Tabriz University of Medical Sciences Medical Journal of Tabriz University of Medical Sciences 2783-2031 40 5 2018 12 05 Effect of eight weeks of jump- landing exercise on feedforward and feedback activation of selected trunk and lower extremity muscles and lower extremity performance in active females 72 82 EN Leila Keshavarz https://orcid.org/0000-0001-9411-5471 Amir Letafatkar https://orcid.org/0000-0003-1704-9604 Malihe Hadadnezhad https://orcid.org/0000-0001-8485-6364 Journal Article 2016 10 01 Background: Jump and landing is the characteristics of most sports and one of the main mechanisms of anterior cruciate ligament injuries. Researchers believed mechanism-based designing the preventive exercises can possibly have a better effectiveness. The aim of this study was to evaluate the effect of eight weeks of jump- landing exercise on feedforward and feedback activation of selected trunk and lower extremity muscles and performance in active females. Methods: In this quasi- experimental study, 25 active females age ranged 18-26 years were participated. The electromyography device ME6000 model and triple hop test were used for muscle activity (hamstring, quadriceps, gluteus medious and maximous in drop landing) and performance evaluation respectively. After pre test, the experimental group underwent to Herrington et al eight weeks of jump- landing exercises. After implementation of training, post test of electromyography and performance were done similar to pre test and data were statistically analysed by using independent and sample t tests. Results: Results of paired t test revealed that the jump- landing exercises led to significant differences in feedforward and feedback activation [VM(Pff=0/002, Pfb=0.001), VL(Pff=0.001, Pfb=0.021), RF(Pff=0.004, Pfb=0.001), MH(Pff=0.001, Pfb=0.001), LH(Pff=0.001, Pfb=0.034), Gmed(Pff=0.001, Pfb=0.001) and Gmax(Pff=0.001, Pfb=0.001)] and performance(P=0.001) in experimental group from pre test to post test whereas there was no significant differences in control group. Conclusion: It can be concluded that jump- landing exercises with modifying and optimizing the knee stabilizer activation and in other hand with improving the performance might have important role in anterior cruciate ligament injury in active females.