Turns out that's false. It's called the Jersey Finger because it's the injury that occurs when someone playing football (or I guess any sport?) gets their finger caught on another player's jersey as that player is running away, thus causing injury to the flexor digitorum profundus tendon and keeping the finger in forced extension. Less fun, and also less relevant to me.
But come on, if this happened to the middle finger, wouldn't you think it would be a cursing reference?
Also, I'm bad at computers (espeeeeeecially for someone who calls herself a blogger) and I have no idea how to flip that image so it's not upside down. Help?