Optimization of Lumbar Oblique-Pulling Manipulation Based on Multi-Rigid Body Mechanical Model / 医用生物力学

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.