Journal articles: 'Spine modeling'

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Rosado, James, Viet Duc Bui, Carola A. Haas, Jürgen Beck, Gillian Queisser, and Andreas Vlachos. "Calcium modeling of spine apparatus-containing human dendritic spines demonstrates an “all-or-nothing” communication switch between the spine head and dendrite." PLOS Computational Biology 18, no. 4 (2022): e1010069. http://dx.doi.org/10.1371/journal.pcbi.1010069.

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Dendritic spines are highly dynamic neuronal compartments that control the synaptic transmission between neurons. Spines form ultrastructural units, coupling synaptic contact sites to the dendritic shaft and often harbor a spine apparatus organelle, composed of smooth endoplasmic reticulum, which is responsible for calcium sequestration and release into the spine head and neck. The spine apparatus has recently been linked to synaptic plasticity in adult human cortical neurons. While the morphological heterogeneity of spines and their intracellular organization has been extensively demonstrated in animal models, the influence of spine apparatus organelles on critical signaling pathways, such as calcium-mediated dynamics, is less well known in human dendritic spines. In this study we used serial transmission electron microscopy to anatomically reconstruct nine human cortical spines in detail as a basis for modeling and simulation of the calcium dynamics between spine and dendrite. The anatomical study of reconstructed human dendritic spines revealed that the size of the postsynaptic density correlates with spine head volume and that the spine apparatus volume is proportional to the spine volume. Using a newly developed simulation pipeline, we have linked these findings to spine-to-dendrite calcium communication. While the absence of a spine apparatus, or the presence of a purely passive spine apparatus did not enable any of the reconstructed spines to relay a calcium signal to the dendritic shaft, the calcium-induced calcium release from this intracellular organelle allowed for finely tuned “all-or-nothing” spine-to-dendrite calcium coupling; controlled by spine morphology, neck plasticity, and ryanodine receptors. Our results suggest that spine apparatus organelles are strategically positioned in the neck of human dendritic spines and demonstrate their potential relevance to the maintenance and regulation of spine-to-dendrite calcium communication.

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Rosado, James, Viet Duc Bui, Carola A. Haas, Jürgen Beck, Gillian Queisser, and Andreas Vlachos. "Calcium modeling of spine apparatus-containing human dendritic spines demonstrates an “all-or-nothing” communication switch between the spine head and dendrite." PLOS Computational Biology 18, no. 4 (2022): e1010069. http://dx.doi.org/10.1371/journal.pcbi.1010069.

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Dendritic spines are highly dynamic neuronal compartments that control the synaptic transmission between neurons. Spines form ultrastructural units, coupling synaptic contact sites to the dendritic shaft and often harbor a spine apparatus organelle, composed of smooth endoplasmic reticulum, which is responsible for calcium sequestration and release into the spine head and neck. The spine apparatus has recently been linked to synaptic plasticity in adult human cortical neurons. While the morphological heterogeneity of spines and their intracellular organization has been extensively demonstrated in animal models, the influence of spine apparatus organelles on critical signaling pathways, such as calcium-mediated dynamics, is less well known in human dendritic spines. In this study we used serial transmission electron microscopy to anatomically reconstruct nine human cortical spines in detail as a basis for modeling and simulation of the calcium dynamics between spine and dendrite. The anatomical study of reconstructed human dendritic spines revealed that the size of the postsynaptic density correlates with spine head volume and that the spine apparatus volume is proportional to the spine volume. Using a newly developed simulation pipeline, we have linked these findings to spine-to-dendrite calcium communication. While the absence of a spine apparatus, or the presence of a purely passive spine apparatus did not enable any of the reconstructed spines to relay a calcium signal to the dendritic shaft, the calcium-induced calcium release from this intracellular organelle allowed for finely tuned “all-or-nothing” spine-to-dendrite calcium coupling; controlled by spine morphology, neck plasticity, and ryanodine receptors. Our results suggest that spine apparatus organelles are strategically positioned in the neck of human dendritic spines and demonstrate their potential relevance to the maintenance and regulation of spine-to-dendrite calcium communication.

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Wang, Shiquan, Hao Jiang, and Mark R. Cutkosky. "Design and modeling of linearly-constrained compliant spines for human-scale locomotion on rocky surfaces." International Journal of Robotics Research 36, no. 9 (2017): 985–99. http://dx.doi.org/10.1177/0278364917720019.

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We present a new spine solution for the locomotion of human-scale robots on steep, rocky surfaces, known as linearly-constrained spines. The spine stiffness is low in the normal direction but high with respect to lateral and bending loads. The solution differs from previous spine arrays used for small robots in having a much higher spine density and less spine scraping over asperities. We present theoretical and empirical results to demonstrate that this solution is capable of shear stresses of over 200kPa, enabling human-scale robots to apply forces parallel to steep rock surfaces for climbing, bracing, etc. The analysis includes the effects of spine geometry, stiffness, backlash and three-dimensional loading angle to predict the overall forces possible in three dimensions of both single and opposed configurations of spine arrays. Demonstrated applications include a gripper for a “smart staff” aimed at helping humanoid robots to negotiate steep terrain and a palm that provides over 700N in shear for the RoboSimian quadruped.

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Jiang, Lei, Zhongqi Xu, Tinglong Zheng, Xiuli Zhang, and Jianhua Yang. "Research on Dynamic Modeling Method and Flying Gait Characteristics of Quadruped Robots with Flexible Spines." Biomimetics 9, no. 3 (2024): 132. http://dx.doi.org/10.3390/biomimetics9030132.

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In recent years, both domestic and international research on quadruped robots has advanced towards high dynamics and agility, with a focus on high-speed locomotion as a representative motion in high-dynamic activities. Quadruped animals like cheetahs exhibit high-speed running capabilities, attributed to the indispensable role played by their flexible spines during the flight phase motion. This paper establishes dynamic models of flexible spinal quadruped robots with different degrees of simplification, providing a parameterized description of the flight phase motion for both rigid-trunk and flexible-spine quadruped robots. By setting different initial values for the spine joint and calculating the flight phase results for both types of robots at various initial velocities, the study compares and analyzes the impact of a flexible spine on the flight phase motion of quadruped robots. Through comparative experiments, the research aims to validate the influence of a flexible spine during the flight phase motion, providing insights into how spine flexibility affects the flight phase motion of quadruped robots.

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Pchitskaya, Ekaterina, Anastasiya Rakovskaya, Margarita Chigray, and Ilya Bezprozvanny. "Cytoskeleton Protein EB3 Contributes to Dendritic Spines Enlargement and Enhances Their Resilience to Toxic Effects of Beta-Amyloid." International Journal of Molecular Sciences 23, no. 4 (2022): 2274. http://dx.doi.org/10.3390/ijms23042274.

