Negin Soltani - Department of Sports Biomechanics, Central Tehran Branch, Islamic Azad University, Tehran, Iran
Razieh Yousefian Molla - Department of Physical Education and Sports Sciences, Faculty of Physical Education and Sports Sciences, Islamic Azad University of Karaj, Karaj, Iran
Ali Fatahi - Department of Sports Biomechanics, Central Tehran Branch, Islamic Azad University, Tehran, Iran

Objective: The aim of this study was to evaluate the effect of increasing the speed on the work of the lower limb joints. Methods: ۲۸ healthy male subjects were selected by available sampling method as research samples. Kinetic parameter of lower limb joint work in the form of positive and negative work for three hip, knee and ankle joints at three different speeds of ۲.۵, ۳.۵ and ۴.۵ m / s by two important camera tools and force plate. Results: Based on the results, it seems that a significant difference was observed between the positive and negative work of all three lower limb joints in all three plates and three axes at three different speeds. Conclusion: According to the results obtained in this study, it seems that with more knowledge about the work of the lower limb joints, better and more practical solutions can be provided for running and increasing speed

running, kinetics, lower limbs, work