I definitely have experienced this. I had worn a stability shoe for running with the normal 10mm drop, then switched VFF's for strength training and walking for a few months without running much, and if I did it was in the VFFs. Tried going back to running in the stability shoe, and couldn't make it more than two miles. Ankles, knees, feet, and hips all felt goofy, like I was running in high heels. I couldn't control my strike with all that gunk tied around my feet, and my muscles HURT being forced to conform to the shoes.

I can't imagine what it would be like wearing even a small heel for a day of standing. You've definitely got different/stronger muscles at play now that you've been wearing minimal shoes for awhile, so it's going to feel different, and probably not pleasant given the natural form of the foot and the contortions we make them do for fashion.

I think your feet just get used to wearing whatever you wear the most often. Two summers ago I lived in equestrian boots with a two inch heel, and was fine in them. For the past 6 months I've switched to mostly Vibrams, flip-flops, or other very thin-soled shoes. I just started training for a firefighting test where I have to wear boots and thick socks, and the first time I wore my boots to train in (it'd been about 6 months since I'd worn them) I ended up with terrrrible blisters and could definitely tell I was working different muscles than normal.

So I'd say, just as you have to ease into wearing minimalist shoes, you also need to ease back into traditional shoes.

I have not experienced this. The most I have probably noticed is slight soreness, as perhaps I use slightly different muscles when not in my Vibrams. As far as scientific evidence goes...I haven't stumbled upon any. You may get alot of n=1 answers. But that's mine. I wear them as much as possible.

I'd say stronger muscles will feel more stiffness and soreness if abused. But if you decided to then spend your life wearing heels then imagine how hard it may be trying to walk barefoot. And the runners will tell you that even the smaller heel of 'normal' shoes rendered them unable to run more than a minute or two barefoot until they adjust. Different sort of injuries of course.

One important thing to consider is stride. How are you walking in your heels? If you are trying to walk in heels with the same stride as you have barefoot, you are going to run into trouble just the same as if you were trying to walk barefoot like you would in high heels.

Use the mindfulness and proprioception you have learned through barefoot training and apply it when you walk in heels. If you never learned how to walk in heels, take a ballroom dance lesson or ask your grandma.

I'm not saying high heels are a prescription for foot health. I'm saying that is you have to do it- and let's face it there are venues where you can't really show up in flats- do it properly and while your muscles may become sore if they have not been recently used, you won't hurt yourself. I switch between wearing my vibrams most of the time to very high heels for evening wear without a problem.