Postural Stability in Osteoarthritis of the Knee and Hip: Analysis of Association With Pain Catastrophizing and Fear-Avoidance Beliefs

Background: Persons with knee osteoarthritis (OA) are at risk of having sensations of instability and sometimes experience buckling. The instability has been associated with psychosocial dysfunction, such as fear of movement, and impaired physical functioning. A high degree of fear of movement is positively correlated with avoidance in other conditions. Objective: To evaluate the relationship between postural stability, the degree of pain catastrophizing, and fear-avoidance beliefs in subjects with knee and hip OA. Design: Descriptive, cross-sectional study. Setting: Four primary health care centers. Subjects: Eighty subjects with knee or combined knee and hip OA. Interventions: Not applicable. Main Outcome Measurements: Postural stability was evaluated using the Multi-Directional Functional Reach Test (MDFRT), and a battery of self-reports was used to assess the following aspects: pain catastrophizing (Pain Catastrophizing Scale), fear-avoidance beliefs (Tampa Scale for Kinesiophobia [TSK-11] and the Fear-Avoidance Beliefs Questionnaire), pain (visual analog scale), disability (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC]), and self-efficacy (Chronic Pain Self-Efficacy Scale [CPSS]). Results: The correlation analysis showed that scores on the MDFRT were negatively associated with scores on the TSK-11 for activity avoidance (r = -0.54; P < .001) and positively associated with the scores on the CPSS for coping (r = 0.59; P < .001). The scores for the MDFRT to the right and the total WOMAC were negatively associated (r = -0.61, P < .001). The scores for the MDFRT to the left were positively associated with the CPSS scores for coping (r = 0.64, P < .001). The scores for the MDFRT forward were predicted by CPSS and TSK-11 scores (28.9% of variance), as well as activity avoidance, avoidance of physical activity, helplessness (34.7% of variance), and CPSS pain coping (34.3% of variance). Conclusions: These findings suggest that pain catastrophizing and fear-avoidance beliefs are related with postural stability in subjects with knee and hip OA. Postural stability is negatively correlated with pain catastrophizing and TSK activity avoidance. Thus, based on these results, psychosocial factors should be taken into consideration in the assessment and treatment of patients with hip and knee OA.