Epidemiology

Patellofemoral pain is defined as pain at or around the kneecap and is mainly diagnosed by excluding other conditions such as patellar tendinopathy, Osgood-Schlatter disease, fat pad impingement, and tibiofemoral joint problems. The lecture explains current diagnostic features, including pain during squatting, stair use, running, and jumping, along with other common findings such as pain after prolonged sitting, crepitus, mild swelling, and tenderness around the patella. A key point is that cartilage damage is not considered a major driver of symptoms, which is why the term chondromalacia patellae is discouraged. Learners are also introduced to the uncertainty around the exact source of pain and the wide variation in pain patterns. The epidemiology section covers prevalence and incidence across groups such as the general population, military recruits, runners, and adolescents. Risk-factor evidence is limited, but weaker quadriceps appear relevant in military recruits, while findings on hip strength in adolescents are more complex and may relate to activity levels and workload rather than a simple cause. The overall message is that patellofemoral pain is common, often persistent, and still not fully understood.