Crushing

Crushing damage (cr) inflicts damage through blunt impact, like a bludgeoning weapon or an explosive blast. It is likely to cause knockback, and is more effective at inflicting blunt trauma than other types of damage.

There is no wounding multiplier for crushing damage.

Crushing damage is not subject to Overpenetration.

Against Flexible Armor: For every 5 points of crushing damage stopped by your DR, you suffer 1 HP of injury due to blunt trauma. This is actual injury, not basic damage. There is no wounding multiplier. If even one point of damage penetrates your flexible DR, however, you do not suffer blunt trauma. If you layer other DR over flexible DR, only damage that penetrates the outer layer can inflict blunt trauma.