Assessment of Quadriceps Muscle Weakness in Association with Symptomatic and Radiological Osteoarthritis of the Knee

BackgroundPrimary knee osteoarthritis is a significant cause of impairment of the lower limbs mobility, making effective rehabilitation particularly important. This study aimed to identify the association of quadriceps strength with pain and disability in comparison to its association with increasing severity of radiological grades of knee osteoarthritis. Methods50 subjects above the age of 40 years with different grades of knee osteoarthritis were evaluated for their radiological grade of osteoarthritis using Kellgren-Lawrence grading criteria for the knee radiographs, isometric quadriceps muscle strength using a modified hand-held dynamometer, pain, and disability using WOMAC questionnaire, all on the same day in this cross-sectional study. ResultsThere is a significant negative correlation between K/L grade and maximum strength of the quadriceps muscle, r (50) = -0.28 (p<0.05). We found a highly significant negative correlation between WOMAC score and strength of the quadriceps muscle, r (50) = -0.41 (p<0.05). DiscussionQuadriceps strength reduced progressively in subjects with more significant radiographic changes, questioning whether quadriceps muscle weakness precedes the onset of osteoarthritis and progressively results in further damage or osteoarthritis itself reduces the quadriceps strength. Though patients may have greater joint destruction on knee radiographs, increasing the strength of quadriceps might reduce the pain and functional disability.