I have bad shoulders... I carry mine forward. Their pushed forward in front of me. I think it's because I have weak rear deltoids though, because I have big front and side deltoids, but when I try to look at my rear ones, I don't really see anything.

I've read around about it, and people pretty much say that I need to work on my rear deltoids, I guess to get them bigger and stronger so that it pulls my shoulders back into a normal position.

Is this true? If not, what do I need to do?