Towards optimal toe-clearance in synthesizing polycentric prosthetic knee mechanism. Issue 6 (26th April 2022)

• Record Type: Journal Article
• Authors: Marisami, P.; Venkatachalam, R.
• Is Part Of: Computer methods in biomechanics and biomedical engineering. Volume 25:Issue 6(2022)
• Page Start: 656
• Page End: 667
• Publication Date: 2022-04-26
• Subjects: Prosthesis -- polycentric knee -- four-bar knee -- Centrodes -- toe-clearance -- irregular terrain -- obstacles; Biomechanics -- Data processing -- Periodicals; Biomedical engineering -- Periodicals; Biomechanics -- Periodicals; Biomedical Engineering -- methods -- Periodicals; Computing Methodologies -- Periodicals; 612.7
• DOI: 10.1080/10255842.2021.1972291
• Languages: English
• ISSNs: 1025-5842

Abstract

Abstract: Stability at the stance phase and near normal able-bodied swing phase kinematics are essential in designing the prosthetic knee mechanism for transfemoral amputees. Primarily, insufficient mid swing toe clearance results in asymmetrical gait patterns, leading to muscular-skeletal pain and joint degeneration. The present work is focused on synthesizing a polycentric knee mechanism to enhance the toe-clearance at mid-swing for safe level ground walking of amputees in developing countries. Both fixed and moving centrodes of the four-bar knee mechanism are considered in optimal synthesis of the mechanism for achieving able-bodied gait patterns using evolutionary algorithms in mechanism design software tools. The knee stability at heel contact, stabilizing moment at push-off, stable knee flexion range, maximum knee flexion and maximum toe-clearance at mid-swing are the parameters used for comparing the knee design with the existing commercially available designs. The optimized results are then verified experimentally by building a functional prototype using a 3 D printing technique. The designed mechanism executes nominal performance in four parameters and offers enhanced toe-clearance during mid-swing. This is a significant improvement over the existing designs for amputees to navigate comfortably on irregular terrain in developing countries.