Rib 9 (left) — false rib

Function

Penultimate-hooped false rib; with 8 and 10 it forms the springy costal margin that the diaphragm presses against.

Landmarks

• Costal groove
• Angle

Articulations (joints)

• T8–T9 vertebrae
• Shared costal margin cartilage

Clinical relevance

Slipping rib syndrome — a hypermobile ninth or tenth cartilage clicking over its neighbour — causes sharp lower-chest pain.