highlight to read-->Patellar injury and dislocation are more prevalent in individuals who participate in certain sports and activities. Anterior knee pain is the most common initial presentation. In order of descending prevalence, soccer players, weight lifters, runners, and shooters regularly complain of acute knee pain. In addition, studies show soccer players and weight lifters have the most potential for long-term knee pain. One study reported 52% of 31 soccer players, 31% of 29 weightlifters, 21% of 28 long-distance runners, and 17% of 29 shooters reported knee pain at least once per month. Swimming also places the athlete at risk for knee pain. On the other hand, sports such as tennis are not associated with knee pain. In summary, factors that cause knee pain include the type, amount, and duration of sports activity.

Patellofemoral dysfunction is the most probable etiology of knee pain. Whether related to sports or not, 1 out of every 4 painful knees has been reported to be the result of patellofemoral dysfunction. To fully understand the nature of patellar injury and dislocation, review baseline properties by examining the causes of knee pain in people who perform different athletic activities.