lumbar stiffness

Goal of the Study?

In this primary research article1, the authors had two goals: (a) Determine and quantify the relationship between biomechanical and neurophysiology measurements in lower back pain patients and (b) examine if the correlations differ when considered regionally (lumbar back) or segmentally.


Why are they doing this study?

To improve our understanding of Lower Back Pain etiology, better non-invasive measurement tools and techniques must be established and quantified. 


What was done?

A sample of 132 patients of the Spine Centre of Southern Denmark who had persistent non-specific Lower Back Pain was measured for three different sensitivities: (a) global spinal stiffness (GS) using a VerteTrack Device which applied a rolling weight across the S1 and T12 spine; (b) deep mechanical pressure pain sensitivity threshold (PPT) using pressure algometer which applied bilateral pressure at each lumbar segment and (c) superficial heat pain sensitivity threshold (HPT) using a handheld thermode at the midline of each lumbar segment. 

A series of statistical tests were performed to determine if there were any correlations between these three quantitative sensory metrics: Global Stiffness (GS), Pressure Pain Threshold (PPT) and Heat Pain Threshold (HPT).


What did they find?

The correlation coefficients (R) for each pair of these three quantitative sensory metrics; GS, PPT and HPT were calculated and tested for statistical significance. 

  • Correlation between GS and HPT were found to be poor and statistically insignificant (R = 0.23)
  • Correlation between GS and PPT were moderate (R = 0.38) and statistically significant
  • Correlation between HPT and PPT were good (R= 0.53) and statistically significant

Unexpectedly, the correlation between GS and PPT was positive, meaning participants with higher global stiffness had a higher pressure pain threshold. The authors expected the reverse. They based their explanation of this unexpected relationship on the body’s adaptive mechanical protection system. Pain is considered a protective response and a stiffer spine is more resilient to applied forces and therefore can tolerate a higher pain threshold.

The other’s unexpected anomaly was that for the three QST’s measured, no differences were found between the individual lumbar segments. This indicates that patients with persistent LBP are probably less able to perceive lumbar stiffness reliably, perhaps due to “Cortical Smudging”, an overlapping of the cortical homunculus. 


Why do these findings matter?

Around four out of five people have lower back pain at some point in their lives. It’s one of the most common reasons people visit healthcare providers. To successfully evaluate both the extent of LBP and the effectiveness of any treatment plan, a reliable metric must first be established. This study is an attempt to use stiffness (GS), heat (HPT) and pressure (PPT) as this critical metric.


At Dynamic Disc Designs, we have developed models with varying lumbar stiffness to help in the education of the possible sources of back pain. This new research is important in establishing greater understanding of the causes and solutions of low back pain.



Low back pain

Goal of the review?

In this paper, 1 the authors provide a research-based overview of the epidemiology, causes, and risk factors. They also describe the clinical presentation and diagnostic criteria, and treatment options for low back pain.



Epidemiology and Socioeconomic burden

The economic impact of lower back pain is widely significant, with estimates of £2.8 billion in the UK and $100 billion in the US. Almost two-thirds of the economic costs from lower back pain stem from indirect costs such as loss of productivity. One study done in 195 countries found low back pain the leading cause of productivity loss in 126 countries. 

Low back pain can be classified as mechanical, neuropathic or nociplastic. Studies have shown that the prevalence of neuropathic pain ranges from 16% and 55% in patients with chronic lower back pain. One systematic review illustrated the prevalence of low back pain to range from 11.9% – 23.3 %, increasing with age and most common in middle-aged to older women.



There is a multitude of factors and causes of lower back pain. These include disc degeneration, radicular (neuropathic) pain, facet arthropathy, myofascial pain, sacroiliac joint pain, spondyloarthropathies (ankylosing spondylitis and psoriatic arthritis), and nociplastic pain (non-specific low back pain).

Low back pain

Professional LxH Model and the Lumbar Spinal Stenosis Model — helping patients understand their source(s) of low back pain.


