominant (MND) limbs, there were no statistically significant differences in the analysis of peak torque; and in the flexor/extensor ratio analyzes, just one significant difference was found at 240°/s. However, the mean values of flexor/extensor ratio are below to the values suggested by the literature. Functional assessments also did not show asymmetries between members; however, the YBT composite score was below to the normative values. Conclusion: The excellent symmetry between the members can be justified by the sport's specificity, as the volleyball's gestures have a symmetrical character during the physical demands of the lower limbs. However, the low values of the flexor/extensor ratio and the YBT composite score may not be directly related to an increased risk of injuries since the reference values used are for adult athletes.

Isokinetic performance of ankle evertor and invertor muscles in adolescent female volleyball athletes

This study aimed to analyze the muscular performance of evertor and invertor ankle muscles of adolescent volleyball athletes. Methods: The information provided by database concerning the isokinetic evaluation of ankle muscles from 20 female volleyball players between the ages of 14-17 years old were analyzed. The isokinetic dynamometer was used in a concentric-concentric mode for the ankle evertor and invertor muscles at angular velocities of 60°/s, and 180°/s. Results: Seven athletes had suffered ankle sprains (6 affected the non-dominant limb and all were lateral ankle sprain) in the one year prior to the isokinetic evaluation. The isokinetic results demonstrated that the mean peak torque values for eversion of the non-dominant limb were significantly lower in comparison to the dominant limb at 60°/s. Moreover, although no difference was observed in the average values of the evertor/invertor ratio between the limbs, the ratios were below the values suggested by the literature. Conclusion: We believe that although the athletes reported no ankle injury and no pain in the previous assessment month, the isokinetic results of the non-dominant limb seemed to be directly related to previous ankle sprains injuries in inversion of this limb. The athletes had similar results to those of subjects clinically diagnosed with ankle joint instabilities despite their being active in sports at the moment of the assessment.(AU)

Isokinetic performance of knee extensors and flexor muscles in adolescent basketball players / Valoración isocinética de los extensores y flexores de la rodilla de jugadores de baloncesto adolescentes

Background: Basketball is one of the most popular and most practiced sports in the world, being played by 450 million people worldwide, and the knee is the most commonly injured region of the body involving adolescent male basketball players. Isokinetic dynamometry is generally considered the best protocol for dynamic strength measurements, which are important for preventing musculoskeletal injuries. Therefore, the objective of the present study was to analyze the muscular performance, the unilateral differences and relationships between the knee extensor and flexor muscles in adolescent male basketball players. Method: The information provided by database concerning the isokinetic evaluation of the knee extensor and flexor muscles from 21 male basketball players under the age of 15 were analyzed. The isokinetic ynamometer was used in a concentric-concentric mode for the knee extensor and flexor muscles at angular velocities of 60°/s, 120°/s, 180°/s, and 240°/s. Results: The results demonstrated no statistically significant differences between the dominant limb and the nondominant limb at the considered velocities, whether for mean peak torque values or for the flexor/extensor ratio. Another important result showed flexor/extensor ratios within normal values for knee joints. Conclusions: This study demonstrated that lower-limb dominance does not interfere in the muscular concentric isokinetic performance of the knee extensor and flexor muscles in adolescent male basketball players. We believe that the short time spent in basketball’s practice (mean time was 2.46 years) appears to be responsible for these results because the adolescent athletes evaluated in this study did not show differences between limbs, in contrast to studies involving older male basketball players

