Your body doesn’t hurt because you were taught wrong.
It hurts because you’re doing it wrong.
You are the only one who can fix it. There’s no teacher out there who can fix it for you.
It doesn’t matter what a teacher says to you. At the end of the day, you are the one who has to fix it.
Teachers are only going to reference their checklists and make sure your body “looks” correct based on their interpretation of the checklist.
But, it’s easily possible that you could “look right” and still be screwing yourself over. After all, these things happen deep inside your body.
It’s not intellectual. It’s physical.
There’s a reason piano teachers spend so much time arguing over which virtuosos have the “correct posture” and which don’t. It’s because there are many ways to do it right.
Every point in the body is physically connected to every other point. When you move one part, all the others move. You can’t isolate them.
The only way to prevent injuries and get rid of pain and fatigue is to find a way of playing that works for the body as a whole.