Advanced metrology in patiens with axial spondyloarthritis: lumbar or thoracic plus lumbar measurements for spinal mobility assessment?

Abstract

Advanced technologies for measuring human mobility have recently emerged, such as motion capture systems, inertial measurement units (IMUs), and wearable devices. Some of these are used to assess mobility in patients with rheumatic diseases. Certain devices focus solely on assessing lumbar mobility. However, Axial Spondyloarthritis (axSpA) reduces spinal mobility across all spinal segments, not just the lumbar region. The objective of this study was to analyze the contribution of the thoracic spine to overall spinal mobility and determine whether this contribution should be considered in the metrological assessment of patients with axSpA. A total of 20 patients with axSpA and 20 age-, BMI-, and sex-matched healthy controls were recruited. Spinal mobility was measured using an IMU-based system (ViMove©), which employs two IMU sensors and calculates the angle between them in real time. Two tests were performed: one using the standard anatomical positions (pelvis and L1) and another combining lumbar and thoracic movement (pelvis and T3). Conventional metrology, radiographic structural damage in axSpA patients, and patient-reported outcomes (PROs) were also collected. The results table displays the mobility measurements for lumbar only and lumbar + thoracic movement in both groups. The thoracic spine’s contribution is expressed as a percentage of total movement. Pearson correlation coefficients (for axSpA patients only) with conventional metrology (BASMI), PROs (BASDAI, BASFI, and ASQoL), and structural damage (mSASSS) are also presented.S