Abstract

Motor reaction time (MT) of the triceps brachii muscle, the interval from the initiation of EMG activities to the overt motor response, was examined for ballistic elbow extension on a horizontal plane testing the simple reaction and the choice reaction paradigm with different elbow angle response amplitudes (15 degrees and 60 degrees). MTs of the simple reaction task were shorter than those of the choice reaction task at either elbow extension amplitude. The rectified and integrated EMG activities (i. EMGs) exhibited in MTs were larger in the simple task than those in the choice reaction task. These results suggest that MT is influenced by the central processing of movement organization since the rate of rapid development of tension depends upon the quality of the motor command, i.e. changes in recruitment orders and firing rates of motor units. Verf.-Referat