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EB3 protein is expressed abundantly in the nervous system and transiently enters the dendritic spines at the tip of the growing microtubule, which leads to spine enlargement. Nevertheless, the role of dynamic microtubules, and particularly EB3 protein, in synapse function is still elusive. By manipulating the EB3 expression level, we have shown that this protein is required for a normal dendritogenesis. Nonetheless, EB3 overexpression also reduces hippocampal neurons dendritic branching and total dendritic length. This effect likely occurs due to the speeding neuronal development cycle from dendrite outgrowth to the step when dendritic spines are forming. Implementing direct morphometric characterization of dendritic spines, we showed that EB3 overexpression leads to a dramatic increase in the dendritic spine head area. EB3 knockout oppositely reduces spine head area and increases spine neck length and spine neck/spine length ratio. The same effect is observed in conditions of amyloid-beta toxicity, modeling Alzheimer`s disease. Neck elongation is supposed to be a common detrimental effect on the spine’s shape, which makes them biochemically and electrically less connected to the dendrite. EB3 also potentiates the formation of presynaptic protein Synapsin clusters and CaMKII-alpha preferential localization in spines rather than in dendrites of hippocampal neurons, while its downregulation has an opposite effect and reduces the size of presynaptic protein clusters Synapsin and PSD95. EB3′s role in spine development and maturation determines its neuroprotective effect. EB3 overexpression makes dendritic spines resilient to amyloid-beta toxicity, restores altered PSD95 clustering, and reduces CaMKII-alpha localization in spines observed in this pathological state.

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Malik, Azeem Tariq, and Safdar N. Khan. "Predictive modeling in spine surgery." Annals of Translational Medicine 7, S5 (2019): S173. http://dx.doi.org/10.21037/atm.2019.07.99.

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Pai S, Anoosha, Honglin Zhang, Nima Ashjaee, et al. "Estimation and assessment of sagittal spinal curvature and thoracic muscle morphometry in different postures." Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 235, no. 8 (2021): 883–96. http://dx.doi.org/10.1177/09544119211014668.

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Spine models are typically developed from supine clinical imaging data, and hence clearly do not fully reflect postures that replicate subjects’ clinical symptoms. Our objectives were to develop a method to: (i) estimate the subject-specific sagittal curvature of the whole spine in different postures from limited imaging data, (ii) obtain muscle lines-of-action in different postures and analyze the effect of posture on muscle fascicle length, and (iii) correct for cosine between the magnetic resonance imaging (MRI) scan plane and dominant fiber line-of-action for muscle parameters (cross-sectional area (CSA) and position). The thoracic spines of six healthy volunteers were scanned in four postures (supine, standing, flexion, and sitting) in an upright MRI. Geometry of the sagittal spine was approximated with a circular spline. A pipeline was developed to estimate spine geometry in different postures and was validated. The lines-of-action for two muscles, erector spinae (ES) and transversospinalis (TS) were obtained for every posture and hence muscle fascicle lengths were computed. A correction factor based on published literature was then computed and applied to the muscle parameters. The maximum registration error between the estimated spine geometry and MRI data was small (average RMSE∼1.2%). The muscle fascicle length increased (up to 20%) in flexion when compared to erect postures. The correction factor reduced muscle parameters (∼5% for ES and ∼25% for TS) when compared to raw MRI data. The proposed pipeline is a preliminary step in subject-specific modeling. Direction cosines of muscles could be used while improving the inputs of spine models.

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Bell, Miriam, Tom Bartol, Terrence Sejnowski, and Padmini Rangamani. "Dendritic spine geometry and spine apparatus organization govern the spatiotemporal dynamics of calcium." Journal of General Physiology 151, no. 8 (2019): 1017–34. http://dx.doi.org/10.1085/jgp.201812261.

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Dendritic spines are small subcompartments that protrude from the dendrites of neurons and are important for signaling activity and synaptic communication. These subcompartments have been characterized to have different shapes. While it is known that these shapes are associated with spine function, the specific nature of these shape–function relationships is not well understood. In this work, we systematically investigated the relationship between the shape and size of both the spine head and spine apparatus, a specialized endoplasmic reticulum compartment within the spine head, in modulating rapid calcium dynamics using mathematical modeling. We developed a spatial multicompartment reaction–diffusion model of calcium dynamics in three dimensions with various flux sources, including N-methyl-D-aspartate receptors (NMDARs), voltage-sensitive calcium channels (VSCCs), and different ion pumps on the plasma membrane. Using this model, we make several important predictions. First, the volume to surface area ratio of the spine regulates calcium dynamics. Second, membrane fluxes impact calcium dynamics temporally and spatially in a nonlinear fashion. Finally, the spine apparatus can act as a physical buffer for calcium by acting as a sink and rescaling the calcium concentration. These predictions set the stage for future experimental investigations of calcium dynamics in dendritic spines.

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Rangamani, Padmini, Michael G. Levy, Shahid Khan, and George Oster. "Paradoxical signaling regulates structural plasticity in dendritic spines." Proceedings of the National Academy of Sciences 113, no. 36 (2016): E5298—E5307. http://dx.doi.org/10.1073/pnas.1610391113.

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Transient spine enlargement (3- to 5-min timescale) is an important event associated with the structural plasticity of dendritic spines. Many of the molecular mechanisms associated with transient spine enlargement have been identified experimentally. Here, we use a systems biology approach to construct a mathematical model of biochemical signaling and actin-mediated transient spine expansion in response to calcium influx caused by NMDA receptor activation. We have identified that a key feature of this signaling network is the paradoxical signaling loop. Paradoxical components act bifunctionally in signaling networks, and their role is to control both the activation and the inhibition of a desired response function (protein activity or spine volume). Using ordinary differential equation (ODE)-based modeling, we show that the dynamics of different regulators of transient spine expansion, including calmodulin-dependent protein kinase II (CaMKII), RhoA, and Cdc42, and the spine volume can be described using paradoxical signaling loops. Our model is able to capture the experimentally observed dynamics of transient spine volume. Furthermore, we show that actin remodeling events provide a robustness to spine volume dynamics. We also generate experimentally testable predictions about the role of different components and parameters of the network on spine dynamics.

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Kumaresan, Srirangam, Narayan Yoganandan, Frank A. Pintar, Dennis J. Maiman, and Shashi Kuppa. "Biomechanical Study of Pediatric Human Cervical Spine: A Finite Element Approach." Journal of Biomechanical Engineering 122, no. 1 (1999): 60–71. http://dx.doi.org/10.1115/1.429628.

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Although considerable effort has been made to understand the biomechanical behavior of the adult cervical spine, relatively little information is available on the response of the pediatric cervical spine to external forces. Since significant anatomical differences exist between the adult and pediatric cervical spines, distinct biomechanical responses are expected. The present study quantified the biomechanical responses of human pediatric spines by incorporating their unique developmental anatomical features. One-, three-, and six-year-old cervical spines were simulated using the finite element modeling technique, and their responses computed and compared with the adult spine response. The effects of pure overall structural scaling of the adult spine, local component developmental anatomy variations that occur to the actual pediatric spines, and structural scaling combined with local component anatomy variations on the responses of the pediatric spines were studied. Age- and component-related developmental anatomical features included variations in the ossification centers, cartilages, growth plates, vertebral centrum, facet joints, and annular fibers and nucleus pulposus of the intervertebral discs. The flexibility responses of the models were determined under pure compression, pure flexion, pure extension, and varying degrees of combined compression–flexion and compression–extension. The pediatric spine responses obtained with the pure overall (only geometric) scaling of the adult spine indicated that the flexibilities consistently increase in a uniform manner from six- to one-year-old spines under all loading cases. In contrast, incorporation of local anatomic changes specific to the pediatric spines of the three age groups (maintaining the same adult size) not only resulted in considerable increases in flexibilities, but the responses also varied as a function of the age of the pediatric spine and type of external loading. When the geometric scaling effects were added to these spines, the increases in flexibilities were slightly higher; however, the pattern of the responses remained the same as found in the previous approach. These results indicate that inclusion of developmental anatomical changes characteristic of the pediatric spines has more of a predominant effect on biomechanical responses than extrapolating responses of the adult spine based on pure overall geometric scaling. [S0148-0731(00)00501-X]

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Qiu, Tian-Xia, and Ee-Chon Teo. "FINITE ELEMENT MODELING OF HUMAN THORACIC SPINE." Journal of Musculoskeletal Research 08, no. 04 (2004): 133–44. http://dx.doi.org/10.1142/s0218957704001302.

