Sounds like a bunch of Lipomas to me. I've had a few on my lower back for years, they never really change, but I have got a few more over the years. I wouldn't worry to much about it, if they start growing or hurting or just plain changing then I would get them looked at.
BTW, you might want to see if they are just in your fat and not your muscle. If they are in your fat then they are probably 90% Lipomas.