Research: Can Pre-existing Risk Factors Affect a Whiplash Injury?

Friday, January 15th, 2016
Pre-existing risk factors for whiplash

I have been treating Amarillo whiplash patients literally for years now here at Amarillo Pain & Accident Chiropractic Clinic. I would guess that I’m probably as close to a whiplash specialist in Amarillo, TX as anyone else you’re going to find.

In fact, I was even acknowledged in District Court in January of 2016 as a Whiplash Specialist during testimony in a car wreck case.

Speaking of car wreck cases, there is no doubt that insurance companies and adjusters tend to use several tactics to discount what they will pay out to a patient when settling a car wreck case. Certainly one that is an Amarillo car wreck case.

Determining factors from the medical records, to the year of the car, to the lost wages, to the direction of impact, to the treating doctor type, to the attorney if the victim happens to have one, to the region of the country and what average pay-outs are in that region, etc…..etc….etc…

What these insurance companies and the attorneys that represent them in car crash cases usually DON’T take into account are the RISK FACTORS that are present in these cases.

Wouldn’t you agree that there are certain things that can pre-dispose a whiplash patient to a more severe injury?

If you said, “Yes,” then you would be correct.

And should the patient be punished by the other driver’s insurance if they just happen to have some of these risk factors present when another driver crashes into them?

I would argue that the answer to that question is, “No.”

In fact, there is a ton of research showing that certain risk factors can most certainly make a whiplash injury worse.

This is a list from Art Croft, DC, M.Sc, MPH, FACO with the Spine Research Institute of San Diego. See if you agree:


Risk for acute injury

  • Being of the female sex
  • Being a female weighing less than 130 lb in frontal crashes
  • Having a history of neck injury
  • Having the head restraint positioned below the head’s center of gravity
  • Having a history of a cervical acceleration/deceleration injury
  • Having poor head restraint geometry as happens with a tall occupant (e.g., 80th percentile male)
  • Being in a rear impact versus being in other vector impacts
  • The use of seat belts and shoulder harness (i.e., standard three-point restraints)
  • Having a smaller body mass index in females only or small framed males (i.e., decreased risk with increasing mass and neck size)
  • Being an out-of-position occupant (e.g., leaning forward/slumped)
  • Non-failure of seat back
  • Having the head turned at impact
  • Being unaware of the impending impact
  • Being of increasing age (i.e., middle age and beyond)
  • Being in the front seat position versus being in the rear seat position
  • Being impacted by a vehicle of greater mass (i.e., ³25% greater)
  • Being involved in a crash with a speed under 10 mph
  • Being a rear struck occupant, when the bullet vehicle has a motor that is longitudinally mounted
  • Being the driver versus being the front seat passenger


Risk for late (chronic) whiplash:

  • Being a female
  • Being in a rear vector impact versus other vectors
  • Having a smaller body mass index in females only or small framed males
  • Experiencing immediate or early onset of symptoms (i.e., within 12 hours) and/or more severe initial symptoms
  • Experiencing initial back pain
  • Experiencing initial decreased cervical spine ROM (females only)
  • Experiencing initial upper back pain
  • Experiencing initial upper extremity numbness or weakness
  • Experiencing initial upper extremity pain
  • Experiencing greater subjective cognitive impairment
  • Experiencing a greater number of initial symptoms
  • Experiencing greater severity or frequency of initial symptoms
  • Experiencing high initial pain intensity
  • The use of seat belt shoulder harness in the case of low back pain
  • The use of seat belt shoulder harness for neck pain
  • Having initial physical findings of limited range of motion
  • Experiencing neck pain on palpation
  • Experiencing muscle pain following the crash
  • Experiencing disturbed vision
  • Experiencing initial sleep disturbance or fatigue
  • Experiencing initial neurological symptoms, radiating pain into upper extremities
  • Having a past history of neck pain
  • Ligament laxity
  • Having a past history of headache
  • Currently suffering headaches
  • Evidence of initial degenerative changes seen on radiographs
  • Evidence of foraminal stenosis (cervical)
  • Evidence of loss or reversal of cervical lordosis
  • Being of increasing age (i.e., middle age and beyond)
  • Being in the front seat position
  • Being in the driver seat versus being in the passenger seat for females
  • Being in the rear seat position
  • Being an occupant of a vehicle manufactured in the late 1980s to early 1990s (OR=2.7 vs those in early 1980s vehicles) This is relevant for rear impact crashes only.
  • Experiencing initial generalized sensory hyperalgesia
  • Having the head rotated at impact; both frontal and rear
  • Being unaware of the impending impact

Now, all of these have A LOT of research backing them up. Particularly for Low Speed Rear Impact Crashes.

This is something that every single narrative report that comes out of our office speaks about. One cannot simply look at the damage of a vehicle and try to correlate it to the severity of injury. This is something I will blog about at another time but, you must take into account the risk factors and/or the severity of the risk factors present when determining the longterm prognosis.

Here is some research that explores this just a bit more.

Why They Did It

  • Figure out what risk factors people had that caused chronic disability following whiplash injuries.
  • Attempt to understand the impact of those risk factors on them.

How They Did It

  • Reports were collected approximately thirty-two days after the traumatic injury and then again twelve months later.
  • There were baseline measurements collected in regards to disability, neck movement/range of motion, pain, psychological and behavioral indicators, as well as chronic disability at the 12 month mark.
  • The main way to measure outcomes was through the use of the Neck Disability Index Questionnaire, which we use regularly here in our office.

What They Found

  • Psychological and Behavioral factors were important factors when considering chronic disability following a whiplash injury.
  • The amount of risk factors involved in the incident is important when evaluating patients and their likely outcomes following whiplash.

Williamson E, et al., “Risk factors for chronic disability in a cohort of patients with acute whiplash associated disorders seeking physiotherapy treatment for persisting symptoms.” Physiotherapy. 2015 Mar;101(1):34-43.

http://www.ncbi.nlm.nih.gov/m/pubmed/24996567/