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Spine Stiffness: A Critical Link Between Degenerative Disc Disease and health

–The Science Behind How Stretching, Compression, and Shear Stress Drive Cellular Physiology and Function.

MOVEMENT SENSORS

Let’s explore Spine Stiffness: A Critical Link Between Degenerative Disc Disease and health and the role of mechanoreceptors. These are sensors present in your body that detect movement and how they facilitate the transmission of mechanotransductive forces. Similar to a windmill that converts mechanical energy from wind into electricity, our body experiences this process through the normal movement of the spine, as long as it is properly aligned with good posture, free from movement dysfunction, and not affected by unresolved DDD. This not only affects nerve-to-brain and body function but also impacts cellular biochemical actions and the expression of DNA!

IN THE WOMB

Interestingly, a study conducted at USC Santa Barbara discovered that even babies developing in the womb are influenced by these forces. Apparently, bed rest during pregnancy, unless warranted by serious reasons, is unsafe and detrimental to the baby’s embryogenesis or development in utero!

In cells, mechanotransduction, like a windmill, translates physical forces such as stretching, compression, and shear stress into biochemical impulses and signals. These biochemical changes are astonishing, as they were only recently discovered. They can involve adjustments to intracellular concentrations of various biochemical components like enzymes, potassium, calcium, etc., as well as the activation of different signaling pathways. These changes can subsequently affect cellular and extracellular structures. This newfound knowledge sheds light on why chiropractic clinical research showcases numerous case studies addressing various health conditions.

IN CELLS

Surprisingly, through these mechanotransduced pathways, the mechanical forces present in the three-dimensional environments where cells exist contribute to regulating even the most fundamental cellular processes. This means that we need to revise our basic science textbooks to include the vital aspect missing in medical education – movement. Not just exercise, but consistent daily movement throughout the day.

 

 

Spine Stiffness: A Critical Link Between Degenerative Disc Disease and health in mechanotransduction

Even when mechanotransduction-related processes within cells are functioning properly, disturbances in the physical inputs they receive from their extracellular environments, especially from damaged, degenerative, or stiff joints, particularly the spine, can then lead to pathological consequences in a wide range of diseases and premature death.

STIFF JOINTS

Stiffness in your spine is usually caused by injury or lack of movement. It mimics what happens to astronauts in space. The loss of bone mass experienced by astronauts living for extended periods in reduced gravity is an interesting example of such a disturbance and its effects. The minimal amount of gravitational force exerted on the astronauts (relative to the gravitational force on the Earth’s surface) causes disruptions to normal mechanotransductive processes in bone tissues, leading to diminished tissue production and reduced bone mass.

A far more common but not unrelated example is the atrophying of muscle tissue that occurs in patients who become bedridden or otherwise immobilized for extended periods of time. And of course, there are the devastating effects of sitting disease and its impact on the body’s biological processes. Sitting for just seven hours a day increases your risk of death by 40%.

MECHANOBIOLOGY

How do we know this? Mechanobiologists have novel ways to look at humans safely, unlike most evidence-based sciences that use rats and animals, not humans. Mechanobiologists use animals, but they aim to study humans safely using novel techniques to validate their opinions. Unlike nearly everyone else, who conducts a rat study and then rationalizes it as applicable to humans. It makes no sense.

Well, I’m not alone in this thinking. It turns out that mechanobiologists have developed new novel ways to detect the changes of force and compression on cells and tissues and how they interact safely with humans.

But I want to talk about what they discovered about these changes of force and stress and the difference between tension stress and compressive stress on the intervertebral disc (IVD) and how it relates to chiropractic care and all-day movement. They have actually developed many ways to detect and measure this. Let me cover some of those, as I believe it will help you understand why you need to move all day long with a well-mobile functioning spine and why a chiropractor is necessary for the family.

INTERVERTEBRAL DISCS (IVDs)

For example, the unique functional and physical characteristics of IVDs, which link the vertebral bodies, constitute the main joints of the spine. They indicate that mechanotransduction plays a particularly prominent role in their normal function and, as the discs age, their dysfunction.

