Hun, babies born with congenital hip dislocation wear a brace when its bad enough to keep their legs out beside them.
When its not so severe something as simple as cloth nappies, or doubled cloth nappies can be enough to stabilise the hip joints enough to help them go back into place.
I think that's what Maz's DS may have had. (I repeat, think)

I find BBH are very wide in the crotch on DS, but they haven't affected his walking. My mum used terry flats on all of us...none of us walked funny, & terry's hold the legs further apart IME.