I had a very similar experience almost a year ago. My beardie decided to see if he could fly off the couch one day when he was running around and hurt his back leg. This was back in December when he was only about 5 months old. We took him to the vet and thankfully there were no broken bones or anything, just a sore leg which stopped hurting after about a week. But I did find out he had a lack of calcium, so ever since I've been dusting his worms with calcium supplements and introducing him to new fruits and veggies (tough because he's stubborn with food). He's grown a lot and is much more active and fat! I also got a much better UVB lighting system that goes all the way across his whole tank. He now measures at nearly a foot and a half, a little over a year old! I hope your little one is okay and all he needs is a few supplements and a new light!! (P.S. the vet I went to advised me to keep any unnecessary items out of his viv to minimize the chance of furthering the injury by falling/getting stuck)