Limited flexibility. In other words, the rib cage is connected to each level of the thoracic spine. One rib is connected firmly on each side of each thoracic vertebra, with one pair extending from either side of T1, another pair from T2, and so on. Also, the ribs attached to T1-T10 curve around to meet at the front of the body and attach to the chest wall, or sternum. In addition, the thoracic spine and rib cage anchoring each level of the spine from T1-T10 provide both stability and a protected space for the heart, lungs, liver and other vital organs.
Furthermore, the ribs connected to T11 and T12 at the bottom of the thoracic spine do not attach the sternum in front but do provide protection for the kidneys in the back of the body. Because these levels have slightly less stability, they are slightly more prone to problems that can cause pain.