COMBINED STATISTICAL STUDY OF JOINT ANGLES AND GROUND REACTION FORCESUSING COMPONENT AND MULTIPLE CORRESPONDENCE-ANALYSIS

The purpose of this research is to propose a general methodology to dr aw gait patterns when including hip, knee and ankle angle excursions i n the sagital plane and the three components of the ground reaction fo rce. The multidimensional signal analysis procedure is divided into th ree main stages: 1) describing the six signals of each step through sl iding averages computed for successive time windows, 2) analyzing sepa rately the six step-by-window tables obtained for each signal through principal component analysis to reduce the excessive quantity of data, and 3) analyzing the most informative time windows of the six signals at the same time. To emphasize both linear and nonlinear relationship s between the respective time windows, the signal range within a windo w is cut into fuzzy modalities such as, ''low'' ''medium'' and ''large .'' The resulting table is investigated using multiple correspondence analysis. The outcomes are gait patterns combining both time and space aspects. The factor planes obtained from multiple correspondence anal ysis constitute initial data models so that new data obtained from pat hological gait can be directly projected onto them. Such an operation can be used to show how the rehabilitation of a particular subject evo lves in relation to normal gait patterns.