Quadriceps weakness in knee osteoarthritis: the effect on pain and disability

Open Access
Publisher Website
Google Scholar
Abstract
OBJECTIVES (1) To determine the importance of quadriceps strength, structural change, and psychological status in terms of knee pain in the community. (2) To determine the relative importance of quadriceps function, structural change, and psychological status with respect to disability in subjects with knee pain. METHODS 300 men and women with pain and 300 controls without pain (aged 40–79) were seen. Isometric quadriceps strength (MVC) was measured and muscle activation was assessed by twitch superimposition. Disability (Western Ontario McMaster Osteoarthritis Index (WOMAC)) and anxiety and depression were assessed (Hospital Anxiety and Depression Index (HAD)). Radiographs were obtained of the tibiofemoral and patellofemoral joints and total score for osteophyte, narrowing, and sclerosis calculated for each knee. RESULTS Subjects with knee pain had lower voluntary quadriceps strength than those without pain (pCONCLUSIONS Quadriceps strength is strongly associated with knee pain and disability in the community, even when activation and psychological factors are taken into account. This has important therapeutic implications.