Knee cap pain is one of the most common knee conditions among adolescents, affecting up to 7% of this population. In adults, knee cap pain affects 17% of runners, and 11 to 17% of the general population.
Knee cap pain is two times more likely to affect women than men.
Boling 2010. Gender differences in the incidence and prevalence of patellofemoral pain syndrome.
Smith 2018. Incidence and prevalence of patellofemoral pain: A systematic review and meta-analysis.
Taunton 2002. A retrospective case-control analysis of 2002 running injuries.