At Dynamic Disc Designs, we believe research to be the foundation of our spine models so practitioners in musculoskeletal health feel confident in the use of an accurate model while they educate patients about their findings.  Historically, models have been inaccurate and most critically, static, making it very difficult for the doctor to be convincing to the patient in the accuracy of diagnosis.

Research is at the roots of any practice. It fuels practice guidelines and directs both the patient and practitioner down the best path of care. Our models help support that voyage. We have worked hard to bring the best to practitioners of musculoskeletal science by scouring databases of spine science, to arrive at the most accurate model for teaching possible.

With over 1000 papers read in full text, Dr. Jerome Fryer leads the way by making sure our models are keeping up to the standards of best evidence. Weekly literature searches on keywords that surround musculoskeletal health are at the core roots of Dynamic Disc Designs.

Upper Cervical Spine Model

A study 1 published in The Spine Journal shared interesting results about CT exams and detecting upper cervical spine injuries. The conclusion hoped the current study’s data might help with earlier detection of craniocervical dissociative injuries.

Why Conduct Such a Study?

Research shows that in fatal cervical spine injuries, the common findings are traumatic occipitocervical (or OC) injuries. These OC injuries include damage being done to the OC as well as AA (atlantoaxial) articulations.

The more traditional diagnostic methods for the evaluation of the human upper cervical spine made use of the relationship between the cervical spine and the skull. It used lateral radiographs for visualization. However, the said method tends to have limited sensitivity as well as specificity. That’s why CT (computed tomography) scans ended up being used more. But, even then, the parameters for identifying normal and abnormal CT anatomy (especially in the upper cervical spine) need more clarity.

The current study was conducted to offer details of the normal anatomical features as well as upper cervical spine relationships, as displayed on the CT scan. The goal was to establish better threshold measurements when it comes to detecting subtle cervical injury or abnormality.

The Method Used

The design of this study can be defined as a retrospective anatomical case review. This study’s patient population was 100. All of them had undergone a screening CT scan (multidirectional) of their cervical spine. The research team randomly selected patients by using the radiology teaching file as well as the trauma registry databases. All of the scans were deemed negative for trauma (focusing on the craniocervical junction).

A total of 76 cervical CT scans (thin-sliced) were randomly selected for this study. Take note; the team made 42 different anatomical measurements of the upper cervical spine.

What Did the Results Conclude?

The results showed the least variation in direct measurements. The mean OC joint space came in at 0.6 mm, with the AA joint space being 0.6 mm. Significantly higher standard deviation as well as variability was demonstrated by the midsagittal structures.

The current data was used to reach certain conclusions. There was no variance (according to demographics) when it came to the left-right symmetry and narrow joint spaces in the cervical spine joints. The consistency in the coronal plane was regarded as the factor enabling precise diagnostic measurements and comparisons. According to this study, such precision can help with accurately identifying abnormal scans.

A better understanding of upper cervical spine-centric relationships may help with earlier detection of subtle craniocervical dissociative injuries (dependent on the data from CT scans). A subtle misalignment could serve as evidence for a severe injury when looking at CT scans.


Knuckle cracking and relationship with hand impairments

An interesting study 1 published in the journal of Orthopedics and Related Research, back in 2016, decided to see if knuckle cracking was related to hand impairments. The results showed a small increase in a range of motion among ‘cracked’ joints.

The Context Behind the Study

According to numerous records, the voluntary cracking of knuckles happens to be a common habit among humans. It has been reported to have a prevalence range of 25%-45%. Apparently, many people have a habit of cracking their knuckles when they’re typing on keyboards because their joints feel tight.

Numerous physicians have continued to be intrigued by such a habit. A previous large study did suggest their being an association between cracking knuckles and functional hand impairment. However, there’s also a counter-stance sharing that cracking knuckles doesn’t have any impact on a person’s hand-centric range of motion (ROM).

The current study decided to use imaging to find certain answers. The research team compared subjects with no history of knuckle cracking with subjects that did. They went over whether or not cracking joints improved range of motion and if Sonographic Evaluation was a reliable option for such observations.

The Methods Used

This study had 40 subjects with no history of joint problems in their hands. These subjects were aged 18 or older. A total of 30 subjects had a history of knuckle cracking, while 10 had no history of such a habit. Each subject had 10 digits, and that made for 400 MPJ (metatarsophalangeal) joints for evaluation.

Take note; there weren’t any differences in age, hand dominance, and gender distribution between the two groups. The subjects were asked to complete the standardized QuickDASH outcome measure questionnaire.

