Hi, I am an Italian physiotherapist. Mezieres technique is widely used in Italy. It is also called Global Postural Re-education. There are other two similar, Souchard and Bienfait, both from France.

It is applied to patient suffering from back pain. It is based on eccentric elongation of the muscular posterior chain (paravertebral muscles, hamstrings, etc). The patient mainly is in supine position and use diaphragmatic breathing elongating the muscles actively. The position progresses to several adjustments that the therapist decides to do to facilitate lengthening (like abducted hips and flexed knees, or hips at 90° and legs straight up).

Treatments start from 30mins to progress to 45mins max. Once a week, usually for around 10 weeks. Personally I have used Bienfait technique, it's just a bit different. Anyway I believe there are other quicker and less boring techniques for back pain, not to mention that few patients are available to wait that long. I have heard from my colleagues though that they can solve the back pain, but no patients basically can change their posture (for example an hyperkiphosis stays as it is, and same for a hyper or hypolordosis)

I hope this help.
Emanuela