Modeling Spinal Mobility in Ankylosing Spondylitis: Towards New Telekinetic Biomarkers

Ankylosing spondylitis (AS) is a chronic inflammatory rheumatic disease that mainly affects the spine and pelvis in its axial form. It is responsible for chronic inflammatory pain and sometimes ankylosis with significant functional retention. Clinicians need markers capable of precisely measuring the restriction of range of motion in these patients, reflections of the activity and/or sequelae of the disease. The Inverstigators validated movement markers in the AS by a device including inertial sensors (XSENS) and computer modeling. The accuracy and repeatability of the XSENS-Awinda system compared to the reference measurement system have been demonstrated. The XSENS-Awinda device offers new real-time evaluation possibilities for quantitative gait analysis. This opens the way to new diagnostic tools, prognostics and therapeutic perspectives for the clinician.

Inclusion Criteria: * Age 18-65 * BMI between 18.5 and 30 * Written informed consent * Same gender and age within +/- 3 years compared to an unmatched AS patient Inclusion criteria specific to the AS group: * Age 18-65 * BMI between 18.5 and 30 * Written informed consent * AS meeting the ASAS (Assessment of Spondylo Arthritis International Society) criteria, i.e. with spinal pain ≥ 3 months old, with an age of diagnosis \< 45 years, with: * Sacroiliitis on imaging AND ≥ 1 sign of spondylarthritis. OR * HLA-B27 (human leukocyte antigen-B27) positive AND ≥ 2 other signs of spondylarthritis Exclusion Criteria: * Traumatic, tumoral or infectious low back pain * History of spinal fracture * History of lumbar, pelvis, hips, ankles, and/or knees surgery * Severe scoliosis defined by a Cobb angle \> 50° * Severe impairment of uncorrected visual acuity * Concomitant pathology responsible for ataxia * Lumbar arthrodesis of two or more stages * Pregnant or breastfeeding women * Patient unable to give consent: patient under guardianship or curators, mentally retarded, dementia, language barrier * Patient not affiliated to a social security plan * Patient under legal protection