Association between Lower Extremity Kinematics and Muscle Strength, Pain, Physical Activity Level, and Functional Status in Females with Patellofemoral Pain

Background: impaired lower extremity kinematics has beenconsidered as acontributing factor to patellofemoral pain (pfp). however, current knowledgeabout the correlation between lower extremity kinematics and muscle strengthis very limited. this study investigated the correlation between lower extremitykinematics and muscle strength, pain, physical activity level, as well as functionalstatus in females with pfp.methods: seventy-five females with pfp participated in this analytical crosssectionalstudy. lower extremity kinematics, maximal isometric strength ofmuscles, pain severity, physical activity level, as well as subjective and objectivefunction were assessed using a motion analysis system, a dynamometer, visualanalog scale, the international physical activity questionnaire, and the kujalaquestionnaire and the step-down test, respectively. the hip and knee kinematicswere determined during the initial contact and the initial phase of landing.pearson’s correlation coefficients were calculated to establish the correlationbetween the variables.results: the knee rotation at the initial contact was significantly correlatedwith quadriceps strength (r=-0.240, p=0.038) and pain severity (r=0.268,p=0.020). pain was significantly correlated with hamstring (r= -0.310, p=0.007)and quadriceps strength (r=-0.253, p=0.029) and the kujala score (r=-0.346,p=0.002).conclusion: our findings do not indicate a strong correlation between musclestrength and joint kinematics in females with pfp. an explanation is thepresence of various subgroups of people with pfp. future studies should focuson evaluating the correlation between the risk factors of pfp in subgroups,classified based on biomechanical, psychosocial, and anatomical characteristics.