Muslims can you answer this?

You are missinterpreting the way it's written. The backbone to the ribs is meant to mean from the bottom of your backbone (your tailbone) ie your pelvis to your ribs. It includes the backbone because this is your spine where your spinal cord connects to your brain. In this sense it is trying to explain that from a single sperm and ovum an inteligent being is created. This is the problem with reading something in translation. It makes much more sense in the origional arabic but you might want to read an english version that has commentary and explanations as well so that it is more clear to you.