Load sharing in lumbar spinal segment as a function of location of center of rotation

Alapan, Yunus; Sezer, Semih; Demir, Cihan; Kaner, Tuncay; İnceoğlu, Serkan

doi:10.3171/2014.1.spine13426

Cited by 18 publications

(13 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It has been reported that the alternation of lumbar COR could cause considerable changes in muscle forces using a musculoskeletal model [10]. In addition, the finite element analysis has also shown that the facet forces, ligament loads, and disc stresses are strongly correlated with the location of COR [11]. In an in vitro study, it was found that the higher position of COR correlated with the lower facet force [12].…”

Section: Introductionmentioning

confidence: 98%

Prediction of the Spinal Musculoskeletal Loadings during Level Walking and Stair Climbing after Two Types of Simulated Interventions in Patients with Lumbar Disc Herniation

Kuai

Guan

Liu

et al. 2019

Journal of Healthcare Engineering

View full text Add to dashboard Cite

Background. Low back pain (LBP) continues to be a severe global healthy problem, and a lot of patients would undergo conservative or surgical treatments. However, the improving capacity of spinal load sharing during activities of daily living (ADLs) after interventions is largely unknown. The objective of this study was to quantitatively predict the improvement of spinal musculoskeletal loadings during level walking and stair climbing after two simulated interventions. Material and Methods. Twenty-six healthy adults and seven lumbar disc herniation patients performed level walking and stair climbing in sequence. The spinal movement was recorded using a motion capture system. The experimental data were applied to drive a musculoskeletal model to calculate all the lumbar joint resultant forces and muscle activities of seventeen main trunk muscle groups. Rehabilitation and reconstruction were selected as the representative of conservative and surgical treatment, respectively. The spinal load sharing after rehabilitation and reconstruction was predicted by replacing the patients’ spine rhythm with healthy subjects’ spine rhythm and altering the center of rotation at the L5S1 level, respectively. Results. During both level walking and stair climbing, the joint resultant forces of the lower lumbar intervertebral discs were predicted to reduce after the two simulated inventions. In addition, the maximum muscle activities of the most trunk muscle groups decreased after simulated rehabilitation and conversely increased after simulated reconstruction. Conclusion. The predictions revealed the different compensatory responses on the spinal load sharing after two simulated interventions, severing as guidance for making preoperative planning and rehabilitation planning.

show abstract

Section: Introductionmentioning

confidence: 98%

Prediction of the Spinal Musculoskeletal Loadings during Level Walking and Stair Climbing after Two Types of Simulated Interventions in Patients with Lumbar Disc Herniation

Kuai

Guan

Liu

et al. 2019

Journal of Healthcare Engineering

View full text Add to dashboard Cite

show abstract

“…The lumbar spine's load-bearing area lies largely within its anterior column throughout most of its range of movement [6] and can be represented by changes in relative disk heights across the endplates [7,8]. In this study, we aimed to identify the load-bearing pattern of each functional spinal unit (FSU) using the changes in relative disk heights that occur during commonly assumed, clinically meaningful physiological postures: flexion (slump sitting), erect (standing), and extension (backward bending).…”

Section: Introductionmentioning

confidence: 99%

Sagittal Radiographic Parameters of the Spine in Three Physiological Postures Characterized Using a Slot Scanner and Their Potential Implications on Spinal Weight-Bearing Properties

