It's most likely got leg joint issues and might need a different type of treatment than for splayed legs. I caught one like this the day it dried in the incubator and was in the brooder. I turned the heat down to 90F in the incubator and put it back in. It slept the better part of an entire day, and ended up fine. A second one I had similar didn't fair so well. I stuck it butt end first into a tube I had that just fit. I stood him up in the incubator set for the same, and this one slept about 12 hours. I took him out to get food/water, and he was better but not perfect, so stuck him back in overnight That did it!
I also gave each a few drops of Nutra-Drench directly to the side of their beak, but you could just put that in their water too.
Here's an article to other ways of fixing that. Scroll down to chick chair. This was sort of on the same principle of the tube I used.
https://www.backyardchickens.com/ar...and-caring-for-the-special-needs-chick.72163/