See-Saw Bowing - tip #43 from Dr. Suzuki

The bow hand moves in special ways so as to execute actions necessary to proper bowing technique. The "seesaw" movement is one of these special movements.

With this movement, the thumb acts as a the fulcrum, or fixed central axis, and the stick functions as the bar that rests on the fulcrum. The two outer fingers, with alternating up and down motions, cause the stick to steadily rock, aligned with the bow path and in a controlled way. The thumb remains immobile, and the two middle fingers are passive, moving only slightly.

This seesaw movement allows string changes, while the elbow remains low.