Disc Herniation Spondylolisthesis

Spondylolisthesis is the slippage of one vertebra on another—frequently found with disc herniation. However, in this recent paper titled: “Over-reporting of the disc herniation in lumbar spine MRI scans performed for patients with spondylolisthesis” 1 they sought to find if disc herniation is over-reported and in turn, possibly over-treated.

Spondylolisthesis is best diagnosed when the spine is under load. Many MRI scans, because done in the lie-down position, miss these small (or large) slippages. To accurately assess one for a spondylolisthesis, the spine is best visualized by x-ray in the forward bending and backward bending position. Upright MRI is also another great way to assess; however, the access to these expensive machines may not be available.

The authors of the above paper discuss how it is imperative to find an accurate diagnosis for both the conservative and surgical management of back pain.

Disc herniation is often found with spondylolisthesis. However, what they found was disc herniation reporting was often over-reported and believed that the disc herniation was more of a pseudo disc herniation rather than an actual disc herniation.


What do the authors mean by pseudo-herniation?


The authors point to a nomenclature issue. In Fardon’s 2014 paper 2 he helps clarify the language professionals use when discussing disc herniation, extrusion, protrusion and bulge. However, the authors of this paper explain that Fardon’s article does not address this nomenclature in light of spondylolisthesis.


They point out in this retrospective study of 258 patients that disc herniation was over-reported because the disc herniation was read with the superior vertebra in mind rather than referencing the lower vertebra. In other words, if the radiological reporting used the lower vertebra as a reference point, the reporting of a disc herniation would be much less because the outer disc border remained anterior to the posterior vertebral ring apophysis. Therefore, it is essential to deferentially diagnose whether symptoms are related to a real disc herniation or due to the mechanics of a spondylolisthesis. A spondylolisthesis can throw off the reporting in this case.



Dynamic Disc Designs creates 3d models to help reveal the dynamics of disc herniation, including the up-roofing of the disc material. This mechanism is shown in our Professional LxH Model, with the added features of spondylolisthesis.


Ergonomic Seating

Lower back pain is a global problem. Its rate has increased steadily over the last several decades, with now more than 637 million individuals suffering around the world. 1

What has also been steadily increasing is the act of sitting. People are working from home more than ever, especially with the recent coronavirus outbreak, forcing people to self-isolate to reduce the spread of the disease. Even before COVID-19, businesses and individuals have increasingly adopted computer-based platforms that increase screen time. Engaging with screens are a large part of life for many and presents a new reality of work life.

What do we know about the origins of lower back pain?

Lower back pain is considered multifaceted with intervertebral disc degeneration (IDD) being the most probable leading cause. IDD is a precursor to many commonly known conditions, with only some of them being disc herniation, spondylosis and lumbar spinal stenosis. 2 A common radiological finding within IDD and the other related spinal conditions are the reduction of spacing between the vertebra. Or, in other words, disc height loss. So how does disc height loss occur?


Disc height loss is normal through the day/night cycle. As humans, we lose approximately 20% of the fluid from our discs over the day to regain it at night, when we lie down to sleep. 3 The regaining or recovery of the fluid and respective height is imperative for the health of the disc. If we do not recover the height, this leads to a state of compression and resulting pain. On the flip side, if discs regain too much fluid, this also results in over expansion as we see with astronauts. Problems also incur if one lies in bed for too long.


So we need a balance—a balance of compression and decompression to our spines. If there is an excess in either direction, problems can arise. To minimize over-compression, we have to look at our postural behaviours. And one act that we just do too much of is sitting. We know that sitting causes disc compression and height loss as the spine undergoes the movement of flexion. 4. And why does the spine round into that posture? Well, the main reason is because of traditional seat pans 5 which cause the lumbar spine to round and causing increased pressure on the disc. 6

So what is it about sitting that is so different?

