ABSTRACT
Objective: The purpose of this study was to obtain the stress-strain of the cervical spine structure during the simulated manipulation of the oblique pulling manipulation and the cervical rotation-traction manipulation in order to compare the mechanical mechanism of the two manipulations. Methods: A motion capture system was used to record the key kinematic parameters of operating the two manipulations. At the same time, a three-dimensional finite element model of the C0-T1 full healthy cervical spine was established, and the key kinematic parameters were loaded onto the finite element model in steps to analyze and simulate the detailed process of the operation of the two manipulations. Results: A detailed finite element model of the whole cervical spine including spinal nerve roots was established, and the validity of this 3D finite element model was verified. During the stepwise simulation of the two cervical spine rotation manipulations to the right, the disc (including the annulus fibrosus and nucleus pulposus) and facet joints stresses and displacements were greater in the oblique pulling manipulation group than in the cervical rotation-traction manipulation group, while the spinal cord and nerve root stresses were greater in the cervical rotation-traction manipulation group than in the oblique pulling manipulation group. The spinal cord and nerve root stresses in the cervical rotation-traction manipulation group were mainly concentrated in the C4/5 and C5/6 segments. Conclusion: The oblique pulling manipulation may be more appropriate for the treatment of cervical spondylotic radiculopathy, while cervical rotation-traction manipulation is more appropriate for the treatment of cervical spondylosis of cervical type. Clinicians should select cervical rotation manipulations for different types of cervical spondylosis according to the patient's symptoms and needs.
ABSTRACT
Background: Oblique-pulling manipulation has been widely applied in treating sacroiliac joint (SIJ) dysfunction. However, little is known about the biomechanical mechanism of the manipulation. This study aims to analyze the SIJ motion under oblique-pulling manipulation, in comparison with compression and traction loads. Methods/Study Design: A total of six specimens of embalmed human pelvis cadavers were dissected to expose the SIJ and surrounding ligaments. Through a servo-hydraulic testing system, biomechanical tests were performed on the stable pelvis and the unstable pelvis with pubic symphysis injury (PSI). A three-dimensional (3D) photogrammetry system was employed to determine the separation and nutation in three tests: axial compression (test A), axial traction (test B), and oblique-pulling manipulation (test C). Results: After applying the testing loads, the range of nutation was no more than 0.3° (without PSI) and 0.5°(with PSI), separately. Except for test B, a greater nutation was found with PSI (p < 0.05). Under both conditions, nutation following test A was significantly greater than that of other tests (p < 0.05). SIJ narrowed in test A and separated in tests B and C, where the range of motion did not exceed 0.1 mm (without PSI) or 0.3 mm (with PSI) separately. Under both conditions, the separation of SIJ in test C was not as apparent as the narrowness of SIJ in test A (p < 0.05). Compared to SIJ, a more significant increasing displacement was found at the site of the iliolumbar ligament (p < 0.05). Nevertheless, when the force was withdrawn in all tests, the range of nutation and separation of SIJ nearly decreased to the origin. Conclusion: Pubic symphysis is essential to restrict SIJ motion, and the oblique-pulling manipulation could cause a weak nutation and separation of SIJ. However, the resulting SIJ motion might be neutralized by regular standing and weight-bearing load. Also, the effect on SIJ seems to disappear at the end of manipulation. Therefore, the stretching and loosening of surrounding ligaments need to be paid more attention to.
ABSTRACT
Objective Comprehensively considering the effectiveness and safety of massage, a method for evaluating the pros and cons of oscillation excitation and pulse excitation for lumbar oblique-pulling manipulation was proposed, and lumbar oblique-pulling manipulation under oscillation excitation was optimized. Methods A multi-rigid body biomechanical model of thoracolumbar spine was established. The manipulation force was used as the input force of the model. Using MATLAB/Simulink, variation of the displacement and acceleration of each lumbar segment with time was simulated. For the optimization of lumbar massage manipulation, the core elements of massage force, namely, frequency (f) and operand (n) were changed, and then the maximum relative displacement and maximum acceleration of each lumbar segment were compared. A new index z was proposed to comprehensively evaluate effectiveness and safety of the manipulation. Results The maximum relative displacement of each lumbar segment was almost equal when lumbar oblique-pulling manipulation under two kinds of excitation was applied. For lumbar oblique-pulling manipulation, the maximum acceleration of each lumbar segment under oscillation excitation was significantly smaller than that under pulse excitation. When the frequency of massage was 1-2.5 Hz, the overall effect of massage was better, and the overall effect had no relation with the operands, and the force of massage lasted for one operand; when the frequency of message was 3.33 Hz and the operands were more than 5, the massage had the best effect, meanwhile the strength of each lumbar segment was relatively large; when the frequency of massage exceeded 5 Hz, and the overall performance of massage was not good. Conclusions Lumbar oblique-pulling manipulation under oscillation excitation is safer than that under pulse excitation. The research findings provide doctors with a reasonable range of operating parameters for lumbar oblique-pulling manipulation under pulse excitation.
ABSTRACT
Objective To observe the influence of the stress and displacement when the normal sacroiliac joint is exerted load simulating oblique-pulling manipulation, and to analyze the stress and displacement distribution when a three-dimensional finite element model of normal pelvis is exerted by oblique-pulling manipulation. Methods Lateral position was simulated on the three-dimensional finite element model of normal pelvis and it exerted loads horizontally forth and back, then the stress and displacement distribution were calculated. Results When the normal sacroiliac joint was exerted load simulating oblique-pulling manipulation, stress of the pelvis was mainly concentrated on the anterior inferior part of the left iliac fossa from the front view, with a maximum stress of 0.540E+07. The maximum value of internal and external strain of normal sacroiliac joint was 8.682 × 10-4m;the maximum value of anteropostreior strain was 3.337 × 10-4m;and the maximum value of up and down strain of normal sacroiliac joint was 3.284 × 10-4m. Conclusions The focus of the sacroiliac joint stress is mainly on the anterior and posterior superior borders when the normal pelvis exerted oblique-pulling manipulation. The internal and external strain of normal sacroiliac joint is maximal, the anteropostreior strain ranges the second, and the up and down strain is minimal.
ABSTRACT
Objective To analyze and study the biomechanical model of oblique-pulling manipulation in traditional Chinese medicine for the treatment of lumbar disc disease such as intervertebral disc protrusion, and compare the mechanical properties of two different manipulations, i.e. traditional oblique-pulling manipulation under impulse excitation and improved oblique-pulling manipulation under harmonic excitation. Methods The vertebra was set as rigid body, while the intervertebral disk and surrounding ligaments as viscoelastic body. A vibration system with 5-degree freedom for simulating lumbar L1-L5 was established. The basic vibration equation was solved using analytical method. Results The effect of improved oblique-pulling manipulation was related to the frequency of harmonic excitation. If the frequency of harmonic excitation was not higher than 1, the maximum displacement of the diseased segment under harmonic excitation was larger than that of traditional oblique-pulling manipulation under impulse excitation. With the lesion location shifted downward, the damage ratio (DR) under harmonic excitation was gradually decreased as compare to that under impulse excitation, indicating the safety of the improved oblique-pulling manipulation increasing. Conclusions The curative effect of oblique-pulling manipulation under harmonic excitation at the frequency lower than 1 was better than that of traditional oblique-pulling manipulation under impulse excitation, especially in that the medical injury can be controlled by oblique-pulling manipulation under harmonic excitation at the frequency no higher than 1.
