Viscoelastic properties of the ovine posterior spinal ligaments are strain dependent

Ambrosetti-Giudici, Sveva; Gédet, Philippe; Ferguson, Stephen J.; Chegini, Salman; Burger, Jürgen

doi:10.1016/j.clinbiomech.2009.10.017

Cited by 13 publications

(11 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus, viscoelasticity is requisite to comprehensively model the functional mechanical behavior of these ligaments. Previous experimental studies have demonstrated strong evidence suggesting that a fully nonlinear constitutive formulation is requisite to capture the viscoelastic behavior of both cervical (Troyer and Puttlitz, 2011) and lumbar (Ambrosetti-Giudici et al, 2010;Little and Khalsa, 2005) expect similar trends in the viscoelastic response at adjacent spinal levels (Lucas et al, 2008).…”

Section: Discussionmentioning

confidence: 96%

“…This formulation is a special (simplified) case of fully nonlinear viscoelasticity wherein it is assumed that the stress relaxation behavior is independent of the applied strain magnitude. Recent investigations have demonstrated strong experimental evidence that suggests spinal ligaments violate this QLV assumption wherein the observed relaxation is a function of strain magnitude (Ambrosetti-Giudici et al, 2010;Little and Khalsa, 2005;Troyer and Puttlitz, 2011). Additionally, current nonlinear viscoelastic models (AmbrosettiGiudici et al, 2010;Little and Khalsa, 2005;Troyer and Puttlitz, 2011) are limited in that they do not incorporate relaxation manifested during loading events (i.e.…”

Section: Introductionmentioning

confidence: 93%

See 1 more Smart Citation

Nonlinear viscoelasticty plays an essential role in the functional behavior of spinal ligaments

Troyer

Puttlitz

2012

Journal of Biomechanics

View full text Add to dashboard Cite

Section: Discussionmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 93%

Nonlinear viscoelasticty plays an essential role in the functional behavior of spinal ligaments

Troyer

Puttlitz

2012

Journal of Biomechanics

View full text Add to dashboard Cite

“…To our own knowledge and observation (Ambrosetti-Giudici et al 2010) during a variety of in vitro experiments, and according to McGill (2007) and Solomonow (2009), the fibre alignment in this ligament is at an oblique angle to the spinous process, rather than parallel. The oblique angle was considered and included in the model with respect to inferior processes at each lumbar level.…”

mentioning

confidence: 85%

Letters to the Editor

Abouhossein

Weisse

Ferguson

2012

Computer Methods in Biomechanics and Biomedical Engineering

Self Cite

View full text Add to dashboard Cite

“…The capsular ligament length was measured at the origin and insertion along the fiber axis of the facet capsule. The cross-sectional area for each ligament was calculated by measuring the width and thickness using a digital caliper and assuming an elliptical cross-section [64]. The cross-section of the CL was approximated by considering the capsular joint as a circle, and thus the ligament having a ring-like shape.…”

Section: Methodsmentioning

confidence: 99%

“…Specimens were affixed to the testing machine using a custom fixture (Figure 25). Each ligament was loaded to 5 N to define a uniform reference point for the initial position and to ensure there was no slack in the ligament [60,63,64]; specimens were preconditioned at 10% strain for twenty loading and unloading cycles [61] at 0.25 Hz. After preconditioning, each specimen was held at zero displacement for 30 seconds and then underwent tensile loading at 3% strain/s [76,77] until failure.…”

Section: Methodsmentioning

confidence: 99%

The biomechanics of the sheep cervical spine

DeVries¹

View full text Add to dashboard Cite

Animal models are essential for making the transition from scientific concepts to clinical application. Such models have proven valuable for spinal research. The cervical spine of sheep is often used because there is similar geometry between sheep and human. Although anatomical similarities are important, biomechanical correspondence is imperative to understand the effects of disorders, surgical techniques, and implant designs. Therefore, the purpose of this study was to conduct a comprehensive study of the sheep cervical spine biomechanics, including experimental and finite element analysis. To determine the flexibility of the multilevel spine, ten adult Suffolk sheep C2-C7 spines were tested, undergoing flexion-extension, lateral bending, and axial rotation. In addition to intact multilevel testing, the roles of the stabilizing structures were studied by sequentially destabilizing function spinal units. The sheep spine is highly flexible, especially in lateral bending (±65˚); motion increases with caudal progression. The sheep spine also has a large neutral zone accounting for 50-75% of the total motion. The facets and capsular ligaments play a key role in stabilization, providing the most stability at the C2-C3 level. In addition to flexibility testing, the sheep spinal ligaments underwent tensile testing until failure to determine the material properties. The ligamentum flavum has the largest failure stress and the capsular ligaments have the largest mean failure force. The longitudinal ligaments have the largest failure strain and the lowest failure force. Overall, the C2-C3 ligaments had the highest failure forces as compared to the ligament type at different levels. This corresponds to the stability the ligaments have at the C2-C3 level during flexibility testing. Moreover, a finite element model of the C2-C7 sheep cervical spine was developed and validated to provide additional insight in the sheep biomechanics. The model compared favorably with experimental testing for all loading cases except ACKNOWLEDGMENTS First and foremost, I want thank my advisor Dr. Nicole Grosland. It was with her encouragement that I pursued my doctorate. Her knowledge and advice has guided me and helped me grow as a researcher, student, and person. Without her patience and direction this would not have been possible. I would also like to thank my committee members for taking time out of their busy schedules. I am grateful for their input and suggestions. Their insights have led to further improvement of this research study.

show abstract

Viscoelastic properties of the ovine posterior spinal ligaments are strain dependent

Cited by 13 publications

References 27 publications

Nonlinear viscoelasticty plays an essential role in the functional behavior of spinal ligaments

Nonlinear viscoelasticty plays an essential role in the functional behavior of spinal ligaments

Letters to the Editor

The biomechanics of the sheep cervical spine

Contact Info

Product

Resources

About