Academy of Chiropractic’s Lawyers PI Program

Build Your Infrastructure #17

From the Desk of :

“Medical-Legal Definitions”

The proper utilization of terminology is critical in reporting causality, bodily injury, functional losses and impairments of your patient. Although most definitions have been clearly defined by the courts in case law, we, as doctors, should be consistent with the language utilized in the American Medical Association, Guides to the Evaluation of Permanent Impairment, Sixth Edition (The Guides). By doing so, you are quoting a higher authority and if ever cross-examined in court or a deposition, it can help make you bulletproof and prevent a lot of angst.

In addition, when dealing with attorneys, the proper utilization of language will also help them realize that you are a true expert. Your full knowledge of this language will help you educate them, further solidifying the relationship. Some of the following language and many of the following definitions were taken from pages 24-29 of The Guides.

Physicians have traditionally been regarded as authorities in their craft and are accustomed to getting their opinions accepted as the final truth. However, in a legal proceeding, the physician's opinion, when unsupported by established science, can lead to challenges and cause needless frustration and anxiety for the physician and others. Contemporary adjudication processes have increasingly questioned the science behind the doctors assertions and doctors are increasingly faced with the challenge of litigants demanding multiple opinions. 

Judicial decisions state that arbitrary and dogmatic opinions, even from well-qualified experts, are not held credible. Therefore, doctors providing independent medical examinations and/or expert testimony must be aware that their opinions must be supported by scientific evidence or they risk losing credibility. The physician who uses the AMA Guides must use objective criteria and all available clinical knowledge, skill, and abilities for deciding whether the measurements and/or test results are consistent and concordant with the pathology being evaluated. If such findings or the impairment estimates based upon these findings conflict with established medical principles, they may not be used to justify impairment ratings for the doctor's independent opinion.

This is consistent with legal standards known as:

FRYE: A 1923 standard for the admissibility of expert testimony which established the “general acceptability by the scientific community” standard for admissibility of expert witness scientific opinion. This was also codified in 1975 by the U.S. Congress.

DAUBERT: In 2002, at the federal level, the United States Supreme Court attempted to provide a broad, discretionary gatekeeping power for the federal trial judges. This power was to be exercised by a list of tests used to determine whether the scientific theory of methodology underlying the opinion of an expert witness should be considered liable.

The above two standards have set the foundation for virtually every state accepting a doctor as an expert. Along with the doctor's credentials, they help to guide the courts as to the admissibility of the doctor and his/her work as an expert. When dealing with attorneys, there are very clear and concise rules which must be adhered to. How you fit into these rules called case law, regulations or legislation, in most cases, is the deciding factor as to whether an attorney CAN work with you. I strongly urge you to keep a copy of these definitions “handy” when writing reports to ensure accuracy until you fully understand them.

Legal vs. Medical Possibility and Improbability:

Legal terminology defines the relationship between an event and an outcome as “probable” if it is more likely than not to occur; if the probability of a cause and effect relationship is greater than 50%. There is a “possible” cause when the likelihood of a causal relationship is equal or less than 50%.

This is in contrast to standards in the scientific and medical literature which require the likelihood that an association between a potential cause and effect to be greater than 95% for the relationship to be considered “probable.” Everything else is only possible.

Legal probability, then, simply means that something is more likely to occur than not (probability exceeds 50%). On the other hand, the probability of an event occurrence equal to or less than 50% is merely a “possibility.”

Causality Exacerbation and Aggravation:

Medical causality is an association between a given cause (an event capable of producing the effect) and an effect (a condition that can result from a specific cause) with a reasonable degree of medical probability. Medical causality requires determination that each of the following has occurred to a reasonable degree of medical certainty:

1.  A medical causal event took place.

2.  The patient that experienced the event has the identified condition.

3.  The event could have caused the condition.

4.  The event caused or materially contributed to the condition within medical probability

Although the circumstances in which an event was the sole or primary cause of a given event, in many instances, patients have pre-existing pathology that may contribute to their clinical conditions.

Aggravation: A circumstance or event that permanently worsens a pre-existing or underlying condition.

Exacerbation – Recurrence – Flare-up: Generally implies a temporary worsening of the condition which subsequently returns to its baseline.

Exacerbation does not equal aggravation.


Note: We have a future consultation that devotes 100% of its topic on apportioning a case. When dealing with the injured this is a very common request from attorneys and a very easy process.

Apportionment is an association of causation among multiple factors that caused or significantly contributed to the injury or disease and resulting impairment. Apportionment requires the determination of the percentage of impairment that is directly attributable to pre-existing conditions as compared with resulting conditions and directly contributing to the total impairment rating derived. In such cases, the reading physician may estimate these contributions by first developing the following contingent readings based on earlier work:

1.  A “total” impairment rating (A) (an all-inclusive current rating) is derived irrespective of pre-existing and resulting conditions.

2.  A second “baseline” rating (B) is derived solely for pre-existing conditions without associated or aggravated re-injury.

3.  The final rating (C) is derived in discounting pre-existing conditions by subtracting the second from the first (A minus B).

If apportionment is needed, the analysis must consider the nature of the impairment and its relationship to each allegedly causative factor, along with an explanation of the medical basis for all conclusions and opinions. Using this approach for apportionment requires accurate information and data in order to determine all impairment ratings of four and higher following the most recent injury. 

Maximum Medical Improvement

Maximum Medical Improvement or “MMI” refers to the status of the patient. Is he/she as good as he/she is going to be from a medical standpoint with all surgical treatment available to him/her? It can also be conceptualized as a date from which further recovery or deterioration is not anticipated, although over time (beyond 12 months), there may be some expected change. The AMA Guides, however, do not permit the rating of future impairment. There can be some scenarios in which individuals reach MMI, but may experience future progression of their diseases.

Thus, MMI represents a point in time during the recovery process, when further formal medical or surgical intervention cannot be expected to improve the underlying impairment. Therefore, MMI is not predicated on the elimination of symptoms and/or subjective complaints. Also, MMI can be determinative when recovery has reached the stage where individuals can be expected to remain stable with the passage of time, or can be managed with palliative measures that do not alter the underlying impairment substantially within medical probability.

Maximum Medical Improvement does not preclude the deterioration or condition that is expected to occur with the passage of time or as a result of the normal aging process; nor does it preclude allowance for ongoing follow-up for optimal maintenance of the medical condition in question.


Permanency is a condition whereby impairment becomes static or well-stabilized with or without medical treatment and is not likely to change in the future despite medical treatment, within medical probability. This term is often synonymous with MMI, usually occurring once all reasonable medical treatment expected to improve the condition has been offered and/or provided.

Impairment ratings are to be performed when an individual has reached a state of permanency. However, many systemic or organ-based conditions are dynamic rather than static in nature and are, to some extent, never reach a state of permanency. In such cases, one can usually anticipate future functional decline based upon the natural history of the disease process which is generally well-established in the literature.