Have you tried (like Taylor Swift says) just shaking it off? I mean letting your wrist go limp and shaking pretty hard.
I'm not fast enough to need to warmup but I used to play osu and stepmania a lot and I was definitely more tense when beginning and not playing for a while. The only method I had was to warmup regularly and if I did not play for a few days I would lose all my stamina and speed, so playing daily helped a lot.