Re: Back Problems
Forgot to mention that the psoas pain pattern (far left in my picture posting) is exactly what you can get from sitting in chairs too long -- exactly as Kevin describes. It has a frontal pain as well. When you've been driving too long or even sitting in seiza too long and stand up suddenly, this is the muscle that feels as tho you've pulled something in the groin area (not to be confused with the groin pull/pain from being tenkan-ed). Its a common cause of chronic backache in karateka (and others) -- and who would know that for real relief, you need to do FRONT stretches and apply the heating pad, etc. to the top of the anterior thigh?
Kevin, I really like your recommendation of "a standing height desk and a sitting height desk." Personally I like a standing height desk / drafting table with a standing height stool/chair for sitting. But either one saves a world of hurt!