[Br1ck]

My thumb joint hurts pretty much all the time, but I can still ignore it. There are a few things I've found to be helpful. Mandolinist Mike Compton has a pick grip that is different than most to create more power. Google him and it should come up. It places the pick over the index knuckle for less flex, so you can lighten up on your thumb pressure and still get a solid attack. The other is just lighten up on everything. Let the guitar do the work. It's is good practice to play as lightly as you can as it opens up more dynamic range on the soft side of things, and a guitar's tone can be really satisfying with a softer attack. Playing soft with speed and articulation is a challenge.