title: Prediction of the elastic strain limit of tendons.
abstract: The elastic strain limit (ESL) of tendons is the point where maximum elastic modulus is reached, after which micro-damage starts. Study of damage progression in tendons under repetitive (fatigue) loading requires a priori knowledge about ESL. In this study, we propose three different approaches for predicting ESL. First, one single value is assumed to represent the ESL of all tendon specimens. Second, different extrapolation curves are used for extrapolating the initial part of the stress-strain curve. Third, a method based on comparing the shape of the initial part of the stress-strain curve of specimens with a database of stress-strain curves is used. A large number of porcine tendon explants (97) were tested to examine the above-mentioned approaches. The variants of the third approach yielded significantly (p<0.05) smaller error values as compared to the other approaches. The mean absolute percentage error of the best-performing variant of the shape-based comparison was between 8.14±6.44% and 9.96±9.99% depending on the size of the initial part of the stress-strain curves. Interspecies generalizability of the best performing method was also studied by applying it for prediction of the ESL of horse tendons. The ESL of horse tendons was predicted with mean absolute percentage errors ranging between 10.53±7.6% and 19.16±14.31% depending on the size of the initial part of the stress-strain curves and the type of normalization. The results of this study suggest that both ESL and the shape of stress-strain curves may be highly different between different individuals and different anatomical locations.
authors.affiliation: Department of Biomechanical Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, Delft 2628 CD, The Netherlands.
authors.forename: A M
authors.initials: AM
authors.lastname: Reyes
authors.affiliation: Department of Orthopedic Surgery, University Hospital, RWTH Aachen University, Aachen, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Jahr
authors.affiliation: UTC Imaging, Stein, The Netherlands; Department of Physiotherapy, Faculty of Medicine, Nursing and Health Sciences, Monash University, Frankston, Australia.
authors.forename: H T M
authors.initials: HT
authors.lastname: van Schie
authors.affiliation: Department of Biomechanical Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, Delft 2628 CD, The Netherlands; Department of Orthopedics and Department of Rheumatology, Utrecht University Medical Center, Utrecht, The Netherlands.
authors.forename: H
authors.initials: H
authors.lastname: Weinans
authors.affiliation: Department of Biomechanical Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, Delft 2628 CD, The Netherlands. Electronic address: a.a.zadpoor@tudelft.nl.
authors.forename: A A
authors.initials: AA
authors.lastname: Zadpoor
mesh_terms: D000818:Animals; D004548:Elasticity; D006736:Horses; D013045:Species Specificity; D013223:Statistics as Topic / Q000379:methods*; D013314:Stress, Mechanical; D013552:Swine; D013710:Tendons
keywords: Elastic strain limit; Fracture; Prediction; Soft tissue mechanics; Tendons