I fought it, but lately muscles in my sides and back have been easily tweaked after long-duration reclines. The solution that some here have settled on is a full supine workstation, i.e. flat on your back. What works for some won't work for others, so I'd just like to compile some options and individual's experiences with each.
Here's what I've tried, and the problems that have arisen:
1. Thick Memory foam mattress. Seems to work at first, but can cause upper back pain from uneven pressure pushing your shoulders in toward your chest. Could definitely be remedied with strategic thinning/thickening (ie just putting something thin and soft under the mattress, along the spine) but this requires very precise positioning when you lie on it. A water pillow seemed to be the best option for the head, but probably any soft one will do.
2. Waterbed. I'm on one now if you can believe it, staring up at my monitors. I've only given it a few days of trial, and it's got potential. The problem at the moment is a new one: nausea, either from motion sickness or the vinyl smell (which may or may not be unhealthy as well). With some extra lower-back support (currently a rolled towel, going to experiment with lumbar memory foam pillows), the waterbed is otherwise the most comfortable option so far. I use a very thin pillow (waterpillow, with no water in it) and am careful not to get it under the shoulders...otherwise the same problem from the memory foam mattress occurs.
I remember many years ago someone recommending EVA foam here (like the floorpads from harborfreight/costco), which is quite firm. I'm not sure how long he was using his supine station, but I need to clock in 12 hour days and that seems a bit torturous. Others have recommended the overpriced zero gravity recliners from relax-the-back, which get you very close to full supine w/ elevated legs. Wolfv had a supine thing going (and gave the idea of the rolled towel for back support, I think) but I don't remember the material and can't find specifics.
Anybody else going full supine? If so, what's working for you?