Association of altered frontal plane kinematics and physical activity levels in females with patellofemoral pain

•Frontal plane kinematics are associated with activity levels in females with PFP.•Knee abduction during a step-down predicts physical activity levels.•Biomechanical assessment may help clinicians identify less active PFP patients. Females with patellofemoral pain (PFP) present with altered frontal plane kinematics, decreased physical activity, and elevated psychological features. However, the relationship between these factors has not been evaluated. Does a relationship exist between frontal plane kinematics, physical activity levels, and fear avoidance beliefs in females with PFP. 16 females with PFP (Age = 23.2 ± 4.9years; Height = 166.1 ± 5.9 cm; Mass = 66.3 ± 13.5 kg) completed a 3-D biomechanical assessment during a single leg squat, step-down, and jogging task. Physical activity was collected with an activity monitor over 2-weeks and the Fear Avoidance Belief Questionnaire physical activity subscale was used to assess fear avoidance beliefs. Frontal plane kinematics were correlated with physical activity and fear avoidance, with significant variables included in a multiple regression. Significant correlations were identified between physical activity and single leg squat hip adduction (r=−0.626, p = 0.01), step-down knee abduction (r=−0.783, p