I have Ankylosing Spondylitis (rheumatoid arthritis of the spine) and it takes a couple of hours to get moving well enough to play my best. Aleve, stretching, and a long slow warm up, and I am ready to go.

I suffer from Psoriatic Arthritis, the same type that Phil Mickelson suffers from, and Ankylosing Spondylitis. I take the same type of drug he endorses, just different brand, Humira. I have to inject once a week, along with a weekely dose of Methotrexate. Pain and soreness comes and goes, I try to ride if I can to minimize stress on joints. I'll take a max dose (1000mg) of naproxen on days I play to help with pain. My last 2 rounds I actually walked and was fine. A little sore the next day, but not as bad as I expected.

Tendonitis: I suffered thru bad tendonitis in my shoulder when I pitched baseball(many years). Ibuprofen is a God-send(for me). Probably the worst thing you can do is use a brace that immobilizes the body part(IMHO). Stretch the tendon!! Put it on a slight stretch until it hurts just a little. Keep doing that on occasion(many times a day) until you can stretch it further and further without pain. Learned this indirectly from a quite famous pitching coach....Leo Mazzoni. He had use a weighted metal ball to go thru our pitching motion(slowly). It worked wonders! I got to thinking why and came up with that thought. Now, years after that, it is becoming the treatment of choice now.
Ibuprophen added 2-4 mph on my fastball. That is quite a bit. I only used it before and after I pitched. In between.....never.

I'm glad I'm way too young to have to worry about any of this.

No your not. I get it. Terribly.

That's what we though about our child..................when she got juvenile arthritis at age 2. Nothing major but she has to watch what she does.

I use a prescription med called Diclofenac SOD 75mg which works really well once in your system a couple of days. I have a friend who has rheumatoid arthritis, that also uses this drug so it must be pretty good to work for that. It is an anti inflammatory drug. Aleve as others have said, is my non prescription pain med of choice.

I have issues with my knees and back, and used to with my elbows. The switch to graphite shafted irons made a huge difference in my elbows. If my knees are really bad I will put a patella tendenitis strap on, but usually I just take 4 advil before I leave the house, and if I feel a hint of pain during my round, I take 3 more. This will generally keep my back from getting all tight and inflamed too.

I have used Diclofenac for a while, it worked great on the arthritis but was tough on the stomach for me. Another that worked almost as well has been mentioned here is Meloxicam, which was a bit easier on the stomach. The absolute best I had was Bextra but it was removed from the market. Now it is just a double dose of Aleve when needed for me.