title: Viscoelastic properties of the cervical spinal ligaments under fast strain-rate deformations.
abstract: The mechanical response of ligaments under fast strain-rate deformations is a necessary input into computational models that are used for injury assessment. However, this information frequently is not available for the ligaments that are routinely injured in fast-rate loading scenarios. In the current study, experiments were conducted at fast strain rates for the cervical spinal ligaments: the anterior longitudinal ligament, the posterior longitudinal ligament and the ligamentum flavum. Bone-ligament-bone complexes at three spine levels were harvested for mechanical testing. Displacement-controlled sub-failure uniaxial tensile tests were performed in both load-relaxation and sinusoidal conditions. A nonlinear (separable) viscoelastic model was used to examine the experimental data. An unexpected result of the modeling was that the instantaneous elastic functions could be approximated as linear for these strain rates. A five-parameter model was sufficient to characterize the ligament viscoelastic responses and had good predictive capacity under different applied loading conditions.
authors.affiliation: Center for Applied Biomechanics, University of Virginia, 1011 Linden Avenue, Charlottesville, VA 22902, USA. slucas@virginia.edu
authors.forename: Scott R
authors.initials: SR
authors.lastname: Lucas
authors.forename: Cameron R
authors.initials: CR
authors.lastname: Bass
authors.forename: Robert S
authors.initials: RS
authors.lastname: Salzar
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Oyen
authors.forename: Chris
authors.initials: C
authors.lastname: Planchak
authors.forename: Adam
authors.initials: A
authors.lastname: Ziemba
authors.forename: Barry S
authors.initials: BS
authors.lastname: Shender
authors.forename: Glenn
authors.initials: G
authors.lastname: Paskoff
mesh_terms: D001696:Biomechanical Phenomena; D002574:Cervical Vertebrae; D004548:Elasticity; D005260:Female; D006801:Humans; D017846:Longitudinal Ligaments / Q000293:injuries / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D013314:Stress, Mechanical; D013997:Time Factors