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Mathematical models, which can accurately represent the geometric, material and physical characteristics of the human spine structure, are useful in predicting biomechanical behaviors of the spine. In this study, a three-dimensional finite element (FE) model of thoracic spine (T1–T12) was developed, based on geometrical data of embalmed thoracic vertebrae (T1–T12) obtained from a precise flexible digitizer, and validated against published thoracolumbar experimental results in terms of the torsional stiffness of the whole thoracic spine (T1–T12) under axial torque alone and combined with distraction and compression loads. The torsional stiffness was increased by over 60% with application of a 425 N distraction force. A trend in increasing torsional stiffness with increasing distraction forces was detected. The validated model was then loaded under moment rotation in three anatomical planes to determine the ranges of motion (ROMs). The ROMs were approximately 37°, 31°, 32°, 51° for flexion, extension, lateral bending and axial rotation, respectively. These results may offer an insight to better understanding the kinematics of the human thoracic spine and provide clinically relevant fundamental information for the evaluation of spinal stability and instrumented devices functionality for optimal scoliosis correction.

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Alimohamadi, Haleh, Miriam Bell, Shelley Halpain, and Padmini Rangamani. "Biophysical Modeling of Dendritic Spine Morphology." Biophysical Journal 120, no. 3 (2021): 47a. http://dx.doi.org/10.1016/j.bpj.2020.11.525.

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Dugailly, Pierre-Michel, Stéphane Sobczak, Fedor Moiseev, et al. "Musculoskeletal Modeling of the Suboccipital Spine." Spine 36, no. 6 (2011): E413—E422. http://dx.doi.org/10.1097/brs.0b013e3181dc844a.

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LEVIN, STEPHEN M. "THE TENSEGRITY-TRUSS AS A MODEL FOR SPINE MECHANICS: BIOTENSEGRITY." Journal of Mechanics in Medicine and Biology 02, no. 03n04 (2002): 375–88. http://dx.doi.org/10.1142/s0219519402000472.

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The commonly accepted "tower of blocks" model for vertebrate spine mechanics is only useful when modeling a perfectly balanced, upright, immobile spine. Using that model, in any other position than perfectly upright, the forces generated will tear muscle, crush bone and exhaust energy. A new model of the spine uses a tensegrity-truss system that will model the spine right side up, upside-down or in any position, static or dynamic. In a tensegrity-truss model, the loads distribute through the system only in tension or compression. As in all truss systems, there are no levers and no moments at the joints. The model behaves non-linearly and is energy efficient. Unlike a tower of blocks, it is independent of gravity and functions equally well on land, at sea, in the air or in space and models the spines of fish and fowl, bird and beast.

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Krutko, A. V., A. V. Gladkov, V. V. Komissarov, and N. V. Komissarova. "MODELING OF THE SPINE COMPENSATORY RESPONSE TO DEFORMITY." Hirurgiâ pozvonočnika 15, no. 3 (2018): 85–91. http://dx.doi.org/10.14531/ss2018.3.85-91.

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Objective. To analyze mathematical model of the efficiency of the compensatory mechanism of the deformed spine. Material and Methods. The developed basic kinematic model of the spine was used. The restoration of the position of the projection of the general center of mass (GCM) was mathematically modeled, and mechanogenesis of the spinal deformity and possibility of its compensation were evaluated. To assess the reliability of the mathematical model, spinal skiagrams taken from patients with clinically confirmed pathology and sagittal imbalance were used. Results. On the basis of quantitative characteristics of the primary spine deformity of a certain clinical case and using the developed algorithm, it is possible to create a model of both a primary deformity and a compensatory response from intact segments of the spine taking into account the influencing factors. This makes it possible to use the proposed kinematic model in scientific research on predicting the course of various types of spinal deformities. Conclusion. The proposed algorithms simulating the development of spinal deformities based on the restoration of the position of the GCM projection reflect their mechanogenesis and can be used to model various pathological conditions of the spine. A complete correction of the deformity does not mean a complete cure, since the required spinal fusion creates a new, prognostically less significant, but pathological situation.

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Tadano, Shigeru, Masahiro Kanayama, Takayoshi Ukai, and Kiyoshi Kaneda. "Three-Dimensional Morphological Modeling of Scoliotic Spine." Transactions of the Japan Society of Mechanical Engineers Series A 61, no. 587 (1995): 1682–88. http://dx.doi.org/10.1299/kikaia.61.1682.

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Marchenko, Olena, Charles W. Wolgemuth, and Leslie M. Loew. "Analysis and Modeling of Dendritic Spine Morphogenesis." Biophysical Journal 106, no. 2 (2014): 424a—425a. http://dx.doi.org/10.1016/j.bpj.2013.11.2392.

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Peleganchuk, A. V., A. V. Gladkov, V. V. Komissarov, A. S. Shershever, and E. A. Mushkachev. "MATHEMATICAL MODELING OF THE HIP-SPINE SYNDROME." Современные проблемы науки и образования (Modern Problems of Science and Education), no. 4 2023 (2023): 41. http://dx.doi.org/10.17513/spno.32844.

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Vaida, Calin, Paul Tucan, Doina Pislă, and Florin Covaciu. "Parametric Modeling for Analyzing Diseases of the Human Spine." Applied Mechanics and Materials 823 (January 2016): 131–36. http://dx.doi.org/10.4028/www.scientific.net/amm.823.131.

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The paper presents a graphical simulation system of the human spine developed using integrated MATLAB software. The application is based on real parameters of the human spine that can be modified and personalized during the analysis and all data are reported with respect to an ideal model of the human spine that is also personalized to the patient in cause. Given the fact that the human spine is one of the most complex systems in the human body a high attention must be paid at every aspect of its geometry and motion during the daily activities of the patient, this application enabling the monitoring of the majority of these aspects by analyzing data obtained from a special designed sensor system attached to the patient body.

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Davis, Kermit G., and Michael J. Jorgensen. "Biomechanical modeling for understanding of low back injuries: A systematic review." Occupational Ergonomics 5, no. 1 (2005): 57–76. http://dx.doi.org/10.3233/oer-2005-5106.

