Firminger, Colin R.Haider, Ifaz T.Bruce, Olivia L.Wannop, John W.Stefanyshyn, Darren J.Edwards, W Brent2024-05-232024-05-232021-09-11Firminger, C. R., Haider, I. T., Bruce, O. L., Wannop, J. W., Stefanyshyn, D. J., & Edwards, W. B. (2021). Are subject-specific models necessary to predict patellar tendon fatigue life? A finite element modelling study. Computer Methods in Biomechanics and Biomedical Engineering, 25(7), 729–739. https://doi.org/10.1080/10255842.2021.19756831476-8259https://hdl.handle.net/1880/11882710.11575/PRISM/46424Patellar tendinopathy is an overuse injury that occurs from repetitive loading of the patellar tendon in a scenario resembling that of mechanical fatigue. As such, fatigue-life estimates provide a quantifiable approach to assess tendinopathy risk and may be tabulated using nominal strain (NS) or finite element (FE) models with varied subject-specificity. We compared patellar tendon fatigue-life estimates from NS and FE models of twenty-nine athletes performing countermovement jumps with subject-specific versus generic geometry and material properties. Subject-specific patellar tendon material properties and geometry were obtained using a data collection protocol of dynamometry, ultrasound, and magnetic resonance imaging. Three FE models were created for each subject, with: subject-specific (hyperelastic) material properties and geometry, subject-specific material properties and generic geometry, and generic material properties and subject-specific geometry. Four NS models were created for each subject, with: subject-specific (linear elastic) material properties and moment arm, generic material properties and subject-specific moment arm, subject-specific material properties and generic moment arm, and generic material properties and moment arm. NS- and FE-modelled fatigue-life estimates with generic material properties were poorly correlated with their subject-specific counterparts (r2≤0.073), while all NS models overestimated fatigue life compared to the subject-specific FE model (r2≤0.223). Furthermore, FE models with generic tendon geometry were unable to accurately represent the heterogeneous strain distributions found in the subject-specific FE models or those with generic material properties. These findings illustrate the importance of incorporating subject-specific material properties and FE-modelled strain distributions into fatigue-life estimations.enThis is an Accepted Manuscript version of the following article, accepted for publication in Computer Methods in Biomechanics and Biomedical Engineering . Firminger, C. R., Haider, I. T., Bruce, O. L., Wannop, J. W., Stefanyshyn, D. J., & Edwards, W. B. (2021). Are subject-specific models necessary to predict patellar tendon fatigue life? A finite element modelling study. Computer Methods in Biomechanics and Biomedical Engineering, 25(7), 729–739. https://doi.org/10.1080/10255842.2021.1975683. It is deposited under the terms of the Creative Commons Attribution-NonCommercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited.http://creativecommons.org/licenses/by-nc/4.0/Patellar tendinopathyOveruse injuryFinite Element ModellingStrainArticlehttps://doi.org/10.1080/10255842.2021.1975683