Certain vertical movements of the wrist-joint, with the hand on the keyboard and elbow at rest, are recommended in my
"Relaxation Studies" when learning to "aim" the tone-producing impulse required in "weight-touch."
These testing movements have been misunderstood by some (or purposely misinterpreted) to signify that I insist on such movements as a necessary part of the technical process. The fulcrum at the wrist needs to remain stable and the change in wrist height is required when implementing
shaping at the keyboard.
The up-and-down movements of the wrist have been suggested only as
test-movements during the learning stage.
I have not recommended these movements during actual performance except as an occasional reference test for freedom.
When playing the piano, it is important to keep the wrists relaxed and flexible, allowing them to move freely as needed to support the movement of the fingers. The wrists should not be rigid or locked in place, as this can restrict the movement of the fingers and cause strain or injury.
Proper hand position and technique are crucial for efficient and comfortable piano playing, and it is important to work with a qualified piano teacher or instructor to develop good habits and avoid injury.