Right Thumb Pain & Powerball

Because of the hurricane I was at home with no power. That day I spent a long time practicing the tsugaru shamisen. I recently corrected myself from hyperextending my right thumb, and felt really great.
But soon after that hurricane practice I have developed a huge pain that I couldn’t hold the bachi. After reading some posts here, I understand I need to stretch more. Also, I was perhaps too confident with my wrist strength since I play taiko.
For years I have been using powerball (gyroscopic wrist exerciser, see link below) daily to help my wrists from using computer and drumming. It is also why I thought I am safe from holding a shamisen bachi. Turns out, when I used the powerball in the position of holding a bachi (bending wrist inward), my wrist felt very weak. After using the powerball slowly that way, most pain was gone and I was able to pick up a bachi to practice again (only lightly). This is exactly how the powerball usually works, but it still blew my mind that it also works in such awkward position. Since my thumb is not as painful anymore, I am really excited.
I wonder if anyone has used the powerball this way to help with bachi related pain? Or in general?

By the way, if anyone is interested to getting a powerball, I recommend the little pricier NSD brand. It is noticeably better built than the cheaper ones which I eventually gave away (like how everyone dislike plastic bachi.) I have owned two mid-grade NSD powerball for at least 6 years and they still work like charm.