Mechanical Properties of Human Lumbar Spine Motion Segments—Part I: Responses in Flexion, Extension, Lateral Bending, and Torsion

1979 ◽  
Vol 101 (1) ◽  
pp. 46-52 ◽  
Author(s):  
A. B. Schultz ◽  
D. N. Warwick ◽  
M. H. Berkson ◽  
A. L. Nachemson
Keyword(s):  
Mechanical Properties ◽  
Lumbar Spine ◽  
Mechanical Behavior ◽  
Human Cadaver ◽  
Lateral Bending ◽  
Human Lumbar Spine ◽  
Flexion Extension ◽  
Spine Motion ◽  
Pressure Changes ◽  
Posterior Elements

In this first part of a three-part report, the mechanical behavior of 42 fresh human cadaver lumbar motion segments in flexion, extension, lateral bending, and torsion is examined. Motions and intradiskal pressure changes that occurred in response to these loads, with posterior elements both intact and excised, are reported.

Mechanical Properties of Human Lumbar Spine Motion Segments—Part II: Responses in Compression and Shear; Influence of Gross Morphology

1979 ◽  
Vol 101 (1) ◽  
pp. 53-57 ◽  
Author(s):  
M. H. Berkson ◽  
A. Nachemson ◽  
A. B. Schultz
Keyword(s):  
Mechanical Behavior ◽  
Intervertebral Disk ◽  
Human Cadaver ◽  
Large Scatter ◽  
Lateral Bending ◽  
Lateral Shear ◽  
Human Lumbar Spine ◽  
Flexion Extension ◽  
Spine Motion ◽  
Anterior Posterior

In this second part of a three-part report, we consider the mechanical behavior of 42 fresh human cadaver lumbar motion segments in compression, and in anterior, posterior, and lateral shear. We report the motions and the intradiskal pressure increases that occurred with posterior elements both intact and destroyed. We also examine to what extent intervertebral disk gross morphology can explain the large scatter in the results presented here, as well as in the results reported in Part I concerning mechanical behavior in flexion, extension, lateral bending, and torsion.

Control of Different FEM Based Musculoskeletal Models of Human Lumbar Spine Under Different Loading Conditions Using Optimization Method

2006 ◽  
Author(s):  
A. Kiapour ◽  
M. Parnianpour ◽  
A. Shirazi-Adl
Keyword(s):  
Lumbar Spine ◽  
Optimization Methods ◽  
Optimization Method ◽  
Complex Model ◽  
Lateral Bending ◽  
Musculoskeletal Models ◽  
Human Lumbar Spine ◽  
Flexion Extension ◽  
Load Vector ◽  
Complex Architecture

In this study the effects of using different musculoskeletal models on load-displacement behavior of FE models of the human lumbar spine under external loads and moments have been analyzed in terms of equilibrium and clinical stability. A simplified and a complex architecture of muscles have been integrated to FE based models of lumbar spine and were loaded to simulate the load carrying behavior of human lumbar spine in flexion, extension and lateral bending. The displacement values as well as muscle forces have been computed and compared in both cases using optimization methods with different cost functions. The models showed similar kinematics in pure flexion but the simplified model showed instability in flexion-lateral bending and pure lateral bending conditions. The complex model was loaded and analyzed with different cost function and it was observed that displacements in the model are lower while the angle between the load vector and spine curvature at each level is minimized. It was shown that the model is less stable in case an asymmetric loading condition is applied.

Mechanical Properties of Human Lumbar Spine Motion Segments

Spine ◽  
1979 ◽  
Vol 4 (1) ◽  
pp. 1-8 ◽  
Author(s):  
ALF L. NACHEMSON ◽  
ALBERT B. SCHULTZ ◽  
MICHAEL H. BERKSON
Keyword(s):  
Mechanical Properties ◽  
Lumbar Spine ◽  
Human Lumbar Spine ◽  
Spine Motion

Hybrid dynamic stabilization: a biomechanical assessment of adjacent and supraadjacent levels of the lumbar spine

2012 ◽  
Vol 17 (3) ◽  
pp. 232-242 ◽  
Author(s):  
Prasath Mageswaran ◽  
Fernando Techy ◽  
Robb W. Colbrunn ◽  
Tara F. Bonner ◽  
Robert F. McLain
Keyword(s):  
Lumbar Spine ◽  
Lumbar Fusion ◽  
Industrial Robot ◽  
Pedicle Screws ◽  
Axial Rotation ◽  
Dynamic Stabilization ◽  
Follower Load ◽  
Lateral Bending ◽  
Intact Specimen ◽  
Flexion Extension

