As far as I know, no one has really taken this on in any sort of serious way. So what the heck, I'll give it a bit of a go.
First there are a few self-explanatory truths to base this project on, that are beyond dispute in my opinion:
1. Energy concepts do not belong in manual therapy.
2. The nervous system is the part keeping a human organism "alive", and it is the part responsible for the phenomenon of felt and experienced pain. Nothing about the pain experience will change until this system is ready to change it, or to let it change.
3. Neuro-modulation in the broadest sense means, supplying a novel input in order to facilitate a new output.
If we are faithful to these three basic concepts, and use Occam's razor, ever so carefully, ever so precisely, we will end up with the following idea: All manual therapy involves touching the body somehow, so therefore all of it is neuromodulatory. The receptors that are affected are mostly mechanoreceptors and exteroceptors, all afferents. We could call ALL manual therapy, "Extero-Mechanorecepto-neuromodulation."
Some forms of manual therapy, or mechanorecepto-neuromodulation, focus on the surface more, while other forms focus on what lies below the surface. For example, acupuncture and needling in general supposedly treat something underneath the skin, but given the depth of cutis/subcutis, and the ubiquity of cutaneous neural twigs, it is more likely that needling stimulates mostly exteroceptors, maybe a few mechanoreceptors. Which is fine. Let's move on.
Manipulative therapy purports to treat joints, including those mechanoreceptors known as proprioceptors. To get to those, it is necessary to get past mechanoreceptors in skin and other tissue; however, manipulative therapy ignores more superficial mechanoreception as if it were not even there.
Soft tissue sorts of therapies, of which there are too many to call out by name, stimulate mechanoreceptors in skin mostly, and in layers just deep to it. So we could classify all these as neuromodulation of the exteroceptor/mechanoreceptor classes of afferents.
So, we could end up with a very small flow chart that depicts all of the manual therapies, with "Manually Applied Neuromodulation" at the top. There would be two branches off this item. One would read, "Extero-mechano-proprio- neuromodulation" (for manipulation of joints) and the other would read "Extero-mechano-neuromodulation" - exactly the same but for proprio (everything else).
Now, the razor can be pulled away for a time, until it is shown that Extero and Mechano only are more than enough effective to permit the dissolution and gradual fading entirely away of that whole first branch of the tree, which basically includes only joint manipulation.
I contend that any "proprio" stimulation necessary can be done without the audible pop noise. Studies support this. I contend also that joint manipulation by whatever name, as a manual therapy, has been kept on life support for a hundred years, and it is time to pull the plug on it. If it can stay alive under its own steam, fine, but no extreme efforts should be made to maintain its existence as a set of "special" knowledge to be handed along in a cult-like manner.