Creating new pose parameters that omit the movement but retain deformation

So I was learning how to create new parameters via edit mode and while messing with a few things I somehow achieved what the title states [Creating new pose parameters that omit the movement but retain deformation]. But I thought nothing of it at the time and now I'm having trouble recreating it. Anyone know what I mean and how to do this?

For example if the arms are raised up for the model and the lats deform as a reaction to this, how do I create a new pose that only retains lat deformation but without moving the arms?

I did something with ERC Freeze/Bake