The evolution of clinical gait analysis part l: kinesiological EMG

Abstract

In 1996, I was asked by Roy Davis, President of the Gait and Clinical Movement Analysis Society, to be the presidential guest speaker at the Birmingham, AL, annual society meeting and present a talk on the development of clinical gait analysis. Following my presentation, James Gage, Editor-in-Chief for Gait and Posture, and David Winter, Associate Editor for review articles requested a manuscript for publication. To address this task I have the advantage of being a participant throughout this exciting era and of personally knowing most of the people mentioned in this manuscript. To prepare for this assignment, I wrote letters and/or made phone calls to them. Their replies to my inquiries, plus their publications, provide documentation for this review paper. The opinions expressed, for better or worse, are my own. Due to space limitations, only a partial list of the many that have contributed is presented and I regret that not all of the important contributors have been included. In some instances they will be found in Part II and Part III. Hopefully, later publications on this subject will correct the omissions. Emphasis has been given to the earliest years and to walking gait. The subject of upper extremity analysis has not been included, though studies of subjects with upper extremity motion problems are carried out in many motion laboratories including our own. A further disclaimer is that the flood of more recent publications does not receive equal coverage. History is being written daily as clinical gait analysis gains momentum. We have barely scratched the surface of the development and potential contributions of clinical gait analysis.

Introduction

The origins of the science of gait analysis began in Europe in the 17th century and continued through the early 20th century. The discoveries of such notables as Borelli [1], Galvani [2], Newton [3], Descartes [4], Marey [5], [6], [7], Carlet [8], the Weber brothers [9], [10], Scherb [11], [12], [13], Duchenne [14], Muybridge [15], and Braune and Fischer [16], [17], [18], [19], [20] provided a solid scientific foundation for our current understanding of human walking. Braun and Fischer employed the principles of Newtonian classical mechanics, the coordinate geometry of Descartes, and Borelli's mathematical concepts for estimating muscle action, to create an elegant representation of the gait of their military subjects carrying backpacks. Although the principles of investigation employed by Braun and Fischer are recognized as valid today, their methods of study were far too labor intensive to permit any practical application for subjects in a clinical setting.

Vern Inman, and colleagues moved the science of gait analysis dramatically forward by adding kinesiological electromyography (KEMG), 3-D force, and energy measurements in the study of walking in normal subjects and amputees (1944–1947). The remarkable contributions of this inspired team, led by Inman, are contained in a report to the National Research Council [21] and are printed in a limited number of publications [22], [23], [24]. Nonetheless, their methods of study were still too labor intensive, invasive, and computationally demanding to permit their application in a clinical setting. Colleagues of Dr Inman published Human Walking [23] in the year following his death. Now in its second edition [25], this book contains a distillation of much of the original work of the team, as well as many new contributions by contemporary researchers. It receives wide recognition as an outstanding presentation of the scientific basis for gait analysis.

The search for improved methods of gait data acquisition began in the decade of the 50's. Former orthopedic residents of Inman, and other investigators inspired by his research, embarked on time-consuming studies, utilizing equipment that had to be conceived, created, constructed and tested. In this manuscript, a review of the process, some of the pivotal developments, the individuals, and the interweaving of their pathways will be described. The prime technological advances and their synthesis into comprehensive gait analysis will follow, along with an account of some of the great achievements. I have divided the topics into KEMG, kinematics, kinetics, and energy in order to focus on each area, but in point of time, there is considerable overlap.