If you look carefully at a single motion segment (vertebra-disc-vertebra complex), each vertebra is separated by three joints. The largest and most important anatomical structure in the fight to resist compression is the intervertebral disc, which supports about 80 percent of the load in the standing posture. The remaining 20% load is distributed through the facet joints. Lumbar Model - Intervertebral Disc and FacetsProfessional LxH Dynamic Disc Model

I often describe this using a tricycle as a metaphor. The big tire on the front is like the disc, and the two facet joints are similarly like the two little tires. Sitting will place all the pressure over the big tire on the front of the tricycle, which increases the pressure on it. And over time, because the disc is a hydraulic structure, water will squeeze water out of it, reducing its height.

Neutral Loading

Office Chairs and Lumbar Alignment

To optimize sitting alignment during sitting, researchers have looked at lumbar supports to balance the motion segments of the spine. 7 These groups of researchers asked one question: Which office chair feature is better at improving spine posture in sitting? What they did was evaluate 28 participants, measuring by x-ray postures in four different chair conditions: control, lumbar support, seat pan tilt and backrest with scapular relief. They concluded that not one of the four stood out with regards to improving lumbar flexion, but the angled seat pan did improve pelvic posture significantly. They also discussed how the tilting seat pan did reduce flexion in the lumbar spine and suggesting that this may still be of practical significance. 8


Ergonomic Seating from Dynamic Disc Designs Corp.

At Dynamic Disc Designs, we are introducing ergonomic seating. Some may know the CEO, Jerome Fryer BSc DC, who has, from an early start in his career, observed the increasing trend of global sitting. In 1998, he made a simple observation during his training years as a chiropractor. And this simple observation of self-decompression led to two publications in The Journal of Bodywork and Movement Therapies and also The Spine Journal.

With the knowledge gained, he thought it was time to bring it to others.

With an adjustable seat pan and a saddle orientation to keep your hips in a more neutral position, the Ergonomic Saddle – Task Chair will optimize lumbopelvic posture. A 12-degree seat pan tilt is adjustable to each user’s unique lower back.

Seat Pan Angle Adjustability

Adjustable Tilt






Telehealth in light of COVID19

The current focus of health systems on hospital preparedness and public health measures to reduce spread of the COVID-19 virus, and flatten critical illness curves, has led to the reduction, or temporary closure, of many in-person clinical services around the world.  Despite the importance of readiness for spikes in critical illness related to COVID-19, as well as for maintaining physical distance to curb spread of disease, it is also crucial to keep in mind that many patients are currently at risk for experiencing gaps in care, as services deemed non-urgent have been put on hold.  Health care providers are finding that telemedicine may present a possible solution to the issue of continuity of care while maintaining physical distance during the COVID-19 pandemic restrictions.

What is Telemedicine?

The World Health Organization defines telemedicine as “The delivery of health care services, where distance is a critical factor, by all health care professionals using information and communication technologies for the exchange of valid information for diagnosis, treatment and prevention of disease and injuries, research and evaluation, and for the continuing education of health care providers, all in the interests of advancing the health of individuals and their communities.”1  As this definition suggests, there are many potential contexts for leveraging telemedicine technologies and approaches – as well, there is a growing body of literature to support and inform the use of telemedicine in practice.

Telemedicine is currently demonstrating utility in an environment where it is necessary to maintain distance while providing optimal patient care.2,3  Lock downs or quarantines due to COVID-19 have pressed the need to move the delivery of certain health care services onto a telemedicine platform for a number of patient scenarios.  One of these is to facilitate ongoing dialogue between patients and their health care providers regarding existing and/or chronic health conditions.4 A crucial part of this dialogue is clear, sound and effective patient education.

Patient education on a telemedicine platform – to support the initiation of treatment regimens, follow-up and/or self-care at home – can be carried out in accordance to evidence-based findings for effective in-person patient education practice. One such finding is the utility of demonstrations and visual aids in order to elucidate to patients their pathology and reasons for their symptoms, and in order to explain why and how certain treatment or self-care regimens/behaviours will be effective.5,6  In the case of patient care related to spinal and musculoskeletal conditions, this could include the use of spine and intravertebral disc models.

