Classification of abnormal gait patterns of poststroke hemiplegic patients in principal component analysis.

Abstract

The objective of this study was to classify the 10 types of characteristic abnormal gait by principal component analysis using quantitative indices of 10 types of abnormal gait. For abnormal gait pattern classification, principal component analysis was performed using the deviation values of the 10 types of abnormal gait of 90 subjects. Scatter plots of the factor loadings of the 1st and 2nd principal components of the 10 types of abnormal gait were prepared, and those arranged at near sites were grouped based on the positional relationship, through which abnormal gait patterns were classified. It was suggested that abnormal gait patterns can be classified into insufficient knee flexion, hip hiking, and excessive lateral shift of the trunk over the unaffected side in the swing phase; knee extensor thrust pattern accompanying forefoot contact in the stance phase in addition to circumduction gait of the swing phase; and flexed knee gait pattern accompanying retropulsion of the hip in addition to median whip in the stance phase and excessive hip external rotation in the swing phase. It was clarified by these principal component analyses that information contained in the results of the 10 quantitative indices of abnormal gait of the 90 poststroke hemiplegia patients was compressed into several abnormal gait patterns. If observational abnormal gait analysis is performed after understanding this gait pattern classification, it may help improve the accuracy of gait analysis by observation.