A New Method to Prescribe Wedges Custom Made For Individuals With Transfemoral Amputation Using Principal Component Analysis

Wedges custom made have been used to improve the gait pattern of individuals with transfemoral (TF) Amputation. However, the prescription and test of these wedges is mostly based on a highly subjective gait evaluation. The purpose of this study was to develop a rational and quantitative method to prescribe wedges custom made for the sound limb of individuals with TF using Principal Component Analysis (PCA).

First, the effect of different wedges was assessed in able-bodied subjects (CG). Second, using the influence of the wedges in CG, and the gait pattern of each TF individually, wedges were prescribed in order to modify their gait according to the specific effect of each wedge. The variables analyzed were the ground reaction force components and center of pressure displacement. The Mahalanobis distance for each variable and the 95% confidence interval (CI) based on CG data was calculated. Results showed, by the Mahalanobis distance of the variables, that TF subjects improved their gait pattern, TF subjects improved their gait; the variables that were out of the boundaries of 95% CI of CG, moved inside these boundaries with the use of wedges.

The application of wedges to the sound limb of TF amputees can improve their gait patterns, thus the application of PCA can help clinicians to decide the best device for each patient, and consequently improve TF patient quality of life.