How Spine Models by Dynamic Disc Designs could help

Spine models by Dynamic Disc Designs are anatomically accurate with features that can easily and clearly be pointed out to patients during their education sessions with their health care provider.  This is especially useful when utilizing a telemedicine platform, where the patient may need extra support to feel connected to the health care provider’s message.

Jordan van der Westhuizen is a Managing Partner and an Occupational Therapist (Hons) at Enhanced Occupational Therapy in Perth Australia.  He utilizes Dynamic Disc Designs spine models in his patient education sessions, both in-person and via telemedicine.  He notes,  “…Not only for in-person consultations but now for telehealth, our spine model allows the patient to understand their back issues and mechanisms causing pain which is a key component in the patient’s health journey.”

Telehealth - Spine Education

Dr. Robert Peace is a chiropractor in Tulsa Oklahoma who also currently utilizes Dynamic Disc Designs models for patient education sessions via telemedicine.

“The ddd spine models are an invaluable resource for the relating of findings and communicating the many causes of spine pain. The patients always seem to get a better understanding of their condition when viewing the detailed anatomy on this model.  I’m looking forward to receiving my next model – the Medial Branch Dynamic Disc Model – to even better demonstrate and educate the patients in regards to facet joint inflammation and medial branch involvement.”

We are currently experiencing a global health environment that calls for innovation in patient care on many levels. Health care provided through telemedicine offers opportunities for health care providers to safely and quickly triage patients with symptoms that may be related to COVID-19, but also provides a platform for continuity of care for patients with other illnesses, particularly those that are chronic and thus require ongoing, long-term follow-up.   The use of visual aids such as spine and disc models for patients with spinal issues can enhance the patient education that is an integral component of optimal care for patients with chronic conditions



  • World Health Organization. (1998, December 11-16). A health telematics policy in support of WHO’s health-for-all strategy for global health development: report of the WHO group consultation on health telematics. Geneva. Geneva. https://apps.who.int/iris/handle/10665/63857
  • Xiaoyun Zhou, Xiaoyun Zhou, Centaine L. Snoswell, Louise E. Harding, Matthew Bambling, Sisira Edirippulige, Xuejun Bai, and Anthony C. Smith. (2020, March 23). The Role of Telehealth in Reducing the Mental Health Burden from COVID-19. Telemedicine and e-health, 26(4). https://doi.org/10.1089/tmj.2020.0068
  • Judd E. Hollander, M.D., and Brendan G. Carr, M.D. (2020, March 11). Virtually Perfect? Telemedicine for Covid-19. New England Journal of Medicine[online]. DOI: 10.1056/NEJMp2003539 https://www.nejm.org/doi/full/10.1056/NEJMp2003539
  • Vivek Chauhan, Sagar Galwankar, Bonnie Arquilla, Manish Garg, Salvatore Di Somma, Ayman El-Menyar, Vimal Krishnan, Joel Gerber, Reuben Holland, Stanislaw P Stawicki.(2020) Novel coronavirus (COVID-19): Leveraging telemedicine to optimize care while minimizing exposures and viral transmission. Emerg Trauma Shock[serial online], 13(1), pp.20-24. http://www.onlinejets.org/article.asp?issn=0974-2700;year=2020;volume=13;issue=1;spage=20;epage=24;aulast=Chauhan
  • Audrey Jusko Friedman, Roxanne Cosby, Susan Boyko, Jane Hatton-Bauer & Gale Turnbull. (2010, December 16). Effective Teaching Strategies and Methods of Delivery for Patient Education: A Systematic Review and Practice Guideline Recommendations. Journal of Cancer Education volume 26, pp12-21. https://link.springer.com/article/10.1007/s13187-010-0183-x
  • Robert P. Riemsma Erik Taal  John R. Kirwan  Johannes J. Rasker. (2004, December 8). Systematic review of rheumatoid Arthritis patient education. Arthritis care & Research, 51(6), 1045-1059. https://doi.org/10.1002/art.20823



A recent study done during 2019 1 by several specialists was conducted to uncover the relation of immediate and increasing back pain to exposures to seated postures. It’s a systematic review of studies that include objectively measured sitting time.

