Tracking 3D objects from 2D image data often leads to jittery tracking results. In general, unsmooth motion is a sign of tracking errors, which, in the worst case, can cause the tracker to loose the tracked object. A straightforward remedy is to demand temporal consistency and to smooth the result. This is often done in form of a post-processing. In this paper, we present an approach for online smoothing in the scope of 3D human motion tracking. To this end, we extend an energy functional by a term that penalizes deviations from smoothness. It is shown experimentally that such online smoothing on pose parameters and joint angles leads to improved results and can even succeed in cases, where tracking without temporal consistency assumptions fails completely.