Shahid Beheshti University of Medical Sciences The Scientific Journal of Rehabilitation Medicine 2251-8401 9 2 2020 06 21 Effect of Surface Stiffness on the Risk Factors Related to Ground Reaction Force during Two-Leg Landing Effect of Surface Stiffness on the Risk Factors Related to Ground Reaction Force during Two-Leg Landing 318 325 1100911 10.22037/jrm.2019.110520.1344 FA Seyed Abbas Farjad Pezeshk Assistant professor of Sport Biomechanics,Faculty of Sport Sciences,University of Birjand, Birjand, Iran 0000-0001-6563-9882 Heydar Sadeghi Professor, Biomechanics Faculty, Kharazmi University, Tehran, Iran 0000-0001-6563-9882 Mohammad Shariatzadeh Assistant professor in Sports Physiology, Sport Sciences Research Institute of Iran, Tehran, Iran 0000-0003-3706-6057 Zahra Safaie Pour Assistant Professor of Social and Rehabilitation Sciences University, Tehran, Iran Journal Article 2019 06 14 <strong>Background</strong><strong> and Aims :</strong> There is a general agreement regarding the importance of surface on which human beings walk as a key factor on the frequency and severity of lower limb injuries. The aim of the preset study was to investigate the effect of surface stiffness on the risk factors of lower limb injuries during bilateral landing. <br /><strong>Materials and Methods:</strong> In the current study, we investigated the lower limb stiffness and the ground reaction force of 15 young male individuals during the landing on five surfaces with different stiffness from 200 to 500 KN/m. <br /><strong>Results:</strong> The results of ANOVA showed that there is a significant difference between lower limb stiffness and maximum ground reaction force during landing on surfaces with different stiffness. <br /><strong>Conclusion:</strong> According to the results of the present study, during landing and when approaching to the surface, humans act differently in comparison to rigid masses, so that, depending on the task, maintain the natural dynamics of the center of mass and effectiveness of movement and reduce the loads. <strong>Background</strong><strong> and Aims :</strong> There is a general agreement regarding the importance of surface on which human beings walk as a key factor on the frequency and severity of lower limb injuries. The aim of the preset study was to investigate the effect of surface stiffness on the risk factors of lower limb injuries during bilateral landing. <br /><strong>Materials and Methods:</strong> In the current study, we investigated the lower limb stiffness and the ground reaction force of 15 young male individuals during the landing on five surfaces with different stiffness from 200 to 500 KN/m. <br /><strong>Results:</strong> The results of ANOVA showed that there is a significant difference between lower limb stiffness and maximum ground reaction force during landing on surfaces with different stiffness. <br /><strong>Conclusion:</strong> According to the results of the present study, during landing and when approaching to the surface, humans act differently in comparison to rigid masses, so that, depending on the task, maintain the natural dynamics of the center of mass and effectiveness of movement and reduce the loads. https://medrehab.sbmu.ac.ir/article_1100911_edef640c47493b4191774a6bcaedd8c5.pdf