title: A database of lumbar spinal mechanical behavior for validation of spinal analytical models.
abstract: Data from two experimental studies with eight specimens each of spinal motion segments and/or intervertebral discs are presented in a form that can be used for comparison with finite element model predictions. The data include the effect of compressive preload (0, 250 and 500N) with quasistatic cyclic loading (0.0115Hz) and the effect of loading frequency (1, 0.1, 0.01 and 0.001Hz) with a physiological compressive preload (mean 642N). Specimens were tested with displacements in each of six degrees of freedom (three translations and three rotations) about defined anatomical axes. The three forces and three moments in the corresponding axis system were recorded during each test. Linearized stiffness matrices were calculated that could be used in multi-segmental biomechanical models of the spine and these matrices were analyzed to determine whether off-diagonal terms and symmetry assumptions should be included. These databases of lumbar spinal mechanical behavior under physiological conditions quantify behaviors that should be present in finite element model simulations. The addition of more specimens to identify sources of variability associated with physical dimensions, degeneration, and other variables would be beneficial. Supplementary data provide the recorded data and Matlab® codes for reading files. Linearized stiffness matrices derived from the tests at different preloads revealed few significant unexpected off-diagonal terms and little evidence of significant matrix asymmetry.
authors.affiliation: University of Vermont, Department of Orthopaedics and Rehabilitation, Burlington, VT 05405-0084, USA. Electronic address: ian.stokes@uvm.edu.
authors.forename: Ian A F
authors.initials: IAF
authors.lastname: Stokes
authors.affiliation: University of Vermont, Department of Orthopaedics and Rehabilitation, Burlington, VT 05405-0084, USA.
authors.forename: Mack
authors.initials: M
authors.lastname: Gardner-Morse
mesh_terms: D000293:Adolescent; D000328:Adult; D001696:Biomechanical Phenomena; D016208:Databases, Factual; D005260:Female; D020342:Finite Element Analysis; D006801:Humans; D007403:Intervertebral Disc / Q000502:physiology*; D008159:Lumbar Vertebrae / Q000502:physiology*; D008875:Middle Aged; D008954:Models, Biological; D009038:Motion; D055815:Young Adult
keywords: Database; Frequency-dependence; Lumbar spine; Preload; Spine; Stiffness