When you
shake your fist while raising your arm, much
like someone with parkinsons does when they're
angry.
It's also known as the Old Man Fist Pump.
A
guy cuts you off while driving, you show him the Parkinsons Uppercut!
When someone tells a bad joke, you can let them
know you're going to give them the Parkinsons Uppercut, in which you'll hit them 100 times...very softly.