Avoidance of activity and limitations in activities in patients with osteoarthritis of the hip or knee: a 5 year follow-up study on the mediating role of reduced muscle strength

• Published in: Osteoarthritis and cartilage 2014-02, Vol.22 (2), p.171-177
• Main Authors: Pisters, M.F, Veenhof, C, van Dijk, G.M, Dekker, J
• Format: Article
• Language: English
• Subjects: Activities of Daily Living; Aged; Aged, 80 and over; Avoidance of activity; Disease Progression; Female; Follow-Up Studies; Humans; Limitations in activities; Male; Middle Aged; Motor Activity - physiology; Muscle strength; Muscle Strength - physiology; Muscle Weakness - etiology; Muscle Weakness - physiopathology; Muscle, Skeletal - physiopathology; Osteoarthritis; Osteoarthritis, Hip - complications; Osteoarthritis, Hip - physiopathology; Osteoarthritis, Hip - rehabilitation; Osteoarthritis, Knee - complications; Osteoarthritis, Knee - physiopathology; Osteoarthritis, Knee - rehabilitation; Pain - etiology; Physical activity; Rheumatology; Self Report
• ISSN: 1063-4584; 1522-9653
• DOI: 10.1016/j.joca.2013.12.007

Summary Objective To evaluate the mediating role of reduced muscle strength in the relationship between avoidance of activity and limitations in activities in patients with knee or hip osteoarthritis (OA). Methods A longitudinal cohort study with 5 years follow-up was conducted. Patients with knee or hip OA ( n  = 288) were recruited at rehabilitation centers and hospitals. Self-reported and performance based limitations in activities, avoidance of activity and muscle strength were assessed at baseline, 1, 2, 3 and 5 years follow-up. Generalized Estimating Equations (GEE) analyses were used to evaluate mediation. Results In patients with knee OA, reduced knee extensor muscle strength mediated the relationship between avoidance of activity and limitations in activities. In patients with hip OA reduced hip abductor muscle strength mediates the relationship between avoidance of activity and limitations in activities. Conclusion The results of this longitudinal study support the theory that avoidance of activity leads to deterioration of muscle strength and consequently to more limitations in activities in patients with knee and hip OA.