Amirkabir University of Technology Amirkabir Journal of Mechanical Engineering 2008-6032 56 11 2025 01 20 Biomechanical analysis of the lumbar spine under different loading conditions Biomechanical analysis of the lumbar spine under different loading conditions 1475 1496 5693 10.22060/mej.2025.23781.7812 FA Ali Kamali Department of Mechanical Engineering, Engineering Faculty, Shahid Chamran University of Ahvaz, Iran Laleh Fatahi Department of Mechanical Engineering, Engineering Faculty, Shahid Chamran University of Ahvaz, Iran Ali Reza Naeimifard Department of Mechanical Engineering, Engineering Faculty, Shahid Chamran University of Ahvaz, Iran Journal Article 2024 12 29 <span style="letter-spacing: .05pt;">The human body is exposed to many forces and moments during daily activities. The spine is one of the most important structures that bear these forces and may be prone to multiple injuries. Therefore, numerical modeling and analysis of the lumbar spine under various loading conditions is very beneficial to prevent injuries. This study aims to provide a valid finite element model of the L4-L5 segment of the human lumbar spine for static analysis. The model includes two vertebrae, intervertebral discs, end plates, and ligaments. To model the mechanical properties of the lumbar spine, elastic and hyperelastic behaviors have been used for different parts of the spine. Moreover, stress and strain distribution in different tissues, under various loading conditions, were compared with the allowable thresholds of the tissues to investigate the possibility of tissue damage. Note that it was assumed that tissue damage occurs when the stresses and strains in the desired tissue exceed the elastic range. However, based on the obtained results, under the investigated loading conditions, none of the model components were damaged.</span> <span style="letter-spacing: .05pt;">The human body is exposed to many forces and moments during daily activities. The spine is one of the most important structures that bear these forces and may be prone to multiple injuries. Therefore, numerical modeling and analysis of the lumbar spine under various loading conditions is very beneficial to prevent injuries. This study aims to provide a valid finite element model of the L4-L5 segment of the human lumbar spine for static analysis. The model includes two vertebrae, intervertebral discs, end plates, and ligaments. To model the mechanical properties of the lumbar spine, elastic and hyperelastic behaviors have been used for different parts of the spine. Moreover, stress and strain distribution in different tissues, under various loading conditions, were compared with the allowable thresholds of the tissues to investigate the possibility of tissue damage. Note that it was assumed that tissue damage occurs when the stresses and strains in the desired tissue exceed the elastic range. However, based on the obtained results, under the investigated loading conditions, none of the model components were damaged.</span> https://mej.aut.ac.ir/article_5693_5ba47c07b9b6a8f2718d94fa3f48fe9f.pdf