What is the purpose of floating ribs?

One of the overall functions of the ribs is the protection of internal organs. The floating ribs, located at the bottom of the rib cage in the kidney area, shelters these vital organs. Floating ribs are not as involved in breathing as the other 10 pairs of 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.