Experimental Measurement and Applied Modelling of Patellar Tendon Strain

Firminger, Colin Robert

Experimental Measurement and Applied Modelling of Patellar Tendon Strain

dc.contributor.advisor	Edwards, William Brent
dc.contributor.author	Firminger, Colin Robert
dc.contributor.committeemember	Stefanyshyn, Darren
dc.contributor.committeemember	Hart, David
dc.date	2021-11
dc.date.accessioned	2021-05-31T16:21:37Z
dc.date.available	2021-05-31T16:21:37Z
dc.date.issued	2021-05-27
dc.description.abstract	Patellar tendinopathy is an overuse injury that occurs from repetitive loading of the patellar tendon in a scenario resembling mechanical fatigue. Tendon strain is correlated with the number of repetitive loading cycles that can be withstood prior to fatigue failure, and therefore represents a potential metric to infer patellar tendinopathy risk. To this end, I first quantified the mechanical fatigue behaviour of the patellar tendon in a cyclic loading scenario. I discovered that initial peak nominal strain, initial peak median strain, creep rate, and damage rate all displayed significant power law relationships with fatigue life. Based on the non-linear relationship between strain and fatigue life, I examined the effect of shoe outsole stiffness and surface construction on in vivo estimates of patellar tendon strain with the aim of exponentially increasing the number of jumps that could be performed prior to fatigue failure. Unfortunately, I discovered that neither intervention altered patellar tendon strain during jumping, potentially because the differences in shoe stiffness and surface construction were not large enough to require kinetic and/or kinematic changes at the knee. Finally, I assessed the effect of two strain estimation methodologies with varied levels of subject-specificity on fatigue-life estimates. I discovered that nominal strain models overestimated patellar tendon fatigue life compared to finite element models as they do not account for strain concentrations both within the tendon midsubstance and near the entheses, while fatigue-life estimates from both finite element and nominal strain models were sensitive to the use of generic material properties but not generic geometry. The results of these studies form a principled basis for the estimation of patellar tendon strain and additional time-dependent metrics to characterize patellar tendinopathy risk from a mechanical fatigue perspective, and further illustrate appropriate methodological approaches to do so.	en_US
dc.identifier.citation	Firminger, C. R. (2021). Experimental Measurement and Applied Modelling of Patellar Tendon Strain (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.	en_US
dc.identifier.doi	http://dx.doi.org/10.11575/PRISM/38900
dc.identifier.uri	http://hdl.handle.net/1880/113461
dc.language.iso	eng	en_US
dc.publisher.faculty	Schulich School of Engineering	en_US
dc.publisher.institution	University of Calgary	en
dc.rights	University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.	en_US
dc.subject	Patellar tendon	en_US
dc.subject	Patellar tendinopathy	en_US
dc.subject	Strain	en_US
dc.subject	Modelling	en_US
dc.subject.classification	Engineering--Biomedical	en_US
dc.title	Experimental Measurement and Applied Modelling of Patellar Tendon Strain	en_US
dc.type	doctoral thesis	en_US
thesis.degree.discipline	Engineering – Biomedical	en_US
thesis.degree.grantor	University of Calgary	en_US
thesis.degree.name	Doctor of Philosophy (PhD)	en_US
ucalgary.item.requestcopy	true	en_US