The thoracolumbar junction is where the thoracic and lumbar vertebrae meet and it is in the thoracolumbar junction that most of our twisting happens when we practice Yoga. Before going further into the thoracolumbar junction, let’s first take a quick look at the beautiful, complex spinal structure.
The vertebral column goes all the way from your skull down to your pelvis and it is made up 33 individual bones, known as vertebrae, not all of which are independently movable. The reason for so many bones is so the spine remains strong, flexible and cushioned with the help of spongy intervertebral discs.
The Spine is divided into five sections:
Cervical (neck) – seven vertebrae, labelled C1 through C7
Thoracic (mid-back) – twelve vertebrae, labelled T1 through T12
Lumbar (lower back) – five vertebrae, labelled L1 through L5
Sacrum (pelvis) – five fused vertebrae, labelled S1 through S5
Coccyx (tailbone) – three to five vertebrae
The thoracolumbar junction is the area of joints L1/T12 and T12/T11. The T12/T11 joint has a greater range of rotation and it is located below the ribcage which is meant to be less mobile to protect the heart and lungs.
This junction is also flat, allowing for more gliding motion than the junction of the lumbar vertebrae which tend to be more like pieces of a puzzle fitting together so they are more locked, which allows for very little mobility. It is said that the thoracolumbar junction is the first place in the spine above the sacrum that can freely rotate. In fact, the lumbar spine can only rotate about 5 degrees and it varies depending on the individual. However, the thoracic spine has an average rotation of 35 degrees and a great deal of this rotation happens at the thoracolumbar junction.
The thoracolumbar junction is also the first place above the sacrum and lumbar region where the spinous processes (wing-like bony structures that stick out) point straight toward the back of the body. This creates more mobility in the thoracolumbar junction as well because these spinous processes do not interfere with each other during rotation. On the other hand, the spinous processes of the lumbar spine point diagonally toward the floor which adds more to the locking mechanisms of the lumbar vertebrae.
In addition to the thoracolumbar junction, can you think of any other sections in the spine that also might have a great deal of mobility?