Ah, so even when he is in is cage, he has trouble moving around?
Rango is fine when he is in his cage. He cruises around, digs under the aspen and shoves his hide some lol. Like i said, for me, it's only when i pick him up or put him down in an unfamiliar place od anywhere outside his cage really. He is happy to sit perched around the back of my neck though lol.
Well, if your special needs boa gets big and is a hadnful to deal with, you can just pet him inside his enclosure and stuff every few days. I cant always get my snakes out for adventure time so i at least try and pet them and stuff every couple days when i change their water. They seem pretty content and sometimes, one of them will be social and actually climb up on my arm and try and come out. I'll try and let them sit on me while i do stuff for a little while in that case.
You should have lots of time as boas grow slow. Also if he is rigid, it should make it easier to get him out if anything. Rosey and Gina are so lazy most of the time i drag them out. They just let their tail drag behind them unless you mess with it, then they snap it to their body lol. I'm sure your guy will be fine :)