Introducción: El baloncesto es uno de los deportes más populares y más practicado en el mundo, siendo jugado por 450 millones de personas alrededor del mundo. La rodilla es la región del cuerpo más comúnmente lesionada en jugadores de baloncesto adolescentes. La dinamometría isocinética es generalmente considerado el mejor protocolo para medir la fuerza dinámica, que es importante en la prevención de lesiones musculoesqueléticas así como para el seguimiento del entrenamiento deportivo. Por lo tanto, el objetivo del presente estudio fue analizar el rendimiento muscular, las diferencias unilaterales y relaciones entre los músculos extensores y flexores de rodilla de jugadores de baloncesto adolescentes. Métodos: Se analizó la información de una base de datos en la evaluación isocinética de los músculos extensores y flexores de rodilla de 21 atletas de baloncesto masculino menores de 15 años. El dinamómetro isocinético fue utilizado en modo concéntrico-concéntrico para los músculos flexores y extensores de la rodilla en las velocidades angular de 60°/s, 120°/s, 180°/s y 240°/s. Resultados: Los resultados no mostraron ninguna diferencia estadísticamente significativa entre el miembro dominante y el miembro no dominante en las velocidades consideradas, tanto para los valores promedio de los pico torque, como para la relación flexores/extensores. Otro resultado importante es que la ratio flexores/extensores mostro valores normales para la articulación de la rodilla de nuestros deportistas. Conclusiones: El estudio ha demostrado que no hay diferencias entre la extremidad dominante y la no dominante en los valores obtenidos de fuerza isocinética concéntrica de los extensores y flexores de la rodilla de los jugadores de baloncesto adolescentes. Creemos que el poco tiempo empleado en la práctica de baloncesto (el tiempo medio fue de 2,46 años) parece ser responsable de estos resultados, dado que los atletas adolescentes evaluados en este estudio no mostraron diferencias entre los miembros, en contraste con estudios realizados en atletas mayores de baloncesto

Desempenho muscular isocinético dos ombros em atletas de rúgbi / Isokinetic muscle performance of shoulders in rugby athletes

OBJETIVOS: Verificar a existência de assimetrias dos músculos rotadores externos e internos entre os dois ombros, em atletas amadores de rúgbi do gênero masculino. MÉTODOS: Avaliações isocinéticas de atletas amadores do rúgbi masculino foram acessadas a partir do banco de dados do Instituto de Medicina do Esporte e Ciências Aplicadas ao Movimento Humano da Universidade de Caxias do Sul (IME-UCS). Foram incluídas as avaliações do ombro e excluídos os casos sem assinatura do Termo de Consentimento Livre e Esclarecido Institucional do IME-UCS prévia ao teste. O dinamômetro isocinético foi utilizado no modo concêntrico-concêntrico para os rotadores externos e internos dos músculos dos ombros nas velocidades angulares de 60°/s e 180°/s. Foram analisados os valores do pico de torque e da razão rotadores externos/internos dos ombros desses atletas. Para verificar a existência de assimetrias entre os dois lados do mesmo indivíduo, foi utilizado o teste T de Student e considerado o nível de significância de <0,05. RESULTADOS: Foram analisados os dados de 12 atletas homens. Na análise do pico de torque na velocidade angular de 60º/s, os valores médios da musculatura do membro dominante apresentaram-se significativamente superiores quando comparados ao não dominante: rotadores externos, 43,35±4,72 Nm no membro dominante versus 38,92±4,22 Nm no membro não dominante (p=0,0012); rotadores internos, 65,58±11,88 Nm no membro dominante versus 61,69±11,98 Nm no membro não dominante (p=0,0021). A 180º/s, os valores médios do membro não dominante apresentaram uma tendência a valores inferiores quando comparado ao membro dominante, mas sem significância estatística. Com relação aos valores médios da razão rotadores externos/internos, não foram encontradas diferenças estatisticamente significativa em nenhuma das velocidades angulares analisadas. CONCLUSÕES: Os atletas amadores de rúgbi apresentaram um desempenho muscular inferior do membro não dominante quando comparado ao membro dominante na análise do pico de torque. Essa diferença não havia sido encontrada nos demais estudos com atletas de rúgbi e acreditamos que este resultado se justifique pela falta de treinamentos mais frequentes e adequados desses atletas amador.

