Other movements are added to the in-and-out movement to prevent it from becoming too large. In-and-out can sometimes place a burden on the shoulder, so to avoid strain, the up-and-down movement of the wrist is added. The up-and-down movement of the wrist is combined with the in-and-out to accomodate the physical layout of the keyboard.

In a scale passage, the up movement of the wrist helps the thumb to fall into place. The thumb is the pivot upon which the right hand moves in the right hand descending scale. In the right hand, finger 3 will pass over the thumb, then later finger 4 passes over the thumb and this pattern continues. As the thumb pivots, it is an exaggeration of rotation that brings the whole hand and arm over, free and easy with no use of muscle power. The left hand will use this technique in the ascending scale. The purpose of the whole technique is to make everything happen naturally.

The purpose of the whole technique is to achieve a sense of continuous motion. The importance of this shaping is that the thumb uses an alternate muscle in contrast to the other four fingers of the hand, for it plays down with the hand and arm supporting it. The movement of the thumb is very slight but very important.
To learn a passage quickly and easily, first start with rotation, for it puts the arm and finger into play. Rotation is fundamental to all movement, for coordination must come first. The prodigy has natural rotation with the balance of weight on each finger as it plays.