The vertebral processes can either give the structure Rigidity.

http://en.wikipedia.org/wiki/Vertebral_column

The vertebral processes can either give the structure rigidity, help them articulate with ribs, or serve as muscle attachment points. Common types are transverse process, diapophyses, parapophyses, and zygapophyses (both the cranial zygapophyses and the caudal zygapophyses).