What was the Context?

Low back pain (LBP) is one of the most prominent causes of disability globally. The years spent living with a disability caused by LBP has increased to more than 50% in-between 1990 to 2015. For years, prolonged periods of sitting time are reported to be associated with LBP. 

Sitting too much because of your job has been suggested as a risk factor for LBP, however, data to support these claims are slightly unclear. One reason for this lack of data can be linked to the high prevalence of sitting and LBP in the general population. This in addition to the multifactorial nature of LBP itself.

The review study was published and done to carry out a systematic review of studies. It’s aimed to find out if sitting times measured objectively is connected to the swift increase of low back pain (LBP).

It’s measured objectively through a time trial that’s laboratory-controlled, wearable sensors, and direct observation. An increase in LBP is ascertained by the pain scale rating in individuals who are 18 years old and older.

What was the Methodology?

The review protocol was registered with the International Prospective Register of Systematic Reviews on October 19, 2017. The reporting format of the review followed the recommendations and guidelines of the Preferred Reporting Items of Systematic Reviews and Meta-analyses.

The researchers looked at four electronic databases. They were EMBASE, PubMed, SPORTDiscus, and Cumulative Index to Nursing and Allied Health Literature. All four were carefully examined from the beginning up to September 1, 2018. 

Studies used were cross-sectional studies and cohort, and randomized controlled trials. Sitting time was measured objectively, and it was matched with a measure of low back pain in adults. 

figure 1.2 LBP study

However, excluded studies are those with no control session and each done during a separate day. The full-text review, screening, data extraction, and the risk of bias assessment (Quality in Prognosis Studies) of included papers were independently completed by 2 reviewers. There was also a third reviewer present to take care of the disagreements.

What were the Results?

606 articles were pinpointed through the database searches. In addition, 3 articles were identified by reviewing a list of references or relevant papers, along with a hand search. Among these articles, the researchers removed 248 duplicates. 

Titles and abstracts of the 361 remaining articles were screened. For further review of eligibility, 75 full papers were accessed. The 65 articles were excluded. The 10 articles left and the data for 330 participants were included in this study.

All in all, a total of 609 articles have been identified. However, 361 titles and abstracts were screened. Afterward, 75 full-text articles were examined for being eligible. 10 articles fit the criteria for inclusion. 

Every one of them except for 1 reported that sitting time is associated with the immediate increase in lower back pain. 6 of the articles have reported clinically relevant pain levels.

One-half of the studies included were found to have low risks of bias. What remained was determined simply as having a moderate bias risk.

What Has Been Discussed?

The researchers found that sitting down for total durations ranging from 1 hour to 6.96 h/d for 5 days is connected to the immediate increases in LBP in people. 

It happens with and without a clinical history of LBP — both in the field and laboratory settings. Similar results can be found when the studies included only had a low risk of bias.

table 1 01

table 1 02

table 1 03

table 2

The consistency of the findings was high. Participants who have a history of LBP report high levels of pain intensity compared to asymptomatic controls. This was reported after an identical exposure to sitting in a laboratory setting. 

However, pain responses (even if they’re lower) were in both parties, with or without LBP. It is typically assumed that sitting aggravates the existing cases of LBP. But then they also found that sitting also provoked pain in individuals, even if they don’t have a history of lower back pain.

The strength of this review is that a systematic and comprehensive search strategy was used to identify potential articles that are related to the research question. The researchers particularly looked for articles that involved sitting over sedentary behavior. 

The study also has no limitation of time or language. It minimizes the chance of missing potential articles to include.

The objective measures of sitting time are linked to the immediately increased ratings of perceived LBP in adults, with and without a recent history of lower back pain. 