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With the enormous burden that low back pain has on society, researchers are constantly attempting to find effective evaluation techniques that identify mechanisms of injury. One of the more widely used methods utilized to understand the physical loading on the lumbar spine is biomechanical modeling. While there are a wide variety of spine load models, they all operate under a load-tolerance premise. The current review discusses key considerations that current and future biomechanical models need to take into account such as injury site, torso posture, torso dynamics, individual differences, gender and age differences, and detailed anatomy. A detailed description of the potential injury sites and nociception reveals the importance of understanding the complexity of the spine and the necessity of looking beyond the intervertebral disc. This review provides a broad overview of current models, including a description of the prominent spine load models in the literature. Finally, future directions of spine biomechanical models are discussed, providing insight to potential new frontiers to increase our understanding of how low back injuries and pain is initiated.

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Ma, Haibo, Chaobo Wang, Ang Li, Aide Xu, and Dong Han. "An Accurate Book Spine Detection Network Based on Improved Oriented R-CNN." Sensors 24, no. 24 (2024): 7996. https://doi.org/10.3390/s24247996.

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Book localization is crucial for the development of intelligent book inventory systems, where the high-precision detection of book spines is a critical requirement. However, the varying tilt angles and diverse aspect ratios of books on library shelves often reduce the effectiveness of conventional object detection algorithms. To address these challenges, this study proposes an enhanced oriented R-CNN algorithm for book spine detection. First, we replace the standard 3 × 3 convolutions in ResNet50’s residual blocks with deformable convolutions to enhance the network’s capacity for modeling the geometric deformations of book spines. Additionally, the PAFPN (Path Aggregation Feature Pyramid Network) was integrated into the neck structure to enhance multi-scale feature fusion. To further optimize the anchor box design, we introduce an adaptive initial cluster center selection method for K-median clustering. This allows for a more accurate computation of anchor box aspect ratios that are better aligned with the book spine dataset, enhancing the model’s training performance. We conducted comparison experiments between the proposed model and other state-of-the-art models on the book spine dataset, and the results demonstrate that the proposed approach reaches an mAP of 90.22%, which outperforms the baseline algorithm by 4.47 percentage points. Our method significantly improves detection accuracy, making it highly effective for identifying book spines in real-world library environments.

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Yap, Jiajun, R. N. V. Krishna Deepak, Zizi Tian та ін. "The stability of R-spine defines RAF inhibitor resistance: A comprehensive analysis of oncogenic BRAF mutants with in-frame insertion of αC-β4 loop". Science Advances 7, № 24 (2021): eabg0390. http://dx.doi.org/10.1126/sciadv.abg0390.

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Although targeting BRAF mutants with RAF inhibitors has achieved promising outcomes in cancer therapy, drug resistance remains a remarkable challenge, and underlying molecular mechanisms are not fully understood. Here, we characterized a previously unknown group of oncogenic BRAF mutants with in-frame insertions (LLRins506 or VLRins506) of αC-β4 loop. Using structure modeling and molecular dynamics simulation, we found that these insertions formed a large hydrophobic network that stabilizes R-spine and thus triggers the catalytic activity of BRAF. Furthermore, these insertions disrupted BRAF dimer interface and impaired dimerization. Unlike BRAF(V600E), these BRAF mutants with low dimer affinity were strongly resistant to all RAF inhibitors in clinic or clinical trials, which arises from their stabilized R-spines. As predicted by molecular docking, the stabilized R-spines in other BRAF mutants also conferred drug resistance. Together, our data indicated that the stability of R-spine but not dimer affinity determines the RAF inhibitor resistance of oncogenic BRAF mutants.

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Lund, M., and H. Shayestehpour. "ENHANCING BIOMECHANICAL SPINE MODELS WITH NON-LINEAR RHYTHMS." Orthopaedic Proceedings 106-B, SUPP_18 (2024): 52. http://dx.doi.org/10.1302/1358-992x.2024.18.052.

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IntroductionThis research aims to enhance the control of intricate musculoskeletal spine models, a critical tool for comprehending both healthy and pathological spinal conditions. State-of-the-art musculoskeletal spine models incorporate segments for all vertebra, each possessing 3 degrees-of-freedom (DOF). Manually defining the posture with this amount of DOFs presents a significant challenge. The prevalent method of equally distributing the spine's overall rotation among the vertebrae often proves to be an inadequate assumption, particularly when dealing with the entire spine.MethodWe have engineered a comprehensive non-linear spine rhythm and the requisite tools for its implementation in widely utilized musculoskeletal modelling software (1). The rhythm controls lateral bending, axial rotation, and flexion/extension. The mathematical and implementation details of the rhythm are beyond this abstract, but it's noteworthy that the implementation accommodates non-linear rhythms. This means, for example, that one set of rhythm coefficients is used for flexion and another for extension. The rhythm coefficients, which distinguish the movement along the spine, were derived from a review of spine literature. The values for spine and vertebra range-of-motion (ROM) vary significantly in published studies, and no complete dataset was found in any single study. Consequently, the rhythm presented here is a composite, designed to provide the most consistent and average set of rhythm coefficients.ResultThe novel spine rhythm simplifies the control of detailed spine models, accommodating varying amounts of input data. It allows for the specification of only the overall motion or the posture at a more detailed level (i.e., lumbar, thoracic, neck). The tools and rhythm coefficients are publicly available on GitHub.ConclusionThe innovative spine rhythm enhances the usability of cutting-edge spine models. For flexion/extension of the spine, it introduces a non-linear rhythm, exhibiting distinct behaviour between flexion and extension - a feature not previously observed in musculoskeletal spine models.1) The AnyBody Modeling System

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Teo, J. C. M., C. K. Chui, Z. L. Wang, et al. "Heterogeneous meshing and biomechanical modeling of human spine." Medical Engineering & Physics 29, no. 2 (2007): 277–90. http://dx.doi.org/10.1016/j.medengphy.2006.02.012.

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Yoganandan, Narayan, Srirangam Kumaresan, Liming Voo, and Frank A. Pintar. "Finite Element Applications in Human Cervical Spine Modeling." Spine 21, no. 15 (1996): 1824–34. http://dx.doi.org/10.1097/00007632-199608010-00022.

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Liebschner, Michael A. K., David L. Kopperdahl, William S. Rosenberg, and Tony M. Keaveny. "Finite Element Modeling of the Human Thoracolumbar Spine." Spine 28, no. 6 (2003): 559–65. http://dx.doi.org/10.1097/01.brs.0000049923.27694.47.

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Marchenko, Olena, and Charles Wolgemuth. "Modeling Actomyosin Contractility in Motile Dendritic Filopodia Resolves Spine Shape in Mature Dendritic Spines." Biophysical Journal 102, no. 3 (2012): 349a. http://dx.doi.org/10.1016/j.bpj.2011.11.1915.

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Rethorn, Zachary D., Alessandra N. Garcia, Chad E. Cook, and Oren N. Gottfried. "Quantifying the collective influence of social determinants of health using conditional and cluster modeling." PLOS ONE 15, no. 11 (2020): e0241868. http://dx.doi.org/10.1371/journal.pone.0241868.

