Refining Haar detection

Question

I'm trying to make a hand detection program by using OpenCV and Haar cascade. It works quite well but it's very jerky. So I'm asking myself if this is a trouble of the haar file that would be too 'cheap' or if there's a way to refine the detection by using contours or feature detection (or may be some other techniques).

What I would like to perform would be the same as this face detection, but for hands : Face Detection (see FaceOSC)

Thanks a lot.

EDIT : here is the kind of stuff I would like to do : Hand extraction It seems that he performs it with contour detection, but how to find the hand ?