Help, Limping Chicken

2 days ago our 6 year old hen couldn't walk on her right leg, if she did it was for a short distance and she just balled up her foot and hobbled on it.  I did some research on Mereks and I don't think she has that, she is normal in every way, eyes clear and just chats with you when you talk to her, she doesn't seem to be in any pain if she is laying down...which she does mostly.  She has an appetite and makes her way to the food and water.  I looked into lack of Riboflavin as causing her sciatic nerve to swell and be the cause I'm sceptic because right now they are mostly feed fed.  I gave her some beef liver today and will do that twice a day.  Any other thoughts on what might be causing this?  

No, it's clean.  She doesn't seem to be getting around any better, but still no other symptoms, she's still her chatty self.  

Update;  I went out today to check her over and make sure I didn't miss any black spots, and it seems like her right leg is paralyzed.  I can move it around, it doesn't seem to pain her any.  She still seems fine otherwise and eats when I give her food. I'm not sure what could've caused this that we might be able to help her, or if it's because she is old.  Any thoughts?

She can't move her right leg at all, it's as if it's paralyzed from the thigh down, with no swelling or pain when I move it. She shows no signs of improvement or worsening, and there are no vets in the area that treat chickens. Is there anything I can do if it's her sciatic?   If anyone has any idea what this might be I would greatly appreciate it.  

SpeckledHills, is there possibly a video showing the slipped tendon and how to fix it?