Dynamic malalignment (DM), abnormal muscle activation, and static malalignments all might lead to patellofemoral pain (PFP) but have not been examined using a multifactorial approach.
To determine which measures of static malalignment, DM, and muscle-onset times best predict PFP.
Design and Setting:
2 groups (PFP and uninjured) of 16 subjects each.
EMG and 3-D kinematic data were recorded during a step-down. Five static-alignment assessments were performed.
Three discriminant analyses using injury as the grouping variable and static measures, joint angles, and EMG onsets as the predictor variables. A final combined discriminant analysis using the most predictive variables from each set.
The static-alignment discriminant function was most predictive (81.3% correct), followed by the kinematic (69%) and the EMG (67%) functions. The final discriminant function included iliotibial-band flexibility, navicular drop, pronation, knee flexion, hip adduction, gluteus medius, and vastus medialis obliquus onset time and correctly classified 92.3% of PFP subjects.
PFP can most accurately be predicted when multiple measures of lower extremity function are considered together.
Earl is with the Dept of Human Movement Sciences, University of Wisconsin–Milwaukee, WI 53201. Hertel is with the Dept of Human Services, University of Virginia, Charlottesville, VA 22904-1389. Denegar is with the Dept of Kinesiology, University Park, PA 16801.