This paper describes a new approach for modeling joints in an articulated 3D body model for tracking of the configuration of a human body. The used model consists of a set of rigid generalized cylinders. The joints between the cylinders are modeled as artificial point correspondences within the ICP (iterative closest point) tracking algorithm, which results in a set of forces and torques maintaining the model constraints. It is shown that different joint types with different degrees of freedom can be modeled with this approach. Experiments show the functionality and robustness of the presented model