  MagnetoMyoGraphy (MMG) is a method of studying muscle function via weak
magnetic fields generated from human active organs and tissues. The
correspondence between MMG and electromyography means directly derived from the
Maxwell-Amp\`ere law. Here, upon briefly describing the principles of voltage
distribution inside skeletal muscles due to the electrical stimulation, we
provide a protocol to determine the effects of the magnetic field generated
from a time-changing action potential propagating in a group of skeletal muscle
cells. The position-dependent and the magnetic field behaviour on account of
the different currents in muscle fibres are performed in temporal, spectral and
spatial domains. The procedure covers identification of the fibre
subpopulations inside the fascicles of a given nerve section, characterization
of soleus skeletal muscle currents, check of axial intracellular currents,
calculation of the generated magnetic field ultimately. We expect this protocol
to take approximately 2-3 hours to complete for the whole finite-element
analysis.