The research team did the clinical assessment for grip strength, swelling, grip, and ROM before as well as after performing the distraction maneuvers on the MPJs. A dedicated ultrasound unit was used for Sonography.

What Were the Results?

The results showed that on comparing subjects that had a history of habitual knuckle cracking with those who didn’t, the QuickDASH scores showed no differences.

The ROM comparisons between the two groups showed increased ROM in the knuckle-cracking subjects after ultrasound recorded manipulation. And swelling wasn’t observed at all in any of the subjects.

What Was Concluded?

The results of this study shared that yes, conflicting opinions do exist when it comes to knuckle cracking and the possible relationship with impairments. However, this study was unable to find any adverse effects of knuckle cracking habits in human hands.

The results did share that a person with such a habit does tend to have a higher likelihood of cracking other joints in their body. Maybe to help relax their posture?

Also, small increase in ROM was seen in joints that were cracked compared to ones that weren’t. But more research should be done to examine any possible long-term effects (both beneficial or adversarial) of the knuckle-cracking habit.


LBP and Disability

A cross-section study 1, in Spine, was conducted to investigate the link low back pain (LBP) and disability had with the structural features of the thoracolumbar fascia. The results shared that a relationship existed between these factors.

The Context

While the Global Burden of Disease Study has researched LBP to be the leading cause of disability in humans, a lot of work needs to be done to fully understand the etiology associated with LBP. More research needs to be done to address all of the factors linked to LBP. Such understanding is crucial because it will help with creating targeted prevention strategies to help millions around the globe.

Previous research has analyzed LBP and disability to be associated with structural abnormalities of the lumbar spine. Furthermore, MRI has shown LBP to be linked to disc protrusion, disc degeneration, nerve root displacement or compression, and high-intensity zone. While more research is still needed, the present results do suggest that the issues of LBP and disability can be addressed by targeting structural factors. Take note, there’s evidence that suggests the thoracolumbar fascia may be linked to LBP. However, few MRI studies have examined such a link.


The Study

The current study had an aim to examine the link present between the lumbar fascia’s length and LBP as well as disability. The study used MRI.

A total of 72 participants (49 females and 23 males) were recruited. They weren’t required to have any history of LBP or current LBP to participate. The MRI was performed, in this study, using a 3.0-T magnetic resonance unit (with the participants in supine position). The study administered the Chronic Pain Grade Questionnaire (CPG) at the time of the MRI.

The study used the Logistic regression analyses for examining any likely associations between fascial length and high pain intensity (or disability).

What did the Results Conclude?

The results of the study concluded that there was a significant association between a shorter length of fascia and high-intensity LBP and/or disability. Such association was after adjusting gender, age, and the body mass index. The association was strengthened after adjustment for the cross-section area (in the paraspinal compartment).

While more studies are required, the current results do suggest that fascia’s structural features likely play a role in disability and LBP.

Static Flexion

A study 1 in the journal of Clinical Biomechanics shared results pointing toward the relationship between the muscular flexion-relaxation response in humans and period of static flexion. The aim was to further understand the phenomenon and its link to muscular modification (including low back pain).

Understanding Static Lumbar Flexion

Research has shown that workers are at risk of static lumbar flexion. However, not a lot of data is present that experimentally addresses the physiological biochemical and histological processes that are active in the evolutionary progression of the resulting low back disorder. Studies, involving animals, have shared that static lumbar flexion is responsible for the development of creep in associated viscoelastic tissues. This leads to elicit spasms and even modifies muscle function.

The current study set out to investigate neuromuscular changes while assessing normal (health-wise) human participates through the flexion-relaxation phenomenon.

The Study

The current research included male and female participants. There were 24 males and 25 female participants. The males ranged from 22 to 40 in age (the mean being 23.7 years old). The females were 19 to 30 in age (with the mean being 23.3 years). None of the participants reported issues in their spinal functions. Take note, six additional participants served as a control group.

They were asked to perform three bouts of lumbar flexion-extension before as well as after a 10 minutes long period of static flexion. The researchers recorded the surface electromyographic from the erector spinae muscles along with the flexion angle.

ANOVA was utilized on the angle in which electromyographic was reduced during flexion and initiated during the extension stage.

The Results

The study saw that the human erector spinae were active through a significantly larger angle during the flexion stage and were able to initiate activity significantly earlier during the extension stage (after static flexion). More pronounced changes were seen in the female participants (compared to the male participants). Furthermore, spasms were recorded by the researchers in more than 50% of the participants during the static flexion period.

