Principal component analysis of the techniques of manual stretching for equinovarus

Abstract

[Purpose] The aim of this study was to develop a method to statistically analyze the techniques of manual stretching for equinovarus. [Subjects and Methods] Six physical therapists (PTs) and three stroke survivors participated in this study. The manual stretching motions of PTs and forces and torques applied to the patient’s heel were measured by a motion capture system and a six-axial force sensor. For statistical analysis, principal component analysis (PCA) was expanded and performed on the recorded data. [Results] Three principal components were extracted by the statistical analysis. According to the primary component, PTs increased their force, on the toe side, and moment on dorsiflexion with slight abduction moments. The second and third components indicated the differences in the abduction/adduction and eversion/inversion torques around the heel and in the forces pulling or pushing the heel. [Conclusion] Our method based on PCA enables the statistical analysis of the similarities and differences of complex manual stretching techniques among PTs.