GneissSchist

The muscles that flex for me are the ones in the back of my head. If you place your hand on the back of your head directly between your ears (so just about where your skull begins to curve in and your neck muscles begin) it’s the ones just on either side of the center line that do the flexing and pull my ears back. Try imagining scrunching up the back of your head.

I had assumed they were, but I’d never heard anything confirming it.