Classification of able-bodied gait using 3-D muscle powers

The purpose of the paper was to determine if more than one gait pattern exists in able-bodied young men, by analyzing the dissimilarities in the three-dimensional (3-D) muscle powers, developed at the joints of the right lower limb. The subjects were members of the general community and they were evaluated in an attempt to extract normative data. Nineteen young male volunteers participated in the study, all of them were able-bodied, right-sided, they did not have any orthopedic or neurological disorders which could affect their walking pattern. Multiple gait trials were used for the classification of the peak muscle powers using cluster analysis. The detailed description of the clusters was based on a multivariate general linear model. The peak values of the 3-D muscle power patterns for each of the lower extremity joints were determined by the inverse dynamic approach. Five distinct able-bodied gait patterns were identified by means of the cluster analysis classification method of 56 trials from the 19 subjects. The principal gait parameters identified in the classification process were: (a) at heel-strike, the sagittal and frontal peak hip powers, (b) at mid-stance, the sagittal and frontal knee peak powers, and (c) at push-off, all sagittal peak powers as well as the frontal hip peak powers. The variability observed in able-bodied gait may be the result of multiple normal dynamic strategies employed by the different subjects. (C) 1998 Elsevier Science B.V.