Rotation is a way to change edges in which in the middle of the turn your body is twisted inside the turn. It is the most natural and comfortable position for carving because deflections of the basic position are minimum.
The purport of rotation as a movement lies in partial unweight of the snowboard in the process of changing the edge and that facilitates edge transferring without harsh change in trajectory of motion. Also rotation allows you to control the board more smoothly and quickly because after changing the edge your board follows its radius providing a secure cohesion between the edge and the slope from the very beginning of the turn.
To study this technique in details we will divide it into two parts – frontside and backside. Pay attention to the fact that in the moments of edge changing you will be in basic position in both of these parts of the turn and it means that both parts of the turn we are talking about will start with basic position. In addition you need to remember about terms ‘plus’, ‘minus’ and ‘half-plus’.
In the very beginning of the carve your body is in basic position, in ‘half-plus’. While you make your turn you need to twist your body smoothly and tensely inside the turn starting with your knees and finishing with your shoulder. In the end of the turn but still on the frontside your shoulders should be almost in ‘minus’ position, your head is directed forward, you look above your shoulder towards the direction of your board motion, both hands are inside the turn placed on your thighs. In the moment of edge transferring your shoulders return to ‘half-plus’ position smoothly but quickly.
In the beginning of the carve your body has ‘half-plus’ position and while you make the turn your body is twisting more inside the turn towards the leading leg. In the end of the carve but still on the backside your body has ‘plus’ position, your head is directed up and forward, the leading hand is pressed to the leading knee at its left, your back hand is reaching forward for your forearm according to the direction of the board motion.
Note that in rotation your body is like trying to catch the board that is making the turn and in every moment till the fall line a rider is in basic position. In the moment of edge transferring the shoulders return to ‘half-plus’ position smoothly but quickly.