The first joint up from the hand. The upper joint, and the knuckle are ok. I'm not sure if I use that finger to shift...I will have to pay more attention. I bet I do. But it's swollen all the way to the tip of my finger. Not a whole lot of pain, but I have a very high tolerance. I do think I need to get my bike fitted, because it just seems off...maybe I need to adjust the handlebars? I dunno...I was expecting a sore bum, sore arms/wrists, but not a swollen finger! lol leave it to me to be the weird one!