Eccentric and concentric torque and power of the knee extensors of females.

The purpose of this study was to compare differences in eccentric and concentric peak torque and power measurements of knee extensors at different velocities. The subjects included 21 females between the ages of 19 and 28, who had no history of knee pain or abnormality. Eccentric and concentric contractions of the knee extensors of the dominant leg of each subject were tested on an isokinetic dynameter at 60 degrees/s, 120 degrees/s and 180 degrees/s. Eccentric peak torque was greater than concentric at each of the three velocities tested, whereas eccentric power was significantly greater only at the two higher velocities. The lack of change in concentric peak torque between 120 degrees/s and 180 degrees/s contrasted with results of other studies, probably owing to methodological differences. Eccentric torque increased from 60 degrees/s to 120 degrees/s, but decreased again at the highest velocity. Both concentric and eccentric power increased with velocity.