Abstract:

Objective　To observe the change rule of intervertebral disc stress and strain in the operation of tilting rotation by the method of finite element analysis, and to explore the scientificalness and safety of the method to treat lumbar spine disease.　Methods　Simulated loading of “Side bending -rotation manipulation” was loaded on lumbar L4~5 model. The distribution and change of technique effect in the process of intervertebral disc stress, displacement and strain of nucleus pulposus and annulus were observed.　Results  The changes of the stress in the intervertebral disc began to appear from the right rear, and spread around the arc, and the change of stress was reduced. Disc strain minimum position occurred in the nucleus and increased from the center to the periphery in an arched shape. The position of the maximum strain increment occurred mainly in fiber ring, especially in the right edge of intervertebral disc.　Conclusions　The stress in manipulation is mainly concentrated on the posterior small joints. The stress changes of the intervertebral disc are relatively small, suggesting that the manipulation is safe. There are obvious strains in the posterolateral operation of the annulus fibrosus, and the change of local displacement may be one of the mechanisms of therapeutic effect of manipulation.

Key words: Lumbar vertebrae; , Finite element;  , Side bending -rotary manipulation;  , Intervertebral disc