The purpose of the discs is to transmit physical forces, namely, physical forces resulting from muscle movement and the weight of the body, to the spinal column, with the discs providing the tension, flexion, and bending capacity that give the spine its flexibility. In effect, each disc functions much like a small shock absorber in a car, absorbing the physical forces delivered to the spine and protecting the bony vertebrae above and below it by keeping them separate. Of course, the main purpose of the disc is to protect the major nerves that exit and supply every tissue, cell, and organ in the body.

Spine Stiffness: A Critical Link Between Degenerative Disc Disease and health in spinal function

In addition, the disc in the spine is more than just a spacer. As it compresses and experiences changes in stress from daily movement, these forces propagate nerve signals to the brain and from the brain to the body for the functioning of tissues, cells, and organs of your body, just like a windmill or a power generator.

 

Central Nervous System

Your central nervous system which is your brain, spinal cord, and the 33 pairs of nerve roots exiting out between the IVD is the master controller to every system in your body, and its largely controlled by mechanotransductive forces through the normal motion of your spine, meaning the proper movement, spinal alignment, posture and frequency of spinal movement and it’s related structures is vital to the pathogenesis of numerous diseases and the ability to heal and regenerate. This is no longer a theoretical conjecture. It’s all worked out in science. 

We don’t want stiff spinal joints, and we want our backbones moving around 8-10 miles a day, the way our genetic constitution was written, like our ancestors who moved that way for a millennium. That’s what you need to take from this video. But I like to geek out on that science, time to prove what I said earlier. It’s all worked out in science…. so here we go…

ANATOMY OF THE DISC

Intervertebral discs (IVDs) consist of two main parts: the annulus fibrosus and nucleus pulposus. The annular fibrous is a thick outer ring composed of multiple layers of fibrocartilage. It surrounds the nucleus pulposus, which forms an inner core with a softer, gelatinous texture. Cartilage endplates on the top and bottom of each disc provide an interface between the disc and the vertebrae above and below it.

Spine Stiffness: A Critical Link Between Degenerative Disc Disease and health

The disc contains aggrecan, the primary proteoglycan responsible for maintaining tissue hydration. The nucleus has a higher concentration of proteoglycans than the annulus, providing greater hydration and a gel-like texture. The compressive strength of the spine is dependent on this water-binding capacity and the normal motion of the spine.

The interplay between mechanical, electrochemical, and biochemical forces is essential for the growth, maintenance, and healthy function of IVDs. The process of spinal movement stimulates mechanotransduction, translating external mechanical forces into biochemical processes within cells, tissues, organs, and even DNA.

Research Demonstrates

Various studies have demonstrated that mechanical stress affects gene expression and metabolism in IVD cells, both in vivo and in vitro. This impact extends to basic biological functions, healing, and pathology in virtually every level of disease within the body. Furthermore, spinal health during pregnancy is crucial, demonstrating the significance of chiropractic care during this stage.

Overall, understanding the relationship between spinal mechanics, IVD health, and mechanotransduction provides insight into the prevention and treatment of diseases associated with degenerative disc disease and spinal stiffness.

MOVEMENT MATTERS

It is startling to discover that mechanical forces play a critical role in nerve to tissue signaling and all cell types, including protein synthesis in DNA. These forces also impact disc formation during embryogenesis. Recent research has found that mechanical force contributes to the formation of intervertebral discs (IVDs) by pushing notochord cells into the IVDs during embryonic development.

 

In contrast, a study on human lumbar discs examined the effects of mechanical forces in vivo. Using discs from patients with idiopathic adolescent scoliosis, scientists studied how tensile stress and compression affect disc health. The study showed that such stress can cause decreased water content and cell density, matrix degeneration and calcification, and breaks in specific locations within the discs.

But how do we know this is scientifically proven and not just a theory?

EXPERIMENTS

Scientists can now measure the activation of nerve terminals under pressure using glass pipettes and pressure jets. Compression hypo-osmotic stretching can stimulate dorsal root ganglion on sensory neurons, allowing scientists to measure their response. However, these tests fail to fully account for structural interactions, such as focal adhesions in tissues. To address this, scientists have developed elastomeric matrices that replicate the physiological conditions of living tissues.

