Hi

I can't talk for you, amigo. My experience is that I felt stress ooze out of me almost immediately using SFQ. After a week or so, I felt healthy, distinctly so. The feeling faded after a day or two, but overall I feel somewhat healthier than before. Chun Li says that, in that situation, it's important to keep on meditating for at least 6 weeks.
About your legs...personally, I'm really overweight. So I don't do the exercises standing up at all. I'd like to invite you to stand up until it feels definitely uncomfortable, and then to sit down while doing the exercises as best you can. The point of SFQ is to help one to be healthier, not to contribute to pain.
At least them's my take on it. I am a real newbie, though, compared to Gallen or Pete, so you might want to check up with them before going with this advice.
best wishes,
Mike
moochy_hope@yahoo.com