The author of “Playing the Piano Naturally” Dr. Vicki King, would like to share this to all piano players.
The height of the bench is of utmost importance. Sit comfortably with the feet solidly on the floor and position the hips at the front of the bench, so that the upper body is free and can move easily.
The arms should be level with or slightly higher than the keys—never lower. The hands should be placed over the black keys, NOT at the edge of the white keys.
Many pianists curve the fingers unnaturally and play with the fingers at the edge of the white keys. Allow the KEYS to support the fingers, just as the floor supports the feet. Place the fingers ON the keys and simply put the keys down.
Relax the fingers and the keys come up of their own accord, always keeping finger-key contact. This connection of fingers to keys gives freedom to the hands, wrists, and arms. This is the biggest way to prevent injuries over a period of time.
Tendonitis is caused by putting pressure on the carpal tunnel, either from sitting too low, or by holding the arms slightly above the keys, rather than allowing the fingers to connect to the keys at all times.
Dr Vicki King is using the music stand for piano and she mentioned it here. Please check 2:34 section in the video where Dr King mentioned the Grand Stand for Piano.