Gross Motor Function Measure (GMFM-66 & GMFM-88) User's Manual.

Russell DJ, Rosenbaum PL, Avery LM, Lane M. London, United Kingdom, WC1V 6RL, Mac Keith Press, 2002, hardcover (with enclosed CD-ROM), 244 pp, illus, ISBN: 1-89868329-8, $80.

A user's manual is an essential part of any test. It should contain critical information about the test's purpose; its intended uses; its theoretical background; standardized procedures for administration, scoring, and interpretation; and the qualifications that users need to administer the test. This Gross Motor Function Measure (GMFM) manual has all of these important qualities for the intended audience of clinicians (pediatric therapists) and researchers, and it also has many unique features.

The original 88-item test (GMFM-88) was designed to quantify change in gross motor function in children with cerebral palsy. The scoring for the 88 items is based on ordinal data and therefore has limits in the interpretation of the score. The GMFM-66 was developed after the application of Rausch analysis, which eliminated 12 items from the GMFM-88 and made the new test unidimensional. The development of the original test (including validation and intratester and intertester reliability testing) and the basis for the statistical analysis (including change to interval-level scoring) are clearly reported and explained.

This manual's prerequisite elements for operational use of the test are written in a consistent style throughout its 7 chapters. Tim first chapter is an overview of the GMFM. The next chapter; "Conceptual Background," very briefly explains the nature of cerebral palsy and the need to quantify physical ability and limitations, and it has a concise and easily readable presentation of general issues of measurement. Readers with limited statistical knowledge will welcome the review and specific applications to the GMFM.

Chapters 3 and 4 discuss the development and validation of the GMFM-88 and GMFM-66 respectively. Each chapter contains information and data supporting the validity and reliability of the measurements. By providing this information, the authors enhance (1) the reader's understanding of the statistical properties and the potential usefulness of these tools and (2) the reader's ability to make a decision about which version is most appropriate. Each chapter also offers unique information. The chapter on development and validation of the GMFM-88 contains details for training test administrators of the GMFM and provides information about how to obtain the Self-Instructional Training Program on CD-ROM. The chapter on the validation of the GMFM-66, although short and appropriately limited in detail, expertly explains the basics of Rasch analysis and item response theory and the application of the Rasch analysis to the GMFM, a discussion that makes it easier for readers to interpret and expand the tools' applications.

Chapters 5 and 6 provide detailed directions and guidelines for administering, scoring, and interpreting the tests. This information is consistent across the 5 dimensions and each item of the test. Chapter 5 contains the directions for administering all 88 test items; items in the GMFM-66 are marked by an asterisk so that the user knows which items to score for this version of the test. Additional features in chapter 5 are the detailed equipment list for both versions of the test, explanations of terms such as "crawl and hitch" located at the end of the chapter, and specific instructions on how to administer the test to children with Down syndrome. The thoughtful feature of the chapter on administration and scoring is the linger type print that the authors deliberately selected to make the text more easily readable from a distance. The last chapter is a short discussion of new and future applications.

In addition, this manual offers some distinctive components that make it very user friendly. After opening the front cover, the reader discovers a CDROM containing a program, called the Gross Motor Ability Estimator, for scoring the GMFM-66. This program is the only way that the GMFM-66 can be scored, which may be a drawback for the user who does not have access to a computer. The tutorial for using the estimator is on the disc and is contained in appendix 2 of the manual. The disc also contains the programs for entry and storage of individual data and calculating a score.

The second item available--a hard copy of the Score Sheet (GMFM-88 and GMFM-66 scoring) Version 1.0--is contained in the back of the book. In addition, the user can print a copy of the Score Sheet from the CD-ROM; however, this score sheet has flaws on page 5 and 6, the summary sheets for the scores. Letters are missing from many of the words on these pages, making it useless for recording or sharing data. Even going to the Web site noted on the CD-ROM will not provide the user with a useable copy of this from; the same flaws are present.

The multiple appendixes in this manual contain other unique features, including: (1) the Gross Motor Function Classification System for Cerebral Palsy, a classification system that defines the severity of the child's cerebral palsy beyond mild, moderate, and severe, (2) case scenarios, (3) data from cross-sectional studies regarding change scores, and (4) statistical explanations not found in the main body of the text.

Overall, the authors provide clear directions and rationale for use of the GMFM-66 and GMFM-88 by researchers and clinicians. Anyone who is in the position to assist in decision making regarding services for children with cerebral palsy will find this test, and thus the manual, very, helpful.

Karen Kott, PT, PhD

SUNY Upstate Medical University

Syracuse, NY

Dr Kott is Assistant Professor in the Department of Physical Therapy Education, where she teaches pediatric physical therapy and conducts research on examination of function in children.