Michael–
Is your thumb joint jammed?
If it is or think it could be:
Take your other hand and wrap 2-3 fingers around the other thumb.
Pull your thumb in a straight line away from the hand.
If the joint is jammed it you will feel it move back. This will reset the position and it should start improving.

Michael,

Any taping advice for “smartphone” thumb? I’ve narrowed down the pain when I use my phone to read. It’s a big phone and I have to contort my thumb to hold it. The right thumb is imflammed and painful at the mcp joint. There is a large bump forming on the top of it and I feel the need to pop the joint below (cmc) it to release some tension throughout the day several times. The ligament on the outside of the thumb (not the ulnar collateral to the inside) is sore and “loose” and allows the proximal to sit offset on the metacarpal. It’s like it’s sliding off the finger. It hurts like hell to push it back to sitting centered but then it feels better in a few hours. Like a good stretch. Taking it through all the range of motions and pulling on it a bit too. any wrist work needed? My pinch strength was down to nothing last week. The I stopped using the thumb to let it heal and its getting better so I’d like to tape it to help it along more. I’m off the phone for now but will be aware of how I hold it from now on.

Have you looked for something to set your phone in so you are not holding it?
This is a situation where it may be beneficial to consult a doctor so you can identify exactly what is happening and how to address it.