Spine Anatomy for Yoga: The Five Regions and How Each One Moves

There is one piece of spine anatomy that changes how a person teaches yoga more than any other, and it is this: the lower back barely rotates. Not a little less than the rest of the spine — almost not at all. Perhaps five percent.

Most teachers learn it late, usually after years of cueing twists in a way that asks the one region of the spine least able to do the job. This post is the vertebral column as a yoga training teaches it: what a vertebra is, the five regions, how each one moves, and what follows for the way you practice and cue.

This is anatomy for teaching, not for treating. If a student has back pain, the answer is a doctor, and nothing below changes that.

What the spine is doing

The vertebral column is a flexible column of 33 vertebrae connecting the trunk of the body to the skull and the limbs. It is designed to move in several directions — flexion, lateral flexion, extension and rotation — and at the same time to house and protect the spinal cord.

Those two jobs pull against each other, which is the whole story of the spine. It has to be mobile enough to bend and rigid enough to protect the main pathway between the brain and the rest of the nervous system. Every region resolves that tension differently, and the differences are not small.

Deviations from neutral alignment are common, and they matter, because the spine's position directly affects how the body functions. That is why so much of a Hatha syllabus keeps returning to the same instruction to lengthen before you bend.

What one vertebra is made of

Each vertebra has two main parts.

• The body, a massive block at the front (anterior). This is the weight-bearing part.
• The vertebral arch, at the back (posterior). It carries the bony landmarks you can feel through skin: the spinous processes down the midline, and a transverse process out to each side.

The gap between the body and the arch is the vertebral foramen, and when the vertebrae are stacked those gaps line up into the channel the spinal cord runs through.

Between the vertebral bodies sit the intervertebral discs — fibro-cartilaginous pads that absorb shock. They are the reason a spine can take the load of standing all day, and the reason loaded flexion is treated carefully in any responsible teaching.

Those spinous processes are also the most useful landmark a teacher has. When you place a hand on a student's back in a twist or a backbend, they are what is under your fingers.

The five regions, and how each one moves

Cervical spine — the neck

The vertebral bodies here are small and the discs between them thinner than anywhere else. This region has the greatest mobility in the whole spine, and its spinous processes are short, which allows for greater extension.

Mobility bought at the cost of stability, in other words — which is why the neck deserves more caution than any other region. It moves beautifully and it is the least protected part of the column. In anything weight-bearing on the head or shoulders, this is the region to be conservative about.

Thoracic spine — the upper and mid back

The vertebral bodies are more circular here and not as thick as the lumbar ones. What distinguishes this region is that it carries additional facet joints to join the ribs, and the shape of those joints primarily allows rotational movement.

Two things limit it in return. The shape and direction of the spinous processes restrict extension, and twelve ribs limit forward and lateral bending. So the thoracic spine is the rotating region of the spine and the reluctant backbending one — which is the opposite of how most people instinctively try to use it.

The rib cage — not a region, but it decides two of them

Twelve pairs of ribs and the sternum form the cage. The first seven pairs are true ribs, attaching directly to the sternum. Ribs eight to twelve are false ribs, connected to the seventh rib by cartilage, which gives them more mobility. The last two pairs, eleven and twelve, are floating ribs with no attachment at the front at all.

That graduated freedom from top to bottom is why the lower ribs move so much more in a full breath than the upper ones, and it is worth knowing before you teach anybody to breathe into the sides of the body.

Lumbar spine — the lower back

The vertebral bodies here are the thickest in the column, because this is where the load is. The facet joints allow forward flexion, lateral flexion and extension.

What they do not allow is rotation. There is no axial rotation in the lumbar spine — perhaps five percent, and that is being generous. The navel sits at roughly L3, which gives a usable rule of thumb: there is no rotation below the navel.

Sacral and coccygeal — the fused base

The bottom two regions are barely regions by adulthood. Five sacral vertebrae have fused into one sacrum and four coccygeal vertebrae into one coccyx. They are structure rather than movement, transmitting load from the spine into the pelvis.

What “no rotation below the navel” does to a twist

Take a seated twist. A student is told to twist deeper. If they try to find that depth in the lower back, they are asking a region with almost no rotational range to produce rotation — and what usually happens instead is that the pelvis turns, or the lumbar spine is levered around by an arm braced against a knee.

The thoracic spine is where a twist belongs. So the useful cues change:

• Length before rotation. Lifting through the spine first makes room between vertebrae; twisting a compressed spine does not.
• Turn from the ribs and the upper back rather than from the waist, and say so in those words.
• Treat the arm against the knee as a place to rest, not a lever to crank on. A twist produced by leverage is one the spine did not choose.
• Keep the pelvis honest. If the sitting bones lift and turn, the twist stopped being a twist.
• Expect the neck to over-deliver, because it is the most mobile region and it will happily supply range the mid back would not. A head turned further than the chest is not a deeper twist.

The same logic applies to backbends in reverse. The thoracic spine resists extension by design, so a backbend that feels like it is happening entirely in the lower back usually is, and the answer is to open the front of the chest and the hips rather than to push further into the crease.

The core, and what it is for

In a yoga context the core is not an aesthetic project. It is the muscular support that lets the spine hold a neutral position under load and return to it afterwards — which is why core work sits in a syllabus next to spinal health rather than next to strength training.

How that support works — muscles in opposing pairs, one shortening while its partner lengthens — is covered in the muscular system in yoga.

Where to learn the rest of it

Spine anatomy is the part of this subject where reading takes you furthest, and also the part where the last step has to happen in a room. You can learn the five regions from a page. Learning to look across a class and see which student is twisting from the ribs and which is levering from the waist takes somebody standing beside you saying so.

On our 200 hour yoga teacher training in Rishikesh, anatomy and physiology is taught as a daily class alongside alignment, correction and adjustment, with 15 to 18 students in the room — which is few enough that the theory gets tested against real spines the same morning it is taught.

Next in the series

The channel running through every vertebra in this post is the spinal cord, and that leads to the next system: yoga and the nervous system. For the frame the spine is part of, see the skeletal system in yoga, and for the overview of all seven systems, yoga anatomy for teachers.