I have a pulling sensation from my belly button down to my pubic region, like a string connecting it, when I lean back it hurts worse. What is it?

?muscular? The rectus abdominis muscles are the paired "6-pack" muscles that run from the rib cage to the pubic bone. Pain at the umbilicus that radiates to the groin may be caused by a pulled muscle. If the pain persists, i advise you to seek out medical attention as a physical examination would be very helpful in this situation.
Hard to tell. I would recommend and exam nd ct scan.