Variability in the center of pressure resulting from changes in cane placement and method of weight-bearing

Abstract

The aim of this study was to examine the changes in the center of pressure that result from changes in cane placement and method of weight-bearing, and the effects of these changes on standing balance. Using principal component analysis, we studied the characteristics of the center of pressure under various conditions. The possible values for cane placement were center (CP), front (FP), and rear (RP), and for the method of weight-bearing were no weight (NW), body weight (BW), and arm weight (AW). We represented the variability of the center of pressure in the form of an ellipse, in which the directions of the major and minor axes indicated the direction of pressure, and the length of the axes indicated the eigenvalue. In cases where the ellipse was horizontally long, indicating that the eigenvalue of the major axis was high, we recognized that only one characteristic was controlling the direction and magnitude of the force vector in that condition. This pattern was observed in the BW-FP and BW-CP conditions; this demonstrates that body weight and a cane positioned either the front or the center of the body will provide a more stable standing balance.