Do postural changes affect balance in patients with ankylosing spondylitis?

Objective: To investigate the effect on balance control of postural changes related to ankylosing spondylitis. Design: Thirty-four subjects with ankylosing spondylitis and 34 healthy individuals were enrolled. Examination of postural alignment was conducted using lumbar Schober, hand to ground distance, tragus to wall distance and occiput to wall distance measurements, and Bath Ankylosing Spondylitis Metrology Index. Balance was evaluated by Berg Balance Scale, Functional Reach Test, Lateral Reach Test, and Static Balance Index. Postural sway during quiet standing was assessed by centre of pressure displacement in 2 conditions: eyes open and eyes closed. Results: Functional reach test and right-side lateral reach tests were significantly lower in subjects with ankylosing spondylitis. Eyes closed anteroposterior centre of pressure sway was significantly higher in the subject group. Conclusion: Ankylosing spondylitis can lead to balance deterioration due to postural changes.