Sitting is very bad for backs. Standing is very good. This is what many experts on the subject of computer ergonomics remind us every year. I think the whole

Sitting is very bad for backs. Standing is very good. This is what many experts on the subject of computer ergonomics remind us every year. I think the whole logic behind this is simply that if your body becomes accustomed to sitting, your standing and walking posture will be "look" less human the longer this is done, which is already a good sign that something is wrong, never mind the pain that might already be a good indicator. So the alternative is to optimize your body for standing and walking, and then to sit in such a way such that it doesn't affect your standing and walking. Doing so won't hurt your back when you sit or walk, which proves the human body was not designed for sitting for hours at a time, but for upright movement. It's not something a person does that's bad, it's just the way the human body has evolved over the years. The first problem I see with this report is that there is no mention of which chair was used and how long the subjects had to adjust to it. They probably had people sit down in a study-provided chair for a minute, then took the scans. It's possible the subjects didn't really get into as comfortable or realistic position as they could have, given a couple of weeks to adjust to the chair, or to bring their own. Secondly, if one works out, they may be able to sit upright and still have great posture without slouching. It would be nice if a follow up study was done with subjects who work out regularly. It would nice to know what the purpose of the chair was, as well--to allow users to sit in the "proper" way given measurements made by the manufacturer, or to compensate for the more realistic way a human might sit? I've read that car seats have been redesigned because of the discovery that people don't actually sit the same way as expected, though I don't recall if this was a comparison of American sitting habits between this decade to another, or that of Americans drivers compared to those of other countries. Finally, the suggested solution should not have been to sit at 120-135 degrees, but to exercise regularly, weight train, and take frequent breaks.