Verification of determining the curvatures and range of motion of the spine by electromechanical-based skin-surface device

Abstract

There is an increasing awareness of the risk and dangers of exposure to radiation associated with repeated radiographic assessment of spinal curvature and spinal movement. As such, attempts are continuously being made to develop skin surface devices for use in examining the progression and response to treatment of various spinal disorders. However, devices must be verified before use in research or in a clinical environment. The aim of this study was to examine the reliability of measurements using a skin-surface device, the Spinal Mouse on 30 healthy volunteers. Spinal curvature was measured with the Spinal Mouse during standing, flexion, and extension (each five times by each of two examiners). The method was calibrated by a ZEBRIS ultrasound-based measuring method with WINSPINE software commercially available, and the measurement error rate of the method was determined by statistical calculations. On the basis of calibration and error calculations it could be established that the accuracy and the reproduci bility of the method were appropriate, because the maximum value of intraobserver variation is 0.97 degrees (18.8%), that of interobserver variation is 1.54 degrees (27.1%). A second way of verifying the method is to specify the difference between the angles determined by the two methods. The maximum value of the average difference is 1.62 degrees (26.6%).