Hey¹,

Ng²,

Loh³

et al. 2021

Asian Spine J

View full text Add to dashboard Cite

To compare and understand the load-bearing properties of each functional spinal unit (FSU) using three commonly assumed, physiological, spinal postures, namely, the flexed (slump sitting), erect (standing) and extended (backward bending) postures. Overview of Literature: Sagittal spinal alignment is posture-dependent and influences the load-bearing properties of the spine. The routine placement of intervertebral cages "as anterior as possible" to correct deformity may compromise the load-bearing capabilities of the spine, leading to complications. Methods: We recruited young patients with nonspecific low back pain for <3 months, who were otherwise healthy. Each patient had EOS images taken in the flexed, erect and extended positions, in random order, as well as magnetic resonance imaging to assess for disk degeneration. Angular and disk height measurements were performed and compared in all three postures using paired t-tests. Changes in disk height relative to the erect posture were caclulated to determine the alignment-specific load-bearing area of each FSU. Results: Eighty-three patients (415 lumbar intervertebral disks) were studied. Significant alignment changes were found between all three postures at L1/2, and only between erect and flexion at the other FSUs. Disk height measurements showed that the neutral axis of the spine, marked by zones where disk heights did not change, varied between postures and was level specific. The load-bearing areas were also found to be more anterior in flexion and more posterior in extension, with the erect spine resembling the extended spine to a greater extent. Conclusions: Load-bearing areas of the lumbar spine are sagittal alignment-specific and level-specific. This may imply that, depending on the surgical realignment strategy, attention should be paid not just to placing an intervertebral cage "as anterior as possible" for generating lordosis, but also on optimizing load-bearing in the lumbar spine.

show abstract

“…The kinematics and kinetics of the lumbar spine may be sensitive to the location and radius of the COR. Alapan et al [12] constructed and validated a 3D finite element model of an L4–L5 unit and then assessed the kinematic and kinetic changes in the lumbar spine in different COR positions. They found that ROM, facet forces, ligament loads, and disc stresses were strongly correlated with the location of the COR.…”

Section: Introductionmentioning

confidence: 99%

Influence of Deviated Centers of Rotation on Kinematics and Kinetics of a Lumbar Functional Spinal Unit: An In Vitro Study

Kuai

Guan

et al. 2019

Med Sci Monit

View full text Add to dashboard Cite

Background Center of rotation (COR) has been used for assessing spinal motion quality. However, the biomechanical influence of COR deviation towards different directions during flexion-extension (FE) remains largely unknown. This study aimed to investigate the alteration in the range of motion (ROM), compressive force, shear force, and neutral zone size (NZ) in a lumbar functional spinal unit (FSU), caused by the deviated COR in different directions during FE. Material/Methods Twelve human cadaveric lumbar FSUs (6 for L2–L3, 6 for L4–L5) were tested in a 6-degree-of-freedom servo-hydraulic load frame. These FSUs were firstly applied a 7.5 Nm pure moment to perform FE to obtain their natural COR during FE. Subsequently, they were subjected to FE around 9 established deviated CORs with 6 Nm cyclical loading. Results It was found that the ROM and NZ increased significantly when the COR moved from the superior plane to the inferior plane for the L2–L3 unit and when the COR located in the superior plane compared with the inferior plane for the L4–L5 unit. The compressive forces for both FSUs demonstrated significant changes caused by COR shift in the same horizontal plane, while the shear forces demonstrated significant changes caused by COR shift in the same vertical plane. Conclusions The ROM, NZ, and shear force of FSU are sensitive to the vertical COR shift, while the compressive force of FSU is highly sensitive to the horizontal COR shift. Additionally, the kinematics and kinetics of the L2–L3 unit are more sensitive to COR location than those of the L4–L5 unit.

show abstract

Load sharing in lumbar spinal segment as a function of location of center of rotation

Cited by 18 publications

References 48 publications

Prediction of the Spinal Musculoskeletal Loadings during Level Walking and Stair Climbing after Two Types of Simulated Interventions in Patients with Lumbar Disc Herniation

Prediction of the Spinal Musculoskeletal Loadings during Level Walking and Stair Climbing after Two Types of Simulated Interventions in Patients with Lumbar Disc Herniation

Sagittal Radiographic Parameters of the Spine in Three Physiological Postures Characterized Using a Slot Scanner and Their Potential Implications on Spinal Weight-Bearing Properties

Influence of Deviated Centers of Rotation on Kinematics and Kinetics of a Lumbar Functional Spinal Unit: An In Vitro Study

Contact Info

Product

Resources

About