Standing. Turns out you shouldn’t be standing with locked knees. I learned it in my twentees. People with hyperlordosis have tendency to do that it seems.
It's also better advice for not fainting while standing long periods than rolling onto balls of feet and back to heels - the reason that works is that it forces you to unlock knees, if you can just unlock/bend slightly without doing that it's fine (and how you should be anyway as you say).
