GaitCD.

Vaughan CL. Western Cape, South Africa, Kiboho Publishers, 1999, CD-ROM, $49.95. [System Requirements: 486/66 MHz PC, 8 MB RAM (50 MB free disk space), Microsoft Windows '95, '98, or NT, CD-ROM drive, VGA color monitor with 800 x 600 resolution.]

This CD-ROM features a set of 4 applications for the study of normal human gait residing on a single disc. This disc brings together 2 previous print publications--Dynamics of Human Gait, 2nd edition, by CL Vaughan, BL Davis, and JC O'Connor and Biomechanics of Human Gait: An Electronic Bibliography by Vaughan--with animation software and a simulated 3-dimensional gait analysis program.

The software was tested on a Pentium II/350 MHz processor with 128 MB of RAM and installed on a partitioned segment of the hard .drive other than drive C: with approximately 1.2 GB of free space.

The CD-ROM comes with a brief user manual describing basic elements of the software, how to install it, Adobe Acrobat[R] Reader (to read .PDF files), and instructions to run each of the 4 main programs. More extensive setup and user information, including a "Reader Online Guide," are included in .PDF files once the software has been installed. GaitCD may be run from a computer's hard drive or directly from a CD-ROM drive.

Software installation was uneventful using the Run option from the Windows '98 Start button on the desktop. The soft, ware is initially configured as 5 .ZIP files that are extracted and decompressed as self-executing files using a DOS protocol. Extraction is accordingly quite slow, even for a Pentium II machine, and could take a long time with a computer with less processing power. For instance, a minimally configured 486 processor with 16 MB of RAM will take a very long time to decompress files. In addition, although a DOS "Finished" message is displayed at the top left of the decompression window, this message could easily be missed by an inexperienced user and mistaken as a system "freeze-up."

Five file folders are set up in the GaitCD main directory. The first folder includes version 3.0 of Adobe Acrobat[R] Reader and related control files. The Reader is used to view accompanying .PDF files in the other folders. The system used to test the software was already configured with version 4.0 of Acrobat[R] Reader, and this caused a conflict when I attempted to read .PDF files by double-clicking on the file of interest. An "Illegal Operation" error was returned. The problem was resolved by first bringing up the Reader (either version) and then opening files in the usual manner. The author should seriously consider upgrading to version 4.0 of Acrobat[R] Reader in future revisions of this CD-ROM. The conflict between installed Versions and subsequent error messages might lead an inexperienced computer user to assume that there is an irreconcilable error with the software. The remaining 4 folders installed included the substantive elements of the software: "Animate," "GaitBib," "Gaitbook," and "GaitLab."

Each of the 4 main program elements is activated by double-clicking on the respective application files in each folder from the Windows Explorer (file manager). This is inherently a clumsy way to control program execution and would have been handled much more efficiently by including a master menu from which the user could click on the program of interest. While program execution procedures are described in the accompanying manual, inexperienced computer users, or users who rely on written documentation only as a last resort, will have difficulty opening programs. This problem might be ameliorated somewhat by copying, dragging, and installing program icons from either the "File Manager" or from the file folders in the "Control Panel" onto the desktop. Installing program icons requires more than a basic understanding of the Windows environment, and only more advanced computer users are likely to attempt it. In addition to the 5 folders, README files in .PDF and Microsoft[R] Word formats and an uninstall program are included in the main directory.

"Animate" uses .MOV files played on a Windows Media Player, which included on the CD-ROM, to view animations of the lower extremities in a sagittal view while walking, jogging, and jumping. Four animation options are available: muscles, forces, moments, and dynamics. For example, using the muscle option, the user may visualize the quadriceps, hamstrings, and pre- and post-tibial muscles during a complete gait cycle. The file may be allowed to run continuously, or the user has the option of stopping anywhere in the gait sequence. Muscle activity is demonstrated by colored highlighting that fades in and out, in accordance with the muscles' activation patterns. This method would be excellent for physical therapist students studying normal gait, because it allows them to focus on multiple muscle actions during the gait cycle.

"GaitBib" is an extensive electronic bibliography of gait references configured as .PDF files. Specific content areas (eg, EMG activity of the thigh muscles) are searchable using the Acrobat[R] Reader. Reference "hits" are displayed as "3 x 5 cards" providing the pertinent citation information.

"GaitBook" is the second edition of Dynamics of Human Gait and is configured as a .PDF file. It is a 153-page book that includes a comprehensive discussion of basic and advanced topics in normal and abnormal gait analysis, including figures and an extensive reference section and index.

Finally, "GaitLab" uses .DST files to simulate 3-dimensional analysis of gait in a laboratory setting. Pre-saved files of stick figures of the lower extremities of subjects walking, jogging, and running are opened and run using GaitLab for Windows, a .DST file player. Figures move continuously across a 3-dimensional grid and may be stopped using the Animate option on the task bar above the main screen. The Plot option allows for gait markers that are applied to bony landmarks to be plotted and displayed as graphs in x, y, z coordinate space.

Overall, the substantive elements of this software provide the user with an excellent discussion of basic and advanced gait analysis and very useful 2- and 3-dimensional animated simulations making the package well-suited for physical therapist students and anyone else interested in studying the complexities of human gait. The electronic version of Dynamics of Human Gait is an added benefit that makes the package a true bargain. However, program execution and control was awkward and may be difficult for inexperienced computer users to use. A master menu from which all program elements could be selected by clicking on control buttons would solve this problem.

Andrew L McDonough, PT, EdD New York University New York, NY

Dr McDonough is an Associate Professor of Physical Therapy and currently teaches anatomy, kinesiology, and research methods. His research interests include gait analysis and the quantification of manually applied forces to human tissues using force transducers.