Here is my understanding:
If I would like change the location of the hand relative to my body, e.g. the current location of the right hand is at the level of my belly button, and the destination is at my eye level in front of the right shoulder, how can I achieve that without moving the hand?
- Don't move the hand, but I can move any other part of the body to achieve the same result.
- Keep the hand at the same coordinates in this three-dimensional space, and sink my body down, which in turn causes my elbow to go from above the hand to below the hand. Then perform the 2nd half of the positive circle.