A full set of governing dynamical equations for Hanavan's human body model are developed. The model consists of ellipsoids, elliptical cylinders, and frustrums of elliptical cones. It contains 34 degrees of freedom. The model is considered to be in an arbitrary force field and the limb motions may be either specified or left free. The governing equations then determine the internal limb moments (muscle forces), the limb displacements, and the displacement of the model itself in an inertial reference frame. An example motion representing the model response to an impulsive force loading is also presented.