Brain change, behavioural and genetic factors

Low back pain can be caused by changes in the brain, such as alterations in blood flow and changes to white and grey matter in the brain. Behavioural factors can also play a role. Studies show the role that emotion and emotional experiences can have on low back pain. For example, negative expectations, depression, and anxiety have been shown to predict poor pain outcomes in patients. Finally, there are also genetic factors that contribute to low back pain. Research has illustrated that heritability contributed to 26% lifetime prevalence of low back pain, 36% for functional limitations and 25% to pain intensity.


Clinical presentation, diagnosis, and screening

Low back and leg pain can be a manifestation of intervertebral disc herniation. Often, this type of pain will resolve itself in a few weeks. However, some patients can have recurring pain for up to two years. 

A large percentage of back pain is non-specific and resolves without any formal diagnosis. However, most guidelines recommend that patients have a physical exam and that history is taken. Some patients may require a neurological exam or vascular-focused exams to differentiate different types of claudication. Routine imaging is not required for most lower back pain cases. However, CT scan, MRI, and x-ray can be useful depending on the case.

Different screening tools have been developed that assist in preventing and treating low back pain, identifying patients prone to chronic pain, and distinguishing neuropathic from non-neuropathic pain.


Prevention and Treatment

Research demonstrates that a combination of exercise, education and ergonomic changes are effective as prevention strategies for lower back pain. These behavioural, non-pharmacological approaches are also used as first-line treatment. This can include clarification-oriented and exposure-based interventions that can help patients self-manage their pain and pain behaviours. 

For patients whose pain persists, pharmacological and procedural options can be explored. The American College of Physicians Guidelines recommends that treatment begins with non-steroidal anti-inflammatory drugs (NSAIDs) and muscle relaxants, tramadol, or duloxetine as second-line treatment and opioids as the last choice. Due to the addictive potential and negative side effects, opioid treatment is not recommended for most patients. 

There are also non-pharmacological interventions for low back pain. Steroid injections in the foramen, between the vertebrae, and in the sacroiliac joints have positive therapeutic effects. Other interventions such as facet joint blocks and radiofrequency are used but have mixed evidence supporting them. Spinal cord stimulation has shown positive outcomes and can be cost-effective, depending on the patient. 

When other interventions have not been successful, surgery may be an option for some patients. Research shows that for herniated nucleus pulposus, surgery can provide relief for a period but does not result in long-term benefits. For patients with lumbar spinal stenosis, decompression surgery can provide substantial improvement compared to a traditional approach.



Low back pain is globally prevalent and increasing as lifestyles become more sedentary. Lower back pain is a complex condition with various factors; therefore, diagnosis and treatment can be challenging. Existing research provides important evidence that can be used to develop inter-disciplinary and multimodal approaches to treatment and diagnosis. 

Facet angle

Goal of the Study? 

In this study 1 the authors use MRI to measure changes in the facet angles of the lumbar spine and analyze the relationship between angle changes and the herniated lumbar intervertebral disc. 


Why are they doing this study?

The incidence of lower back pain (LBP) is prevalent in today’s society and can place an enormous burden on individuals and health systems. There are many causes of LBP, including lumbar facet joint (LFJ) degeneration, lumbar disc herniation (LDH), compression of nerve roots, and others. There is currently little understanding of the role of lumbar facet joint angle changes and lumbar disc herniation play in LBP. The authors comment that there is a lack of knowledge on whether the structural abnormality of the spine resulting from LFJ degeneration causes the abnormal force of the lumbar intervertebral disc herniation. Additionally, there is a need to understand whether lumbar facet joint angle changes are common in patients with lumbar disc herniation.


Professional LxH Model (L4-5) with asymmetric facet angles


What was done?

First, the authors review both direct and indirect signs of lumbar disc herniation as seen on MRI. They state that MRI provides an advantage to obtain horizontal and sagittal three-dimensional scanning of the spinal cord, subarachnoid space, vertebral body and intervertebral discs. They review the various signs of the nucleus pulposus, schmorl nodules, lumbar dural sac, lumbar spinal cord and nerve root compression.

