I'm having a mini-epiphany tonight: STAND UP AND DRAW COMICS!!!
I have a bad back from 6 years as a scenic carpenter (I'm tall and lanky, which is a bad build for working on your knees all day and slinging around sheets of plywood). And sitting all the time drawing Comics doesn't help that. I do stretches in the morning (sit ups! strengthen those stomach muscles which support your back!) and sometimes I wear a back-brace to help me sit up straight, but I'm still often in a lot of pain. Tonight was one of those nights....
SO. I own an Alvin Fold-A-Matic drafting board, which is just about my favorite thing in the world. It can acheive 0 degrees flat horizontal and 90 degrees straight vertical (plus everything in between) at a range of heights. And I found long ago, that keeping my drafting table "steep" helps me NOT hunch over the board, so my back doesn't hurt as much.
But then tonight I realized I could even adjust the table so I am STANDING UP while I was drawing! It was super comfortable and I drew for 3 hours straight without any back pain. I'm sure after a while it would hurt to be on your feet, but I now know I can switch back and forth. If other people have bad backs, they should give this a try! You can probably rig something up with your boards or with a sheet of plywood or something.