Simply its your balance mechanics, Feet to Ear. Whats happening here is, this young Man is moving whats underneath Him, His base. Where in movement what moves you, is the Floor. So the Body is working overtime to compensate, to correct the Bodies Balance mechanics. Ive taken it a step further. This Kid is a very talented Soccer Player, and been doing this stuff a while, easy it isnt, but it transfers to any discipline in Sport. Everything is working.