The finger splint!!
I have one I bought off a spoonie artisan made out of titanium (because I also have nickel allergy, so a lot of metals are a no-go but titanium is good). I use it specifically when I am chopping food in the kitchen, because the way I hold knives gets my knuckles stuck in an overextended position and I have to pull them out and it hurts. It keeps my finger from overextending, those are great!