Continue to monitor. His legs should not be affected. He could be in the early stages of MBD (metabolic bone disease) which affects the spine and then the legs. Could you include pictures of your setup and include what lights you use, as specific as you can get.
Remember with beardies, that they like the heat, so putting him in too cool of water could shock his system. I would also try putting him in a luke warm
bath and see if he will drink for you. (note that their skin does not absorb water...so they only way they can get it is through their mouth) Or you can put a few droplets on his nose and see if he licks them off. He may be a little dehydrated due to being overheated.
Hope all will get back to normal soon!