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Objectives Our objective was to analyze the collective effect of social determinants of health (SDoH) on lumbar spine surgery outcomes utilizing two different statistical methods of combining variables. Methods This observational study analyzed data from the Quality Outcomes Database, a nationwide United States spine registry. Race/ethnicity, educational attainment, employment status, insurance payer, and gender were predictors of interest. We built two models to assess the collective influence of SDoH on outcomes following lumbar spine surgery—a stepwise model using each number of SDoH conditions present (0 of 5, 1 of 5, 2 of 5, etc) and a clustered subgroup model. Logistic regression analyses adjusted for age, multimorbidity, surgical indication, type of lumbar spine surgery, and surgical approach were performed to identify the odds of failing to demonstrate clinically meaningful improvements in disability, back pain, leg pain, quality of life, and patient satisfaction at 3- and 12-months following lumbar spine surgery. Results Stepwise modeling outperformed individual SDoH when 4 of 5 SDoH were present. Cluster modeling revealed 4 distinct subgroups. Disparities between the younger, minority, lower socioeconomic status and the younger, white, higher socioeconomic status subgroups were substantially wider compared to individual SDoH. Discussion Collective and cluster modeling of SDoH better predicted failure to demonstrate clinically meaningful improvements than individual SDoH in this cohort. Viewing social factors in aggregate rather than individually may offer more precise estimates of the impact of SDoH on outcomes.

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Sciortino, Vincenza, Salvatore Pasta, Tommaso Ingrassia, and Donatella Cerniglia. "A Population-Based 3D Atlas of the Pathological Lumbar Spine Segment." Bioengineering 9, no. 8 (2022): 408. http://dx.doi.org/10.3390/bioengineering9080408.

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The spine is the load-bearing structure of human beings and may present several disorders, with low back pain the most frequent problem during human life. Signs of a spine disorder or disease vary depending on the location and type of the spine condition. Therefore, we aim to develop a probabilistic atlas of the lumbar spine segment using statistical shape modeling (SSM) and then explore the variability of spine geometry using principal component analysis (PCA). Using computed tomography (CT), the human spine was reconstructed for 24 patients with spine disorders and then the mean shape was deformed upon specific boundaries (e.g., by ±3 or ±1.5 standard deviation). Results demonstrated that principal shape modes are associated with specific morphological features of the spine segment such as Cobb’s angle, lordosis degree, spine width and height. The lumbar spine atlas here developed has evinced the potential of SSM to investigate the association between shape and morphological parameters, with the goal of developing new treatments for the management of patients with spine disorders.

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Pasha Zanoosi, AA, R. Kalantarinejad, and M. Haghpanahi. "Spine injury assessment under spaceflight landing conditions using multibody model." Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics 232, no. 4 (2018): 555–67. http://dx.doi.org/10.1177/1464419318757782.

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The novelty of the study relies on the fact that current simulations of human body to assess spine injury are based on finite element method. Spine injury assessment is an important point in designing spacecraft seat especially during landing. The finite element-based human body simulations are very time-consuming and computationally expensive. These problems make it difficult to perform high computational simulations such as optimization, sensitivity analysis, and so forth. Hence, in this study, it is tried to resolve these problems by developing a multibody model of human body in landing phase of spacecraft. This model makes designers able to perform corresponding simulations faster with acceptable accuracy. This study presents a dynamic multibody model of spacecraft seat-occupant system for spine injury assessment under landing conditions. The landing situation of spacecraft exposes shock loads to the spacecraft and astronaut. Hence, spine injury assessment under landing conditions enables optimal injury design of seat-occupant system. The modeling method is based on using the multibody modeling to achieve a detailed description containing the nonlinear properties and the accuracy of a multibody dynamic model considering whole body comprising stretching of vertebrae. The human body model comprises head, spine, femur, and shank lying on a flexible polyurethane foam as seat cushion. To model the spine, viscera, and pelvis in the sagittal plane, the spine column considered to be rigid bodies accompanied by spring-damper elements. To validate the developed model, the modal analysis and seat-to-head transmissibility of the spine has been validated by comparing with previously published models. Finally, as an application, the developed model has been exposed to a landing shock load for spine injury assessment.

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Afaunov, Asker Alievich, Vladimir Dmitryevich Usikov, Ali Ibragimovich Afaunov, and Igor Mikhailovich Dunaev. "OPPORTUNITIES OF TRANSPEDICULAR SPINAL INSTRUMENTATION FROM THE POSITION OF BIOMECHANICAL MODELING." Hirurgiâ pozvonočnika, no. 2 (May 26, 2005): 013–19. http://dx.doi.org/10.14531/ss2005.2.13-19.

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Objective. The authors analyze the causes of destabilization of transpedicular spinal instrumentation and prove the measures of its prevention basing on biomechanical modeling results and clinical data. Material and Methods. Experimental study included three series of 10 tests and one series of 12 tests with human spine cadaver specimens. The stability of injured spinal segments after transpedicular instrumentation was studied under mechanical load similar to that experienced by the human spine. Clinical study included the outcome analysis of transpedicular instrumentation in 107 patients with unstable thoracic and lumbar spine injuries. Results. The bone tissue mass around screws inserted in a cranial vertebra for two-segment spinal fusion proved to be the weakest place in a system consisting of a fourscrew transpedicular metal construction and spinal segments. The static mechanical strength of the injured vertebral motion segment stabilized with transpedicular device turned to be lower by 8–42 % (depending on loading conditions) than that of a corresponding intact vertebral motion segment. The identified factors negatively affecting the mechanical stability of transpedicular fixation were the following: osteoporosis, incomplete correction of deformity, motion coordination disorder due to neurological deficit, excessive weight, and postoperative regimen breach. A differentiated approach to reposition and transpedicular instrumentation for significant spinal deformities was offered allowing the restoration of anatomical interrelations and stable fixation in the spine regardless of the time of trauma.

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Yoganandan, Narayan, Srirangam Kumaresan, and Frank A. Pintar. "Biomechanics of the cervical spine Part 2. Cervical spine soft tissue responses and biomechanical modeling." Clinical Biomechanics 16, no. 1 (2001): 1–27. http://dx.doi.org/10.1016/s0268-0033(00)00074-7.

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Laughlin, Justin G., Christopher T. Lee, J. Andrew McCammon, Rommie E. Amaro, Michael Holst, and Padmini Rangamani. "Modeling the Impact of Spine Apparatus on Signaling and Regulation in Realistic Dendritic Spine Geometries." Biophysical Journal 116, no. 3 (2019): 237a. http://dx.doi.org/10.1016/j.bpj.2018.11.1303.

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Khavinson, Vladimir, Anastasiia Ilina, Nina Kraskovskaya, et al. "Neuroprotective Effects of Tripeptides—Epigenetic Regulators in Mouse Model of Alzheimer’s Disease." Pharmaceuticals 14, no. 6 (2021): 515. http://dx.doi.org/10.3390/ph14060515.

