How to track the center of mass of a human in a video

[RubinLicht]

So a few months or years ago I learned that most of the energy from swinging comes from raising the center of mass at the lowest point of a swing.

I also recently found a method of swinging that maximizes this energy gain. You squat on the swing, and stand up every time it gets to the lowest point of a swing. I can swing to almost horizontal with just five passes like this.

What i want to know is whether or not there are programs/methods for tracking the center of mass of a human. Perhaps through input of the majors joints in the body (ankle, hip, shoulders, top of head, elbows, hands, knees), or something. If not, what is the least amount of input that can generate a fairly good estimate of where the center of mass is?

Assuming average human proportions, ignoring deviations like obesity, or bodybuilder type bodies where the upper body is disproportionately large. (imagining a body builder play on a swing is pretty amusing)

Any ideas are welcome, even not very doable ones.

Clarification: input can be either 3d(actual location) or 2d (video)

 

[CWatters]

Google found a paper which I've not read but the title would suggest it's very relevant..

http://ieeexplore.ieee.org/document/5752084/?reload=true

"Real time estimation and tracking of human body Center of Mass using 2D video imaging"