i-Socket: Design, Development, and Pilot Evaluation of an Individualized Multi-Material, Multi-Thickness Transtibial Prosthetic Socket

TL;DR

This study introduces a personalized multi-material, multi-thickness transtibial prosthetic socket designed to improve comfort and reduce pressure, demonstrating significant pressure reduction and enhanced gait symmetry in pilot tests.

Contribution

It presents a novel method for designing individualized prosthetic sockets with optimized material and thickness based on pressure thresholds, validated through pilot experiments.

Findings

The i-Socket is 22% lighter than the participant's original socket.

Pressure inside the socket decreased by 45% at the Tibia and 31% at the Fibula.

Knee and ankle joint symmetry increased by 65% and 2%, respectively.

Abstract

The prosthetic socket is an essential part in ensuring comfort and stability for the overall prosthesis system. This study proposes a multi-material/thickness individualized transtibial prosthetic socket that focuses on providing comfort. This study aims to identify the proper material and thickness to protect Calf areas and reduce the pressure around bone areas. First, the socket is divided into four parts depending on the pressure-sensitive/tolerant regions. After identifying the thickness range for each concerned area, the thickness and material are selected based on the Pressure-Pain Threshold (PPT) test, and the finalized design is then prototyped. The prototyped individualized socket (i-Socket) is 22% lighter than the participant's own socket. Results of the pilot experiments with an amputee participant showed that the pressure inside the socket decreased by 45% and 31% for the Tibia and Fibula regions, respectively. Additionally, the self-selected CoM velocity for the walking experiment is increased by 15% compared to the similar studies in the literature. Regarding the kinematic results, symmetry in the knee and ankle joints increased by 65% and 2% when using the i-Socket compared to the results with the participant's own socket.