Postural Biofeedback and Exercise in Axial Spondyloarthritis

The goal of this clinical trial is to learn whether adding a wearable postural biofeedback device to a standard exercise program affects disease activity, pain, and functional parameters in individuals with axial spondyloarthritis. The main questions it aims to answer are: Does adding postural biofeedback to a standard exercise program improve disease activity? Does adding postural biofeedback to a standard exercise program reduce pain? Does adding postural biofeedback improve functional parameters, including spinal mobility, quality of life, posture, and functional exercise capacity? Researchers will compare a standard exercise program with the same exercise program combined with a wearable postural biofeedback device to determine whether the addition of postural biofeedback provides greater benefits. Participants will: Participate in a physiotherapist-supervised standard exercise program twice a week for 8 weeks Use the wearable postural biofeedback device three days per week for at least 3 hours per day during prolonged static posture activities if assigned to the intervention group Complete assessments before and after the 8-week intervention, including measures of disease activity, pain, physical function, spinal mobility, quality of life, posture, and functional exercise capacity

Inclusion Criteria: * Be between 18 and 65 years of age. * Have a diagnosis of ankylosing spondylitis or axial spondyloarthritis according to the modified New York or ASAS classification criteria. * Have had stable medical treatment with no changes in medication during the previous 3 months. * Have axial/spinal pain intensity of at least 4 out of 10 on the Numeric Pain Rating Scale during the previous week. * Be able to walk independently. * Voluntarily agree to participate in the study and provide written informed consent. Exclusion Criteria: * History of spinal surgery within the previous 6 months. * Any change in medical treatment, including biological agents or analgesic treatment, within the previous 3 months. * Presence of fibromyalgia or another secondary chronic pain syndrome that may substantially affect pain perception. * Serious cardiopulmonary, neurological, or orthopedic conditions that prevent participation in exercise. * Pregnancy. * Dermatological or allergic skin reactions or other skin conditions that prevent the use of the wearable device. * Regular participation in a structured exercise or rehabilitation program supervised by a physiotherapist for axial spondyloarthritis within the previous 3 months.