Eccentric and concentric torque-velocity characteristics of the quadriceps femoris in man

Abstract

The primary purpose of this investigation was to study the eccentric and concentric torque-velocity characteristics of the quadriceps femoris in man using a recently developed combined isometric, concentric and eccentric controlled velocity dynamometer (the SPARK System). A secondary purpose was to compare the method error associated with maximal voluntary concentric and eccentric torque output over a range of testing velocities. 21 males (21–32 years) performed on two separate days maximal voluntary isometric, concentric and eccentric contractions of the quadriceps femoris at 4 isokinetic lever arm velocities of 0° · s⁻¹ (isometric), 30° · s⁻¹ 120° · s⁻¹ and 270° · s⁻¹. Eccentric peak torque and angle-specific torques (measured every 10° from 30° to 70°) did not significantly change from 0° · s⁻¹ to 270° · s⁻¹ (p>0.05) (with the exception of angle-specific 40° torque, which significantly increased;pp0.05), and increased slightly with increasing eccentric velocity (p>0.05). A tension restricting neural mechanism, if active during maximal eccentric contractions, could possibly account for the large difference seen between the present eccentric torque-velocity results and the classic results obtained from isolated animal muscle.