Chicken is limping, nothing seems broken...

I'm sorry if someone has answered this already, but I can't find it. My favorite (of course!) hen (a 7 month old Dominique) has been limping for nearly 2 weeks now. At first, she really didn't want to put any weight on her left foot at all, though I could find nothing wrong with her leg. I immediately put her in a large dog crate in the garage with our bantam Leghorn for company.
She's gotten a little better every day, for the last week or so she is practically running on it, but when she walks it's like her left leg is longer than her right. So she has this really up-and-down gait. She is acting completely normally except for this; laying eggs, eating, drinking, cuddling, everything.
Has anyone seen this before? We've felt the leg and foot, nothing seems broken, no bumble foot, nothing that we can find. At this point, I think I need to bind her leg up to her body, but I don't think that will help if it's dislocated. I'd be grateful for any advice.