Thank you for all the information you have provided me (: I can't wait to have my own property so I can actually turn my horse(s) out and let them run. I am going to have the vet do a full evaluation for me and see what he thinks of my boy.
I have to consider that he is 23, has been a racehorse, a five foot eventer and neglected twice in his life. His career as a riding horse might be pretty over. I don't plan on letting him just waste away, but I might "retire" him the sense that I won't use him as my main riding horse and will keep him fit by lunging and ground driving instead. I sat on him bareback today and didn't even ask him to move around or anything. After that he was noticeably more sensitive on his back :( Not the reaction I was hoping for after giving him a week and a half off with massages every other day.
But it all depends on what the vet finds. If I do retire him and just do ground work with him I do have the option to move him into a bigger run. It is about 60ft long but probably like 60ft wide as well instead of like 12ft wide. This is not an option unless I take on another horse to use as a riding horse cause this particular run/area is reserved for people that have more than one horse that they want to keep together unfortunately. Who knows, something is bound to work out.