Effect of Flat Foot on Excursions of Lower Limb Joints during Running

Introduction: The relationship between biomechanical parameters and different types of posture problems in association with running is unknown. Therefore, this study aimed to investigate the excursion changes at the hip, knee, and ankle joints during running in the patients with flat foot. Methods: The participants comprised 12 healthy men and 12 others suffering from flat feet disorder. They were divided into two experimental and control groups based on the normalized criterion of navicular. Motion excursions during the stance phase of running were calculated for all three planes of motion at the hip, knee, and ankle joints. A Vicon (200 Hz) motion analysis system with four T-Series cameras were used to measure parameters by Vicon Nexus 1.8.5, Polygon 4.1.2 software. Data were analyzed using SPSS24, and Independent sample t-test test. Results: There were no significant differences in all excursions of lower limb joints between the healthy and flat foot groups (P>0.05). There were significant differences observed between the healthy and flat foot groups in the dorsiflexion of the ankle (P=0.00), ankle plantarflexion (P=0. 00), hip flexion (P=0.000), hip extension (P=0.002), and knee flexion (P=0.000). Conclusion: The results showed that some observed changes in excursion parameters are due to the effects of compensatory mechanisms, and some might be considered as pathologic characteristics of the flat foot. Also, flat foot had strong effects on other joints.