Evaluation of static and dynamic postural stability in established rheumatoid arthritis: Exploratory study

Background: It has been proposed that people with rheumatoid arthritis experience difficulties in postural control and activities of daily living such as walking. The aim of the study is to evaluate postural stability in rheumatoid arthritis patients. Method: A convenience sample of 19 rheumatoid arthritis patients (mean duration 13.1 ± 9.2 years) were aged matched with a non-rheumatoid group (n = 21). Postural stability was measured using a force plate for anterior–posterior and mediolateral centre of pressure excursion for 30 s with eyes closed and open. Patients also performed three walks at a self-selected speed and mean temporal–spatial parameters were recorded. Findings: Significant differences were observed between the groups in anterior–posterior centre of pressure excursion during the eyes open task and the eyes closed task (P < 0.05). No significant differences were found in the mediolateral centre of pressure excursion during either condition (P > 0.05). The rheumatoid group displayed a significantly slower mean walking velocity, double support, cadence and cycle time than the non-rheumatoid group (P < 0.05). Interpretation: The results from this study showed that rheumatoid arthritis patients displayed a significantly larger centre of pressure excursion in the anterior–posterior direction during quiet standing, when compared to a non-rheumatoid arthritis control group suggesting that postural control mechanisms such as ankle strategies are impeded by the rheumatoid process.