Segmenting a human body point cloud into limbs
Suggestion: for each point $P$ in the point cloud, find which bone it is nearest to, and associate it with that bone.  In other words, find which point $Q$ on the skeleton is closest to $P$, and associate $P$ with $Q$.  Now associate $Q$ with a particular part of the skeleton (e.g., arm, leg, etc.); that will let you associate $P$ with a particular part of body (e.g., arm, leg, etc.).  Do this for each point in the point cloud.

Try that -- it's a very simple approach, and it might just work.