However, it continues to be unknown whether this increase has clinical implications. There’s also an absence of a conclusion in-between sitting and clinically relevant episodes of LBP that can be made.

And based on their findings, the researchers would recommend and suggest prospective studies in the future that would match the objectively measured exposures, which were analyzed objectively with temporally related measures of pain. It is done to determine if sitting time is a trigger of a clinical episode of LBP.


A study 1 conducted by several researchers in the Department of Orthopedic Surgery in Rush University Medical Center in Chicago USA looked closely on the biomechanics of the lumbar facet joint, and its effects on the overall spine mechanical behavior.

Why Conduct Such a Study?

Facet joints, also known as zygapophyseal, are complicated biomechanical structures in the spine. It has a complex 3D anatomy, in addition to variable mechanical functions when there are different spinal movements and effects on the overall spine mechanical behavior.

The facet joint’s 3D morphology is linked to its biomechanical function. The failure of the facet joint’s biomechanical function can lead to osteoarthritic changes in it. It can also implicate other spinal disorders. This includes degenerative spondylolisthesis.

The review article summarized the anatomy of the lumbar facet joint relevant to its biomechanical function. It also examined the biomechanical behaviors of the lumbar facet joint when put under different loading conditions.

What Was the Methodology?

Facet joints and intervertebral disks are part of the entity called the spinal motion segment. It’s also called the three-joint complex.

Sometimes, it’s also referred to as the articular triad. As they function together, the structures in the spinal motion segments give physiological spinal motion. It protects the spine through preventing activities that can cause injury.

The loss of intervertebral disk height is associated with disk degeneration. This affects the mechanical behavior of facet joints.

Sufficient understanding and proper knowledge of the anatomical geometry of the facet joint surface and capsular structures is essential for understanding the biomechanical function of the lumbar facet joint.

What Were the Results?

Interaction Between the Intervertebral Disc and the Facet Joint

Intervertebral disks and facet joints are part of the spinal motion segment. As they function together, the structures in the spinal motion segments provide physiological spinal motion. It protects the spine through preventing activities that can cause injury.

Mechanisms of Axial Compressive Load Transmission Through the Facet Joint

There are complex mechanisms by which facet joints transfer the axial compressive load because the lumbar facet joints from a synovial joint with low friction and nearly vertical articulating surfaces.

There are 3 possible mechanisms:

  • Through the articular joint surfaces.
  • Through capsular ligaments.
  • Through direct connection in between the tips of the articular processes and the lamina (the pars interarticularis).

Axial compressive load transmission via direct contact in between the tips of articular processes and the neural arch is essential, especially when the lumbar spine is extended.

Facet Biomechanical Functions at Different Spinal Positions

Facet joints accomplish different biomechanical functions when faced with different spinal positions. This section reviewed the biomechanical behaviors in:


Contact between the tips of the inferior articular process and the pars interarticularis can occur in lumbar extension. Especially if the intervertebral disk loses its height. The results of finite element analysis simulations suggest that hyperextended activities can cause impaction of the inferior process.

Forward Flexion

In a lumbar forward flexion, the inferior articular processes move superiorly in allusion to the superior articular process of the lower level.

Facet joints have an essential part in keeping lumbar stability in forward flexion. Apart from the restriction of normal physiologic flexion, the one that is being forced over the superior process is the inferior articular process. Afterwards, the compressive loads borne by the facets amplify again compared to those supported in the neutral position.

This phenomenon, however, is considered as a possibility that can cause degenerative spondylolisthesis.

Axial Rotation

The facet joint’s articular surfaces press together on one side, and then often open up on the other. This is what happens in a lumbar axial rotation.

We have the results of trabecular orientation and photoelastic experiments. And it suggests that the superior articular processes undergo bending stress within an axial rotation through compression in the tension and in the lateral direction.

Lateral Bending

There’s limited information present in publications on the facet joint’s biomechanical behavior under lateral bending. Here, the inferior articular process glides in the superior direction. It does so in reference to the superior articular process of the inferior vertebra. It’s on the convex side of the spinal curve, and on the opposite direction on the concave side.

