Is there a best practice method for determining medical causation following a traumatic injury?

Our Answer:

Yes! We recently had a case of a 51-year-old man who developed a work-related repetitive motion injury that resulted in a symptomatic Thoracic Outlet Syndrome. Opposing counsel raised the question if the injury was unrelated to the client’s work. We were asked by our attorney client to write a report with our opinion concerning causation. Of course, similar issues often come up in personal injury cases as well. 

There are different ways to determine traumatic causation including a method proposed in a book published by the AMA. In the causation chapter, the authors’ state to determine causation: first, identify evidence of disease, then review & assess the available epidemiologic evidence, obtain & assess the evidence of exposure, consider other relevant factors and finally consider the validity of testimony. In our opinion, the advice may be very good, but impractical and not concise and formulaic enough for a good forensic report being read mostly by lay people. 

In our opinion, and apparently in the many opinion of judges, the Freeman criteria are felt to be clear & concise. Further, case law bears out the Freeman criteria to be a valid method to assess causation.

Here is an example from our report:

 In 2007, Freeman et al. in Whiplash and Causation demonstrate a practical method for individual clinical determinations of causation following traumatic injury.  It is my opinion that Freeman’s criteria of traumatic symptom causation applies to any body part and can be applied to work-related injuries as well. 

 In 2009, Freeman et al. had a follow up journal article titled A Systematic Approach to Clinical Determinations of Causation in Symptomatic Spinal Disc Injury following Motor Vehicle Crash Trauma.  Using the criteria outlined in the 2007 and 2009 journal articles, Mr. Doe meets the injury symptom causation requirements for his work-injury related headaches.

 First, there must be a biologically plausible or possible link between the exposure and the outcome.  Mr. Doe’s repetitive movements at work (exposure) are followed by the onset of a neurogenic Thoracic Outlet Syndrome, diagnosed by EMG, including persistent headaches (outcome).  It is well accepted in the medical literature that headaches are common to Thoracic Outlet Syndrome as noted above.

 Second, there must be a temporal relationship between the exposure and the outcome.  At the time of Mr. Doe’s diagnosis of Shoulder Impingement Syndrome due to his repetitive stress injury (exposure), Mr. Doe was experiencing clear cut complaints of headaches (outcome) as described in his medical records. 

 The third criteria states there must not be a more likely or probable alternative explanation for the symptoms.  There is no question that there is not a more likely explanation of Mr. Doe’s headaches.  Mr. Doe did not suffer any other injuries to his head, neck shoulders or back.  He was not in any type of personal situation, accident, activity or participant sport that could have directly caused the onset of his headaches. 

There was nothing in Mr. Doe’s medical history or day-to-day life activities that suggest something other than repetitive movements at work (exposure) precipitated his headaches (outcome).

To summarize, the best practice method of determining medical causation is using the Freeman criteria.