Illinois Statutes Chapter 820. Employment § 305/8.1b. Determination of permanent partial disability

(a) A physician licensed to practice medicine in all of its branches preparing a permanent partial disability impairment report shall report the level of impairment in writing. The report shall include an evaluation of medically defined and professionally appropriate measurements of impairment that include, but are not limited to: loss of range of motion; loss of strength; measured atrophy of tissue mass consistent with the injury; and any other measurements that establish the nature and extent of the impairment. The most current edition of the American Medical Association's “Guides to the Evaluation of Permanent Impairment” shall be used by the physician in determining the level of impairment.

(b) In determining the level of permanent partial disability, the Commission shall base its determination on the following factors: (i) the reported level of impairment pursuant to subsection (a); (ii) the occupation of the injured employee; (iii) the age of the employee at the time of the injury; (iv) the employee's future earning capacity; and (v) evidence of disability corroborated by the treating medical records. No single enumerated factor shall be the sole determinant of disability. In determining the level of disability, the relevance and weight of any factors used in addition to the level of impairment as reported by the physician must be explained in a written order.