Association Between Body Mass Index and Anterior Knee Pain–Related Function in Physically Inactive Young Adults: A Cross-Sectional Study

Abstract

Background: Anterior knee pain is a common musculoskeletal complaint in young adults and may be influenced by body mass index and physical inactivity. Excess body weight can increase patellofemoral loading and may worsen pain-related functional limitation. Objective: To compare anterior knee pain-related function between physically inactive young adults with normal BMI and increased BMI. Methods: This cross-sectional study included 377 physically inactive young adults aged 17–35 years from universities in Sialkot, Pakistan. Physical activity was assessed using the International Physical Activity Questionnaire, and only participants with low activity levels, defined as <600 MET-min/week, were included. BMI was calculated from height and weight, and anterior knee pain-related function was assessed using the Kujala Anterior Knee Pain Scale. Normality was assessed using the Shapiro–Wilk test, and between-group comparison was performed using the Mann–Whitney U test. Results: Of 377 participants, 186 had normal BMI and 191 had increased BMI. The mean age was 25.46 ± 4.73 years, mean BMI was 24.41 ± 3.43 kg/m², and mean Kujala score was 75.60 ± 24.81. Kujala scores differed significantly between BMI groups, with higher mean ranks in the normal-BMI group than the increased-BMI group (237.24 vs. 139.33; U = 8327.00, Z = -8.813, p < 0.001; r = 0.45). Conclusion: Increased BMI was significantly associated with poorer anterior knee pain-related function among physically inactive young adults.