Object The object of this study was to evaluate the effect of hybrid dynamic stabilization on adjacent levels of the lumbar spine. Methods Seven human spine specimens from T-12 to the sacrum were used. The following conditions were implemented: 1) intact spine; 2) fusion of L4–5 with bilateral pedicle screws and titanium rods; and 3) supplementation of the L4–5 fusion with pedicle screw dynamic stabilization constructs at L3–4, with the purpose of protecting the L3–4 level from excessive range of motion (ROM) and to create a smoother motion transition to the rest of the lumbar spine. An industrial robot was used to apply continuous pure moment (± 2 Nm) in flexion-extension with and without a follower load, lateral bending, and axial rotation. Intersegmental rotations of the fused, dynamically stabilized, and adjacent levels were measured and compared. Results In flexion-extension only, the rigid instrumentation at L4–5 caused a 78% decrease in the segment's ROM when compared with the intact specimen. To compensate, it caused an increase in motion at adjacent levels L1–2 (45.6%) and L2–3 (23.2%) only. The placement of the dynamic construct at L3–4 decreased the operated level's ROM by 80.4% (similar stability as the fusion at L4–5), when compared with the intact specimen, and caused a significant increase in motion at all tested adjacent levels. In flexion-extension with a follower load, instrumentation at L4–5 affected only a subadjacent level, L5–sacrum (52.0%), while causing a reduction in motion at the operated level (L4–5, −76.4%). The dynamic construct caused a significant increase in motion at the adjacent levels T12–L1 (44.9%), L1–2 (57.3%), and L5–sacrum (83.9%), while motion at the operated level (L3–4) was reduced by 76.7%. In lateral bending, instrumentation at L4–5 increased motion at only T12–L1 (22.8%). The dynamic construct at L3–4 caused an increase in motion at T12–L1 (69.9%), L1–2 (59.4%), L2–3 (44.7%), and L5–sacrum (43.7%). In axial rotation, only the placement of the dynamic construct at L3–4 caused a significant increase in motion of the adjacent levels L2–3 (25.1%) and L5–sacrum (31.4%). Conclusions The dynamic stabilization system displayed stability characteristics similar to a solid, all-metal construct. Its addition of the supraadjacent level (L3–4) to the fusion (L4–5) did protect the adjacent level from excessive motion. However, it essentially transformed a 1-level lumbar fusion into a 2-level lumbar fusion, with exponential transfer of motion to the fewer remaining discs.

Mechanical properties of lumbar spine motion segments under large loads

1986 ◽  
Vol 19 (1) ◽  
pp. 79-84 ◽  
Author(s):  
J.A.A. Miller ◽  
A.B. Schultz ◽  
D.N. Warwick ◽  
D.L. Spencer
Keyword(s):  
Mechanical Properties ◽  
Lumbar Spine ◽  
Spine Motion

Design and development of a novel expanding flexible rod device (FRD) for stability in the lumbar spine: A finite-element study

2020 ◽  
Vol 43 (12) ◽  
pp. 803-810 ◽  
Author(s):  
Masud Rana ◽  
Sandipan Roy ◽  
Palash Biswas ◽  
Shishir Kumar Biswas ◽  
Jayanta Kumar Biswas
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Range Of Motion ◽  
Pedicle Screw ◽  
Axial Rotation ◽  
Von Mises Stress ◽  
Lateral Bending ◽  
Intact Bone ◽  
Flexion Extension ◽  
Von Mises

The aim of this study is to design a novel expanding flexible rod device, for pedicle screw fixation to provide dynamic stability, based on strength and flexibility. Three-dimensional finite-element models of lumbar spine (L1-S) with flexible rod device on L3-L4-L5 levels are developed. The implant material is taken to be Ti-6Al-4V. The models are simulated under different boundary conditions, and the results are compared with intact model. In natural model, total range of motion under 10 Nm moment were found 66.7°, 24.3° and 13.59°, respectively during flexion–extension, lateral bending and axial rotation. The von Mises stress at intact bone was 4 ± 2 MPa and at bone, adjacent to the screw in the implanted bone, was 6 ± 3 MPa. The von Mises stress of disc of intact bone varied from 0.36 to 2.13 MPa while that of the disc between the fixed vertebra of the fixation model reduced by approximately 10% for flexion and 25% for extension compared to intact model. The von Mises stresses of pedicle screw were 120, 135, 110 and 90 MPa during flexion, extension, lateral bending, and axial rotation, respectively. All the stress values were within the safe limit of the material. Using the flexible rod device, flexibility was significantly increased in flexion/extension but not in axial rotation and lateral bending. The results suggest that dynamic stabilization system with respect to fusion is more effective for homogenizing the range of motion of the spine.

scholarly journals Effect of degeneration on the six degree of freedom mechanical properties of human lumbar spine segments

