Postural stability in patients with ankylosing spondylitis

Abstract

Purpose. The aim of this study is to determine whether the postural changes in ankylosing spondylitis (AS) affected postural stability.Method. A total of 64 patients with a diagnosis of AS and 50 healthy volunteers were included in the study. The patients were divided into two groups according to a tragus-to-wall distance <15 cm (Group I, n = 30) and ≥15 cm (Group II, n = 34). The control group (Group III) consisted of 50 healthy volunteers. The postural stability was evaluated with the Biodex Stability System (BSS). The results of Antero-Posterior Stability Index (APSI), Medio-Lateral Stability Index (MLSI) and Overall Stability Index (OSI) were evaluated.Results. There were statistically significant differences between the three groups for OSI, APSI and MLSI. MLSI results were significantly different among patient groups. When Group II and the control group were compared, there were significant differences for OSI, APSI, and MLSI. Comparing Group I with the control group revealed a more significant difference for OSI, APSI, and MLSI.Conclusions. We have found that postural stability decreases in patients with AS in both the early and the late stages of the disease, but especially in the latter ones. This result may be thought to be related with increased kyphosis which is seen during the course of the disease.