We speet more time on the skeleton which detected by the kinect sensor.
There are several joints on one skeleton, head, 2 shoulders, 2 elbows, 2 hands, 2 knees and each joint has its own corrdinate position.
To achieve the function of the gesture, what we should do is to program some codes calculating the change of the joints positions.

we will use the lastest version of the kinect SDK 1.6 to develop.