Hypersensitivity of trunk biomechanical model predictions to errors in image-based kinematics when using fully displacement-control techniques

Eskandari, A. H ; Sharif University of Technology | 2019

714 Viewed
  1. Type of Document: Article
  2. DOI: 10.1016/j.jbiomech.2018.12.043
  3. Publisher: Elsevier Ltd , 2019
  4. Abstract:
  5. Recent advances in medical imaging techniques have allowed pure displacement-control trunk models to estimate spinal loads with no need to calculate muscle forces. Sensitivity of these models to the errors in post-imaging evaluation of displacements (reported to be ∼0.4–0.9° and 0.2–0.3 mm in vertebral displacements) has not yet been investigated. A Monte Carlo analysis was therefore used to assess the sensitivity of results in both musculoskeletal (MS) and passive finite element (FE) spine models to errors in measured displacements. Six static activities in upright standing, flexed, and extended postures were initially simulated using a force-control hybrid MS-FE model. Computed vertebral displacements were subsequently used to drive two distinct fully displacement-control MS and FE models. Effects of alterations in the reference vertebral displacements (at 3 error levels with SD (standard deviation) = 0.1, 0.2, and 0.3 mm in input translations together with, respectively, 0.2, 0.4, and 0.6° in input rotations) were investigated on the model predictions. Results indicated that outputs of both models had substantial task-dependent sensitivities to errors in the measured vertebral translations. For instance, L5-S1 intradiscal pressures (IDPs) were considerably affected (SD values reaching 1.05 MPa) and axial compression and shear forces even reversed directions as translation errors increased to 0.3 mm. Outputs were however generally much less sensitive to errors in measured vertebral rotations. Accounting for the accuracies in image-based kinematics measurements, therefore, it is concluded that the current measured vertebral translation errors at and beyond 0.1 mm are too large to drive biomechanical models of the spine. © 2019 Elsevier Ltd
  6. Keywords:
  7. Finite element model ; Monte Carlo Method ; Musculoskeletal ; Sensitivity ; Spine ; Biomechanics ; Displacement control ; Errors ; Kinematics ; Medical imaging ; Monte Carlo methods ; Musculoskeletal system ; Bio-mechanical models ; Compression and shear ; Intradiscal pressures ; Monte carlo analysis ; Sensitivity-of-results ; Finite element method ; Computer assisted tomography ; Controlled study ; Human ; Male ; Measurement error ; Prediction ; Priority journal ; Sensitivity analysis ; Shear strength ; Standing ; Trunk ; Vertebra dislocation ; Body position ; Diagnostic imaging ; Joint characteristics and functions ; Mechanics ; Physiology ; Skeletal muscle ; Weight bearing ; Aged ; Biomechanical Phenomena ; Finite Element Analysis ; Humans ; Mechanical Phenomena ; Molecular Imaging ; Muscle, Skeletal ; Posture ; Pressure ; Range of Motion, Articular ; Torso ; Weight-Bearing
  8. Source: Journal of Biomechanics ; Volume 84 , 2019 , Pages 161-171 ; 00219290 (ISSN)
  9. URL: https://www.sciencedirect.com/science/article/pii/S0021929019300053