In order to advance current human figure motion models, a more realistic model of the body must include a flexible torso and spine. The spinal column is a series of interdependent joints with three degrees of rotational freedom. A study of anatomical architecture supports the model's principal ideas, and indicates the parameters for spinal movement. By defining a database of spine attributes (obtained from medical data), and a small set of input parameters, inverse kinematic control of the spine may be achieved.