LAUSR

Background: At present, the quantifiable pressure distribution at the interface between the socket and stump is seldom applied in the design and fabrication of the socket. Objectives: This study aimed to optimize the socket based on the interface pressure of residual limb–socket, thereby avoiding excessive local load on the residual limb, reducing the load on the pressure-sensitive (PS) regions and making the limb more evenly loaded. Methods: The residual limb was divided into the main load-bearing regions, the pressure-tolerant regions, and the PS regions according to the carrying capacity at its different regions. Based on these bearing regions, a mathematical function was developed, which applied modifications/adjustments to the socket design in a Computer Aided Design (CAD) environment by using the adjustment function. Besides, three adjusted sockets were produced by using selective laser sintering 3D printing technology. Results: The wearing of the 3D-adjusted printed sockets reduced the contact interface pressures in the distal tibial region and the fibular head region by 85.6% and 84.4%, respectively. In addition, the walking distance of the subject was increased by 18.34%, and the overall pressure distribution on the stump became more uniform. Conclusions: The pressures in the original overpressure regions and the PS regions could reduce, whereas the pressure in the low-load regions of main load-bearing or pressure-tolerant regions could increase by modifying the socket with the pressure adjustment function. At the same time, the pressure among different regions was more uniform except for the sensitive regions.