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00005768-200305001-0122700005768_2003_35_s221_earl_patellofemoral_5miscellaneous< 18_0_5_0 >Medicine & Science in Sports & Exercise©2003The American College of Sports MedicineVolume 35(5) Supplement 1May 2003p S221KINEMATICS OF LOWER EXTREMITY DYNAMIC MALALIGNMENT IN SUBJECTS WITH AND WITHOUT PATELLOFEMORAL PAIN SYNDROME[E-14N FREE COMMUNICATION/POSTER KNEE]Earl, J1; Hertel, J1; Denegar, C1; Cavanagh, P11Penn State University, University Park, PADynamic malalignment (DM) has been described as contralateral pelvic drop during single leg stance coupled with increased femoral internal rotation and adduction, knee valgus, tibial internal rotation, and pronation. This pattern has been described anecdotally and has been related to patellofemoral pain syndrome (PFP), but not quantified.PURPOSETo identify the kinematics of dynamic malalignment in subjects with and without PFP.METHODSThirty two(16 PFP, 16 healthy) subjects were tested. Three trained clinicians categorized subjects into normal alignment (NA) or DM groups based on their performance on a lateral stepdown, and were blind to their injury status. Nine subjects with PFP, and 7 healthy subjects were categorized as having DM. Three dimensional kinematics of the lower extremity were collected during stair descent and during a lateral stepdown exercise. The loading response phase of stair descent and the descending phase of the lateral stepdown were analyzed. Independent variables were injury status (PFP, healthy) and alignment (NA, DM). Dependent variables were pronation, tibial internal rotation, knee flexion and valgus, and hip adduction and internal rotation. Separate MANOVA's were calculated for each task.RESULTSDuring stair descent hip adduction was greater for those with DM than those with NA, regardless of injury status. For healthy subjects, those with DM had greater tibial internal rotation and faster rates of hip internal rotation than those with NA. These differences were not seen in PFP subjects. PFP subjects had a slower rate of hip internal rotation than uninjured subjects during the lateral stepdown.CONCLUSIONThe pattern of DM can be attributed to significantly greater than normal amounts of hip adduction. Increases were also seen in transverse plane rotation at the ankle and hip in healthy subjects, but not seen in PFP subjects. Many of the PFP subjects may be symptomatic because of DM leading to abnormal patellar tracking. However, other contributing factors are likely to be involved in normally aligned subjects with PFP.KINEMATICS OF LOWER EXTREMITY DYNAMIC MALALIGNMENT IN SUBJECTS WITH AND WITHOUT PATELLOFEMORAL PAIN SYNDROMEEarl, J; Hertel, J; Denegar, C; Cavanagh, PE-14N Free Communication/Poster Knee535