Avoidance of Activities in Early Symptomatic Knee Osteoarthritis: Results from the CHECK Cohort

Background Pain-related avoidance of activities is hypothesized to lead to lower muscle strength and thereby activity limitations. Negative affect (e.g., low vitality, depression) is thought to strengthen the tendency to avoid activities. Purpose The aim of this study was to assess the validity of this "avoidance model" in patients with early symptomatic knee osteoarthritis (OA). Methods Cross-sectional data (n=151) were used. The associations between pain, negative affect, avoidance, muscle strength, and activity limitations were modeled using structural equation modeling. Results Pain and negative affect were associated with lower muscle strength via avoidance (mediation by avoidance). Avoidance was associated with activity limitations via lower muscle strength (mediation by muscle strength). There were also direct associations between pain, negative affect, avoidance, muscle strength, and activity limitations. Conclusions The results support the validity of the avoidance model, which explains the associations between pain, negative affect, avoidance, muscle strength, and activity limitations in patients with early symptomatic knee OA. © The Society of Behavioral Medicine 2012.