Paediatric Prosthetic Knee Design: The Technical Requirements of a Swing Phase Control Mechanism Are Correlated With Parameters of Childhood Growth

Edgar, Caitlin E.; Jones, Richard K.; Bull, Anthony M.J.

Abstract

Objective: There is a lack of innovation in affordable prosthetic knee joints for children. One significant reason is the absence of technical requirements which consider the foundation of childhood: growth. This study aims to develop and use a modelling tool to determine the technical requirements throughout childhood growth for one prosthetic knee design feature, a swing phase control mechanism (SPCM). Methods: 3D gait data of 31 able-bodied children across a range of physical maturities were analyzed. For each participant 2 models were created from a validated paediatric able-bodied musculoskeletal model. The model was first linearly scaled, then a corresponding unilateral right knee-disarticulation amputation model produced by removing segments below the knee and replacing with prosthetic componentry. Long established low-cost prosthetic componentry and a novel polycentric knee were implemented. For each participant, inverse dynamics were conducted and the SPCM torque requirements defined. Results: Prosthetic knee SPCM torque requirements were significantly less than the able-bodied knee to emulate able-bodied gait at free speed: 17.9% (± 10.2) and 66.3% (± 17.0) reduction in maximum extension and flexion torque, respectively. Maximum knee extension torque showed the strongest negative correlation with intact body mass (ρ = -0.6251) whereas flexion torque showed the strongest correlation with height (ρ = 0.6611). Corresponding linear regression fits produced RMSE of 1.91and 1.73 Nm, respectively. Results were also determined for slow and fast speeds. Conclusion: The torque requirements of an affordable paediatric prosthetic knee SPCM are defined and found to strongly correlate with parameters of childhood growth (body mass, height, and age). Significance: Current results recommend low-cost paediatric prosthetic SPCM designs can be tailored to accommodate growth. The creation of musculoskeletal models facilitate multiple future studies.

Citation

Edgar, C. E., Jones, R. K., & Bull, A. M. (2024). Paediatric Prosthetic Knee Design: The Technical Requirements of a Swing Phase Control Mechanism Are Correlated With Parameters of Childhood Growth. IEEE Transactions on Biomedical Engineering, 71(12), 3593-3601. https://doi.org/10.1109/tbme.2024.3434477

• Journal Article Type: Article
• Acceptance Date: Jul 26, 2024
• Online Publication Date: Jul 26, 2024
• Publication Date: Dec 6, 2024
• Deposit Date: Sep 16, 2024
• Publicly Available Date: Sep 17, 2024
• Journal: IEEE Transactions on Biomedical Engineering
• Print ISSN: 0018-9294
• Electronic ISSN: 1558-2531
• Publisher: Institute of Electrical and Electronics Engineers
• Peer Reviewed: Peer Reviewed
• Volume: 71
• Issue: 12
• Pages: 3593-3601
• DOI: https://doi.org/10.1109/tbme.2024.3434477