There is always plenty of discussion around “proven results” from treatment or exercise. Many professionals require scientific proof of the effectiveness for certain treatment approaches before recommending its use.
The reality is however that true scientific proof requires very stringent methodology. Very few complex treatment theories can be tested scientifically. You could argue that you cannot scientifically prove that the sun will rise tomorrow despite being fairly sure that it will.
When it comes to health the use of science in logical decision making is essential, as is the continued scientific testing of various interventions. What is most important however is the effectiveness of a treatment or exercise. It’s no use scientifically demonstrating that you can improve a person’s movement if it takes 10 treatment sessions and delivers only marginal improvement.
A good therapist should understand that people require results from treatment that are meaningful to them and not to a scientist that happens to be walking past.