The mid back (thoracic spine) has been a common place for many injuries recently. However, there are many reasons as to why mid back pain can develop, here are some common reasons.
Cervical-thoracic postural pain: commonly existing in the upper to mid thoracic region and often associated with a headaches and a heavy head. There is often a gradual onset of discomfort that increases by the end of the day. Worse with jobs that have a sustained posture (sitting all day) and no movement.
Acute/ Traumatic sprain of the spine: often occurs when loading the body in the outer range of motion, which results in a sudden onset of discomfort. There is often a specific directional movement restriction, tenderness around the area of injury and often pain with breathing. Commonly associated with an inflammatory response and a fracture could be possible.
Acute thoracic joint lock: very similar to a locked neck and similar to the sprain above, however there is no tissue injury, which will result in a quicker recovery. Can lock in extended postural positions or with low loads. Pain can often be very high, rotation restricted, high irritability with breathing and often located around the mid thoracic region.
Mid thoracic hypomobility disorders: spontaneous onset of discomfort or due to an unresolved acute trauma. Often located bilaterally around the mid T3-9 region. Pain at night, stiffness in the morning and often aggravated with end of range movements and sustained posture.