AGGRAVATION RULE

aggravation rule. Workers’ compensation. The principle that when an on-the-job injury combines with a preex-isting injury, resulting in a greater disability than that which would have resulted from the on-the-job injury alone, the entire disability is compensable as if it had occurred at work. [Cases: Workers’ Compensation 552–566. C.J.S. Workmen’s Compensation §§ 325–337.]