The relation of integrated EMG of the triceps brachii to force in rapid elbow extension.

The relationships between the integrated EMG (iEMG) of the first burst activity of the triceps brachii muscle and biomechanical variables such as acceleration, velocity and kinetic energy were examined for ballistic elbow extension in five healthy men. The duration of the first burst ceased within 100 msec in every subject. Although the regression analysis of each variable to iEMG was all significant, the correlation coefficient was the largest for mean or peak acceleration and the smallest for kinetic energy. The motor center would control the force output to initiate ballistic movement by changing the amount of the EMG activity keeping its duration constant.