What does it all mean?

According to the study, it was concluded that creep which was developed during a short static lumbar flexion was able to elicit a significant change in the flexion-relaxation phenomenon’s muscular activity pattern (in humans). It was observed that due to the loss of tension in the lumbar viscoelastic tissues, the muscles offered some compensation. The recorded spasms suggested minor micro-damage due to the viscoelastic tissues. The data was helpful in understanding why static lumbar flexion was an activity that was a risk factor for the development of the low back disorder in humans.

Does the Human Body Hold Potential for Improved Regeneration

A recent study 1 from the journal Science Advances analyzed protein turnover that occurs in articular cartilage from lower limb joints in humans. The results showed a potential for regeneration that could likely be exploited to improve joint repair.

What was the Context?

While regeneration exists in certain animal species, humans are believed not to have the ability to counter cumulative damage. In this context, the said type of damage is caused by repetitive joint use as well as certain injuries due to which cartilage breaks down and gives rise to osteoarthritis (OA). According to previous research, the turnover of insoluble collagen in human adult cartilage has been suggested to be quite limited. However, take note, humans do have the limited regenerative capacity. For example, during childhood, the regrowth of distal portions of amputated digits has been observed.

miRNA has been observed to play a significant role in regeneration; however, miRNA’s regenerative role is low in humans. The current study set out to explore the articular cartilage’s protein turnover (in the human lower limb joints).

The Design

The current study collected articular cartilage (as waste surgical specimens) from Duke University Hospital. The full-thickness cartilage was collected from the hip, knee, and ankle joints from patients that had end-stage OA who had undergone total arthroplasty surgery. Take note; the cartilage was from the perilesional regions of the hip, knee, and ankle joint’s load-bearing area.

A total of 18 samples were collected. The samples included three types of joints (hip, knee, and ankle), two types of disease state (healthy as well as OA), and three biological replicates of each type with matched age range. The mean age of healthy non-OA patients was 58.8 years. Their age range was 30 to 82 years. Also, the mean age of the patients with OA was 59.8 years (with the range being 42 and 87 years).

The analysis was performed on a quadrupole Orbitrap benchtop mass spectrometer (Q Exactive) equipped with an EASY-nLC 1000 system. Furthermore, protein identification was performed using the Homo sapiens taxonomy) setting of the Swiss-Prot database with Proteome Discoverer 2.1.

Also, miRNA quantification was done by a real-time polymerase chain reaction. The Deamidation rate was analyzed using the Swiss-PdbViewer.

What were the Results?

The study demonstrated a position-dependent gradient (distal high, proximal low) of protein turnover in human lower limb cartilage. The findings of this study have helped reveal a dynamic anabolic effect in human limbs that showcase a potential (limited) natural regenerative capacity in human cartilage.

According to these results, increased expression of matrix proteins is seen in OA knee cartilage. Also, the higher prevalence of hip and knee OA (compared to ankle OA), might explain the lack of repair in proximal joints.

What was Concluded?

The results suggested the role of regenerative miRNA present in cartilage homeostasis, intrinsic repair capacity, and turnover. Also, the limited regenerative capacity in humans is proposed to be primarily controlled by location rather than the shape of the joint or loading. The use of in vivo protein deamidation molecular clocks helped find a distal-proximal gradient of protein turnover.

The current data also suggested that anabolic treatments may be required in addition to anticatabolic treatments, especially for human hip joints, to prevent or, at least, slow OA’s rate of progression.

The study concluded that more functional studies on the effects of these associated miRNAs would be required to further reveal their regulatory role in cartilage repair and to help prevent certain ailments (including Low Back Pain).

Interestingly, the study suggested that injection of key regenerative miRNA in a joint (either singly or in combination) might have the potential to improve endogenous repair and help resist the degeneration of joint tissues in all types of arthritis.


Defining The Term ‘Flare’ in Low Back Pain (LBP)

It turns out, there isn’t much of a consensus when it comes to the definition of Low Back Pain Flare. A study 1 from The Journal of Pain set out to change that to possibly help LBP patients, clinicians, and researchers around the globe.

Why Focus on LBP Flare?

Low back pain tends to vary over time. Numerous terms are used by medical professionals and researchers to describe the fluctuations. The term “Flare” is used for describing symptom fluctuation. However, the definition of the said term isn’t the same for everyone.

