Ohmigosh, the high arches have something to do with this? I can fit a tennis ball under my arches when I'm standing flat-footed! Well, maybe not a tennis ball, at least not without touching my foot, but close!
When I was really heavy, I could barely walk, and my feet went from a size 9 1/2 - 10 to an 11 - 12. I wore Birkenstock sandals winter and summer for four years. Now that I've lost a lot of weight, I can wear shoes again! Yippee! I sure didn't know it affected other things besides just my feet, though!
I never have managed to get my balance with lunges or, as you said, anything with split legs. I got to where I could keep my balance for a short time with weights, but then I realized I wasn't going very far down into the lunge, so I dropped the weight and lowered my lunges, which seems more effective. Even after all these years, I'm still using a chair or a balance pole for lunges, but I always feel I'm "cheating." I'm trying to be easier on myself, though. I'm 42, I've been waaaaay out of shape for 10 years, and I just have to convince myself that what I'm doing is a 300% improvement over what I was doing before. It's hard, though. I'm an achiever. I want to do it ALL!!!!
Thanks so much for the encouragement. I really do feel better about making these modifications now.
Shari