Hello junior _physiotherapist. As answer to your question I can only say "don't know" and "don't know" The Bad Ragaz Ring method was established many years ago (I worked in Bad Ragaz about 26 years ago and used it as part of rehab treatment)in order to use manual and water resistance in rehabilitation and strenghthening/mobilizing. I have no idea how much research has been done on this method. "Depending "on it's results depends on presumably many factors like who is using it (physio competence) and the patients and pathologies in question. Maybe it's comparable to the use of PNF in treatments, can't help you more I'm afraid.regards JM