I should have remembered that bending from my waist to pull weeds and grass ends up causing my knee a lot of pain. It's pulling on the extension, I think, and that's what ends up making me hurt. I know when I was doing the extension exercises more often, I suffered for 2 or 3 days, so I stopped them. Bending from the waist must be doing just about the same thing. Without having kneecaps I haven't been able to squat for the last 20+ years, so waist bending is the only way I can clean the flowerbeds. My extension is better, but it's not equal with the other knee. That's one is in the negative range. That's where I want this one. That way I can 'lock' it when standing and not have to worry about it giving out. It used to lock before the surgery, so I should be able to get it back.