Paediatric Chiropractic Part 2: Force Measures For Children And Infants

Dr Angela Todd is tireless in her efforts to serve the chiropractic profession. 2015 and 2016 saw her author noteworthy papers on adverse events due to chiropractic and other manual therapies for infants and children, and forces of commonly used chiropractic techniques for that cohort. She is the CEO of 20 chiropractic clinics, has been a PhD candidate, is a member of the Australiasian College of Chiropractors and the College of Chiropractic Paediatrics, and holds a Diplomate in Chiropractic Neuro-Developmental Paedatrics. We caught up with her to talk about technique selection, force measures, and the role of chiropractic care in the life of the child.

When it comes to this issue, hers is a particularly well-qualified opinion. It’s also a point she feels quite strongly about:

“Modern chiropractic should include paediatric care, and care across the entire lifespan. It should include newborns and young children. We know we are safe. (We’ve done an article on that [1]). We know that we have techniques we can use on any age and modify them. We know we can do that safely. We know students can be trained to improve their understanding.”

It’s an opinion that comes from research – not just Todd’s own work, but also that of Italy’s Dr Aurelie Marchand among others. Marchand first put force measures under the proverbial microscope in 2015, undertaking a large-scale survey of chiropractors and subsequently proposing a safety model [2].

Background: The Marchand Model, and the Koch Brothers Bradycardia Findings

The fact that tensile strength differs in adults and children is an obvious one. A newborn and infant cervical strength is vastly different to that of a fully mature adult, thus the force used to adjust that precious little spine is much lower. As with all things, however, the devil is in the detail.

When Dr Marchand evaluated these tensile strengths, the data pointed her in a direction some may find surprising. “The results from various studies, when combined together, suggest that there is a nonlinear increase in the tensile strength of the cervical spine based on increasing age [2].”

It seems that, rather than a steady increase over time, there are key ages and stages that a chiropractor needs to observe when checking and adjusting paediatric patients. Marchand’s proposed model split paediatric patients into four grades and recommended force measures and technique adaptations (in comparison to adult SMT* force) for each one [2]:

  • Grade 1 (0-2 months): low force, low speed, with a force maximum of 10% of adult SMT
  • Grade 2 (3 – 23 months): low force, low speed, with a force maximum of 30% of adult SMT
  • Grade 3 (2 – 8 years): moderate force, moderate speed, with a maximum of 50% of adult SMT
  • Grade 4 (8 – 18 years): moderate force, high speed, with a maximum of 80% of adult SMT.

In her report, Marchand discussed an earlier, discarded proposed model of safety. The reasons for its obsolescence included some important learnings [2]:

“During the initial phase of model development, it was proposed to not exceed forces of 197 N in the cervical neonatal spine because such load has been shown to lead to tissue damage. Similarly, it was proposed to avoid using of loads above 560 N in the cervical spine of 1- to 23-month-olds, 970 N in 2- to 8-year-olds, 1500 N in 8- to 18-year-olds, and 1750 N in adults to prevent tissue damage, as suggested by the data obtained from this review. However, this approach was not considered relevant and was therefore discarded…”

The reasons for the discarding of this approach included a number of factors. Among them were reports that “models based on solely [sic] on the tensile strength of spinal segments may not take into consideration subcatastrophic tissue damage occurring at lower values. Indeed, the displacement observed during mobile testing of the cervical spine shows that the pediatric spine can withstand higher structural displacements (up to 5 times more) compared with adult spine, but the pediatric spinal cord was not able to withstand such displacement without serious compromise (spinal cord injury). [2, 3]”

Marchand cited a study by the Koch brothers that revealed episodes of bradycardia and apnoea after thrusts ranging from just 30-70 N (with an average of 50 N) to the upper cervical spine in young infants [3]. Whilst the study did report that 20,000 children received chiropractic manipulation without serious adverse reactions, it flagged a concern of which chiropractors should be informed.

