Kinematic analysis of gait cycle using a fuzzy system for medical diagnosis

Development of human gait analysis systems has become of great interest in the medical field because of their capacity to acquire information and perform diagnosis. This paper presents the design of a fuzzy system able to provide a linguistic interpretation of the kinematic analysis for the thigh and knee in the sagittal plane. This analysis allows the detection of anomalies like hyperflexion, excessive flexion, inadequate flexion, inadequate extension, slight extension, excessive extension or normal angular movements during the gait cycle phases. The fuzzy system is based on the mapping of reported normal behavior curves to fuzzy rules. The fuzzy system is expected to work directly with information generated by 2D or 3D vision systems. Tests on pathological as well as normal cases for thigh and knee showed correct analysis by the fuzzy system.