Human Electro-Muscular Incapacitation (HEMI) weapons are developed with the intent to incapacitate a subject without being lethal. However, under some use cases, these weapons have been linked to serious injury and even death. Applied Research Associates, Inc. (ARA) has been developing a generalized computational model based on underlying physical and biological processes, which will use device characteristics and potential military exposure scenarios as inputs. The goal of this research is to develop a product that estimates the risks of rhabdomyolysis, cardiovascular, and respiratory effects under different use scenarios or with different device characteristics. The research and development work outlined in this report covers methods to model the electrical dosimetry, motor neuron excitation, and muscle excitation-contraction.