We don’t actually know if the bradycardia and apnoea documented by the Koch brothers had any long-term effect beyond the initial moment [3]. “What the Koch brothers found in doing their studies was that a few of the children they adjusted held their breath, and had a very short- heart-rate change. This occurred at 50-70 N of medically applied spinal manipulation (modified HVLA). Those younger than 3 months were twice as likely to have a significant drop in their heart rate compared to any other age groups,” said Dr Todd, when she spoke with Spinal Research. “It only lasts a few seconds, but its something to be aware of.”

She also raised the possibility that those children could be having a strong but momentary sympathetic/parasympathetic responses.  The Vagus nerve traverses the upper cervical spine, and adjustments to the region can often stimulate this nerve.  “This means that its possible the effect noted by the Koch brothers may be the brain taking a tiny pause to interpret the adjustment,” she suggested.

Dr Angela commented that the Marchand force recommendations were estimations based on a large cohort of over 900 practitioners who were questioned on the percentage of force they would use on a newborn compared to an adult. “They all estimated about 10% [for a newborn]” she remarked. “The Koch brothers looked at what actually was the force. They found it was about 50-70 N on average for a newborn, but many techniques go down to about 20 N which is much more gentle. [3]”

Force Measures and Tensile Strengths

Dr Angela’s work on tensile strengths and force measures saw her undertake a comprehensive review on the available data [4].

“When we put together the information on the different forces for the different instruments and techniques, we searched the literature and found information regarding most but not all of the common ones,” reports Dr Todd. These included: Neuromuscular impulse, SMT, SOT*, Touch and hold, and Activator instruments.

“What we didn’t find (accurately measured and documented in peer-reviewed literature) was Gonstead and Diversified techniques on an infant or child. There was literature for an adult, but not for a child. Gonstead is HVLA, so is Diversified,” she remarked. The Koch brothers’ work provided information in terms of HVLA*, which they measured to be between 50 and 70 N, but they also measured it down to 30 N [2]. This highlights a wide variance in the HVLA approach.

 “What we found in the forces data was that Activators 4 and 5 could fire at between 30 and 40 N on their lowest settings.  An Activator 2, at its lowest setting could fire at 20 N.  Marchand suggested in the work she did that we should be looking at applying at 20 N and below to be in a good range.”

“The Marchand study suggests techniques that use forces of the lower value should be used in the cervical spine of infants under 3 months.  If we are going to be using our hands, a thrust well below 50 N would fit into Marchand’s guidelines.  All of the Activators are under that 50 N,” said Dr Angela.

 

Dr Todd is quick to point out that this is about reporting what exists in the literature, not commenting on which techniques are better than others. It is certainly not to say that there is no place for manual adjusting, or even that Dr Todd is adverse to these techniques.

“You can do something manual.  ‘Manual’ could be putting your fingertip on the atlas and just rocking it side to side. It’s a very gentle impulse. Its like a tap,” she said. This gentle impulse is also focused on the cervical spine – an area approached with a lot of care in all cases!

“From two years on, more techniques might be used where they are appropriately modified to be safely applied for the age and condition of the patient, as we are trained to do.” said Dr Todd.

Safety: Is It Really Just About Force?

One of Dr Todd’s objectives was to investigate whether the safety data published was purely about force, or if it had more to do with the quality of the history, the use of a proper exam and whether a practitioner has appropriately modified their choice of technique.

The safety data reveals there’s never been a paediatric death associated with care from a chiropractor [1].  Sadly, practitioners in other professions have had deaths contributed to their actions while using techniques similar to or the same as those used by some chiropractic practitioners.

“The data that came up in the adverse events paper revealed 2 deaths in infants in Europe with no underlying pathology. One was under the care of a physiotherapist, and another under someone doing craniosacral therapy, not a member of the osteopathic profession. It was not done correctly. He was using a stretch and hold technique that is in the chiropractic and osteopathic repertoire to reduce dural tension, but not in a manner anyone in either profession would apply it. The infant was held for a long time in forced flexion on their side and asphyxiated on the table, said Dr Todd.”

