Increased levels of physical activity[1] Malalignment of the patella as it moves through the femoral groove[4] Quadriceps muscle imbalance[4]</ref>Briani RV, De Oliveira Silva D, Flóride CS, Aragão FA, de Albuquerque CE, Magalhães FH, de Azevedo FM (2018). "Quadriceps neuromuscular function in women with patellofemoral pain: Influences of the type of the task and the level of pain". PloS One.