When measuring the surface EMG with bipolar lead, we must paste electrodes alonga muscle fiber direction. However, the pinnate muscle is known as that the pinnate angle will change by its contraction strength. Also, there is a research that we must consider about the 3-dimential positional relationship between the muscle bundle and the aponeurosis, when we measure the pinnate angle. Therefore, we think the muscle fiber direction of the pinnate muscle will change by its contraction strength. The aim of this study is development of new EMG measurement method responding to muscle movement. Our new EMG measurement method can calculate the EMG signal among to muscle fiber direction if muscle fiber direction changes during movement. In this study, we have confirmed the usefulness of our estimation method using simulated EMG generated by an EMG model. In addition, we measured the surface EMG of the vastus lateralis muscle and estimated the muscle fiber direction by our estimation method.