The authors used cross-sectional images of the MRI to measure angles of the articular processes on both sides. They included 500 cases of patients with a clinical diagnosis of lumbar disc herniation and concurrent lumbar disc MRI examination. This included 227 males and 273 females with an average age of 41. This was broken down into 137 cases in the central LDH group, 140 cases in the left paralateral LDH group, 127 cases in the right-side LDH group and 75 cases in the control group. The cases were based on those who met the diagnostic criteria over 18 and relevant imaging and clinical data. Statistical software was used for statistical analysis.


What did they find?

The authors found no statistically significant relationship between age, gender, height and weight of the groups and LDH. They found no statistically significant relationship between MRI and CT measurements of the facet joint angle. They argue a correlation between the changes illustrated in MRI images of lumbar disc herniation and the TCM syndromes of lumbar intervertebral disc herniation. They found that the L4/5 and L5/S1 segments of the lesion in the central LDH group and the left paralateral LDH and right-side LDH were all significantly different from the control group.  Facet joint asymmetry is closely related to lateral lumbar disc herniation. However, the asymmetry of the facet joints is not related to the central lumbar disc herniation. They argue that MRI has a high sensitivity concerning measuring angles of the facet joint and changes to those angles and how they correlate with herniated discs. 


Why do these findings matter?

Understanding the relationship between lumbar facet joint angle changes and lumbar disc herniation is useful for preventing and treating LBP

Centre of Rotation

Goal of the Study?

In this study 1, the authors investigated the flexion-extension range of motion (ROM) and centre of rotation (COR) of lumbar motion segments in a large population, as well as the relationship between lumbar movement and sex, age and intervertebral disc degeneration (IVD).

Why are they doing this study?

Research on the in vivo motion of the spine has a long history. However, many of these studies have used non-invasive technologies with inherent limitations impacting their accuracy and precision. Moreover, many studies have included a lower number of subjects, preventing the data’s ability to represent the general population.

The authors argue that the use of radiographic techniques in this study helps to overcome these limitations as the images allow for better visualization of each vertebra and movements of the lumbar segments. Additionally, the use of a large sample size for this study addresses the issue of representation and is the largest study to date looking at in vivo lumbar motion. 

What was done?

The researchers did a retrospective study looking at the lumbar spine radiographs in full flexion and extension for 602 patients, with the age and sex documented for each one.  Additionally, they used MRI scans of 354 patients. 

All spinal levels between T12-L1 and L5 – S1 were analyzed, resulting in 3612 lumbar motion segments from the radiographic images. They also examined 2124 images from the MRI scans looking at disc degeneration. ROM and COR were calculated for all lumbosacral segments using the software. They then examined the associations between motion and age, sex, spinal level and disc degeneration.

What did they find?

The median ROM in this study was 6.6 °. The researchers found an association between age and ROM, with older individuals, have lower ROMS. They argue these findings clearly demonstrate a relationship between age and lumbar spine flexibility independent of any signs of spinal degeneration. They also found that lower ROMS were associated with disc degeneration. However, they did not find any association between sex and ROM.   

In this study, they did not find an association between the COR and the spinal segment’s position. The most common COR was at the centre of the lower endplate of the IVD or slightly lower. With degeneration, particularly severe degeneration, they found the COR location spread randomly around the centre of the intervertebral space.


One of the main limitations of this study was the sole focus on the lumbar spine’s flexion-extension motion rather than including information on movements of different areas of the back. 

Why do these findings matter?

This study comprises the largest examination of the in vivo lumbar spine in flexion-extension, paying attention to age and spinal degeneration issues. Understanding the relationship between age and spinal mobility provides patients and doctors with information to better treat back pain and instability.


Goal of the Study?

The goal of this study 1 is to better understand whether the morphology of the facet joint contributes to spondylolysis.


Why are they doing this study?

