I then tried a half-reclined chair which was a bit better. Then I switched to a flat hard chair without back support. That was tough initially (more so than standing desk) but seems to be the best option so far. Other than moving, of course.
The desk-treadmill is even more interesting to me, as you can even exercise while working. But at this point a little over my budget, would love to rent one to try for a while :)
The one I bought was a bit too narrow though so the rails have gone back on and I just use it for us intended purpose now.
get a cheap 1 usd camping pad insulate,fold it, and you got a 200 usd ergonomic mat.
Lots of people I know use them though, and report loving them. Most people have a thick mat to stand on, and say they shift their weight a lot. Some of them don't end up standing for long periods because they're in and out of their office so much.
It's also a lot less expensive and lot less bulky to try a standing desk setup than a treadmill, so either way I'd recommend standing first. You can even use a bunch of boxes to prop up your keyboard & monitor -- or bricks under the desk legs -- before you invest in any other equipment.
I saw a video a year ago, looks like a good idea, I am planing to buy a small one
I loved walking while I worked. I can't stand and work, my feet start to hurt surprisingly fast, but walking I can do all day. I felt better, and it cured my afternoon post-lunch crash, I no longer went through an hour of trying to stay awake. It helped my back feel better too. One hard part about using it for me is the constant stream of interruptions I have, people needing to talk to me during the day. I have to turn it on and off a lot. (The Trek Desk, btw, made it slightly harder to reach the start/stop buttons.)
Even with them being small, one of the biggest problems I had is the setup is still bulky. The treadmill takes a lot room in a small office. It's pretty noisy too, even just walking, so consider the noise if you're in a shared work space.
Half day sitting down and half standing up seems best.