The thoracic spine is the middle part of the back between the neck and the lower back. A thoracic spine strain is due to stretching and tearing of the muscle fibers that support the spine. This may happen because of severe coughing or heavy lifting. Or it may be caused by twisting injuries of the upper back, such as from a fall or a car or bike accident.
A strain in the thoracic spine often causes more pain when you move or breathe deeply. This may take 3 to 6 weeks or longer to heal.