Hip external rotation isometric torque for soccer, basketball, and volleyball athletes: normative data and asymmetry index.

BACKGROUND: Deficits in strength of the hip external rotators (ER) affect trunk, hip, and knee movement patterns, potentially contributing to injury in athletes. OBJECTIVES: To provide normative data on isometric torque for hip ER in athletes of three distinct sports and to determine if isometric torque for the hip ER and torque asymmetry between legs differ among sports and between sexes. METHODS: Basketball, soccer, and volleyball athletes (n=451) were evaluated. Hip ER torque was quantified bilaterally with athletes in prone and 90° of knee flexion using a hand-held dynamometer. RESULTS: Data are expressed as mean and 95% confidence interval. Hip ER torque values in Nm/kg for the dominant and non-dominant limbs were, respectively, 0.46 (0.44, 0.48) and 0.42 (0.40, 0.44) for male soccer athletes; 0.35 (0.32, 0.37) and 0.27 (0.25, 0.29) for male basketball athletes; and 0.37 (0.34, 0.39) and 0.35 (0.32, 0.37) for male volleyball athletes. Hip ER torque in Nm/kg for the female volleyball athletes was 0.29 (0.26, 0.33) for the dominant and 0.29 (0.25, 0.32) for the non-dominant limb. The Limb Symmetry Index for male soccer, basketball, and volleyball players was, respectively, 94% (91, 97), 81% (75, 87), and 95% (91, 99). For female volleyball players the Limb Asymmetry Index was 102% (95, 108). Male volleyball athletes showed higher torque values than female volleyball athletes. CONCLUSIONS: This study reported normative values for hip ER isometric torque of youth athletes. Clinicians can use the reported data as reference to identify torque deficits in athletes of the three reported sports.

Achilles tendinosis: a morphometrical study in a rat model.

This study addresses the morphopathogenesis of Achilles tendinosis, using a rat model and presenting quantitative analysis of time-dependent histological changes. Thirty Wistar rats were used, randomly split in experimental and control groups. Animals of the experimental group were submitted to a treadmill running scheme. Five animals of each group were euthanized at four, eight and sixteen weeks. Achilles tendons were collected and processed routinely for histopath sections. Slides were stained by Hematoxylin-Eosin, Picrosirius Red, Alcian Blue, AgNOR, TUNEL and evaluated morphometrically. Cellular density decreased slightly along the time and was higher in the experimental group than in controls at fourth, eighth and sixteenth weeks. Fiber microtearing, percentual of reticular fibers and glycosaminoglycans content increased along the time and were higher in experimental group than in controls at all-time intervals. AgNOR labeling here interpreted as a marker of transcription activity was higher in the experimental groups than in controls at all-time intervals. Apoptotic cells were more frequent and diffusely distributed in tendinosis samples than in control groups. These results suggest that as mechanical overload is becoming chronic, cellular turnover and matrix deposition increases leading to tendinosis. The combination of staining techniques and morphometry used here to describe the evolution of lesions occurring in a rat model system has proved to be suited for the study of induced Achilles tendinosis.

Modelos experimentais de indução à tendinose por esforço repetitivo: revisão de literatura / Repetitive efforts induction experimental models of tendinosis: literature review

Objetivo: Revisar os modelos experimentais que buscaram induzir a tendinose em animais através de esforços repetitivos (overuse). Materiais e métodos: Foi realizada uma busca exaustiva e sistematizada no Pubmed/Medline, Cochrane/Bireme e PEDro limitada ao período de 01/01/1950 à 15/03/2007, no idioma inglês, em experimento animal e utilizando associações das palavras-chaves: tendinopaty, animal, tendon e overuse injury. Resultados: Nove artigos foram encontrados, sendo que quatro utilizaram modelos de indução através de contração ativa. Discussão: Os modelos que utilizaram contração induzida por eletro-estimulação apresentaram pouca similaridade à evolução da tendinose em humanos, uma vez que os animais estavam sob anestesia e todo o metabolismo se encontrava alterado. Por outro lado, os modelos que utilizaram contração ativa se assemelhavam, com maior fidedignidade, ao que realmente acontece no desenvolvimento clínico da tendinose, principalmente naqueles em que o tendão tem participação ativa durante a atividade imposta. Conclusão: Muito ainda falta para termos modelos experimentais padronizados e sistematizados para os diversos tendões. Futuros modelos devem levar em consideração à especificidade de cada tendão e procurar induzir a lesão da maneira similar ao que acontece em humanos.