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.