The middle of your back is the section of the spine called the thoracic spine. There are 12 thoracic vertebrae. Itís likely that you are feeling the spinous process (SP) of the thoracic vertebra.
Each vertebra in the spine is made of the same parts. A round block of bone forms the main section of each thoracic vertebra from T1 to T12. This is called the vertebral body.
A bony ring attaches to the back of each vertebral body. This protective ring of bone surrounds the spinal cord, forming the spinal canal. Two pedicle bones connect directly to the back of the vertebral body. Two lamina bones join the pedicles to complete the ring.
The SP is the knob you feel where the two lamina bones join together at the back of the spine. Bony extensions also point out from the side of the bony ring. There's one on the left and one on the right. These projections are called transverse processes (TP). The TPs are just off to the side of the SPs.
Pain or tenderness at either of these sites can be an indication of infection, tumor, or misalignment of the bones. If you are having any signs of illness (fever, chills, sweats), you should see your doctor right away. This is especially true if you've had a recent infection of any kind anywhere in your body.
If you are otherwise healthy, you may want to wait and see if the soreness goes away with a little time. If not, an X-ray may be warranted. If the problem is caused by the way the bones line up, then you may need a chiropractor, osteopath, or physical therapist to adjust the spine and help restore normal motion.