I work as a graphic designer at times. Sometimes sitting at the computer, the urge to move is too strong and I have to get up and walk around. Or sometime instead I start hitting my desk with my hands, kind of like drumming but I'm just trying to get the energy or something out.
I also have to keep my legs or feet moving when sitting down.
However, its not painful and the truth is I don't want to sit behind a desk, lol. So I don't know what I have but as long as I can move I am ok.