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KED and EDR peptides prevent dendritic spines loss in amyloid synaptotoxicity in in vitro model of Alzheimer’s disease (AD). The objective of this paper was to study epigenetic mechanisms of EDR and KED peptides’ neuroprotective effects on neuroplasticity and dendritic spine morphology in an AD mouse model. Daily intraperitoneal administration of the KED peptide in 5xFAD mice from 2 to 4 months of age at a concentration of 400 μg/kg tended to increase neuroplasticity. KED and EDR peptides prevented dendritic spine loss in 5xFAD-M mice. Their action’s possible molecular mechanisms were investigated by molecular modeling and docking of peptides in dsDNA, containing all possible combinations of hexanucleotide sequences. Similar DNA sequences were found in the lowest-energy complexes of the studied peptides with DNA in the classical B-form. EDR peptide has binding sites in the promoter region of CASP3, NES, GAP43, APOE, SOD2, PPARA, PPARG, GDX1 genes. Protein products of these genes are involved in AD pathogenesis. The neuroprotective effect of EDR and KED peptides in AD can be defined by their ability to prevent dendritic spine elimination and neuroplasticity impairments at the molecular epigenetic level.

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Korzh, M. O., V. O. Radchenko, V. O. Kutsenko, et al. "Mathematical and computer modeling of carbon endoprosthesis for thoracic interbody fusion." EMERGENCY MEDICINE 16, no. 7-8 (2021): 46–56. http://dx.doi.org/10.22141/2224-0586.16.7-8.2020.223703.

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Based on mathematical modeling using the finite element method, the paper presents the results of modeling the stress-strain state of endoprosthesis made of carbon after surgical treatment with replacement of damaged tissues to restore the integrity of the thoracic spine.

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Barysh, Oleksandr, Stanislav Kozyryev, and Oleksandr Yaresko. "Mathematical modeling of interbody fusion on the cervical spine." ORTHOPAEDICS, TRAUMATOLOGY and PROSTHETICS, no. 2 (July 1, 2015): 92. http://dx.doi.org/10.15674/0030-59872015292-99.

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Radchenko, V. A., K. A. Popsuyshapka, M. Yu Karpinsky, E. D. Karpinska, and S. A. Teslenko. "Experimental modeling of burst fractures of the thoracolumbar spine." TRAUMA 18, no. 2 (2017): 46–52. http://dx.doi.org/10.22141/1608-1706.2.18.2017.102558.

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Rerikh, V. V., A. V. Gladkov, V. V. Komissarov, V. A. Bataev, N. G. Fomichev, and V. D. Sinyavin. "MODELING OF ISOLATED DEFORMATIONS SPINE IN THE SAGITTAL PLANE." Современные проблемы науки и образования (Modern Problems of Science and Education), no. 1 2022 (2022): 3. http://dx.doi.org/10.17513/spno.31368.

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Aubin, C. É., Y. Petit, I. A. F. Stokes, F. Poulin, M. Gardner-Morse, and H. Labelle. "Biomechanical Modeling of Posterior Instrumentation of the Scoliotic Spine." Computer Methods in Biomechanics and Biomedical Engineering 6, no. 1 (2003): 27–32. http://dx.doi.org/10.1080/1025584031000072237.

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Baer, Steven, Sharon Crook, and Michael McCamy. "Modeling structural plasticity in dendrites with multiple spine types." BMC Neuroscience 9, Suppl 1 (2008): P104. http://dx.doi.org/10.1186/1471-2202-9-s1-p104.

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Jalalian, Athena, Ian Gibson, and Eng Hock Tay. "Computational Biomechanical Modeling of Scoliotic Spine: Challenges and Opportunities." Spine Deformity 1, no. 6 (2013): 401–11. http://dx.doi.org/10.1016/j.jspd.2013.07.009.

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Radchenko, Volodymyr, Mykyta Skidanov, Nataliya Ashukina, Valentyna Maltseva, Artem Skidanov, and Oleksandr Barkov. "Modern approaches to modeling in vivo degenerative spine diseases." ORTHOPAEDICS, TRAUMATOLOGY and PROSTHETICS, no. 1-2 (November 15, 2022): 108–17. http://dx.doi.org/10.15674/0030-598720221-2108-117.

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Every year, more and more people suffer from illnesses and disabilities that occur due to lumbar pain. Many studies, someof that use in-vivo models, are conducted to decrease the socioeconomic impact of the consequences of degenerative spinediseases. Objective. To evaluate the advantages and disadvantages of different in vivo models that are used to study the mechanisms of development of degenerative disturbances in spinal motion segments and test prospective methods of treating them. Methods. A search was conducted in the PubMed, Google Scholar, and Base scientific databases with the following key words: Spinal Diseases, Spine Disorder, Intervertebral Disc Degeneration (Repair), Facet Joint Degeneration (Repair), Animal Model, Facet (Zygapophyseal) Joint Osteoarthritis, Canine (dog), Swine (Pig), Ovine (sheep), Rabbit, Rat, Mice. The depth of the search was 10 years. Results. Rodents, pigs, goats, dogs, sheep, and primates are used to study mechanisms of development of degenerative disturbances in spinal motion segments and to test different approaches. Studies on larger animals are conducted due to their similarities in size, anatomy, biomechanics, and histological structure of vertebrae and intervertebral discs to humans. Models using dogs and alpacas are specifically of interest because of the natural age-related degradation of their intervertebral discs. However, experiments using large animals are restricted by high costs and bioethics regulations. The use of rabbits, rats, and mice in experiments is promising. For these animals, degenerative disturbances in the spine are modeled by creating traumatic injuries (disturbing the integrity of facet joints, endplates, annulus fibrosus, and nucleus pulposus, nucleotomy, and discectomy) or injection of chemical agents. Conclusions. The advantages of using of rodents instead of large animals to model the mechanisms of development of degenerative spine diseases and to test treatment methods include the relative ease of use and reproducibility of experiments, and economic and ethical viability. However, models should be chosen carefully and according to with the aims of the study.

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Zhang, Hongwei. "Fine Modeling and Mechanical Analysis of Human Lumbar Spine." Journal of Clinical Medicine Research 5, no. 1 (2024): 88. http://dx.doi.org/10.32629/jcmr.v5i1.1793.

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This paper has created a skeletal model of the human lumbar spine and proved its effectiveness. Simulated scenarios when the human body is moving, including forward bending, backward extension, left bending, and left rotation. Compare range of motion, vertebral displacement, annulus fibrosus displacement, endplate displacement, nucleus pulposus displacement, annulus fibrosus stress, endplate stress, nucleus pulposus stress, and cortical bone stress. The model of this study was based on anatomical principles for detailed drawing of the human lumbar spine. ROMs under different physiological motions including flexion, extension, and lateral bending with 300N preload and 3.75N·m moment were measured under the normal finite element model. The degrees of flexion of L1-S1 were 17.204°. The degrees of extension of L1-S1 were 13.959°. The degrees of lateral bending of L1-S1 were 10.326°, axial rotation were 6. 466°. The maximum stress for intervertebral disc flexion is 1.4285MPa. The maximum stress of the extension intervertebral disc is 1.1296MPa. The maximum stress of the intervertebral disc with lateral bending is 1.7589MPa. The maximum stress of the axial rotating intervertebral disc is 1. 1698MPa. After comparing with classical literature, the model of this study meets clinical research standards and may be a good choice for clinical surgical analysis.

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Sciortino, Vincenza, Salvatore Pasta, Tommaso Ingrassia, and Donatella Cerniglia. "On the Finite Element Modeling of the Lumbar Spine: A Schematic Review." Applied Sciences 13, no. 2 (2023): 958. http://dx.doi.org/10.3390/app13020958.

