Page 527 - IJB-10-3

International

Journal of Bioprinting

RESEARCH ARTICLE
Tuning the mechanical responses of 3D-printed

ankle-foot orthoses: A numerical study

Chenxi Peng 1,2 id , Phuong Tran 3 id , Simon Lalor 4 id , Oren Tirosh 5 id ,
and Erich Rutz 1,2,6,7,8,9 id
*
1 Department of Paediatrics, The University of Melbourne, Parkville, Victoria, Australia
2 Murdoch Children’s Research Institute, Parkville, Victoria, Australia
3 RMIT Centre for Additive Manufacturing, School of Engineering, RMIT University, Melbourne,
Victoria, Australia
4 Orthotic and Prosthetic Department, The Royal Children’s Hospital Melbourne, Parkville,
Victoria, Australia
5 School of Health and Biomedical Sciences, STEM College, RMIT University, Bundoora,
Victoria, Australia
6 Bob Dickens Chair Paediatric Orthopaedic Surgery, The University of Melbourne, Parkville,
Victoria, Australia
7 Orthopaedics Department, The Royal Children’s Hospital Melbourne, Parkville, Victoria, Australia
8 The Hugh Williamson Gait Analysis Laboratory, The Royal Children’s Hospital Melbourne, Parkville,
Victoria, Australia
9 Medical Faculty, The University of Basel, Basel, Switzerland

Abstract
*Corresponding author:
Erich Rutz
(erich.rutz@unimelb.edu.au) Ankle-foot orthoses (AFOs) are frequently prescribed for children with cerebral
palsy (CP) to correct specific features of abnormal gait. However, traditional AFO
Citation: Peng C, Tran P, Lalor
S, Tirosh O, Rutz E. Tuning manufacturing and design involve labor-intensive processes and rely on subjective
the mechanical responses of evaluations of clinicians. Recent advances in three-dimensional (3D) printing allow
3D-printed ankle-foot orthoses: the rapid prototyping of AFOs, but the expanded design options complicate decision-
A numerical study. Int J Bioprint.
2024;10(3):3390. making. This study aims to evaluate how AFO design affects the mechanical responses
doi: 10.36922/ijb.3390 of 3D-printed AFOs. The lower limb geometry is established by a 3D-scanning system,
and a prototypical AFO is designed, 3D printed, and tested under compression. A
Received: April 9, 2024
Accepted: May 8, 2024 parametric study on the effect of base materials, thickness, and trimline location is
Published Online: June 7, 2024 conducted based on a validated numerical model. The results reveal that AFOs exhibit
Copyright: © 2024 Author(s). distinct behaviors under plantarflexion and dorsiflexion motions, with AFO stiffness
This is an Open Access article correlating to thickness through a power function. AFO stiffness is more sensitive
distributed under the terms of the to posterior trim depth than inferior, while both trim depths significantly influence
Creative Commons Attribution
License, permitting distribution, stress concentration around the ankle region. This investigation demonstrates the
and reproduction in any medium, potential of combining 3D printing and computational modeling to improve the
provided the original work is design and fabrication process of AFOs, providing insights into the development and
properly cited.
customization of 3D-printed AFOs.
Publisher’s Note: AccScience
Publishing remains neutral with
regard to jurisdictional claims in Keywords: Cerebral Palsy; Ankle-foot orthoses; 3D printing; Computational
published maps and institutional
affiliations. modeling; Stiffness; Dorsiflexion; Plantarflexion

Volume 10 Issue 3 (2024) 519 doi: 10.36922/ijb.3390