I had a year-long nasty case of frozen shoulder. Tried PT and various other treatments including a shot of cortizone. Finally my MD (who also has an acupuncture license) said let's try acupuncture. She gave me two treatments each lasting twenty minutes with needles attached to a mild electric current. The shoulder improved 50% after the first treatment, a week later 100% after the 2nd.
You can also get a lot of pain in the shoulder capsule if you use a computer mouse too much. If this is the case, try shifting to a track ball, and make sure your forearm is resting on something (chair arm) the same height as the trackball so that the fingers do all the work, and there is no shoulder movement.

Jon