Rotate model at the waist

So I have an Archer model up in a tower and I’m using a basic slerp rotation to track an approaching enemy but I need to attach some rotation code to the spine object of the model to make it bend at the waist for when the enemies are close to the base of the tower. Any ideas on a good way to pull this off?


Thanks for the reply. What would you use for the rotation? Quaternion.Euler?