There is a proper way to sit at the piano. By being mindful of this from the start, you can ensure good habits for life.
I used to suffer greatly from carpal tunnel syndrome from typing on the computer with poor hand positioning. Once I became conscious and aware of this, I have cured myself. Well, it did take some massive reconditioning and even occupational therapy along with a cortisone shot to start changing my habit! So, you see, habits can be tough to break.
Height of the seat at the piano is important as the arms need to be flat and level with the floor. There should be no tension or bending at the wrists as it will cause friction and that is the cause of all the pain. For my youngest students, I have to constantly remind them not to rest their palms or wrists on the edge of the piano or else the crocodiles that live under the piano will come bite them!
Another important note is how far from the piano should you sit.
Sometimes what looks like a low sitting position causing the wrists to “break” backwards is only because they are sitting too close to the piano. Some of my young students sit with their belly almost up to the keyboard. I always tell them that you can’t play like a Tyrannosaurus Rex! (they had short little arms.)
I’ve taught my son piano from an early age which can be a challenge as being father and teacher. When he was 10, I sent him to another teacher, and the first thing he says when comes home was, “Suzan says that I need to sit further back from the piano.”
I couldn’t believe it! I’ve been only saying that for the last 6 years!