Lumbar spondylolysis is one of the most common sports injuries in adolescents. This is a condition in the lower back where there is a defect in the part of the vertebra known as the pars interarticularis, which is a part of the bone that connects the facet joints at the back of the spine. 

Existing research suggests that individuals with more coronally (frontal) oriented facets in the lower lumbar vertebrae, combined with facet tropism (growth or turning) are at a greater risk of developing spondylolysis at L5. However, to date, there are only a few studies looking at how the morphology (shape or arrangement) of the facet joint is associated with unilateral and bilateral spondylolysis in adolescents. 


What was done?

The participants for the study were 68 junior athletes who went to the Funabashi Orthopedic Hospital due to lower back pain between April 2012 and June 2014. 

All participants had computer tomography (CT) and MRI scans done to determine their grouping. From this, they were classified into three groups:

  1. Group B – 22 athletes (18 males and 4 females) with L5 bilateral spondylolysis
  2. Group U – 27 athletes (21 males and 6 females) with L5 unilateral spondylolysis
    1. Reclassified into two groups: one with a spondylolysis side (UL group) and the other with a normal side (UN group)
  3. Group C – 19 athletes (13 male, 6 female) without spondylolysis whose back pain eventually disappeared. 

Patients with multivertebral spondylolysis and previous lumbar surgery were excluded. 

Using CT, a researcher measured the sagittal alignment of the L4/L5 and L5/S1 facet joint angles from the axial sections. These angles were compared for differences among the groups. All of the measurements were repeated three times by the same person to increase validity.


What did they find?

The researchers found that for participants in groups B and UL, the L4/L5 facet joint angles were significantly more coronally oriented (more in the frontal plane) than those in group C. However, there were no significant differences found in L4/L5 facet joint angle between groups:

  • B and UL
  • B and UN, UL
  • UN and C

Additionally, there were no significant differences in L5/S1 facet joint angle were found among the groups.


L4 Tropism Spondylolysis

L4 Vertebra from the Professional LxH Dynamic Disc Model. Tropism


Why do these findings matter?

Compared to a normal orientation, a more coronal (frontal) orientation of the L4/L5 facet joint angle is likely to increase the stress on the vertebral arch of L5 during trunk extension. Therefore, if an adolescent athlete has a coronally oriented L4/L5 facet joint, they are more at risk of developing unilateral spondylolysis at L5. This knowledge can assist in identifying which young athletes are more likely to develop spondylolysis and help to implement appropriate prevention efforts by limiting certain activities in young athletes. 





Goal of the study?


To evaluate the frequency of lesions (injuries) in the lumbar region (lower back) of asymptomatic adolescent soccer players using MRI.


Why are they doing this study?


To date, there are very few studies that look at the frequency of spinal lesions in young athletes. Most of the research has focused on adult athletes and has shown that the lower back region is the most common site for problems. However, we know that the pediatric musculoskeletal system is particularly at risk to injury because adolescent bodies have not finished growing. Injuries at such a young age can result in an imbalance in bone tissue and muscles, which may cause an increased risk of injury, pain and limit young adolescents’ daily activities. These injuries can also get worse as we age. Therefore, it’s important to know if adolescent soccer players are getting lower back lesions that are not being identified and treated.



Modic Model


Who was involved?


The study 1 looked at two groups of asymptomatic male adolescents aged 13-18. 


  1. Soccer players who practiced the sport for at least two consecutive years, at least three times per week for 1-3 hours.
  2. Control group was made up of asymptomatic adolescents and was matched for age, gender, height and weight. They could not play soccer or any other sport more than once a week for more than 1 hour.


  • No one in the study could have any history of lesions, surgery, chronic disease or a high BMI score.
  • While they originally recruited 60 adolescents (30 in each group), because of exclusions the final sample size was 45.


What was done?


The researchers used MRI to evaluate the spine and look for the frequency of lesions in the lower back of adolescent soccer players. 


