Went to the climbing wall last night, did my usual warm up with stretching etc but even on the early problems I felt like my middle finger needed to be clicked (something I do a fair bit anyway).
I sacked the session off to be careful and this morning it's feeling alot worse. - When I extend my middle finger I can't fully straighten it without a fair bit of pain.
For some context reaching for the top letters on the keyboard is fairly painful. Any ideas of what it could be and best way to treat - Will rest it for the next week regardless.