 

Now, let me geek out for a moment and explain some of this in more detail. Your doctor may not be familiar with this information, but that’s because they have a different area of expertise, such as chiropractic medicine.

Spine Stiffness: A Critical Link Between Degenerative Disc Disease and health and Chiropractic Care

We have methods to measure various forces on cells and tissues, which may eventually be applied in chiropractic research facilities. Shear loads, compressive loads, and twisting loads can all be measured using scientific tests.

Research has shown the importance of mechanical forces in cell and tissue health, particularly in relation to degenerative disc disease. Understanding these forces can contribute to advancements in chiropractic care.

Methods in Research

Using an elastic substrate, we can measure pressure changes similar to the deformation of a rubber band or stretched saran wrap when an object is placed on it. This method allows us to determine how pressure changes from small movements and mechanical forces affect the three-dimensional network of cells. This network consists of extracellular macromolecules and minerals, such as collagen, enzymes, and glycoproteins, which provide structural and biochemical support to surrounding cells. By using this technique, we can measure how sensory neurons and nerve signaling are influenced by movement stimulation, especially in the spine, and how it affects chemical changes within the cell.

Additionally, nanotechnology allows us to measure the natural traction forces that occur in the body during movements like squatting, standing, sitting, getting out of bed, and bending over. These small traction forces between spinal joints impact cellular responses in the intervertebral disc (IVD) and the surrounding tissues, including ligaments, muscles, and tendons, at a cellular level.

Amazing Techniques

Through traction force microscopy, we can examine the mechanical interactions between fibroblast migration and collagen deposition, which play a role in tissue regeneration, including wound healing and the regeneration of collagen within the IVD.

Furthermore, magnetic twisting cytometry can be employed to induce sheer loads and forces on cells, influencing the spinal morphology, IVD disc loads, and healthy stresses during the normal movement of the spine. A study published in The Spine Journal demonstrated how chiropractic adjustments and postural corrections affect spinal coupling and mechanical loads on spinal tissues. By correcting spinal alignment, posture, and spinal mobility through chiropractic care, the postural and shear loads on the spine can be normalized.

Restoring Segmental Motion with Chiropractic Care

Next, this restoration of motion segments and improvement in posture, in turn, activate sensors within spinal joints, acting as a “windmill” that transforms these healthy mechanical signals into stronger nerve signaling to the brain and throughout the body, down to the cellular level and even impacting DNA expression.

IVDs are impacted by various mechanical stimuli, such as shear stress, hydrostatic pressure, torsion, flexion, and electrokinetic changes. Chiropractic care, along with continuous movement of the spine, postural exercise, and spinal hygiene exercise, affects these mechanical stimuli.

 

IVD’s in Research

For instance, a recent study utilized a device with elastomeric substrates to investigate the effects of shear fluid flow and uniaxial strip stretching on actin cytoskeleton and cell orientation in IVDs. The results showed that after only 3 hours of application, the cytoskeleton and cells aligned themselves in the direction of the applied force.

Although there is no direct study correlating this to chiropractic adjustments, it can be inferred that within 3 hours following an adjustment, the mobilization of bones and stretching of tissues causes shear fluid flow and stretching on the cytoskeleton within cells. This leads to the alignment of cells within the tissue matrix, promoting healing and regeneration of tissues like ligaments, tendons, muscles, nerves, and especially IVDs.

 

Another similar study demonstrated how shear fluid flow and equibiaxial stretching influence the regenerative functions during fibroblast recruitment of fibronectin, with perturbed cells showing increased fibronectin fibril formation and localization at their peripheries. This indicates that mechanical forces from proper movement can stimulate biochemical responses that aid in tissue healing and regeneration, even repairing DNA.

FUTURE

In the future, with advancements in nanotechnologies, chiropractic research may be able to directly measure these impacts. However, this basic science research provides evidence of the benefits of chiropractic care, even without direct correlated studies. Although it would be nice to have direct research proving these benefits, we already know through our understanding of basic science. Nevertheless, it is encouraging that we are moving closer to having that direct evidence.

