Impairment Tutorial: Rating Peripheral Nerve Disorders of the Upper Extremity

Abstract

Abstract The AMA Guides to the Evaluation of Permanent Impairment, (AMA Guides) Fourth Edition, states that peripheral nerve impairments are determined by determining the percentage of the patient's motor and sensory loss. This article discusses the six steps necessary to rate a peripheral nerve impairment of the upper extremity: First, identify the nerve or nerves affected using relevant tables and figures. Second, locate the table that lists the nerve identified, and record the maximum loss attributed to that nerve for motor and sensory function. A table lists peripheral nerve charts in the AMA Guides, including nerves rated, table and page numbers, and type of rating (upper or lower extremity, foot, and so on). Third, grade the motor deficit of the nerve, and, using the appropriate table, find the percentage range and choose a number within the range that is appropriate for the patient; multiply the graded percentage by the total motor impairment found in step two. Fourth, determine the total deficit for the nerve by combining the motor and sensory deficits using the Combined Values Chart. Fifth, combine the total nerve deficit with other appropriate impairments. A table instructs raters how to convert to a whole person impairment. Sixth, grade the sensory deficit of the nerve. An example illustrates application of the six steps.