AIMS: To verify the existence of shoulder external and internal rotator muscle asymmetries in male amateur rugby athletes. METHODS: Isokinetic evaluations of male amateur rugby athletes were accessed from the database of the Institute for Sports Medicine and Applied Sciences in Human Movement of Universidade de Caxias do Sul (IME-UCS). Shoulders evaluated were included in the study, whereas those cases without a free and informed consent form signed prior to the test were excluded. The isokinetic dynamometer was used in a concentric-concentric mode for the shoulder external and internal rotators at angular velocities of 60°/s and 180°/s. The peak torque and the external to internal rotator ratio were analyzed. Student's t test and a significance level of <0.05 were used to verify the existence of asymmetries between the two sides of the same individual. RESULTS: Data from 12 male athletes were analyzed. Regarding the peak torque at the angular velocity of 60º/s, the mean muscle strength values of the dominant limb were significantly higher when compared to non-dominant limb: external rotators, 43.35±4.72 Nm for the dominant limb vs 38.92±4.22 Nm for the non-dominant limb (p=0.0012); internal rotators, 65.58±11.88 Nm for the dominant limb vs 61.69±11.98 Nm for the non-dominant limb (p=0.0021). At 180º/s, the mean values of the non-dominant limb tended to be lower when compared to the dominant limb, without statistical significance. Regarding the mean values of the external to internal rotator ratio, no significant differences were found at any of the angular velocities analyzed. CONCLUSIONS: Amateur rugby athletes showed lower muscle strength of the non-dominant limb when compared to the dominant limb in the peak torque measurements. This difference was not found in other studies with rugby athletes, and we believe that this result is justified by the lack of more frequent and adequate training of these amateur athletes.

Desempenho isocinético dos músculos do joelho de atletas de futsal durante a pré-temporada e o meio de temporada / Isokinetic performance of knee muscles in futsal athletes during pre-season and middle-season

O futsal é um esporte de múltiplos sprints, com constantes mudanças de direção, de velocidade e chutes. Além disso, as demandas impostas aos atletas durante uma temporada regular podem resultar em desequilíbrios musculares entre os membros e entre os músculos extensores e flexores do joelho, consequentemente, diminuindo a performance muscular e aumentando o risco de lesões nos atletas. Objetivo: Analisar as diferenças bilaterais; e o impacto de uma temporada regular na força dos músculos do joelho e as relações entre os músculos extensores e flexores. Método: As informações provenientes de um banco de dados sobre as avaliações de pré-temporada e meio de temporada de 15 atletas profissionais de futsal do sexo masculino foram analisadas. O dinamômetro isocinético foi utilizado no modo concêntrico-concêntrico para avaliar os músculos extensores e flexores do joelho nas velocidades angulares de 60º/s, 120º/s, 180º/s e 240º/s. Resultados: Não foram encontradas diferenças significativas nos valores de pico de torque (PT) dos extensores e flexores do joelho e na razão flexores/extensores na comparação entre os membros quando comparados na mesma avaliação e velocidade angular. Entretanto, os valores de PT da avaliação do meio de temporada mostraram-se, em sua maioria, significativamente maiores quando comparados às avaliações de pré-temporada. Conclusão: Estes achados indicam que o treinamento prescrito durante a temporada foram adequados, permitindo aos atletas o aumento da força muscular e evitando desequilíbrios musculares

Futsal is a multiple sprint that require constant changes in direction, speed, kicks and tackles, therefore the lower limbs, and specifically the knee muscles, play a crucial role during these futsal's actions, as the intense demands put on athletes during a futsal regular season can result in muscle imbalances between the lower limbs and between the extensor and flexor muscles of the knee, thereby, decreasing the muscular performance and increasing the risk of knee injuries. Objective: The aims of this study were to analyze the lower limbs differences after the demands of a regular season on the knee's muscles' strength, and the relations between the extensor and flexor muscles. Method: Data on 15 professional futsal players at pre-season and middle-season, provided by a database were analyzed. The database provided data from isokinetic dynamometer evaluations in a concentric-concentric mode for the knee extensor and flexor muscles at angular velocities of 60°/s, 120°/s, 180°/s and 240°/s. Results: No significant differences in peak torque (PT) of the extensor and flexor muscles, and of the flexor/extensor ratios were found between the limbs when compared at the same angular velocity and at the same time, either pre-season or middle-season. However, the PT values for the middle-season were almost always significantly higher when compared to the pre-season. Conclusion: These findings indicate that the training prescribed during the season was adequate and allowed to increase the muscle strength and also prevented imbalances