RESUMEN
ABSTRACT We aimed to assess upper and lower limbs explosive strength, and its correlation with biceps brachii (BB) and vastus lateralis (VL) architecture. Absolute and maximum torque normalized rate of torque development (RTD) were measured from isometric elbow flexion (EF) and knee extension (KE). BB and VL architectures were assessed by ultrasound. Absolute RTD of KE was higher (129-272%), although normalized RTD was higher in EF (80-21%). The absolute RTD was correlated to muscle thickness only in the BB (r=.39-46). No relationship was found between muscle architecture and normalized RTD. In conclusion, the higher RTD from KE seems to be due to their greater strength. Only the muscle architecture could not explain the differences found in the RTD.
RESUMO Nosso objetivo foi avaliar a força explosiva de membros superiores e inferiores e a sua correlação com a arquitetura do bíceps braquial (BB) e vasto lateral (VL). A taxa de desenvolvimento de torque (TDT) absoluta e normalizada pela força máxima foi medida na flexão de cotovelo (FC) e extensão de joelho (EJ). A arquitetura do BB e do VL foi avaliada por ultrassonografia. A TDT absoluta de EJ foi maior (129-272%), mas a TDT normalizada foi maior na FC (80-21%). A TDT absoluta foi correlacionada com a espessura do BB (r=.39-46). A TDT normalizada não foi correlacionada à arquitetura muscular. Concluindo, a TDT superior da EJ parece causada pela maior força máxima. Apenas a arquitetura muscular não parece explicar a diferença na TDT.
RESUMEN Nuestro objetivo era evaluar la fuerza explosiva de los miembros superiores y inferiores y su correlación con la arquitectura del bíceps braquial (BB) y vasto lateral (VL). Se medio la tasa de desarrollo de torque (TDT) absoluta y normalizada por la fuerza máxima in la flexión de codo (FC) e extensión de rodilla (ER). La arquitectura del BB y VL fue evaluada por ultrasonido. La TDT absoluta de ER fue mayor (129-272%), pero la TDT normalizada fue mayor en la FC (80-21%). La TDT absoluta se correlacionó con el grosor del BB (r=.39-46). La TDT normalizada no se correlacionó con la arquitectura. En conclusión, la TDT superior del ER parece estar causado por la mayor fuerza máxima. La arquitectura muscular sola no parece explicar la diferencia en la TDT.
RESUMEN
PURPOSE: The purpose of this study was to examine the relationships between hamstring muscle thickness and knee flexion peak torque, and rate of torque development (RTD) calculated during 0–50 ms (RTD50) and 0–200 ms (RTD200).METHODS: Thirty-six active individuals' dominant side hamstring thickness were measured using portable ultrasound device. Participants performed maximal isometric voluntary contraction (MVIC) of knee flexion. Peak torque was identified as the maximum torque during MVIC testing. RTD was calculated initial 50 ms and 200 ms after the onset of joint torque. Pearson's correlation (r) coefficients were utilized to assess relationships between muscle thickness and knee flexion peak torque, RTD50 and RTD200. The significant level of hypothesis verification is set-up as α=0.05.RESULTS: Greater peak torque and RTD200 was associated with greater muscle thickness of semitendinosus and semimembranosus (p<0.05). Greater RTD50 was associated with greater muscle thickness of semitendinosus only. Biceps femoris thickness was not associated with knee flexion peak torque, RTD50, and RTD200.CONCLUSION: These results suggest that the training specific hamstring muscle (medial hamstrings) for improving muscle thickness would be effective for increasing knee flexion peak torque and RTD.