A Biomechanical Study of the Lumbar Intervertebral Disc by Lever Positioning Manipulation

Study on the Stress-Strain and Flow-Solid Coupling Effects on Lumbar Intervertebral Discs Under Transient Loading by Lever Positioning Manipulation with Different Triggering Modes

Purpose of Study:

The purpose of this clinical trial is the clinical efficacy of different trigger modes of lever positioning manipulation (LPM) for the treatment of lumbar disc herniation (LDH). At the same time, the investigators considered from the perspective of virtual simulation and applied 3D finite element technology combined with dynamic capture system and mechanical sensing system to comprehensively evaluate the characteristics of biomechanical effects of different triggering modes of LPM on LDH.

The main questions ansthe investigatorsred are:

(1) To clarify what is the clinical effect of LPM in treating lumbar disc herniation?(2) Summarize the spatial motion laws and mechanical characteristics of the two triggering modes of LPM. Analyze the correlation betthe investigatorsen the LPM operation characteristics and the individual characteristics of LDH patients as the investigatorsll as the imaging parameters, and clarify the differences betthe investigatorsen the two LPM two trigger modes.(3) To analyze the stress-strain effects of the two LPM triggering modes on the L4/5 intervertebral discs and related accessory structures in different zones, and to elaborate the optimal type of LPM triggering modes for the treatment of LDH from the biomechanical point of view.(4) Under the condition of porous elasticity of the intervertebral discs, the investigators will study the effects of transient load on the flow-solid coupling of the intervertebral discs with different degrees of degeneration at L4/5 in the two triggering modes of the LPM, so as to reveal the mechanism of the LPM intervention in the intervertebral discs' degeneration.

The main research includes the following four aspects:

(1) Clinical efficacy study and standardized data collection of LPM.This study plans to recruit 128 volunteers from the Third Hospital Affiliated to Zhejiang University of Traditional Chinese Medicine will be recruited for the study. Sixty-four LDH patients and 64 healthy volunteers the investigatorsre planned to be included in this study. The LDH patients the investigatorsre divided into lever positioning manipulation group (group 1, n=32) sham manipulation group (group 2, n=32) using random number table method. In this group, unilateral wrenching mode was used for patients with paracentral LDH and bilateral wrenching mode was used for patients with central LDH. Manipulation was performed every two days, receiving a total of 6 sessions over 2 the investigatorseks. Healthy volunteers the investigatorsre similarly categorized into unilateral trigger mode group (group 3, n=32) bilateral trigger mode group (group 4, n=32) using random number table method. LPM treatments the investigatorsre administered every two days, receiving a total of 6 sessions over 2 the investigatorseks. Participants in both Group 1 and Group 2 the investigatorsre required to complete clinical questionnaire assessments, including the Visual Analog Scale (VAS) and the Japanese Orthopaedic Association (JOA) scoring system. During the LPM operation, the performer wore a mechanical sensing glove to collect the mechanical parameters of the maneuver, while a motion capture system was used to collect the kinematic parameters of the LPM, and the individual characteristics and imaging parameters of all the volunteers the investigatorsre collected, so as to analyze the correlation betthe investigatorsen the mechanical parameters, kinematic parameters, and the individual factors of the patients with LDH.(2) Virtual simulation model building and maneuver loading analysis.One standard volunteer was selected among 64 healthy volunteers, and the lumbar spine-pelvis imaging CT data the investigatorsre imported into Mimics software for geometric model extraction and preliminary processing. Geomagic and other software the investigatorsre utilized to construct the lumbar spine 3D finite element simulation model. And based on Abaqus CAE finite element simulation software, two kinds of wrenching mode maneuvers of LPM the investigatorsre simulated and loaded. The kinematic and mechanical parameters of the LPM the investigatorsre disassembled and loaded into each model to obtain the analytical models of manipulation in different trigger modes. The experimental results the investigatorsre obtained by calculating and analyzing the working conditions of LPM through Abaqus software. Observe the stress and strain on the intervertebral disc and ancillary structures under the action of LPM in different pulling modes.(3) Fluid-solid coupling effect of LPM on lumbar intervertebral disc under transient loads.Under the condition of considering the porous elasticity of the intervertebral disc, the coupled flow-stress simulation in Abaqus CAE was utilized to study the coupled flow-solid effect of the intervertebral disc, and then loaded to simulate the LPM manipulation, and observed the changes such as the stress displacement of the intervertebral disc under the manipulation.

Inclusion Criteria:

Healthy volunteers:

1. Healthy subjects with no history of lumbar spine disease, aged 20 to 60.
2. No obvious lumbar spine pain or previous diagnosis of lumbar spine-related disease.
3. Willing to participate in the study and have signed an informed consent form.

Patients:

1. Aged 20 to 60 years.
2. Diagnosed with L4-L5 lumbar disc herniation by CT or MRI.
3. Stable vital signs, no serious systemic diseases, and no complications.
4. Willing to accept manipulation as a test subject.

Exclusion Criteria:

1. Lumbar vertebrae fracture or dislocation.
2. Lumbar spine or lumbar soft tissue tumor, tuberculosis.
3. Lumbar spine fusion, paravertebral bone bridges, or severe osteoporosis.
4. History of lumbar spine surgery.
5. History of serious lumbar trauma.
6. Lumbar skin inflammation, skin breaks, or other skin conditions.
7. Serious primary diseases of the cardiac, hepatic, renal, or hematopoietic systems; psychiatric patients.
8. Extreme frailty or pregnancy.
9. Participation in other manipulative therapies that may interfere with the study.
10. Intolerable adverse reactions.