Low Pre-Season Hamstring-to-Quadriceps Strength Ratio Identified in Players Who Further Sustained In-Season Hamstring Strain Injuries: A Retrospective Study from a Brazilian Serie A Team.

A common pre-season injury prevention assessment conducted by professional football clubs is the hamstring-to-quadriceps (H:Q) strength ratio calculated by peak torque (PT). However, it is debatable whether players that present low pre-season H:Q ratios are more susceptible to further sustaining in-season hamstring strain injuries (HSI). Based upon retrospective data from a Brazilian Serie A football squad, a particular season came to our attention as ten out of seventeen (~59%) professional male football players sustained HSI. Therefore, we examined the pre-season H:Q ratios of these players. H:Q conventional (CR) and functional (FR) ratios, and the respective knee extensor/flexor PT from the limbs of players further sustaining in-season HSI (injured players, IP) were compared to the proportional number of dominant/non-dominant limbs from uninjured players (UP) in the squad. FR and CR were ~18-22% lower (p < 0.01), whereas quadriceps concentric PT was ~25% greater for IP than UP (p = 0.002). Low scores of FR and CR were correlated (p < 0.01) with high levels of quadriceps concentric PT (r = -0.66 to -0.77). In conclusion, players who sustained in-season HSI had lower pre-season FR and CR compared to UP, which appears to be associated with higher levels of quadriceps concentric torque than hamstring concentric or eccentric torque.

How are hamstring strain injuries managed in elite men's football clubs? A survey with 62 Brazilian physical therapists.

OBJECTIVE: To describe perceptions and practices of physical therapists from elite men's football clubs on the management of athletes with hamstring strain injury (HSI). DESIGN: Cross-sectional study. SETTING: Online survey. PARTICIPANTS: Physical therapists from clubs engaged in the two main divisions of Brazilian men's football. MAIN OUTCOME MEASURES: Practices for assessment and rehabilitation of athletes with HSI. RESULTS: This survey had 62 physical therapists from 35 of the 40 eligible clubs (87.5% representativeness). Despite heterogeneity on assessment practices, all respondents use imaging exams, adopt injury classification scales, and evaluate aspects related to pain, range of motion, muscle strength, and functional status of athletes with HSI. Rehabilitation programs are usually divided into 3 to 4 phases. All respondents usually apply electrophysical agents and stretching in HSI rehabilitation programs, 98.4% apply strengthening exercises (93.5% include eccentrics), 96.8% manual therapy, 95.2% exercises that mimic the functional demands of football, and 93.5% lumbopelvic stabilization exercises. Muscle strength was the most reported return to play criterion (71% of respondents). CONCLUSION: The present study allowed the sports physical therapy community to become aware of the approaches usually adopted for management of athletes with HSI who play in the highest level of Brazilian men's football.

Avaliação isocinética dos músculos extensores e flexores de joelho em jogadores de futebol profissional / Isokinetic evaluation of knee extensor and flexor muscles

INTRODUÇÃO E OBJETIVOS: Estudos que relacionam parâmetros de desempenho muscular em diferentes esportes, e, especialmente no futebol, têm sido frequentemente reportados na literatura. Entretanto, as variações metodológicas entre os diversos estudos, o tipo de dinamômetro usado em cada pesquisa e o posicionamento dos sujeitos durante as avaliações resultam na divergência dos dados coletados. Portanto, o objetivo deste estudo foi realizar uma coleta de dados que forneçam valores sobre o perfil muscular e estabelecer parâmetros normativos relativos ao desempenho muscular de jogadores profissionais de futebol, fundamentando a pesquisa científica e estudos futuros. MÉTODOS: A amostra consistiu de 39 atletas pertencentes a um clube de futebol de elite da capital gaúcha. Para avaliação do desempenho muscular foi utilizado um dinamômetro isocinético e os testes consistiram de contrações concêntricas máximas, sendo testados os músculos extensores e flexores do joelho nas velocidades 60º/s e 240º/s. Realizou-se a análise das médias através do teste t (amostras independentes) para investigar diferenças bilaterais nos parâmetros avaliados. Para todos os procedimentos estatísticos, o intervalo de confiança foi de 95 por cento (p < 0,05). RESULTADOS: Os resultados deste estudo caracterizaram o perfil muscular de jogadores profissionais do futebol relativo à capacidade de produção de torque, trabalho e potência máxima, normalizados pelo peso corporal. Além disso, foram observadas diferenças significativas entre pernas em algumas variáveis. CONCLUSÃO: Os dados normativos estabelecidos podem ser utilizados como valores de referência na prevenção, treinamento e reabilitação dos atletas, além de servirem de referência para futuros estudos que tenham como objetivo relacionar os parâmetros de desempenho muscular à incidência de lesões no futebol.

