Backpain b/t shoulder blades?

Thoracic: The mid thoracic pain is most likely due to thoracic spine strain/sprain, or underlying spondylitic arthritis symptoms. However, referred pain from internal chest problems could be a cause (rarely have seen pts with gastric and esophageal problems present this way, and aortic aneurysms rarely also are a cause)..Most likely this is transient, but if not better in a few days, see your doc.

Likely cervical: With cervical problems that is a common area to have muscle spasms and pain.