Pins and Needles in My Hand: What's Going On?

It could be neuropathy

Definitely sounds like a nerve thing with the pins and needles... I get a 'thunk' in my hand after certain motions and I'm pretty sure it's a tendon thing.

It sounds a lot like your joints are shifting to pinch your nerve. When I was a kid I injured my hand so badly I almost needed stitches and it messed up my nerves in a way where every time I popped my pinky it'd catch the nerve and feel like that for awhile