The affect of relative lordosis on dynamic torsional stability in the lumbar spine

Abstract

The purpose of the study is to investigate one of the factors that appear to be responsible for the high incidence of back pain and disability, inefficacious lumbar lordosis. It has been the observation of many back pain specialists that patients with back pain and disc problems have a decreased lumbar curvature; this has been presumed by some to be a result of muscle spasm, but by others as a cause of the primary malady. Six cadaver spinal segments were tested on a materials testing system (MTS) in varying degrees of lumbar curvature to see whether the curvature had an affect on stability with compression and rotation, the motions responsible for many back injuries. In all cases, increased lumbar lordosis correlated with increased stiffness, This correlation was at a maximum with respect to the spines tested, in the one with the least amount of osteopenia (estimated by radiographs and age of specimens). The results suggest that lumbar lordosis correlates with increased stiffness in cadaveric specimens. This study is ongoing and preliminary results suggest a larger sample size for the mechanical testing is needed for the study to be conclusive and statistically valid. Once that is achieved, the correlations and clinical significance can be determined.