10 years ago by
A Pianist
Ouch!
A distressing injury, and not the type we typically get reported here. If you don't want to re-injure yourself, from what you describe it sounds to me like a major revamp of your technique will be in order. Sorry for the bad news!
It sounds as if you have been "karate chopping" the bass notes with the side of your hand almost more than your fifth finger itself - correct me if I'm mistaken. You're going to need to develop a sense of the functional strength of your hand's arch to remedy this - but the fifth, being relatively small and weak, is not the place to start. Get a sense of your hand's wonderful grasping power especially in the strongest fingers, your second and third, and when that's familiar, the whole hand, and then slowly learn to individuate, to get that grasping action at work in the fifth itself.
This will take a good deal of time if you want to do it right. Go slow, but really monitor the changes and understand what you have learned; you should do OK.
Welcome to the Forum!
All best,
AFF