EMG Reaction in Muscles about the Knee to passive Velocity, Acceleration and Jerk Manipulations

Twenty subjects, 10 adults and ten children were tested in this study. Each test consisted of applying an ensemble of velocities to the lower limb using a torque motor in such a way that the entire range of motion of the knee was traversed. Eight velocities between 60 deg/sec and 280 deg/sec were reached at 2-3 different acceleration rates and 1-2 different rates of jerk. EMG from three muscles, vastus, rectus, and hamstring were recorded during each move. Regression and correlation coefficients between EMG and kinematic parameters indicated different reactions in both muscle groups and age groups to each of the three parameters