せきつい不安定性の生体力学的評価法

抄録

Spinal instability is one of the important causes of low-back pain. Therefore, many researchers have tried to define this disease clinically. However, the biomechanical definition of spinal instability has not been clarified sufficiently, because of great personal or level differences of disc deformation. In this paper, a new method is proposed to judge the spinal instability regardless of personal and disc level differences. The geometry of a disc was measured from functional lateral X-ray films. The deformation ratio of each disc to the whole lumbar spine was evaluated under flexion. Consequently, the linear relationship between the geometry and the deformation ratio was obtained in normal intervertebral discs. The degree of spinal instability could be evaluated statistically by calculating a residual value from the regression line of normal intervertebral discs.