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Finite element modelling of the lumbar spine is a challenging problem. Lower back pain is among the most common pathologies in the global populations, owing to which the patient may need to undergo surgery. The latter may differ in nature and complexity because of spinal disease and patient contraindications (i.e., aging). Today, the understanding of spinal column biomechanics may lead to better comprehension of the disease progression as well as to the development of innovative therapeutic strategies. Better insight into the spine’s biomechanics would certainly guarantee an evolution of current device-based treatments. In this setting, the computational approach appears to be a remarkable tool for simulating physiological and pathological spinal conditions, as well as for various aspects of surgery. Patient-specific computational simulations are constantly evolving, and require a number of validation and verification challenges to be overcome before they can achieve true and accurate results. The aim of the present schematic review is to provide an overview of the evolution and recent advances involved in computational finite element modelling (FEM) of spinal biomechanics and of the fundamental knowledge necessary to develop the best modeling approach in terms of trustworthiness and reliability.

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Wang, Kuan, Zhen Deng, Xinpeng Chen, et al. "The Role of Multifidus in the Biomechanics of Lumbar Spine: A Musculoskeletal Modeling Study." Bioengineering 10, no. 1 (2023): 67. http://dx.doi.org/10.3390/bioengineering10010067.

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Background: The role of multifidus in the biomechanics of lumbar spine remained unclear. Purpose: This study aimed to investigate the role of multifidus in the modeling of lumbar spine and the influence of asymmetric multifidus atrophy on the biomechanics of lumbar spine. Methods: This study considered five different multifidus conditions in the trunk musculoskeletal models: group 1 (with entire multifidus), group 2 (without multifidus), group 3 (multifidus with half of maximum isometric force), group 4 (asymmetric multifidus atrophy on L5/S1 level), and group 5 (asymmetric multifidus atrophy on L4/L5 level). In order to test how different multifidus situations would affect the lumbar spine, four trunk flexional angles (0°, 30°, 60°, and 90°) were simulated. The calculation of muscle activation and muscle force was done using static optimization function in OpenSim. Then, joint reaction forces of L5/S1 and L4/L5 levels were calculated and compared among the groups. Results: The models without multifidus had the highest normalized compressive forces on the L4/L5 level in trunk flexion tasks. In extreme cases produced by group 2 models, the normalized compressive forces on L4/L5 level were 444% (30° flexion), 568% (60° flexion), and 576% (90° flexion) of upper body weight, which were 1.82 times, 1.63 times, and 1.13 times as large as the values computed by the corresponding models in group 1. In 90° flexion, the success rate of simulation in group 2 was 49.6%, followed by group 3 (84.4%), group 4 (89.6%), group 5 (92.8%), and group 1 (92.8%). Conclusions: The results demonstrate that incorporating multifidus in the musculoskeletal model is important for increasing the success rate of simulation and decreasing the incidence of overestimation of compressive load on the lumbar spine. Asymmetric multifidus atrophy has negligible effect on the lower lumbar spine in the trunk flexion posture. The results highlighted the fine-tuning ability of multifidus in equilibrating the loads on the lower back and the necessity of incorporating multifidus in trunk musculoskeletal modeling.

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Gohari, Ehsan, Mohammad Haghpanahi, Mohammad Parnianpour, Mohammad Saleh Ganjavian, and Mojtaba Kamyab. "NUMERICAL ANALYSIS (FINITE ELEMENT METHOD) OF BRACE EFFECTS ON THE ADOLESCENT IDIOPATHIC SCOLIOSIS DURING 24 HOURS." Biomedical Engineering: Applications, Basis and Communications 26, no. 03 (2014): 1450046. http://dx.doi.org/10.4015/s101623721450046x.

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In the adolescent idiopathic scoliosis (AIS) treatment, a brace is prescribed to the patients who have 20 to 45° curves on their spines to prevent the disorder's advancement. For the analysis of Milwaukee brace effects during time, finite element models (FEMs) of the spine (the thoracolumbar region) and the ribcage (contained 10 pairs of the ribs and the sternum) were prepared for two patients. For modeling the spine part, a new element was used in which a disc (as viscoelastic 3D beam) and a vertebra (as rigid link) were modeled as an element and the ribs and the sternum modeled by 3D elastic beams. The gravity, Milwaukee brace constraints and the forces of the brace's different regions were considered as the FEM boundary conditions. By running the patients' FEMs, the spine deformities of each patient were predicted for 24 h. For AIS patients, the brace should not only correct the deformity of the spine by inserting the forces, but also support the spine from the bending moments being caused by the gravity forces in different spine regions. Moreover, in studying scoliosis pathomechanisms, the stresses in different levels of the vertebra are important. Therefore, the bending moments and compressive stresses, caused by the gravity forces, were calculated in each level of the vertebra and the brace forces effects on them were analyzed. According to the patients' FEM responses, for the female patient: lumbar scoliosis was increased, thoracic scoliosis was decreased and kyphosis and lordosis were increased, and for the male patient: lumbar scoliosis was increased, kyphosis was increased and lordosis was decreased. In standing position, the brace forces reduced the bending moment and the compressive stress in vertebral levels of thoracolumbar region for the female patient and increased them for the male patient.

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Hwang, Jaejin, Gregory G. Knapik, Jonathan S. Dufour, and William S. Marras. "A Comparison of Performance Between Straight-Line Muscle and Curved Muscle Models." Proceedings of the Human Factors and Ergonomics Society Annual Meeting 61, no. 1 (2017): 1339–40. http://dx.doi.org/10.1177/1541931213601817.

