Identification of Surface and Deep Layer Muscle Activity by EMG Propagation Direction

It is generally difficult to identify surface and deep layer muscle activity. If we could identify surface and deep layer muscle activity, we can provide effective tools for rehabilitation. Therefore, in this study, we aim to identify surface and deep layer muscle activity using surface electrodes. We focused on the intersection of muscle fibers of surface layer muscle and deep layer muscle. On such a place, we found that we could measure independent muscle activity along each muscle fiber. In this result, we could confirm that we could measure surface layer muscle activity independently by comparing with the signal which is measured on extended line of surface muscle fiber and on outside of the deep layer muscle. Additionally, we identified propagation direction of EMG signal using electrode array. It was determined from delay time of EMG signal measured on each electrode. When we activated surface and deep layer muscle independently, each propagation direction of EMG signal corresponded to each muscle fiber direction. Thus, we indicated that identification of surface and deep layer muscle activity is possible.