Tabriz University of Medical Sciences Medical Journal of Tabriz University of Medical Sciences 2783-2031 37 3 2015 08 05 The EMG Activation of Postural Stabilizer Muscles during Sudden Acceleration in Base of Support in Patients with Acute Lateral Ankle Sprains 34 39 EN Mehrangiz Qorbani Nader Farahpoor Alireza Yavarikia Journal Article 2013 10 27 2014 01 21 Background and Objectives: Lateral ankle sprain (LAS) is the most common sport injury and routine activities of life. The purpose of this study was to evaluate the EMG activation of posture stabilizer muscles during sudden acceleration to provide clinicians biomechanical perspectives of acute ankle sprains on muscle response. Materials and Methods: In a semi experimental method with case and controls. The sinker–card protocol was be used as a dynamic balance test with simulating fall upon 4 posture stabilizer muscles in two sides of the body after sudden acceleration in forward and backward directions study was done in 19 young adult men in two groups (9 LAS; 23.9 ± 2.03 yrs and 10 normal person; 26.4 ± 3.2 yrs). The data were assessed by multivariate test and one-way ANOVA. Results: The results showed a significant muscle interaction. In forward direction higher bilateral TA activity was observed in LAS group than normal group. Higher MGR activity in normal group than LAS group in backward direction significantly showed. These findings suggest that compared two sides of the body in two directions for 4 muscles EMG activities between and within group for balance control recovery in simulating fall. EMG activations of two sides of the body in LAS patients were symmetric significantly. Conclusion: LAS not only create mechanical and functional instability, but also, have long-term biomechanical alternations for example different mechanisms of balance recovery on musculoskeletal system.