Spinal Column | yogawithjames

The Spine & Corresponding Movements

The spine is the primary structure that supports our body. Its shaped in a unique way that provides both movement and stability. The individual shapes allow for some movement, while preventing others. There are various muscle groups that attach to the spine, other bones that connect as well. Our nervous system is housed and protected by this column. Simply put, it does a lot for us, and so keeping our spine healthy is of great importance.

The vertebral column is comprised of 3 main curves. The parts that curve forward are called lordotic curves, and the opposite curve is called kyphotic.

Starting at the bottom the 5 vertebrae between the ribs and pelvis are part of the Lumbar spine. These are the biggest vertebrae of our spine which have a lordotic curve. As mentioned in the core musculature component on this site, these vertebrae are supported by these groups of muscles because of the lack of bone support in this volume of our body. Moving upward the Thoracic spine are 12 vertebrae where the ribs attach. The Thoracic spine and the ribcage comprise the Thorax. These vertebrae have a kyphotic curve. And then lastly at the top of our spine are 7 vertebrae that make up the Cervical spine. They are very short and small relative to the vertebrae beneath them, and so they are very vulnerable to injury. Just like the Lumbar, they have a lordotic curve. At the bottom, below our Lumbar, there is a wedge shaped section of the spine that is fused before birth known as the Sacrum. This wedge fits snug into our pelvis which forms the Sacroiliac joint. And at the very bottom below the Sacrum is our Coccyx (tailbone), which is fused as well.

The vertebrae are a collection of similarly shaped bones stacked on top of one another. The dimensions or size of the vertebrae decrease as you move up the spine. In total there are 24 unique vertebrae and 9 fused vertebrae. In between each vertebrae are known as Intervertebral discs. These discs provide shock absorption, allow movement, and provide support in holding the vertebrae together. Injuries tend to happen where one curve of our spine meets the next. The majority of these injuries tend to happen at the bottom where the Lumbar meets the Sacrum. This is because the very highly mobile lumbar is joining the stiff/rigid Sacrum, and the disc in between takes on a lot of force. Most spine injuries involve these Intervertebral discs. And when there is injury to the discs, the shock absorption, freedom of movement, and stability that the discs provide is not done as well.

More on these discs. The structure contains a outer shell, and inside is a nucleus which moves like a jelly donut. The outer shell is very fibrous so that the discs don't slip around. The force of the fluid inside the disc is outward in all directions. By applying actions in our asana practice that creates Axial Extension (lengthening the spine), the weight of the spine above is reduced, and therefor less pressure is exerted on the discs below. More about how to create this Axial Extension is discussed here.

Damage to this discs are very common. Bulging discs, herniated discs and ruptured discs are often associated with pain or other sensations in the back, head, neck, shoulders, arms & legs. The reason these conditions lead to pain is because this fluid presses into the nerves mentioned earlier than run through the center of the spine. Ow. Carefully practicing yoga with good instruction can fix this. A good rule of thumb is that when we are experiencing pain in a joint, we can engage and strengthen the connective tissue that supports that joint to alleviate pressure. More on this later, but know that solutions do exist!

The degree of movement in our spine varies. The cervical spine moves freely in all directions, and is the most flexible part of our spine. The thoracic spine is able to move in all directions as well, but it does not move as freely as the cervical spine. The lumbar spine is very mobile when in movements of forward/backward and side to side, but it is somewhat limited in rotation.

While this is very brief, I'll be diving much deeper with the spine and how it moves in the Asana guide, within the specific positions discussed.