Although the thoracic spine doesn’t get much attention, it’s literally the backbone of your lungs and heart, surrounded by your rib cage, which protects these vital organs. Of the spine’s 70 joints, 50 percent are in the thoracic spine. If you factor in the additional 20 specialty joints (called the costotransverse joints) that help your ribs articulate and move, you’ll quickly understand that your thoracic spine is a workhorse responsible for two-thirds of the movement in your torso—so the odds of something going awry are high.
Despite the thoracic spine’s potential for movement, the unique design of your upper back and rib cage does not allow for as much movement as you may think. This is to protect your lungs and heart: excess motion here could impact these key organs. What’s more, the vertebrae of the thoracic spine interlock with one another and act as a hard stop during backbends—again, to defend your internal organs.
The hallmark of a healthy spine is that it can access all its inherent ranges of motion. Once you start leaving a motion out, the joints and tissues stiffen—and in the case of the upper back, this can translate into breathing issues. An excessively immobile thoracic spine can lead to a stiff rib cage, which can then restrict the capacity of your diaphragm and lungs. Because breath control gives us access to our nervous system and emotional centers, the interplay between the upper back and breath are critical for permitting relaxation, well-being, emotional attunement, and whole-body health.