Knowledge & Health8420130702Investigation of the Effect of Mental Imagery Training on Electrical Fluctuation of Muscles Motor Units and Muscles Strength in Lower Limbs17117510.1234/knh.v8i4.49FAAkbarZeraatpishe. Jiroft_university@yahoo.comSeyed MohammadNiazi20130813Introduction: The purpose of the present study was to investigate the effect of mental imagery training on electrical fluctuation of muscles motor units and muscles strength in lower limbs.Methods: In this study, 30 healthy, previously untrained students with the mean age of 22.4±1.25 years, the mean height of 176.18±5.62 cm, and the mean weight of 67.65±6.15 were randomly assigned to a mental practice group (n=15) or control group (n=15). Mental practice group trained mental contraction of plantar flexion movement for 4 weeks (5 day per week), and control group did not train but participated in all measurements. The practice program included 50 mental maximal voluntary contractions for 2 sets of 25 repetitions. To determine the statistical difference in variables of the study the t-student test was used with the significant level of P≤0.05.Results: The results of this study indicated that mental practice group significantly increased their plantar flexor maximal voluntary contraction (MVC) (P≤0.05). Also mental practice group significantly increased their gastronomies muscle EMG (P≤0.05). We concluded that mental practice can increase strength plantar flexor muscle, and this strength gain is attributed to the training-induced changes caused by programming central nervous system which increases activation level of agonist muscles and decreases activation level in antagonist muscles.Conclusion: Results showed that imagery training can affect athletic performance.