A SYSTEM lOR GAIT ANALYSIS

Abstract

Human gait has been extensively studied in the past in the hope that a more thorough understanding of the differences between normal and abnormal gait, and the relationships between electromyogram (E.M.G.) and the force, may be obtained. In order to study these phenomena, both kinematic data regarding the limbs, and E.M.G. data for the muscles in question must be gathered. This thesis presents a minicomputer based data acquisition system for the analysis of human gait. The E.M.G. data is gathered by means of a seven channel, optically isolated, telemetry system. The data is fed into a frequency counting interface board connected to the computer. Synchronous with the counting of the E.M.G. frequency, the computer gathers kinematic data about the limbs in the form of a photograph. Infrared L.E.D.'s are placed over strategic points on the subject's limbs, and flashed each time the E.M.G. data is counted. A time photograph is taken of the L.E.D.'s, providing the trajectories of the points. Data input is controlled by a foot switch which delimits the stride during analysis. Subsequent to the data acquisition, the E.M.G. data is stored on magnetic tapes. Photographic data of the kinematic trajectories is input to the computer via an X,Y digitizer. Software was written to control the data acquisition process and to recover and display the data for analysis. This thesis shows that automated synchronous acquisition of both E.M.G. data and kinematic data in human gait is possible, and can be economically realized.