I knew the subject line would get your attention.  LOL!!

I think I might be getting some arthiritis or it may be Carpul Tunnel, not sure.

My middle finger on my left hand hurts like hell at the knuckle every time I pick something up or after a gig.  Anyone else ever experience this?

Yeah, the technique is fine.  I'm just seeing if anyone else has had the same sort of symptoms.  I've been meaning to go to the doctor about it as well as my bad back and bad knee, but just can't find the time...LOL...it's hell to get old!

I to am sore after I play a Marathon weekend. I played Friday about 3 or 4 hours on my own.
I played last night with one band,  Another 4 hours.  Today I will be putting 3 -4 hours in with another band. This morning my hands are a bit swollen.  My 46 year old body feels like I have been working out doing reps not heavy weights.  I will take some Aleve for the next couple of days.  It is part of getting old and my style of drumming can be very physical at times. I remember a Thread on here where Mr. A was saying he takes something before he plays the first night to help him the next day.  Aleve works this way.  You build a level in your body and keep that level of antiflamatory drugs up.  Your middle finger could be something else. I would see a doc.
                        Nutty

Yes. For me I found a root cause and a working cure. My day gig is in a lab. It involves stirring very thick mixes in hand held jars, putting lids on and taking them off, etc. I had  pain in the back of my hand(near knuckles) and at the outside part of the wrist.

When I worked I had to hold jars very tight for them not to slip while stirring with my other hand.

I now use a tennis ball to massage my forearms a couple times a week. I stand facing a wall with my forearm parallel with the floor, wrist in neutral postilion. I place the tennis ball between my elbow and the wall and roll it about 1/4 to 1/2 way down the arm. I lean into it with as much force as I can handle and work for about 30 seconds in each of three positions:

1. With the thumb facing the wall - wrist up
2. Back of the hand facing the wall - thumb up
3. Pinky towards wall - Knuckles up

Another issue was with the ergonomics. I changed my drum set up so that all of the components could be reached with my wrist in neutral position. Or, at least near neutral; I avoided any extreme cocking of the wrist. I also changed how I positioned myself at work.

When you get a pain in a part of your body, normally it is not what you are doing at the time of the "injury" that is the cause. Overworking, fatigue, weakness and ergonomics are normal root causes.