To perform comparable simulations of human movements with robotic devices, it may be required to include the dynamics of the robotic actuators, instead of using simplistic, ideal force/torque models. Therefore, in this project, we develop a class of DC motor, that is a popular type actuator used in developing assistive robotic devices (e.g., prostheses, exoskeleton). The motor can be use to simulate powered robotic devices working within musculoskeletal systems.