Peak torque values of the knee extensor and flexor muscles of females.

Two hundred and forty-one females between the ages of 18 and 28 years were subjects for this study. Subjects were tested for knee extension and knee flexion on a Cybex(R) II isokinetic dynamometer at 60 degrees /sec using a modified seating arrangement which placed the back rest at 20 from the vertical. To familiarize subjects with the Cybex II, two practice trials of complete extension and flexion were allowed. The actual test included four consecutive trials of voluntary maximum isokinetic contractions of the knee extensors and flexors. The mean torque value of the knee extensors was 96.47 ft-lb and 51.77 ft-lb for the knee flexors. The corresponding ratio was 1.86: 1.00. The trials demonstrating the maximum peak torque values for the knee extensors and flexors were chosen to determine the time to peak torque. The mean time to peak torque for the knee extensors (2.76 sec) was only slightly longer (0.02 sec) than the mean time to peak torque for the knee flexors (2.78 sec). Based on the outcome of the investigation and the size of the sample, it is suggested that young and untrained women who have no history of health-related conditions of the knee demonstrate an approximate ratio of knee extensor strength to knee flexor strength of 2: 1 at 60 /sec. J Orthop Sports Phys Ther 1985;7(2):65-68.