“Shoulder pain has many causes and can be difficult to treat. The best evidence available to date is encouraging but not compelling for a number of approaches: exercise and spinal manipulation.
On balance the treatment with the most favourable risk-benefit profile seems to be Physiotherapeutic exercise.”
Complementary Therapies for Pain Management. An Evidence-Based Approach. 2007. Editors: Edzard Ernst, Max Pittler and Barbara Wider.