AbstractBackground: Knee osteoarthritis (KOA) is a chronic, progressive joint disease characterizedby cartilage degradation, joint space narrowing, and changes in subchondral bone. It is aleading cause of pain and disability, especially in individuals with overweight or obesity.Radiographic KOA, identified through structural changes on imaging, develops gradually andis often preceded by symptoms such as knee pain, stiffness, and reduced function. Whileoverweight/obesity is a known risk factor for KOA, less is known about the role of musclepercentage, physical activity, and quadriceps strength in the development of KOA in thisgroup. There is limited longitudinal evidence within risk groups for KOA, and therefore theaim of this study was to investigate how these factors are associated with the possibledevelopment of radiographic KOA in these individuals. Method: In this five-yearlongitudinal cohort study, 100 adult individuals from the HALLOA cohort with knee pain andBMI >25 kg/m² were included. Muscle percentage (via bioelectrical impedance analysis,BIA), self-reported physical activity (questionnaire), and quadriceps strength (handhelddynamometer) were assessed at baseline. KOA was evaluated five years after baseline usingthe Ahlbäck classification, with grade ≥1 indicating KOA. Non-parametric tests and logisticregression were used to analyse associations, with adjustments for age, BMI and waistcircumference. Statistical significance was set at p ≤ 0.05. Result: No associations werefound between muscle percentage, physical activity, or quadriceps strength and KOA.However, a trend between higher muscle percentage and KOA was observed when adjustedfor BMI and age (OR = 1,13, 95% CI = 0,99–1,29, p=0.08). Conclusion: The findingssuggest a potential area for further investigation. Future studies should include larger samplesize.