EMG Conduction Model of Individual Muscle Activities in Forearm

Muscle activities are generally measured with surface electromyography (sEMG). However, the individual muscle activities are quite difficult to obtain because of superimposition of the sEMG signals called "crosstalk problems". The crosstalk is highly complicated in a forearm having a number of muscles in the small volume. A method to resolve the crosstalk to become able to measure individual activities of muscles would be useful. This paper proposes a method for reverse-estimating the individual muscle activities in the forearm from the sEMG distribution using an EMG conduction model. The individual muscle activities were calculated by conforming the measured sEMG distribution to the simulated results of the mathematical model. To verify the reverse-estimation results, physical work experiments were carried out for three subjects applying a flexion load with weights (0.5kg, 0.75kg, 1kg) to the proximal interphalangeal joint of the middle finger. The muscle activation values were calculated from the measured sEMG. The results show there are significant differences (p<0.05) in the activation of flexor digitorum superficialis in all combinations of the loads in all subjects. Kinesiologically, the simulation method proposed here was able to estimate individual activation values.