Muscle-driven forward dynamic active hybrid model of the lumbosacral spine

  • Most spine models belong to either the musculoskeletal multibody (MB) or finite element (FE) method. Recently, coupling of MB and FE models has increasingly been used to combine advantages of both methods. Active hybrid FE-MB models, still rarely used in spine research, avoid the interface and convergence problems associated with model coupling. They provide the inherent ability to account for the full interplay of passive and active mechanisms for spinal stability. In this paper, we developed and validated a novel muscle-driven forward dynamic active hybrid FE-MB model of the lumbosacral spine (LSS) in ArtiSynth to simultaneously calculate muscle activation patterns, vertebral movements, and internal mechanical loads. The model consisted of the rigid vertebrae L1-S1 interconnected with hyperelastic fiber-reinforced FE intervertebral discs, ligaments, facet joints, and force actuators representing the muscles. Morphological muscle data were implemented via a semi-automated registration procedure. Four auxiliary bodies were utilized to describe non-linear muscle paths by wrapping and attaching the anterior abdominal muscles. This included an abdominal plate whose kinematics was optimized using motion capture data from upper body movements. Intra-abdominal pressure was calculated from the forces of the abdominal muscles compressing the abdominal cavity. For the muscle-driven approach, forward dynamics assisted data tracking was used to predict muscle activation patterns that generate spinal postures and balance the spine without prescribing accurate spinal kinematics. During calibration, the maximum specific muscle tension and spinal rhythms resulting from the model dynamics were evaluated. To validate the model, load cases were simulated from −10° extension to +30° flexion with weights up to 20 kg in both hands. The biomechanical model responses were compared with \(\textit {in vivo}\) literature data of intradiscal pressures, intra-abdominal pressures, and muscle activities. The results demonstrated high agreement with this data and highlight the advantages of active hybrid modeling for the LSS. Overall, this new self-contained tool provides a robust and efficient estimation of LSS biomechanical responses under \(\textit {in vivo}\) similar loads, for example, to improve pain treatment by spinal stabilization therapies.

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Author:Robin RemusORCiDGND, Sascha SelkmannORCiDGND, Andreas LipphausORCiDGND, Marc NeumannGND, Beate BenderORCiDGND
Parent Title (English):Frontiers in bioengineering and biotechnology
Subtitle (English):combined FEM and multibody simulation
Publisher:Frontiers Media
Place of publication:Lausanne
Document Type:Article
Date of Publication (online):2023/03/04
Date of first Publication:2023/09/27
Publishing Institution:Ruhr-Universität Bochum, Universitätsbibliothek
Tag:Open Access Fonds
active hybrid model; finite element model; forward dynamics; lumbar spine; motion capture; muscle-driven; musculoskeletal multibody model; spinal stability
Issue:Artikel 1223007
First Page:1223007-1
Last Page:1223007-23
Article Processing Charge funded by the Deutsche Forschungsgemeinschaft (DFG) and the Open Access Publication Fund of Ruhr-Universität Bochum.
Institutes/Facilities:Lehrstuhl für Produktentwicklung
Dewey Decimal Classification:Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften, Maschinenbau
open_access (DINI-Set):open_access
faculties:Fakultät für Maschinenbau
Licence (English):License LogoCreative Commons - CC BY 4.0 - Attribution 4.0 International