Eccentric/Concentric torque deficits in the quadriceps muscle.

The purpose of the present investigation was to estimate the percentage of asymptomatic subjects who demonstrate an eccentric/concentric torque deficit in leg extension. One hundred and five subjects with a mean age of 23.51 were tested on the KIN-COM(R) dynamometer for maximum eccentric and concentric torque during leg extension using an 80 degrees range of motion at 50 degrees /sec velocity. The subjects were categorized as demonstrating a deficit if at any point in the range of motion the eccentric torque was 85% or less of the corresponding concentric torque. The results revealed that 35-54% of the subjects, depending upon sex or leg tested, demonstrated a deficit. These results suggest that many asymptomatic individuals possess an eccentric/concentric torque deficit. These findings question the validity of previous clinical research indicating that patients with anterior knee pain tend to possess an eccentric/concentric torque deficit and that correction of the deficit alleviates the pain. J Orthop Sports Phys Ther 1989;11(4):142-145.