One or more pull force vectors are applied to one or more force receiving locations of {HEAD ~ the model} to pull the model in an XY plane towards the silhouette of the human target in the observed depth image when {TAIL ~ portions} of the observed depth image are shifted away from the silhouette of the model 
One or more pull force vectors are applied to one or more force receiving locations of { HEAD ~ the model } to pull the model in an XY plane towards the silhouette of the human target in the observed depth image when { TAIL ~ portions } of the observed depth image are shifted away from the silhouette of the model
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH