Complementary medicine or alternative medicine are terms used to describe a very wide range of treatment approaches that tend to be practiced outwith the setting of traditional medical care. As time goes on some of these techniques such as acupuncture are becoming adopted into "traditional" medical practice. Others such as reflexology or shiatsu remain - as it were - waiting in the wings.
I am not trained in any particular complementary medicine technique so the insight I can give you is based on the published research data and on what my patients have told me.
What evidence is there?
Without meaning to sound flippant here - it depends on who you ask!
In traditional medical research terms the level of evidence is weak that any of the complementary therapies
provide reliable and predictable benefit.
That's not to say that they don't benefit patients. They sometimes
do - but unlike traditional medicine - the research does not allow us
to say what technique will benefit which patient.
Complementary medicine therapists often tell me that they have extensive research to back up their treatments. My difficulty is that the research has been conducted in a way that wouldn't allow any comparision with normal medical techniques.
All in all, I am not against the idea of you trying any complementary medicine technique. If it works for your shoulder then that's great - but do bear in mind that your shoulder will improve spontaneously anyway. Don't necessarilly give all the credit to the treatment technique (this advice is just as true for more "conventional" treatments of course.)