The majority of commercially available passive prosthetic feet are not capable of providing joint mechanics that match that of the intact human ankle. Due to their cantilever design, their stiffness characteristics contrast with what has been observed in the biological ankle, namely, an increase in stiffness during the stance phase of walking. In this paper, we introduce the design and control of a pneumatic foot-ankle prosthesis that attempts to provide biomimetic mechanics. The prosthesis is comprised of a pneumatic cylinder in series with a fiberglass leaf spring, and a solenoid valve to control the flow of air between the two sides of the cylinder. The solenoid valve acts as a mechanical clutch, enabling resetting of the ankle's equilibrium position. By adjusting the pressure inside the cylinder, the prosthesis can be customized to provide a range of ankle mechanics. A mechanical testing machine is used to compare the torque-angle curve of the pneumatic prosthesis with a low-profile passive prosthetic foot. Finally, data are presented of one transtibial amputee walking with the prosthesis at 1.2 m/s. The testing shows that the pneumatic prosthesis is capable of providing an appropriate range of motion as well a maximum torque of 94 Nm, while returning approximately 11.5 J of energy.

Download full-text PDF

Source
http://dx.doi.org/10.1109/TNSRE.2017.2699867DOI Listing

Publication Analysis

Top Keywords

pneumatic foot-ankle
8
foot-ankle prosthesis
8
passive prosthetic
8
capable providing
8
solenoid valve
8
pneumatic prosthesis
8
prosthesis
7
pneumatic
5
design characterization
4
characterization quasi-passive
4

Similar Publications

Objectives: Non-pneumatic compression devices (NPCDs) rely on shape-memory alloy technology that allows patients to ambulate and remain active during lymphedema treatment. This study examines the effect of the NPCD on foot and ankle swelling.

Methods: This was a prospective, non-randomized study of patients with phlebolymphedema (venous insufficiency-related lymphedema) treated with a novel NPCD for 4 weeks.

View Article and Find Full Text PDF

Influence of custom dynamic orthoses on tibiotalar joint reaction force and contact stress: A cadaveric study.

J Biomech

December 2024

Department of Orthopedics and Rehabilitation, University of Iowa, 200 Newton Road, Iowa City, IA 52242, United States; Department of Biomedical Engineering, University of Iowa, 200 Newton Road, Iowa City, IA 52242, United States. Electronic address:

Article Synopsis
  • Post-traumatic osteoarthritis (PTOA) often arises after tibial pilon fractures, leading surgeons to prioritize precise articular reduction, which can extend surgery time.
  • A cadaveric study explored how the stiffness of custom dynamic orthoses (CDOs) affects ankle joint reaction force (JRF) and contact stress during the stance phase of walking.
  • Results showed that using CDOs reduced JRF by up to 32%, indicating that post-operative bracing could lower the risk of developing PTOA after such fractures.
View Article and Find Full Text PDF

Standing up using one leg is a challenging task for those with a transfemoral amputation, particularly for elderly users with a low activity level. Active prostheses are generally not accessible to this group and available passive prostheses do not support standing up. This article presents the design and evaluation of the "Energy Restoring Intelligent Knee" (ERiK), which stores energy during sit-down in a pneumatic cylinder and returns it during stand-up.

View Article and Find Full Text PDF

Gait event detection is essential for controlling an orthosis and assessing the patient's gait. In this study, patients wearing an electromechanical (EM) knee-ankle-foot orthosis (KAFO) with a single IMU embedded in the thigh were subjected to gait event detection. The algorithm detected four essential gait events (initial contact (IC), toe off (TO), opposite initial contact (OIC), and opposite toe off (OTO)) and determined important temporal gait parameters such as stance/swing time, symmetry, and single/double limb support.

View Article and Find Full Text PDF

Background: Balance perturbation studies during walking have improved our understanding of balance control in various destabilizing conditions. However, it is unknown to what extent balance recovery strategies can be generalized across different types of mediolateral balance perturbations.

Research Question: Do similar mediolateral perturbations (foot placement versus surface translation) have similar effects on balance control and corresponding balance response strategies?

Methods: Kinetic and kinematic data were previously collected during two separate studies, each with 15 young, healthy participants walking on an instrumented treadmill.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!