Variations in foot posture and mobility between individuals with patellofemoral pain and those in a control group

Background: We sought to determine whether foot posture and foot mobility were increased in individuals with patellofemoral pain syndrome compared with individuals in a control group. Methods: A nested case-control design was used with two controls matched to each patient by sex and age (±1 year). Participants included 43 individuals with a history of unilateral or bilateral patellofemoral pain syndrome and 86 participants in a control group. Data collected included height, weight, and five different measures of foot height and width in weightbearing and nonweightbearing that have been previously shown to have high levels of reliability. Results: Individuals with patellofemoral pain syndrome were found to be four times more likely (odds ratio, 4.04; 95% confidence interval, 1.45-11.32) to have a larger-thannormal difference between nonweightbearing and weightbearing arch height compared with those in the control group. The mean values for difference in arch height and foot mobility magnitude were also statistically significant between the patient and control groups. Foot posture, as determined using the arch height ratio, was not significant between groups (odds ratio, 0.94; 95% confidence interval, 0.34-2.61). Conclusions: Although foot posture may not be different between individuals with patellofemoral pain syndrome and controls, foot mobility assessed using difference in arch height and foot mobility magnitude is different between the two groups.