Two different radiologists examined the MRI images looking for the presence or absence of swelling, protrusions and disc extrusions (bulges). They also looked at stress reactions, cracks or stress fractures in the vertebras, vertebras slipped out of place, enlargements or growths, as well as swelling of the interspinal ligaments and muscles. 


What did they find?


Comparing the two groups, the researchers found that the proportion of spinal lesions was 76% in the soccer players compared to only 35% of the control group. In particular, they found that the percentage of lesions in the anterior and posterior of the spine was significantly higher in the soccer players than the control group. They did not find any significant differences between the age and BMI Z-scores between the two groups.



This study was able to show a high number of lesions in soccer players compared to other youth soccer studies that did not use MRI. However, research on young athletes playing other sports shows a similar frequency of spinal lesions.


What are the limitations?


This study had a very small number of participants. Also, all of the soccer players were studied during their championship season. This means it is likely that they are doing more intense training and playing than during regular season. As of Dec 28, 2020, the paper is still under review and going through the editorial process.


Why do these findings matter?


Lower back injuries in childhood and adolescence can lead to early degenerative changes. Therefore, the high number of lower back lesions in adolescent soccer players should be considered in the changing landscape of a person’s spinal health. Sport specific prevention efforts are important to reduce the occurrence and impact of lower back injuries on young adolescents. Better identification and management of spinal lesions may help to ensure that young people are able to continue playing sport and reduce the impact of these injuries in adulthood and into their senior years to avoid conditions like lumbar spinal stenosis. Learning recovery strategies show promise.

The Dynamic Sitting Exercise (DSE)

Life can be busy. And with this busyness, people often do not have the time for lower back pain exercises. In 2010, Jerome Fryer (the owner and developer of Dynamic Disc Designs Corp.) set out to measure a simple seated decompression strategy for the lumbar spine. A pilot study used an upright MRI to investigate changes in the lumbar spine before and after this Dynamic Sitting Exercise (DSE) 1

It was originally coined “chair-care decompression exercise” to make it memorable. In a recent article written in the Indian Journal of Physiotherapy and Occupational Therapy, the researchers renamed it DSE and compared it to the popular McKenzie prone press-up. 2


Dynamic Sitting Exercise

Dynamic Sitting Exercise (DSE)


McKenzie Prone Press-up

McKenzie Prone Press-up

These researchers recruited thirty adults in the age range of 20-30 years with mechanical low back pain. To read the full inclusion and exclusion criteria, you can visit the full-text link in the references below. They randomly assigned the participants to two groups: the DSE group or the McKenzie prone press-up group. Each subject conducted 6 repetitions within the 5-minute interval with the exercises being conducted at the beginning of the 5 minutes, followed by 4 minutes of rest. Over the course of 30 minutes, each participant would have performed 6 repetitions multiplied by 5 sets for a total of 30 repetitions over the course of 30 minutes. This was equivalent to 2.5 minutes of active exercise over the course of 30 minutes.

Exercise Protocol

Exercise Protocol


The DSE instructions included:

  1. sit upright
  2. place hands-on seat pan
  3. push down on the seat pan to offload the lower spine
  4. participants should feel a slight stretching in the lower back
  5. hold for 5 seconds
  6. return to neutral for 5 seconds
  7. while returning to neutral, draw-in-abdomen.


The McKenzie Prone Press-Up instructions included:

  1. lie down on the abdomen
  2. extend back while on elbows and palms down (neutral position)
  3. perform press-up maneuver with straight arms for 5 seconds
  4. return to neutral for 5 seconds


Over 6 weeks, outcome measures included the Visual Analog Scale for pain and the Short Form-36 Health Survey Questionaire for quality of life.

What did they conclude?

Both forms of exercise demonstrated improvement of pain and quality of life. However, the DSE outperformed the McKenzie Prone Press-up in this group of mechanical low back pain adults.

Overall, this paper could have been written a little better. Their conclusions were bold and overly confident. It is still an important paper to share as the practicality of investing a few seconds of offloading to your work-day while sitting looks to be promising in those with lower back pain in this age range.