Isokinetic and isometric torque relationships in the human body

Abstract

To study the relationship between isokinetic and isometric torque, maximum voluntary contractions were elicited from 352 male volunteers. Knee extensors, knee flexors, elbow extensors, and elbow flexors were tested isometrically and at isokinetic velocities of 30 degrees/sec, 90 degrees/sec, and 180 degrees/sec on a modified Cybex II apparatus. Isokinetic torque declined with increasing velocity of contraction. Intercorrelations of the isometric and isokinetic torque showed a moderate to high relationship between these 2 modes of testing. A higher relationship was noted between the isometric tests and the low-velocity isokinetic tests and between isokinetic velocities that were closest together. The correlations decreased as the isokinetic velocities became more widely separated. These data suggest that the torque elicited at low-velocity isokinetic contractions can be predictive of the torque elicited during isometric contractions. Faster velocities are less related to isometric strength.