Spine Stiffness: A Critical Link Between Degenerative Disc Disease and health

While studies on mechanotransduction in general are of great interest, it is better to focus more closely on the two most significant forces affecting the spine: tensile stress and compression. Tensile stress occurs when pulling forces cause lengthening of the material in the direction of the force and is regularly applied to IVDs and the spine. Cyclic tensile stress refers to repetitive changes in tensile stress over time, which might explain the effectiveness and importance of repetitive chiropractic care in changing spinal structures.

On the other hand, compression involves inwardly directed forces that decrease the length of an object in the same direction as the applied force. Gravity is a common example of a compressive force applied to the spine. Similar to cyclic tensile stress, dynamic compression refers to repetitive changes in compressive force over time, as opposed to static compression.

SPINE

In the spine, the annulus fibrosus provides the primary resistance to tensile stress and the nucleus pulposus provides most of the resistance to compressive forces. In fact, when a compressive force is applied to the nucleus pulposus, the nucleus is deformed, resulting in the application of tensile force to the surrounding annulus fibrosus and endplates. So, even though the two types of forces effectively occur in conjunction, the nucleus pulposus absorbs the compressive force, while the annulus fibrosus dissipates the secondary tensile force. This might explain why nonsurgical decompression actually targets a herniated disc and heals the annular fibers.

The two types of cells also respond differently to the application of cyclic tensile strain. For example, when the cyclic tensile strain was applied in vitro to bovine nucleus pulposus and annulus fibrosus cells, the majority of observable responses—including, for example, inhibition of MMP expression and increased type I collagen transcription—occurred only in the annulus pulposus cells, a fact that likely reflects the different forces encountered by the two different cell phenotypes in vivo.

Don’t Freak Out 

I’m just saying, The positive or negative effects of tensile strain on IVDs are highly dependent on the circumstances and the specific cell types to which they are applied. For example, in a study I noted earlier, they found a variety of negative effects because of tensile stress applied to scoliotic discs, whereas another study by different authors demonstrated that tensile stress applied to fibrochondrocytes isolated from the annulus fibrosus of rats actually has a protective effect under conditions of inflammation.

Specifically, they showed that exposing cells to tensile stress at the same time as they were exposed to an inflammatory stimulus moderated the inflammatory response by decreasing cellular expression of the catabolic mediators of inflammation. You see in bodybuilding, that tensile stress on the muscle has an anabolic effect and the resulting stress builds and strengthens the muscle. The same effect happens when you restore normal motion to the spine, the disc also receives anabolic effects and it regenerates.

Scoliosis and Chiropractic Care

Scoliosis or curvature of the spine has negative effects, too many to discuss here. But after we restore motion through chiropractic care, it decreases cellular expression of the catabolic mediators of inflammation, and using these methodologies, we now have the backing in science as well as the clinical evidence on before and after x-ray evidence following chiropractic care. Again, this is why chiropractic care decreases inflammation naturally and halts or stops the catabolic mediators of inflammation and even stimulating new cartilage cells, especially if you move a restored joint for three minutes every half an hour. I’ll talk later about that.

Another study by one scientist meanwhile, demonstrated further how different cell types and different stimuli can lead to a highly divergent outcome. Specifically, they found that the responses of annulus fibrosus cells to cyclic tensile strain depend both on the frequency of the strain applied and whether or not the annulus fibrosus cells are derived from degenerated or non‐degenerated tissue.

 

For example, cyclic tensile strain at a frequency of 1.0 Hz caused annulus fibrosus cells from non-degenerated tissue to decrease the expression of catabolic genes, whereas cyclic tensile strain at a frequency of 0.33 Hz caused the same type of annulus fibrosus cells to increase matrix catabolism. This is another reason we need to move our spine for three minutes every half an hour, to make sure we stimulate the anabolic in our biology and not the catabolic mechanisms.

Spine Stiffness: A Critical Link Between Degenerative Disc Disease and health in Daily Spinal Hygiene

So maintaining your spinal hygiene by making sure your spine has its all day normal range of motion and all day tiny movement hygiene along with regular chiropractic checkups is essential in today’s sedentary world.

I’m Dr. Matt Hammett, reminding you to: ‘Lighten Up, Move Better and Live Fuller’.

 

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