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The straight-line muscle biomechanical models of the lumbar spine have been utilized to predict spinal loads to assess the potential risk of work-related injuries. The curved muscle paths have been suggested to realistically simulate muscles’ behavior in complex lumbar motions. However, the effect of curved muscle paths on the modeling performances and spinal loads in the lumbar spine model during complex lifting exertions has not been fully investigated. The objective of this study was to characterize the differences in modeling performances and spinal loads between the conventional straight-line muscle model and the curved muscle model of the lumbar spine. Twelve subjects (6 males and 6 females) participated in this study. Mean values and standard deviations of age, body mass, and height of all subjects were 26.6 (5.3) years, 73.6 (13.3) kg, and 172.7 (5.4) cm, respectively. Electromyographic (EMG) activities with surface electrodes (Motion Lab Systems MA300-XVI, Baton Rouge, Louisiana, USA) were collected over 10 trunk muscles (pair of the latissimus dorsi, erector spinae, rectus abdominis, external oblique, and internal oblique) with 1000 Hz sampling rate. The OptiTrack optical motion capture system (NaturalPoint, Corvallis, OR, USA) with 24 Flex 3 infrared cameras was used to monitor whole body kinematics with 100 Hz sampling rate. A Bertec 4060A force plate (Bertec, Worthington, OH, USA) was used to measure ground reaction forces with 1000 Hz sampling rate. Customized Laboratory software via a National Instruments USB-6225 data acquisition board (National Instruments, Austin, TX, USA) was utilized to collect all signals simultaneously and efficiently run the model. Subjects performed complex lifting tasks by various load weight (9.1kg and 15.9kg), load origins (counterclockwise 90⁰, counterclockwise 45⁰, 0⁰, clockwise 45⁰, and clockwise 90⁰), and load height (mid-calf, mid-thigh, and shoulder). Both curved muscle model and straight-line muscle model were tested under same experiment conditions, respectively. The curved muscle model showed better model fidelity (average coefficient of determination (R2) = 0.83; average absolute error (AAE) = 14.4%) than the straight-line muscle model (R2 = 0.79; AAE = 20.7%), especially in upper levels of the lumbar spine. The curved muscle model showed higher R2 than the straight-line muscle model, and the T12/L1 level showed the biggest difference as 0.1. The curved muscle model had lower AAE than the straight-line muscle model, and the T12/L1 showed the biggest difference as 18%. The curved muscle model generally showed higher compression (up to 640N at T12/L1), lower anterior-posterior shear loads (up to 575N at T12/L1), and lower lateral shear loads (up to 521N at T12/L1) than the straight-line muscle model. The biggest difference in spinal loads between two models (especially in anterior-posterior shear and lateral shear loads) occurred at upper levels of the lumbar spine, which could be related to the amount of muscle curvatures at each spine level. The curved muscle model generally showed higher compression and lower anterior-posterior and lateral shear loads than the straight-line muscle model. It might be partially related to the muscle paths of the erector spinae (major power producing muscle). In curved muscle model, erector spinae was placed more parallel with the lumbar spine curvature than the straight-line muscle model. It could affect the spinal load distributions such as higher compression and lower shears loads in the curved muscle model compared to the straight-line muscle model. In conclusion, the improved performance of the curved muscle model indicated that the curved muscle approach would be advantageous to estimate precise spinal loads in complex lifting jobs compared to the straight-line muscle approach.

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Kudiashev, A. L., V. V. Khominets, A. V. Teremshonok, et al. "BIOMECHANICAL MODELING IN SURGICAL TREATMENT OF A PATIENT WITH TRUE LUMBAR SPONDYLOLISTHESIS." Hirurgiâ pozvonočnika 15, no. 4 (2018): 87–94. http://dx.doi.org/10.14531/2018.4.87-94.

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Objective. To assess the results of clinical approbation of individual finite-element biomechanical model of a patient’s spino-pelvic complex with subsequent modeling of the best option of surgical treatment. Material and Methods. A biomechanical modeling of changes in the sagittal profile of a patient with degenerative disease of the lumbosacral spine, bilateral spondylolysis, and unstable grade 2 spondylolisthesis of the L4 vertebra was performed. The developed biomechanical model made it possible to assess the characteristics of the stress-strain state of the spinal motion segments aroused due to development of the disease. Within the built biomechanical model of the patient’s spino-pelvic complex, a corrective operation was further modeled that assumed a preservation of harmonious profile of sagittal spino-pelvic relationships. Post-correction characteristics of the stress-strain state of spinal motion segments were studied and compared with preoperative parameters of the biomechanical model. Results. Using methods of biomechanics and computer modeling allowed to calculate the stress-strain state of the lumbosacral spine under static load for two options of fixation and intervertebral cage implantation at the L4–L5 level: four transpedicular screws (L4–L5 vertebrae) and six transpedicular screws (L3–L4–L5 vertebrae). The simulation results showed that neither metal implants, nor elements of the lumbosacral spine experienced critical stresses and deformations that could lead to the destruction and instability of the implant. Conclusion. The developed individual biomechanical finite-element solid model of the spine and pelvis allowed for biomechanical justification of prerequisites for the formation and further progression of degenerative changes in spinal motion segments associated with violations of the sagittal profile due to grade 2 spondylolisthesis of the L4 vertebra. The model built on the results of radiological examination biomechanically substantiated the best option of corrective spine surgery allowing to minimize stresses and deformations by choosing reasonable magnitude of correction of sagittal spino-pelvic parameters and configuration of transpedicular system.

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BRANDOLINI, NICOLA, LUCA CRISTOFOLINI, and MARCO VICECONTI. "EXPERIMENTAL METHODS FOR THE BIOMECHANICAL INVESTIGATION OF THE HUMAN SPINE: A REVIEW." Journal of Mechanics in Medicine and Biology 14, no. 01 (2014): 1430002. http://dx.doi.org/10.1142/s0219519414300026.

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In vitro mechanical testing of spinal specimens is extremely important to better understand the biomechanics of the healthy and diseased spine, fracture, and to test/optimize surgical treatment. While spinal testing has extensively been carried out in the past four decades, testing methods are quite diverse. This paper aims to provide a critical overview of the in vitro methods for mechanical testing the human spine at different scales. Specimens of different type are used, according to the aim of the study: spine segments (two or more adjacent vertebrae) are used both to investigate the spine kinematics, and the mechanical properties of the spine components (vertebrae, ligaments, discs); single vertebrae (whole vertebra, isolated vertebral body, or vertebral body without endplates) are used to investigate the structural properties of the vertebra itself; core specimens are extracted to test the mechanical properties of the trabecular bone at the tissue-level; mechanical properties of spine soft tissue (discs, ligaments, spinal cord) are measured on isolated elements, or on tissue specimens. Identification of consistent reference frames is still a debated issue. Testing conditions feature different pre-conditioning and loading rates, depending on the simulated action. Tissue specimen preservation is a very critical issue, affecting test results. Animal models are often used as a surrogate. However, because of different structure and anatomy, extreme caution is required when extrapolating to the human spine. In vitro loading conditions should be based on reliable in vivo data. Because of the high complexity of the spine, such information (either through instrumented implants or through numerical modeling) is currently unsatisfactory. Because of the increasing ability of computational models in predicting biomechanical properties of musculoskeletal structures, a synergy is possible (and desirable) between in vitro experiments and numerical modeling. Future perspectives in spine testing include integration of mechanical and structural properties at different dimensional scales (from the whole-body-level down to the tissue-level) so that organ-level models (which are used to predict the most relevant phenomena such as fracture) include information from all dimensional scales.

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Lerchl, Tanja, Kati Nispel, Thomas Baum, Jannis Bodden, Veit Senner, and Jan S. Kirschke. "Multibody Models of the Thoracolumbar Spine: A Review on Applications, Limitations, and Challenges." Bioengineering 10, no. 2 (2023): 202. http://dx.doi.org/10.3390/bioengineering10020202.

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Numerical models of the musculoskeletal system as investigative tools are an integral part of biomechanical and clinical research. While finite element modeling is primarily suitable for the examination of deformation states and internal stresses in flexible bodies, multibody modeling is based on the assumption of rigid bodies, that are connected via joints and flexible elements. This simplification allows the consideration of biomechanical systems from a holistic perspective and thus takes into account multiple influencing factors of mechanical loads. Being the source of major health issues worldwide, the human spine is subject to a variety of studies using these models to investigate and understand healthy and pathological biomechanics of the upper body. In this review, we summarize the current state-of-the-art literature on multibody models of the thoracolumbar spine and identify limitations and challenges related to current modeling approaches.

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Journal articles on the topic 'Spine modeling'

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