The assessment of the axial tibial power flow pattern in females with and without patellofemoral pain syndrome during stance phase of running

Power flow has been known as a useful method for evaluating many of the causes of locomotion disorders and detecting movement strategies of the lower limb. Axial tibial power flow pattern can be used to determine the cause and effect relationship between tibial internal rotation and pronation of the foot as main cause of the patellofemoral pain syndrome during running. The purpose of this study was to assess the axial tibial power flow pattern in healthy and patellofemoral pain syndrome females during stance phase of running. three-dimensional kinematics and kinetics were recorded for 10 healthy and 22 patellofemoral pain syndrome females during running. Mean power around vertical axis of tibia at the first 40% of stance phase and loading response, mid stance, and propulsion phases for statistical analysis was determined. Between-group comparisons were assessed by independent sample T test and chi square (P≤0.05). Results showed that, in healthy females 60% of the subjects had negative and the others had positive power flow during first 40% of stance phase of barefoot running. Furthermore, in females with patellofemoral pain syndrome, 68% and 32% of patients showed negative and positive power flow pattern respectively. In comparison to the healthy group, patients with patellofemoral pain had higher mean axial power during mid-stance phase (p=0.04). It seems the probability of treatment success for patellofemoral pain syndrome with controlled pronation orthoses can be limited. Therefore, reliance on rehabilitation interventions on the proximal part of knee joint should yield better results.