Ultrasound Assessment of Neck Muscles and Balance in Male Patients With Ankylosing Spondylitis

"Intervention Description~Participants in both groups will undergo ultrasonographic measurement of cervical multifidus and longus colli muscle thickness. Postural sway, Limits of Stability (LOS), and a 6-direction balance test (ABC-6) will be assessed using the HUR SmartBalance BTG4 platform under stable and unstable conditions with eyes open and closed. Functional balance will be evaluated with the Berg Balance Scale (BBS), Timed Up and Go (TUG) Test, and Single-Leg Stance Test. Isometric cervical flexion and extension strength will be measured bilaterally using a hand-held dynamometer. Ankylosing Spondylitis patients will additionally complete BASFI, BASMI, BASDAI, and ASQoL questionnaires."