For the following each limb, you need to track them. AE has built in Motion Tracking, Mocha(third party software bundled with AE) does an even better job of tracking(tad more complicated to use). You can also hand track. Some people will use the beam effect to link the points.
Another method is to use this name your price script called Connect Layers
Johnny Cuevas, Editor
"I have not failed 700 times. I have succeeded in proving that those 700 ways will not work. When I have eliminated the ways that will not work, I will find the way that will work."
---THOMAS EDISON on inventing the light bulb.