INTRODUCTION AND OBJECTIVE: Studies that relate parameters of muscular performance in different sports, and especially in soccer, have been frequently reported in the literature. However, the methodological variations among studies, the type of dynamometer used in each search and placement of each subject during the evaluations results in the divergence of the data collected. Therefore, the objective of this study was to perform a data collection to provide figures on the muscular profile and establish normative parameters for the professional soccer players' muscular performance, supporting scientific research and future studies. METHODS: The sample consisted of 39 athletes from a professional soccer club in Porto Alegre. In order to evaluate muscular performance, an isokinetic dynamometer was used and the tests consisted of maximal concentric contractions, being knee flexors and extensors muscles tested at 60º/s and 240º/s velocities. Analysis of means by t test (independent samples) was used to investigate significant differences between legs considering the parameters evaluated in this study. For all statistical procedures the confidence interval was 95 percent (p <0.05). RESULTS: The results of this study characterized the muscular profile of professional soccer players on the capacity of torque, work and maximum power, normalized by body weight. Moreover, significant differences were observed between legs considering some of the study's variables. CONCLUSION: The normative data set can be used as reference values for prevention, training and rehabilitation of athletes, and serve as reference for future studies with the aim to relate parameters of muscular performance and incidence of injuries in soccer.

Lesão do músculo obturador externo em atletas de futebol profissional / Injury of the external obturator muscle in professional soccer athletes

Diversos estudos têm analisado os diferentes tipos de lesões que acometem o jogador de futebol. Nota-se, no entanto, que nenhum cita a lesão do músculo obturador externo. Na medida em que este é um músculo pequeno e monoarticular, sua incidência provavelmente é baixa e pouco documentada na literatura. Sendo assim, o objetivo deste estudo é apresentar quatro casos de estiramentos do obturador externo em uma equipe profissional de futebol no ano de 2006. Os dados foram coletados a partir de um programa de armazenamento denominado Sistema de Preparação Desportiva que fornece dados referentes ao nome, diagnóstico, mecanismo de trauma, história clínica, tempo de afastamento e evolução. Todos os atletas que apresentaram imagem de ressonância nuclear magnética compatível com ruptura do obturador externo foram inclusos no estudo. Quatro lesões por estiramento do músculo obturador externo foram encontradas, de um total de 28 lesões por estiramento muscular durante o ano de 2006. Todos os atletas apresentavam dor difusa na região do quadril durante os movimentos de rotação lateral e medial do quadril. O mecanismo de trauma predominante foi o movimento de rotação lateral do tronco sobre o fêmur em cadeia cinética fechada. Concluímos que a lesão do obturador externo pode ser confundida com uma lesão dos músculos adutores do quadril, devido à localização da dor relatada pelo indivíduo. A avaliação clínica deve basear-se no relato do atleta e na realização dos testes funcionais, principalmente para os músculos rotadores do quadril. O exame de ressonância nuclear magnética foi fundamental para localizar, classificar e avaliar a extensão da lesão neste estudo.

Several studies have investigated different injuries that occur among soccer players. However, it has been noticed that none has mentioned injury to the external obturator muscle. As a small and monoarticulated muscle, its incidence is probably low and barely documented in the literature. Therefore, the aim of this study is to present four external obturator muscle strain cases in a professional soccer team in 2008. The data was collected from a database using the software Sistema de Preparação Desportiva which provides data such as name, diagnosis, trauma mechanism, clinical history, time away from training and progress. All athletes who undertook Magnetic Resonance Imaging (MRI) of the external obturator muscle and presented rupture of the external obturator muscle were included in the study. Four external obturator muscle strain injuries were identified from a total of twenty-eight muscle strains during the year of 2006. All athletes presented diffuse pain on the hip for medial and lateral rotation of the joint. The predominant injury mechanism was lateral rotation of the trunk over the femur on closed kinetic chain. It was concluded that external obturator muscle strain injuries can be mistaken for those related to the hip adductor muscles due to the reported pain area. Clinical examination should be based on the athletes' report and functional tests, mainly for the hip rotator muscles. The MRI scan was essential to the location, classification and evaluation of the injury size.