The study and measurement of the magnetic field from the skeletal muscle is called Magnetomyography (MMG). These magnetic fields are produced by the same ion currents which give rise to the electrical signals that are recorded with electromyography (EMG). Layers between the muscle and skin surface, known as volume conduction, play a critical role during the measurement. This paper presents the volume conduction effect on the electrical and magnetic signals with the finite-difference time-domain simulations using Sim4Life. Sim4Life simulations show that the recorded magnetic signals do not have the same trajectory as electrical signals. Hence, the changes in EMG signals caused by the volume conduction effect can result in signal misinterpretations.