weight, a reduction in muscle strength, time to seek care, and in those who experience symptoms for more than two months. epidemiology patellofemoral pain syndrome is the most common cause of anterior knee pain in the outpatient. specific populations at high risk of primary pfps include runners, bicyclists, basketball players, young athletes and females. bmi did not significantly increase risk of developing pfps in adolescents. however, adults with pfps have higher bmi than those without. it is suggested that higher bmi is associated with limited physical activity in people with pfps as physical activity levels decrease as a result of pain associated with the condition. however, no longitudinal studies are able to show that bmi can be a predictor of development or progression of the condition.