I know many others have encountered this problem and there's always a lot of speculation as to the cause. My 8.5 year old buff orpington started limping & having trouble using her right leg a few weeks ago. I assumed she injured it jumping from the higher roost she was sleeping on(I took that roost out). After asking for advice here and googling last week I examined her thoroughly and could not detect a problem or even signs of pain in the thigh, leg or foot. I started her on metacam for a few days to see if that would help. Virtually no change. She's a really good girl, very docile and sweet so I decided to splurge on a trip to the vet. I'm very fortunate that I have one right in my neighborhood. He did a physical examination and agreed, there's nothing wrong with her leg. He said he thinks its a pinched nerve of sorts caused by an internal tumor. We took an xray (which she was a perfect patient for). Sure enough she has a large tumor in/on her kidney that is making her leg feel like it's "asleep". The only thing we could do is continue the metacam, but I'm concerned it will fatigue the kidney more. The vet agrees she's NOT IN PAIN. So I will continue to monitor her condition and we'll see what happens. This will surely end her life at some point but the vet couldn't say when that might happen. The exam and x-ray was $218 (don't tell my DH, he'll have a stroke). I just wanted to share this info because I know we all do a lot of educated guessing in the care of our flocks. Any info we get from Veterinarians can be super helpful.