I consistently get soreness/inflammation in the knuckles of my right hand the day after even short rides (e.g. 16km yesterday, with a ~2h break in the middle). Bike is a Scott Speedster with Tiagra 4500 STI levers.
Applying some mechanistic reasoning (and from the feeling in my fingers when I'm foolish enough to ride with them still slightly inflamed), it's likely to be from shifting to the larger cogs in the back. I realize that modern levers are supposed to be lighter to shift and therefore older ones require more force and this could be a contributing factor, but I literally cannot find a single other complaint like mine online. All I'm able to come up with is complaints about hands/fingers tingling/going numb. At this point I figure it's either bad technique or bad equipment, am I missing other possibilities? How do I tell which one the problem is?