Postural profile in patients with ankylosing spondylitis: correlation with clinical and electrophysiological findings

ABSTRACT

To assess postural profile in patients with AS and to determine the correlation between equilibrium score and clinical, functional, and electrophysiological findings. Twenty patients with definite AS and fifteen healthy controls were included. Bath Ankylosing Spondylitis Metrology Index, Bath Ankylosing Spondylitis Disease Activity index, and Bath Ankylosing Spondylitis Functional index were used for patients' evaluation. The postural profile was determined using the sensory organization test [SOT]. Electrophysiological studies for detection of central nerve system lesions were carried out. No significant differences could be detected between patients and controls as regards the equilibrium scores, sensory ratios, or strategy scores. All patients, except for two, had their composite equilibrium score well within tile normal limits. Three patients were abnormally more reliant on the hip strategy to regain balance under condition 6 of SOT. The center of gravity [COG] was excessively displaced anteriorly in patients with significant differences between them and controls. Electrophysiological abnormalities consistent with posterior column involvement were detected in six patients [30%]. In one of them, the pyramidal tract was also affected. The equilibrium score did not correlate with clinical, functional indices or electrophysiological findings. Most patients with AS were posturally stable. Their equilibrium scores were maintained well within normal values. The main abnormality was excessive forward displacement of the center of gravity. This was compensated for with no negative impact on balance abilities. The equilibrium score did not correlate with clinical, functional, or electrophysiological findings: