There's more to it than just sitting is bad for you, as someone that has struggled with this for the last decade I have some experience =). Standing desks will rarely fix the issue and a lot of people will suffer as bad if not worse as standing in one position for long periods can be strenuous. Main thing is changing position, its fine to sit for 20 minutes, than stand for 15, squat for 10 etc etc. Unfortunately doesn't make for incredible productivity...