Bobby Lee

An example from a movie would be the opening scene from Horrible Bosses, where the actor, Jason Bateman is performing tasks at a regular "speed" while the background is time lapsed/fast forwarded. In this case the camera is moving, probably on a crane. What I would like to do is just set up a static camera but achieve the same effect.

I'd like to do a type of time lapse where the focus is on a subject walking across the screen. The subject is waking at a normal pace, but the background is time lapsed. The hard part here, I would think is when the subject is walking. I know how to film it with a subject standing still, but I have no idea how I would do it while the subject is walking.