With LBP being a common musculoskeletal condition around the globe, the current study deemed it necessary to bring consensus to the term “Flare” or “Flare up” with regards to LBP. According to research, most people tend to experience LBP at least once. For many others, such a condition lasts throughout their lifespan (with fluctuating trajectories).

The Study

This was a mixed-method study. It consisted of four steps.

  1. Deriving the definition of LBP flare from the perspectives of individuals with LBP.
  2. Using the perspectives of experts.
  3. Undergoing a Delphi process with experts to polish the definition of LBP flare and reach an expert consensus.
  4. Applying qualitative testing to the definition with individuals with LBP.

Flare Low Back Pain

For the first step, five authors met on 3 different occasions for considering the perspective of individuals with LBP. They discussed the terminology to cover the features that separate other symptom fluctuations from flare. The initial definition was refined (involving consultation from an expert consumer writer).

For the second step, a workshop was held at the International Forum for Back and Neck Pain Research in Primary Care (Buxton UK, June 2016) with a group of 19 experts in LBP.

In the third step, a two-round Delphi process was conducted. The goal was to gather feedback from a diverse group of international experts, and to present a definition (from the collected feedback) to the participants for evaluating acceptability.

Take note, the Delphi process was implemented online via a web-based system (Google Drive).

A total of sixty-two experts were invited to participate. This included 19 participants of the Step 2 workshop, 19 members of the organizing committee of the International Forum for Back and Neck Pain Research in Primary Care, and a total of 24 other individuals with expertise in LBP flare or related conditions (or having international recognition in the field of musculoskeletal research).

Testing, during the fourth step, involved scenarios and follow-up questions. The participants were invited via social media, local community, and health centers. One of the eligibility criteria was the individual’s self-identification of previous or current LBP.

Defining The Term ‘Flare’ in Low Back Pain LBP

What did the Results Show?

The results of the study displayed how flare (connected to LBP) is multifaceted. The findings aligned with the research team’s expectations about how not every individual with LBP flare will experience all of the factors mentioned in the definition. However, the definition will be broad enough for many to relate to.

Where There Any Limitations?

The research team does share the current study might not have been able to accommodate every expert opinion because of the utilized selection criteria. Furthermore, the sample was biased toward people with long-term recurring or persistent/chronic symptoms.

What’s the Take-Away?

LBP flare is multifaceted and thus, needs an appropriate definition. The current study was able to propose a definition that might work well in a clinical or research context. The said definition is likely to have a beneficial use in epidemiologic studies as well as have clinical implications in terms of measuring treatment efficacy.

Sacroiliac Joint

According to research, at least 10 to 30% of LBP or low back pain is linked to the sacroiliac joints. A review 1 in the journal of Best Practice & Research Clinical Rheumatology decided to give the said link a more in-depth look.

The Context
As mentioned, studies have shown an approximate 10-30% of all LBP being attributed to sacroiliac joints SIJ. While almost 44% of SIJ pain is associated with trauma onset, the etiology is still unclear. So, even today, there are numerous challenges when it comes to diagnosing as well as treating sacroiliac joints. One of the biggest challenges is determining whether or not pain or dysfunction in the human body is primarily due to the sacroiliac joint. SIJ being a causative factor, while theorized, doesn’t have a lot of evidence for support.

The Purpose of This Review

The current content aimed to cover the available data regarding the anatomy of SIJ along with its examination, etiology, and treatment to assist clinical approaches. One of the major questions dealt with: when pain is experienced at the SIJ, is it better to direct treatment at local tissues, or should it focus on factors that are remote to the joint?

Furthermore, the review also wanted to analyze if the pain in a region was primarily due to SIJ or were other factors in place (on and around the said joint)?

The review went over the anatomy and function of the Sacroiliac joints, the etiology of Sacroiliac joint dysfunction, the clinical assessment of the SIJ, and managing SIJ pain.

The review tried its best to consider all of the complexities associated with SIJ’s diagnosis and management (including sport and exercise-related SIJ pain). It took a bio-psycho-social perspective.

What did the Review Find?

The review summarized that clinicians and researchers shouldn’t conflate sacroiliac pain, stability, and dysfunction (as all three are separate). Furthermore, trauma and repeated training might be associated with SIJ pain in athletes.

Clinical evaluations should administer clustered pain provocation testing. Such a suggestion was made after determining that palpation and mobility test didn’t offer any proven value. When addressing persistent pain, taking a bio-psycho-social approach is crucial. Treatments (backed by evidence) included pelvic compression belts, surgery, manipulation, exercise, and corticosteroid injections.

Also, further research is required for understanding SIJ pain better.