I went to a shoe shop and got Ds properly fitted and picked their brains too - spoke to a very knowledgable lady who said proper soles are best and showed me about the right amount of flex in the sole, support for the ankle etc Don't go with pre-walkers as they're not actually supposed to be walked in. Also, only use them when you need to as bare feet is best. I also Dr Googled it and have a friend who's BIL is a podiatrist- they all seemed to say pretty much the same. I figured for the sake of $10-20 it's worth it and fwiw, he's still in the same shoe size as when he was first fitted (12 months ago!).