Recent Advances in Coupled MBS and FEM Models of the Spine—A Review

Abstract

How back pain is related to intervertebral disc degeneration, spinal loading or sports-related overuse remains an unanswered question of biomechanics. Coupled MBS and FEM simulations can provide a holistic view of the spine by considering both the overall kinematics and kinetics of the spine and the inner stress distribution of flexible components. We reviewed studies that included MBS and FEM co-simulations of the spine. Thereby, we classified the studies into unidirectional and bidirectional co-simulation, according to their data exchange methods. Several studies have demonstrated that using unidirectional co-simulation models provides useful insights into spinal biomechanics, although synchronizing the two distinct models remains a key challenge, often requiring extensive manual intervention. The use of a bidirectional co-simulation features an iterative, automated process with a constant data exchange between integrated subsystems. It reduces manual corrections of vertebra positions or reaction forces and enables detailed modeling of dynamic load cases. Bidirectional co-simulations are thus a promising new research approach for improved spine modeling, as a main challenge in spinal biomechanics is the nonlinear deformation of the intervertebral discs. Future studies will likely include the automated implementation of patient-specific bidirectional co-simulation models using hyper- or poroelastic intervertebral disc FEM models and muscle forces examined by an optimization algorithm in MBS. Applications range from clinical diagnosis to biomechanical analysis of overload situations in sports and injury prediction.

Musculoskeletal spine modeling in large patient cohorts: how morphological individualization affects lumbar load estimation

“…Although respective muscle-related parameters can be derived in vivo from imaging data ( Niklasson et al, 2022 ), the mechanical properties of passive structures can currently only be determined with the help of in vitro studies ( Panjabi et al, 1976 ; Pintar et al, 1992 ; Ashton-Miller and Schultz, 1997 ; Heuer et al, 2007 ; White, 2022 ), which require the isolation of the structure of interest to mount them in respective testing machines and therefore cannot represent the mechanical properties of the modeled subject. In order to obtain consistent datasets for biomechanical models, alternative, noninvasive methods must be developed to determine these parameters in large subject cohorts, e.g., using a combination of experimental studies, multimodal imaging, and artificial neural networks (ANNs), as suggested in earlier publications ( Lerchl et al, 2023 ; Nispel et al, 2023 ). Furthermore, we neglected the effects of intraabdominal pressure (IAP) on spinal biomechanics.…”

Clinical biomechanics of the spine in three unsolved problems. A brief analytical review

“…П и т а н н я щ о д о р о з р а х у н к у ф а к т и ч н о г о навантаження на МХ Д поперекового від ділу в статичному положенні та в динаміці, з урахуванням усіх чинників, що його визначають і впливають на нього, не вирішено. Спроби його розв'язання здійснюють постійно [50,53,68,78,[87][88][89][90][91][92][93][94][95][96][97][98][99][100][101][102] 7]. У зв'язку із цим, максимальне вилучення поперекового згинання із фізичної активності вранці може зменшити маніфестацію болю в попереку [109,110].…”

Advances in Biomechanics-Based Motion Analysis

“…Similarly, Wong et al [ 13 ] used FEMs to evaluate the stress of different thoracolumbar reconstruction constructs on proximal junctional levels, providing insights on the optimal selection of reconstruction constructs to treat thoracolumbar burst fractures and minimize postoperative complications. In addition, Nispel et al [ 14 ] reviewed the contemporary use of coupled multibody models and FEM simulations to analyze both the holistic biomechanics of the spine and the stress distribution within flexible components (e.g., intervertebral discs), providing a more comprehensive view of facilitating the evaluations and diagnoses of spine-related health issues.…”