65 April 2022. Volume 12. Number 2 Razieh Yousefan Molla 1 , Ali Fatahi 2* 1. Department of Physical Education and Sport Science, Faculty of Physical Education and Sports Sciences, Islamic Azad University of Karaj, Karaj, Iran. 2. Department of Sports Biomechanics, Central Tehran Branch, Islamic Azad University, Tehran, Iran. * Corresponding Author: Ali Fatahi, PhD. Address: Department of Sports Biomechanics, Central Tehran Branch, Islamic Azad University, Tehran, Iran. Phone: +98 (912) 5607581 E-mail: fattahiali81@gmail.com Research Paper Analysis of Lower Limb Joint Kinetics With Increasing Running Speed Purpose: Due to the paucity of information regarding the lower limb biomechanics in running at slow speed, as well as the concentration of mos previous sudies on a single movement plane, this sudy aimed to invesigate lower limb joint kinetics with increasing running speed. Methods: Twenty-eight runners were asked to say on the treadmill at a bent velocity which was incrementally increased to 2.5 m/s, 3.5 m/s, and 4.5 m/s speeds. The three-dimensional joint moment and sagittal mechanical muscle power of the lower limb were calculated during the sance phase of running. Repeated measures analysis of variance (ANOVA) with Bonferroni pos hoc tes was used to examine the variables during running at various speeds. Results: The results showed that at the hip joint in the frontal plane, an adduction moment developed in the middle of the sance phase, and the highes peak adduction moment was obvious at the highes speed condition (4.5 m/s). Also, the time elapsed to peak in the highes speed condition was less than the others. In the transverse plane, although the 3.5 m/s-speed condition experienced the maximum external rotation peak moment, the 4.5 m/s-condition speed reached the internal satus earlier than the two other speeds. In the sagittal plane, the highes speed condition showed the highes extension and fexion moments. Conclusion: Increasing running speed in runners leads to more kinetic output and mechanical power gradient. A B S T R A C T Keywords: Kinetics, Running, Lower limb, Biomechanics Citation Yousefan Molla R, Fatahi A. Analysis of Lower Limb Joint Kinetics With Increasing Running Speed. Physi- cal Treatments. 2022; 12(2):65-76. http://dx.doi.org/10.32598/ptj.12.2.416.5 http://dx.doi.org/10.32598/ptj.12.2.416.5 Use your device to scan and read the artcle online Article info: Received: 04 Dec 2021 Accepted: 14 Mar 2022 Available Online: 01 Apr 2022