2016 ◽  
Vol 34 (8) ◽  
pp. 1399-1409 ◽  
Author(s):  
Dhara B. Amin ◽  
Dana Sommerfeld ◽  
Isaac M. Lawless ◽  
Richard M. Stanley ◽  
Boyin Ding ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Lumbar Spine ◽  
Degree Of Freedom ◽  
Human Lumbar Spine ◽  
Six Degree Of Freedom

scholarly journals Effect of compressive follower preload on the flexion–extension response of the human lumbar spine

2003 ◽  
Vol 21 (3) ◽  
pp. 540-546 ◽  
Author(s):  
Avinash G. Patwardhan ◽  
Robert M. Havey ◽  
Gerard Carandang ◽  
James Simonds ◽  
Leonard I. Voronov ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Human Lumbar Spine ◽  
Flexion Extension

A Biomechanical Model of the Lumbar Spine During Upright Isometric Flexion, Extension, and Lateral Bending

Spine ◽  
1996 ◽  
Vol 21 (4) ◽  
pp. 427-433 ◽  
Author(s):  
David C. Guzik ◽  
Tony S. Keller ◽  
Marek Szpalski ◽  
Jane H. Park ◽  
Dan M. Spengler
Keyword(s):  
Lumbar Spine ◽  
Biomechanical Model ◽  
Lateral Bending ◽  
Flexion Extension

scholarly journals Biomechanical Study of Cortical Bone Trajectory Screws in Intervertebral Fixation of Lumbar Tuberculosis

2021 ◽  
Author(s):  
Chen-Wei Zhang ◽  
Shi-Yuan Shi ◽  
De-Xin Hu ◽  
Shen-Ping Hu ◽  
Jin-Ping Hu ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Internal Fixation ◽  
Bone Graft ◽  
Lateral Bending ◽  
Flexion Extension ◽  
Group A ◽  
Group B ◽  
Group D ◽  
State 1 ◽  
Screw Group

Abstract BackgroundWe aimed to explore the biomechanical stability and advantages of cortical bone trajectory (CBT) screws in the treatment of lumbar spine tuberculosis and provide biomechanical basis for the choice of clinical fixation methods. Methods16 pig spine specimens (T12-L5) were selected to simulate the lumbar spine(L2-L3) tuberculosis bone destruction model in vitro. The 16 specimens were randomly divided into 4 groups, and short segments (pedicle screws of the diseased vertebrae) were assigned respectively. Fixation (group A), short-segment fixation (group B), fixation with pedicle screw (group C), fixation with CBT screw (group D), 4 specimens in each group , Each specimen in each group was subjected to biomechanical testing in the state of complete specimen (state 1) and L2-3 spinal tuberculosis model bone graft fusion and internal fixation (state 2). Load each specimen on the spine 3D exercise machine, respectively apply moments of 2N·m, 2.5N·m, 1N·m, 3N·m, meanwhile record the movement of the specimens in the four directions of flexion，extension，lateral bending and torsion ROM, compare Simultaneously analyze each group of ROM. ResultsThe ROMs of flexion, extension, lateral bending, and torsion in group A in state 1 and state 3 modes were （8.47±1.76）°、 （7.01±1.10）°、 （5.03±0.92）°、 （4.48±0.41）°and （4.78±0.07）°、 （2.91±0.16）°、 （2.66±0.09）°、 （2.23±0.05）°; the ROMs of flexion, extension, lateral bending and torsion in group B in state 1 and state 3 modes were （7.32±0.75）°、 （5.35±0.69）°、 （3.44±0.51）°、 （3.36±1.02）°and（3.51±0.29）°、 （1.74±0.04）°、 （1.53±0.31）°、 （1.23±0.08）°; The ROMs of flexion, extension, lateral bending, and torsion in group C in state 1 and state 3 modes were （10.01±0.39）°、 （9.05±0.25）°、 （7.42±1.06）°、 （6.92±1.15）°and （7.21±0.17）°、 （5.07±0.02）°、 （5.12±0.74）°、 （4.58±0.01）°; The ROMs of flexion, extension, lateral bending, and torsion in group D in state 1 and state 3 modes were （9.20±1.37）°、 （7.38±0.88）°、 （6.89±1.22）°、 （6.00±0.52）°and （6.06±0.16）°、 （3.99±0.02）°、 （3.85±0.08）°、 （3.47±0.10）°. The ROM value of each fixed mode group under the state of bone graft fusion and internal fixation was lower than that of the intact state, and the difference was statistically significant (P<0.05)，The t values are 4.531, 5.346, 6.008, 4.149; 9.481, 16.181, 11.814, 4.769; 4.349, 8.002, 4.473, 4.800; 5.041, 4.146, 12.232, 10.58. ConclusionCBT screw disease intervertebral fixation can not only provide sufficient mechanical stability, but also provide stronger stability when using the same fixed segment, and The fixed segments are minimized.

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