It's tough for those w/ no frame of references to conceptualize. So....
What did you do?
Run or jump or pace or bounce while you grab your arm that's throbbing? Make ridiculous, incoherent sounds or grunts as you grit your teeth through the freezing cold?
It's unconscious. It just happens. But it's acceptable - or even funny - in those instances bc there was a clear cause for pain.
So, waving, yelling, hopping, swaying, humming are entirely understandable. And? Just like you.
Creating output to mitigate too much input is pretty common. And normal. Its what creates too much input thats diff.
It's "funny" then, but those w/ SPDs are doing the same thing minus the pepper and plus some other, unseen, equally as upsetting pain.