Absolute and normalized rate of torque development and their association to torque of knee extensors at five angles

The absolute and normalized rate of torque development (RTD) of knee extensors were measured to investigate the interactions between angle-torque and angle-RTD relationships. Eighteen men performed maximal isometric explosive contraction (MIC) of knee extensors at the angles K, K-15°, K-30°, K+15°, and K+30°, where K is the angle of the isokinetic concentric peak torque obtained at 30°/s (knee more flexed at K+30°). From the absolute and normalized MIC torque signals, the maximal value (MT), RTD100 and RTD200 were obtained. The angle significantly influenced MT, absolute and normalized RTD100 and RTD200 (p< 0.01). The absolute angle-RTD100, angle-RTD200, and angle-MT relationship curves presented similar patterns, differently of angle-normalized RTDs. MT was significantly correlated to the absolute but not to the normalized RTD100 and RTD200. It is suggested that absolute RTD is more related to muscle strength, whereas normalized RTD to other muscle skills besides strength.