too many manual therapy clinicians use outdated explanations based on a hip or part of your spine being rotated or out of place
clicking on the above link takes you to a study showing that manipulation (and most likely other techniques) does not alter the boney position of the sacroiliac joint
the tests that measure position and mobility of this area are not very good anyway
even if the treatment did what it was supposed to: "put something back into place" - the tests that measure mobility/position are not valid, a clinician cannot claim they repositioned your joint/bone!
Manipulation works for acute pain and in some cases, more persistent pain. That is not in doubt. The myths are perpetuated by well meaning clinicians who are unfortunately out of date. This makes it seem like you need a special technique or "magic hands" to put something back into place or get it to move
The bottom line is that very few individuals need regular treatment to maintain health. Especially when the length of effects after a spinal manipulation last just a few hours. Treatments that improve mobility and decrease pain can be taught with the right education and often easy repeated motions. If they are not reinforced by the patient, they do not last.