We had a baby chick that did the exact same thing. We separated it from the others (who seemed to be picking on her), by cutting out & taping a small square out of a box - it was within the brooder (under the light). Just make sure the baby has access to it's own food and water dish. We used doll dishes for this.....and the water we just put marbles in. This seemed to give the chick a chance to rest, eat and drink undisturbed for a day or so. The other chicks figured out how to get INTO our little hospital room, but that didn't seem to bother the injured one - they kept her company!
After about 24hrs, SHE jumped OUT of the box and was putting a bit of weight on that foot. We figured that she might have gotten her foot stuck on something and hurt it. It was a full week before she looked back to normal, but now she's totally recovered.
A very wise chicken person told us that she needed time and sleep.
Oh - and we put a few drops of PolyViSol (without iron) into the water - got that at CVS (baby vitamins) - read about that here.
Good luck with your baby. Our is now almost 6 weeks old and is one of the sweetest chicks we have....
** We did try the bandaid/splint thing - but she's a feather leg, so it didn't really work, plus it made her very upset!
