I’m about to finish a two month long bike trip across the country. Obviously I’ve had my hand in a fist for a good couple hours every day holding the handlebars. I tried playing guitar today for one of the first times since we took off. It’s hard to stretch my left hand pinky and I can’t really bend with my ring. It sucks, because I started getting really into playing Mississippi John Hurt type stuff, and that’s all left hand pinky. I’m hoping it’s just something that’ll go back to normal as I’ve obviously been putting a lot of stress on my hand, but I can’t help worrying about it. If anyone has any advice to give, please do.
You just came off a long bike trip in which I'm guessing your hands took some abuse, or at the least over use. They are under pressure and experienced vibration, etc. In addition to this you have probably lost some of the muscle development you had from playing guitar regularly. Both of these things will translate to not being able to play what you could before the trip. I for one would not spend that much time away from practice (and have not for the last 30 years). I usually bring a small practice ax on trips. Something like a Martin Backpacker. Unless this was a cross country race and you couldn't handle the excess weight. I have similar experiences if I overdo things with construction projects at home, e.g. uses manual screw drivers, hammers, etc. The impact and strain on my hands usually makes playing hard the same day but gets better fast, 2 days max. This is assuming you have not really injured your hands. And to the comments posted I would agree that if the issue doesn't clear itself up or if you start getting pain doing other things, e.g. cooking, driving, chores, then see a doctor.
Is it like this?... Swan Finger ... which I have ...
Regardless see a specialist. Swan finger often requires surgery. I can no longer, easily, bend my left pinky. However there's a super easy workaround ... put a little tape over the knuckle so it's already a little bent.