Just How “Severe” is an Adjustment?

Some people are under the impression that Chiropractic is dangerous. They think an adjustment is a severe force applied to the spine that can cause injury. Nothing could be further from the truth. If a Chiropractic adjustment is severe, what do we measure or compare its severity to? Let’s look at a few studies that try and give some perspective to this question.

Before answering the main question, I want to answer a precursor question: How much force does it take to fracture the cervical spine? The notion that an adjustment can fracture or “break” your spine is the main driver behind the false premise that chiropractic is dangerous.

The journal Spine published a study in 2004 titled “Tensile Failure of C2 Pedicles and the Subsequent Direct Repair in a Porcine Model.” This study looked at the force needed to fracture the pedicles of a pig’s cervical bone. The pedicles serve as a bony bridge that joins the front and back parts of the vertebra. They are the most fragile aspect of the structure. In their research, they found it took around 3,200 Newtons of force to fracture the pedicles. Newtons are a universal unit of measurement and about 100 Newtons is equivalent to around 22.5 lbs of force. So, based on this study, it takes about 720 pounds of force to fracture the weakest section of the cervical spine.

Now let’s look at the forces often applied to the spine from an adjustment.

In 2016, there was a research paper published in the Journal of Manipulative and Physiological Therapeutics called “Forces of Commonly Used Chiropractic Techniques for Children: A Review of the Literature.” This study measured the force of an adjustment on the pediatric population from newborns up to 18 years of age. Obtained measurements follow as such:

  • Neonates and infants aged 0 to 2 months: 20 Newtons (~4.5 lbs.)

  • Infants and toddlers aged 3 months to 23 months: 28 Newtons (~6 lbs.)

  • Young children aged 2 years to 8 years: 60 Newtons (~13.5 lbs.)

  • Older children and young adults aged 8 to 18 years: 88 Newtons (~19.75 lbs)

How does the Chiropractic adjustment compare to a medical intervention? Specifically one performed on the pediatric population?

A study published in 2006 in The Australian and New Zealand Journal of Obstetrics and Gynaecology called “Vacuum-assisted delivery: An analysis of traction force and maternal and neonatal outcomes” looked at the force applied to a baby’s head and neck during the vacuum device traction procedure. The forces applied to the fetal head follow as such:

Vacuum device traction

  • The vacuum traction is typically done 4 times during each contraction and push. This force measured at 113 N or ~25 lbs.

Obstetric forceps traction

  • This force was measured at 200 N or about 45 lbs.

This study did not measure the manual tractional force the OBGYN uses when pulling on the baby’s head and neck during contractions. Also, to get a more accurate understanding, we need to combine these numbers with the naturally occurring forces that are impressed on the infant during a vaginal birth.

Those measurements were gathered from a study published in 2009 in the Annual Review of Biomedical Engineering called “On the Biomechanics of Vaginal Birth and Common Sequelae.” The forces that normally occur to a baby’s head and spine during the natural birthing process follow as such:

Intrauterine pressure

  • Intrauterine pressure is the pressure exerted by the uterus on the baby when the muscles are normally at rest. This force measures at 16 N or ~3.5 lbs.

Uterine contraction

  • Uterine contraction is a naturally occurring force that happens without conscious influence. This force measures at 54 N or ~8 lbs.

Volitional push

  • Volitional push is the force that occurs when the mother actively bares down and pushes. This force measures at 120 N or ~27 lbs.

So during a normal vaginal birth; which includes the intrauterine pressure, uterine contraction and volitional push, the force applied to the baby can add up to 190 N or ~42 lbs.

Now, when you add a vacuum traction to a normal vaginal birth, the force can add up to 233 N or around 52 lbs. If you add an obstetric forceps traction force to a normal vaginal birth, the force can jump up to 390 N, which is roughly 88 lbs.

There is one more study I want to explore regarding the medical interventions of birth. While this study was done in the 1800s and might not pass modern scientific and moral standards, the results are compelling. In the 1874 British Medical Journal, a J.M. Duncan, MD published findings from his experiments on the tensile strength of the spinal column. Using fresh-term fetuses, he found that a traction force of 90 pounds caused the vertebral column to give way and break apart. He also found that decapitation occurred when 120 pounds of force was applied.

Comparing the two modern medical studies with J.M. Duncan’s findings, a vacuum device traction delivery can reach the cusp of dissevering the cervical spine. It is easy to think that Duncan’s findings are hyperbolic and unfounded. But, as recently as 2023, a baby’s death at a Georgia hospital was ruled a “fracture-dislocation with complete transection of the upper cervical spine and spinal cord” by the Clayton County Medical Examiner’s Office. Allegedly, the OBGYN applied excessive traction to the baby’s neck when a shoulder dystocia was present and this resulted in the decapitation of the infant.

Taking a step back and analyzing the information provided, it’s difficult to target the Chiropractic adjustment as severe or dangerous. I’m not trying to point fingers, pass blame or highlight other profession’s shortcomings. I’m only trying to widen the lens of perspective. With the proper viewpoint, we can make better health decisions.

- Jarek Esarco, DC, CACCP

Related Blogs:

  1. Does a Chiropractic Adjustment Cause a Stroke?

  2. Are Chiropractic Adjustments Safe?

  3. Can You Adjust Someone With a Spinal Fusion?

  4. "I Heard That Too Many Adjustments Can Wear Down The Disc, Is This True?"

  5. "I'm Pregnant, Might an Adjustment Harm My Child?"

Other Resources:

  1. Research Study: Tensile Failure of C2 Pedicles and of Subsequent Direct Repair in a Porcine Model

  2. Research Study: Forces of Commonly Used Chiropractic Techniques for Children: A Review of the Literature

  3. Research Study: Vacuum-Assisted Delivery: An Analysis of Traction Force and Maternal and Neonatal Outcomes

  4. Research Study: On the Biomechanics of Vaginal Birth and Common Sequelae

  5. Research Study: Laboratory Note: On the Tensile Strength of the Fresh Adult Foetus

  6. AP News: Medical examiner rules death of baby decapitated during delivery was a homicide

Jarek Esarco, DC, CACCP is a pediatric, family wellness and upper cervical specific Chiropractor. He is an active member of the International Chiropractic Pediatric Association (ICPA). Dr. Jarek has postgraduate certification in Pediatric Chiropractic through the ICPA. Dr. Jarek also has postgraduate certification in the HIO Specific Brain Stem technique through The TIC Institute. Dr. Jarek is happily married to his wife Regina. They live in Youngstown, Ohio with their daughter Ruby.

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