Affiliations: [a] University Hospital Rotterdam and University of Nijmegen
Note: [*] Department of Rehabilitation Medicine, University Hospital Rotterdam, Rotterdam, The Netherlands.
Note: [**] Address reprint requests to Dr. H.J. Starn, P.O. Box 49, 4564 ZG St. Jansteen, The Netherlands.
Note: [***] Department of Physiology, University of Nijmegen, Nijmegen, The Netherlands.
Abstract: Isokinetic torque measurements of the knee extensors have become increasingly popular, and in many instances are replacing isometric tests. The aim of this study was to determine whether isometric and isokinetic tests measure the same aspects of muscular output. The torque of the knee extensors of 34 healthy subjects was measured during three sessions at weekly intervals. Testing was performed using the Quadriceps Dynamometer (QD) for both isometric and isokinetic assessments. A significant positive correlation of 0.70 and 0.56 (p < 0.05) was found between the isometric torque and the isokinetic torque at angular velocities of 45 and 90 deg/sec, respectively. However, the common variance was too low to enable a prediction of the result of an isometric test from that of an isokinetic test and vice versa. It was concluded that both methods appear to measure a different area of muscular performance.