What Was the Conclusion?

The lumbar facet joint has a complex 3D geometry. It has small components inside of the small joint. They are all directly linked to facet joint’s biomechanical functions and the motion segment in different spinal positions.

But if we oversimplify the facet joint as a flat joint, it may keep us from properly understanding the functions of the facet joint.

Axial load transmission and forward translation in motion segments can’t be wholly comprehended if one does not consider the special relationship among the lumbar spine’s posterior elements. Medical imaging modalities make room for 3D modeling plus the spinal model’s reslicing in the clinic.

But extracting valid information can’t be done if we do not understand the facet joint’s 3D geometry and its function.

What's the Relationship Between MRI Findings & Clinical Symptoms in Patients with Suspected Lumbar Spinal Canal Stenosis_

A recent study 1 published in the last legs of 2019 set out to find the correlation between clinical symptoms and MRI findings in patients who are suspected to be suffering from lumbar spinal canal stenosis.

What was the Context?

Lumbar spinal stenosis (LSS) is the most common sign that a patient over the age of 65 will need a spinal surgery. What is LSS? It is a condition that shows decrease in the available space for the vascular and neural components of the lumbar spinal cord.

Within clinical practice, symptomatic LSS comes with different symptoms. This includes: buttock pain, bilateral or unilateral neurological disorder, and pain in the lower extremities.

LSS manifests usually because of less space present for neural and vascular structures of the lumbar spine. The definition of LSS has two aspects: structural abnormalities and clinical manifestations. Both are a result of certain physical abnormalities.

Previous studies have shown that clinical symptoms showing mild to moderate lumbar LSS might exist in less than half of patients.

So in order to define destructive LSS, it’s important that clinical symptoms match up with the imaging results. This is the reason why using clinical findings along with radiological evaluation through magnetic resonance imaging (MRI) is seen as proper standard in diagnosing LSS.

Numerous clinical criteria and imaging are available for the diagnosis of LSS. But despite the availability, coming up for the right diagnosis is a challenging part for radiologists and clinicians.

Therefore, this study aims to assess and understand the relation between clinical symptoms and MRI findings in groups of symptomatic and asymptomatic patients having suspected LSS.

What was the Methodology?

Using a case-control study, there are two groups of 100 symptomatic and asymptomatic individuals involved. Their ages range from 20 to 84 years old.

Both the groups have suspected lumbar spinal canal stenosis. They were all referred to the imaging unit for lumbosacral MRI. Within the study, patients’ clinical symptoms and radiological parameters in MRI were recorded. Afterwards, the researchers evaluated the results of the correlation between clinical symptoms and MRI findings.

What Were the Results?

Throughout the duration of the case-control study, 100 patients in the case group with signs and symptoms of LSS were evaluated.

100 patients in the control group who underwent lumbar MRI were also evaluated throughout the study period. Age ranges of the case group were between 21 to 84 years old. While the age range for the control group was 20 to 84 years old.

Table 1 in the study showed the prevalence of clinical symptoms in patients who did or didn’t have LSS symptoms.

Table 1 Frequency of clinical symptoms in patients with and without LSS

Table 2 shows the quantitative and qualitative radiological features in case and control groups.
Table 2. Quantitative and qualitative radiological features in case and

What Does This Mean?

The most common clinical manifestations of patients in both case and control groups involved:

  • Mechanical low back pain
  • Radicular pain
  • Gluteal pain

There were also no significant relationships between most clinical symptoms with each of the radiological indices separately. The highest significant correlation was observed between radiological indices and neurogenic claudication.

What Was Concluded?

Based on the results of the quantitative criteria of MRI imaging findings, the central spinal canal cross-section and lateral recesses cross-section had the highest specificity and sensitivity for LSS diagnosis in asymptomatic and symptomatic patients with suspected LSS.

The strongest observed correlation? It was between neurogenic claudication and LSS diagnostic radiological markers.