The most common upper back pain revenant to this discussion is between the shoulder blades and along the inside border of the shoulder blade. This is a common area for trigger points resulting from stress and muscular imbalance as a result of protracted (forward) head posture, collapsed (slumped) shoulders, or "mouse posture" from long hours at the computer. Neuromuscular therapy, myofascial release and Active Isolated Stretching (AIS) & Proprioceptive Neuromuscular Facilitation are very helpful to correct these problems. The long term solution usually involves corrective actions at home and work to maintain balance in the shoulder griddle muscles.
There are some causes of upper back pain that may be the result of serious conditions requiring medical attention and you should consult your doctor first.
Disclaimer
Massage therapists do not diagnose medical conditions nor is this information intended to replace medical counsel. It is always advised to consult your physician first when you are seeking pain relief as there are many conditions with similar symptoms and some of them are life threatening and require medical attention.