jtoronto,

You are going to continue to struggle if you do not develop a way to keep track of and understand things you have been told.

I said C-1 does not have facets like the lower vertebra. It does not settle into those facets like the lower vertebra.

I did not say head twist and neck pop is not good in general. I said it can be too aggressive for people with subtle injuries that involve C-1. 'Popping' lower vertebra can stress C-1.

"Or can they be as effective with manual/massage techniques as other therapists/modalities?"

What are 'manual/massage techniques as other therapists/modalities' ?

It sounds like you think a chiro or therapist will fix your neck. They only reduce conflict,spasm, etc so your neck can heal. It takes weeks and even months for subtle neck injuries to heal.

"What do you think is the relevant physiological thing going on in the case of the concussion? For example, is it a bruise on the brain? More inflammation?"
Nobody can say. There are no diagnostics to define the physiology.

Conceptualize this. You break a bone. The doctor sets or aligns the broken bones. He fixes them with a cast that prevents you from misaligning those bones with excessive movement. Over time, the bone heals so the cast can be removed and you can start rehabilitating the bone and related joints. Over time, you regain most or all of the use.

The chiro or other therapist properly aligns your cervical vertebra. You work to not misalign them. Inflammation goes down improving blood flow to your brain. The chiro or therapist checks the alignment from time to time. You continue to work to not misalign them. The improved blood flow slowly helps your brain improve.

Pain just means you are sore. Is the massage painful? Did he tell you to ice after the adjustment and massage ? "Pointing the activator toward your brain" is a meaningless comment. Don't fret about everything.

btw, 'Highly regarded chiro' just means he is good at getting and keeping patients. This is usually defined by financial success and lots of touchy-feely systems to make patients feel like they are getting good care. I've known many successful chiros who were worthless to me. As my favorite chiro says. They are good at show and sell.