Gait Kinematics Index, Global Symmetry Index and Gait Deviations Profile: Concept of a new comprehensive method of gait pathology evaluation

Abstract

The objective of the work was to define a new comprehensive method of evaluating gait pathology (Gait Kinematics Index, Global Symmetry Index and Gait Deviations Profile). The article presents in detail a mathematical algorithm of a new comprehensive method of evaluating gait pathology. Input data for the algorithm are the kinematic parameters of gait. The method is based on the determination of the following parameters: standardized angular variables (Wji), kinematic indicators of gait (KIj), gait cycle indicators (GCIi), Gait Kinematic Index (GKI), Gait Deviations Profile (GDP, GDPj), Global Symmetry Index (GSI) and Symmetry Indices (SIj) for kinematic gait values. The algorithm is based on the determination of the difference between results obtained in relation to the kinematics of movement of a given patient and the average value obtained in relation to the standard in each percentage of a gait cycle. The proposed method was tested using results obtained for 59 healthy persons and one patient with locomotor function disorder. The GKI values for the reference group amounted to 0.89 ± 0.23. Information which can be obtained using the proposed gait assessment method was presented using an example of a patient with the disorder of locomotor functions. Areas of gait deviations, which were identified on the basis of the determined indicators, were presented in a graphic form using GDP. The new gait assessment method makes it possible to identify gait using a single numerical value, evaluate movements in individual joints and in subsequent moments as well as to assess the symmetry of gait.