The third edition of the Guides will be a major asset to those who are not already owners/users of the second, published in 1984. No other authoritative document has such a finely honed collection of impairment classifications or comes even close to the sophistication of measurement indices this provides.
The potential value of the Guides far transcends its common use in the evaluation of Workers' Compensation claimants. Of course, virtually every physician involved in any aspect of the disability benefits matrix1 will find it valuable, and there is much evidence of a greater demand for expertise in this area.2,3 The Guides continues to emphasize the distinction between impairment and disability. One cannot help but wonder, though, if the emphasis is diminished by adherence to the concept of percentage impairment of the whole person. While providing a relative measure of the severity of impairment, the primary use of the