Bravo Mulberry, Doctors of medicine have only a hazy idea of the true nature of many of the MSK conditions Physiotherapists treat effectively. It pays to form one's own diagnosis each time and consider the doctor's notes as merely a guide. This is certainly true of the so called "frozen shoulder", same when called
adhesive capsulitis,
rotator cuff syndrome etc. The vast majority of these will be revealed to be neuralgic in nature with appropriate investigation. This condition , as you can tell from reading the posts above , is still not fully understood by many physiotherapists either.