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By Dennis R. Kurth, Attorney

The Arizona workers’ compensation statute requires proof of an “injury” by “accident” within the course and scope of employment to establish a compensable claim. (See A.R.S. §23-1021(A)).  Case law has liberalized the term “accident” to encompass any work activity, even repetitive work activity, that gradually causes an injury over a period of time.  There does not need to be a single, specific traumatic event that causes an acute medical condition immediately in order to prove that an injury occurred.

Likewise, “injury” has been defined by the appellate courts as any work-related condition that causes the need for medical treatment and disability from work.  In cases of pre-existing conditions aggravated by work activity, whether industrial in origin or not, a claimant’s proof must include evidence that the industrial injury acted upon a pre-existing condition to produce a “further injurious result” according to long-standing case law.  (See Professional Furniture Service v. Industrial Commission, 133 Ariz. 206, 650 P.2d 508 (App. 1982)).

The philosophical underpinning of this interpretation of the workers’ compensation statute is the old tort principle that the tortfeasor takes the victim as he or she is with whatever pre-existing conditions or infirmities they may have.  A tortfeasor, it is said, is not entitled to a completely healthy victim and must be responsible for the aggravation of any pre-existing condition his victim carries. In worker’s compensation, the same liability pertains to the employer.

Problematic Rule

In workers’ compensation, furthermore, case law has established that a claimant need not prove that the work activity or trauma caused an organic or anatomic change in the pre-existing condition in order to establish that an injury occurred.  It is enough that the work activity caused the need for medical treatment and disability from work. (See Industrial Indemnity Co.  v. Industrial Commission, 152 Ariz. 195, 731 P.2d 90 (App. 1986) and Mandex v. Industrial Commission, 151 Ariz. 567. 729 P.2d 921 (App. 1986)).  This rule, however, liberal as it may seem, is often problematic in its implementation.

First, it is counterintuitive to treating physicians and surgeons in workers’ compensation cases.  They are trained to look for objective evidence of acute traumatic injury on clinical examination or imaging studies and if they don’t find it is reluctant to find causation or even an “injury” at all.  They, of course, are looking for “medical causation” but ALJ’s are looking for “legal causation” instead.

In litigation before the Industrial Commission, this rule comes up frequently.  IME doctors very commonly ignore it and won’t find causation without proof of an anatomic or organic change in the claimant’s pre-existing condition.  It is extremely rare to see an IME examiner find causation without proof of organic or anatomic change.


Suspicion is that many valid claims get denied or closed improperly because of this misunderstanding of the law.  A large percentage of aggrieved claimants do not seek legal representation and either go it alone in front of the ALJ or just don’t protest the closure or denial of the case at all.

It is incumbent on workers’ compensation claimant attorneys to educate the attending physician or surgeon about the law, including that proof of an organic or anatomic change is not necessary.  Most are not aware of the rule and genuinely want to be effective witnesses before the ALJs.  It can also change their testimony in favor of the injured claimant in many situations.

Contact Us

For more information on Workers’ Compensation or Social Security Disability, please contact Snow, Carpio & Weekley toll-free at 855-325-4781 or visit our website at www.workinjuryaz.com. We serve the entire State of Arizona and have offices located in Phoenix, Tucson, Yuma, and Lake Havasu City.

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