I noticed yesterday that one of my 28 week old poulets was doing a limping thing. Thought maybe she had just bumped it or something as she like to fly over the fence. Today she's limping and holding her leg up and when she does put weight on it her foot folds under like she not bending it enough to put it down flat. I inspected her this morning and could find nothing wrong. Looks and feels just like the other foot. No other problems that I can see and no one else in the rest of the flock seem to have any problems. Any ideas? Not sure what to do for her.