Intrasession reliability of angle specific knee extension torque measurements with gravity corrections

The purpose of this study was to determine the intrasession reliability of gravity corrected angle specific knee extension torque measurements (GCASKETMs) from a Cybex(R) II isokinetic dynamometer. Forty subjects (20 men, 20 women) performed three warm-up, then four maximal knee extension efforts at 60 degrees /sec on a Cybex II isokinetic dynamometer. The torques at 30 and 45 degrees of flexion were corrected for the effects of gravity. Analysis of variance demonstrated no difference in the four GCASKETMs at each knee angle. The intraclass correlation coefficients for the GCASKETMs were 0.958 at 30 degrees and 0.971 at 45 degrees . The results indicate that the reliability of isokinetic knee extension torque measurements is not compromised by the use of undamped angle specific measurements that are corrected for the effects of gravity. Such measures should be considered for clinical application because they more accurately reflect true torque production. J Orthop Sports Phys Ther 1989;11(4):155-157.