In Vivo Passive Axial Rotational Stiffness of the Thoracolumbar Spine

ABSTRACT

The objective of this study was to report the passive axial rotational stiffness of the thoracolumbar spine in asymptomatic volunteers. A secondary objective was to investigate if an asymmetry exists between right and left axial rotational spine stiffness. Eighteen young asymptomatic volunteers, nine male and nine female, were tested using a previously validated axial rotational tester. Volunteers in this study were subjected to six moment magnitudes bilaterally, in a random order, and their passive axial spine rotation was measured. The results from this study showed that there is a statistically significant difference between the right (20.3 ± 5.8 Nm/rad) and left (17.4 ± 4.9 Nm/rad) axial rotational stiffness regardless of gender. This normative information regarding axial rotational spine stiffness can enable clinicians to assess the deviance in clinical samples and assist in treatment selection.