The Influence of Angular Velocity and Fatigue State on the Initial Joint Angle of Each Isokinetic Phase of Knee Extension Tests

Abstract

Movement artifacts related to exercise on an isokinetic device can lead to misunderstandings regarding data interpretation. The transitions among the movement phases of a dynamometer lever arm usually have unique ocurrences that may confound test data and, thereby, the test conclusions. It is not unusual to have erroneous readings of peak torque measurements that are consequences of velocity overshoot artifact. As the correct analysis of isokinetic tests must consider only the data obtained under constant velocity conditions, this study investigated if the initial joint position of each isokinetic phase varies with the changing of angular velocity and fatigue state. Special attention was given to the range where velocity is considered constant (isokinetic). Results showed that no influence is caused by fatigue. Angular velocity did not produce significant differences on isokinetic range what suggests that its initial joint angle can be used as a reference point for torque estimates.