Chairs don't matter. Exercise to get ride of back pain.
Over the years I've tried to find the perfect chair for sitting for long hours, either working 8h a day, or playing for 12h+ (lol). I came across some good ones, but no matter how confortable they were, after 5h of sitting, the pain always came back.
I'm not going to write too much, I just wanted to say that, to all of you that think a good chair takes the pain away, it doesn't.
The solution is simple: start exercising. Start walking/running 2 or 3 times a week, and more importantly, train your back, lower back and abdominal. You should train your whole body of course, but those 3 are the most important if you want to get rid of pain while sitting.
Don't lean against the back of the chair all the time. Move forward, stretch upwards, keep your back straight and try to hold this position for as long as you can. In the beginning you will find yourself automatically switching to the laid back position that you're used to, but with time your body will get used to it and you will start to feel the difference. You don't need to be on this position all the time, you can lean back for some minutes of course.
Even if you don't exercise, you can do this trick. Its just that its much easier if you have muscles on your back and abdominals to help you.
Also, you should have your arms doing aproximately a 90" angle, and relax your shoulders.
Hope this can help someone :)