Lame Chick

My chicks are now 5 days old. They are full of fun and mischief. I check on them hourly or more and they had been doing really well. Today however, when my hubby came home he looked in on them and pointed out one was just sitting. We put out some paper and he picked it up and placed it on this. She chirped and chirped but when he put her down she hunkered. She could not be persuaded to stand, well not on both feet. It would appear she cant put her weight on her right foot! She can stretch it out behind her but she hobbles to and from feeder and drinker. 

We put her in another box with food and water for a few hours with one of the calmer chick, but she didnt do much, so we took out the other and left her alone for a few hours. She can get to food and water but its a struggle, and she ate and drank when i placed her next to them.

I moved away from the brooders and within half hour a chirping was heard. I went into the room and she was the only one up. Stood neck strechted so i knelt and stroked her, to which she fell asleep. I left again and she chirped again. This time i picked her up and she fell asleep in my hand. Because of this i have placed her back with the others. All is quiet on the western front.

Please any and all advice is welcome as to what to do and what could be wrong???

Have read on anothe rpoultry forum about a slipped tendon and just to keep it seperate from the others for a little while. She is still bright eyes thankfully and doing a little better. Will just keep doing what i am and hopfully she gets better.

Thanks for the reply min x