Objectives: To investigate whether patients with ankylosing spondylitis have poorer balance than normal subjects, and to study the relationship between balance and posture.
Methods: Balance was studied in 30 ankylosing spondylitis subjects using sway magnetometry, making quantitative measurements of movement at the hips with eyes open and eyes closed. The results were compared with data from 58 normal subjects. Balance was also compared with quantitative measurements of posture.
Results: The numbers of patients with poor balance, above the 95th percentile for normal, were significantly greater than expected; 18% for eyes open (P = 0. 03) and 23% for eyes closed (P = 0.004). No significant relationships between balance and any of the quantitative descriptions of posture were demonstrated.
Conclusion: A significant proportion of ankylosing spondylitis patients have poorer balance than normal subjects.