While the total number of severe adverse events (14) during 50 years and including millions of treatment interactions across medical, chiropractic, osteopathic and physiotherapy practitioners applying manual therapy to children was extremely low, each event is a tragedy that warrants consideration so we can prevent future adverse events. It prompts questions we should never take for granted.

“Did those other practitioners not modify their technique properly, or was it the fact they didn’t do a proper history? We don’t have that information,” said Dr Angela of her research [1]. “The crux that came out of the adverse events paper is that there’s a whole range of techniques that can be safely used, but you still need to do a thorough examination and history before you do anything.”

She is quick to reinforce the importance of a proper examination and history, stating that there would be some neurological signs to be noted if there was any underlying pathology. If a proper examination and history is taken, this can be ascertained before you apply the thrust, to minimise the risk of an adverse event.

What does this mean for chiropractors?

Todd’s approach is simple. Essentially, it’s a question of ‘least force, most benefit,’ paired with modifying techniques so they are age appropriate, and always undertaking a thorough history and examination.

The literature available at the time of her publication suggests that when adjusting infants and children in the cervical spine particularly, the use of lower forces (sub 70N preferably sub 30N) is paramount in technique selection and application.  As a child increases in age and so does the level of appropriate force [2,3].  All of this should feed into the selection of the technique used. Proper execution of these techniques also matters greatly.

“You can do things incorrectly, and create an issue,” says Dr Angela, before emphasising the extensive training chiropractors go through to modify techniques in order to deliver them safely and effectively. This is something that is not only achievable, but also essential (along with the thorough history and examination).

She also points out a very important distinction.

“Chiropractic is a profession, not a technique.  Just because a technique is implicated as a cause of an incident, doesn’t mean that can be generalised to the profession as a whole.  It just means that the application of that technique, at that time, on that person, was the problem.  A lot of people, when they hear about anything to do with working on the spine and especially with infants, immediately think of when they went to a chiropractor as a thirty year old and their neck was cracked. That’s not what happens with an infant. It never is. The forces, amplitude and depth of thrust are modified. Practitioners are trained to modify them. They can also use instruments to modify them.”

Ours is an impressive safety record. Still, the importance of technique selection, force measures, and a thorough history and examination remains paramount.

In terms of research, a lot of potential lies in the area of chiropractic care and paediatrics. Dr Todd is about to embark on a new study with Dr Heidi Haavik in this area. “We know from other research that we can intervene in pain patterns early in life.  So we are setting out to measure what effect we are really having, and how brain function might change following an adjustment in 5-12 year olds.”

We look forward to this exciting research and the increase in understanding of chiropractic paediatric care.  Thank you Dr Todd for your time.

Read Paediatric Chiropractic Care: Part 1 -The State of Evidence

Terms and References

*SMT – Spinal Manipulative Therapy

*SOT – Sacro Occipital Technique

*HVLA – High Velocity Low Amplitude

[1] Todd A, Carroll M, Robinson A, Mitchell E, (2015), “Adverse Events Due to Chiropractic and Other Manual Therapies for Infants and Children: A Review of the Literature,” Journal Manipulative and Physiological Therapeutics, Volume 38, Issue 9, November-December 2015, pp. 699-712, http://www.sciencedirect.com/science/article/pii/S016147541400178X

[2] Marchand, A (2015), “A Proposed Model with Possible Implications for Safety and Technique Adaptations for Chiropractic Spinal Manipulation for Infants and Children,” JMPT, Vol 38, Is 9, pp. 713-726, http://www.sciencedirect.com/science/article/pii/S0161475413000754

[3] Koch LE, Koch H, Graumann-Brunt S, Stolle D, Ramirez J and Saternus K (2002), “Heart rate changes in response to mild mechanical irritation of the high cervical spinal cord region in infants,” Forensic Sci Int, 128(2002), pp. 168-176

[4] Todd A, Carroll M, Mitchell E, (2016), “Forces of Commonly Used Chiropractic Techniques for Children: A Review of the Literature,” JMPT Vol. 39, Iss. 6, pp 401-410, DOI: https://doi.org/10.1016/j.jmpt.2016.05.006

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