What Is the Purpose of Floating Ribs?

Also known as the vertebral ribs, floating ribs are the two pairs of lowermost ribs, numbered 11 and 12, positioned on each side of the rib cage. They attach to the backbone alone, unlike the other ribs that attach to the backbone and also attach directly or indirectly to the breastbone. This anatomy makes them appear to float, hence the name floating ribs.