I highly recommend a form of physical therapy called Active Release Techniques (http://www.activerelease.com/). I have had tendinitis in both hands/arms for several years, and regular visits to my ART practitioner have, over a year, improved my situation maybe 50%.
Also I have been using (on and off) the DataHand keyboard, which is wonderful for English text, but unfortunately inconvenient for programming because symbols are a pain to type.