I had some biofeedback sessions against backpain a few years back.
In my case, it consisted of a baseline measurement of specific muscle tension plus 4-5 sessions to actually exercise those muscles to "target level".
The idea was to train and better control specific muscle areas to counter the specific pain zones by getting visual feedback when I got it right.
Not sure if that's what you are looking at. I found it helpful as such, as I have good idea now how to mitigate the occasional pain. But the key really was persistent exercise of that muscle group, and a personal trainer would probably have had the same effect.