Passive Prosthetic Foot Shape and Size Optimization Using Lower Leg Trajectory Error

Copyright © 2018 by ASME. A method is presented to optimize the shape and size of a passive, energy-storing prosthetic foot using the lower leg trajectory error (LLTE) as the design objective. The LLTE is defined as the root-mean-square error between the lower leg trajectory calculated for a given p...

Full description

Bibliographic Details
Main Authors: Olesnavage, Kathryn M, Prost, Victor, Johnson, William Brett, Winter, Amos G
Other Authors: Massachusetts Institute of Technology. Global Engineering and Research Laboratory
Format: Article
Language:English
Published: ASME International 2021
Online Access:https://hdl.handle.net/1721.1/135867
_version_ 1811073781178826752
author Olesnavage, Kathryn M
Prost, Victor
Johnson, William Brett
Winter, Amos G
author2 Massachusetts Institute of Technology. Global Engineering and Research Laboratory
author_facet Massachusetts Institute of Technology. Global Engineering and Research Laboratory
Olesnavage, Kathryn M
Prost, Victor
Johnson, William Brett
Winter, Amos G
author_sort Olesnavage, Kathryn M
collection MIT
description Copyright © 2018 by ASME. A method is presented to optimize the shape and size of a passive, energy-storing prosthetic foot using the lower leg trajectory error (LLTE) as the design objective. The LLTE is defined as the root-mean-square error between the lower leg trajectory calculated for a given prosthetic foot's deformed shape under typical ground reaction forces (GRFs), and a target physiological lower leg trajectory obtained from published gait data for able-bodied walking. Using the LLTE as a design objective creates a quantitative connection between the mechanical design of a prosthetic foot (stiffness and geometry) and its anticipated biomechanical performance. The authors' prior work has shown that feet with optimized, low LLTE values can accurately replicate physiological kinematics and kinetics. The size and shape of a single-part compliant prosthetic foot made out of nylon 6/6 were optimized for minimum LLTE using a wide Bezier curve to describe its geometry, with constraints to produce only shapes that could fit within a physiological foot's geometric envelope. Given its single part architecture, the foot could be cost effectively manufactured with injection molding, extrusion, or three-dimensional printing. Load testing of the foot showed that its maximum deflection was within 0.3 cm (9%) of finite element analysis (FEA) predictions, ensuring the constitutive behavior was accurately characterized. Prototypes were tested on six below-knee amputees in India-the target users for this technology-to obtain qualitative feedback, which was overall positive and confirmed the foot is ready for extended field trials.
first_indexed 2024-09-23T09:38:27Z
format Article
id mit-1721.1/135867
institution Massachusetts Institute of Technology
language English
last_indexed 2024-09-23T09:38:27Z
publishDate 2021
publisher ASME International
record_format dspace
spelling mit-1721.1/1358672023-03-01T21:19:49Z Passive Prosthetic Foot Shape and Size Optimization Using Lower Leg Trajectory Error Olesnavage, Kathryn M Prost, Victor Johnson, William Brett Winter, Amos G Massachusetts Institute of Technology. Global Engineering and Research Laboratory Massachusetts Institute of Technology. Department of Mechanical Engineering Copyright © 2018 by ASME. A method is presented to optimize the shape and size of a passive, energy-storing prosthetic foot using the lower leg trajectory error (LLTE) as the design objective. The LLTE is defined as the root-mean-square error between the lower leg trajectory calculated for a given prosthetic foot's deformed shape under typical ground reaction forces (GRFs), and a target physiological lower leg trajectory obtained from published gait data for able-bodied walking. Using the LLTE as a design objective creates a quantitative connection between the mechanical design of a prosthetic foot (stiffness and geometry) and its anticipated biomechanical performance. The authors' prior work has shown that feet with optimized, low LLTE values can accurately replicate physiological kinematics and kinetics. The size and shape of a single-part compliant prosthetic foot made out of nylon 6/6 were optimized for minimum LLTE using a wide Bezier curve to describe its geometry, with constraints to produce only shapes that could fit within a physiological foot's geometric envelope. Given its single part architecture, the foot could be cost effectively manufactured with injection molding, extrusion, or three-dimensional printing. Load testing of the foot showed that its maximum deflection was within 0.3 cm (9%) of finite element analysis (FEA) predictions, ensuring the constitutive behavior was accurately characterized. Prototypes were tested on six below-knee amputees in India-the target users for this technology-to obtain qualitative feedback, which was overall positive and confirmed the foot is ready for extended field trials. 2021-10-27T20:29:43Z 2021-10-27T20:29:43Z 2018 2020-08-13T14:27:31Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/135867 en 10.1115/1.4040779 Journal of Mechanical Design Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf ASME International ASME
spellingShingle Olesnavage, Kathryn M
Prost, Victor
Johnson, William Brett
Winter, Amos G
Passive Prosthetic Foot Shape and Size Optimization Using Lower Leg Trajectory Error
title Passive Prosthetic Foot Shape and Size Optimization Using Lower Leg Trajectory Error
title_full Passive Prosthetic Foot Shape and Size Optimization Using Lower Leg Trajectory Error
title_fullStr Passive Prosthetic Foot Shape and Size Optimization Using Lower Leg Trajectory Error
title_full_unstemmed Passive Prosthetic Foot Shape and Size Optimization Using Lower Leg Trajectory Error
title_short Passive Prosthetic Foot Shape and Size Optimization Using Lower Leg Trajectory Error
title_sort passive prosthetic foot shape and size optimization using lower leg trajectory error
url https://hdl.handle.net/1721.1/135867
work_keys_str_mv AT olesnavagekathrynm passiveprostheticfootshapeandsizeoptimizationusinglowerlegtrajectoryerror
AT prostvictor passiveprostheticfootshapeandsizeoptimizationusinglowerlegtrajectoryerror
AT johnsonwilliambrett passiveprostheticfootshapeandsizeoptimizationusinglowerlegtrajectoryerror
AT winteramosg passiveprostheticfootshapeandsizeoptimizationusinglowerlegtrajectoryerror