FIND A GOOD TEACHER! I have back problems, knee problems and a hairline fracture in my toe. My sister-in-law has back problems. (We live 3 hours apart. ) We both took belly dance lessons. She quit because what the teacher was telling her to do, hurt her back. My class is an even split between the young, pretty, things with rubber for bones and the middle aged, thicker crowd with certain limitations!
My teacher warns us older gals that this move could hurt, if so, DON'T DO IT! She tailors her classes to our strengths. Also if you can do a move and the teacher can't, there are always videos. Join a good, supportive BD forum and lots of helpful people will give you the list of instructional videos.
Go for it! And Good Luck!
Devon