Validating assessment of spinal stiffness: bench-top performance of the VerteTrack system

In the conservative management of non-specific spinal pain, manual therapists commonly assess spinal stiffness to identify aberrant joint motion and to direct treatment. There are various manual and mechanical test methods employed to assess spinal stiffness. The validation of spinal stiffness assessment methods is a multistep process. This thesis has two discrete objectives: (i) to review the literature on reliability of manual and mechanical methods used in the assessment of spinal stiffness, and (ii) determine the bench-top performance of a novel mechanical spinal stiffness assessment device, the VerteTrack. The VerteTrack was designed to measure spinal stiffness at either a single spinal level (static indentation), or multiple spinal levels (dynamic indentation). A review of the literature found that for the assessment of spinal stiffness, manual methods had variable reliability whereas mechanical methods had high reliability but limited clinical utility. The bench-top performace of the VerteTrack demonstrated a high level of accuracy (equivalent to the resolution of the reference test equipment). In this study, comparison of dynamic to static indentation modes revealed a small negative systematic bias (lower spinal stiffness). Future research is required to assess the reliability of the VerteTrack in human subjects.