This paper presents a new technique for estimating the center of mass of articulated rigid body systems. This estimation technique uses the statically equivalent serial chain, a serial chain representation of any multi-link branched chain whose end-effector locates directly the center of mass. This technique works based on a knowledge of only the kinematic architecture of the system and does not require the total mass, or any of the individual body's mass or length properties. This constitutes an advance in center of mass estimation, providing an alternate to techniques requiring a force plate. A comparison of these estimation techniques is presented. The modeling and estimation technique is then implemented on a human subject.