Rib 9

The rib 9 (ninth rib) is a false rib. It attaches to the eighth rib via an interchondral cartilaginous connection, forming part of the costal margin.The ninth rib does not directly attach to the sternum but contributes to the costal cartilage that connects to the sternum indirectly through the seventh rib.

The ninth rib is also notable for its mobility; in cadaveric studies, the tip of the ninth rib was found to be mobile in 86% of evaluations. This mobility can sometimes lead to conditions such as slipped rib syndrome, where the rib subluxates and impinges on the intercostal nerve, causing pain.

In terms of its structural characteristics, the ninth rib has a length of approximately 99.1 mm and varies in width and thickness along its length