Medicina Sportiva (2012), vol VIII, no 4, 2003-2008 Romanian Sports Medicine Society The effect of 6 weeks core stabilization training program on the balance in mentally retarded students Rahmat Ahmadi 1 , Daneshmandi Hasan 1 , Barati Amir Hosin 2 1 Guilan University, Faculty of Sport Science and Physical Education, Department of Physical Education and Sport Sciences, Rasht, Iran 2 Shahid Rajaee Teacher Training University, Faculty of Sport Science and Physical Education, Department of Physical Education and Sport Sciences, Tehran, Iran Abstract. The purpose of this study was to examine the effect of core stabilization training program on the balance of mentally retarded students. Thirty one mentally retarded male students were selected. Methods. Subjects were divided randomly into two groups, training (TRN: n= 17) and control (CTL: n= 14). The dynamic balance was measured with the modified Star Excursion Balance Test (Y test). TRN group performed a core stabilization program for 6 weeks and three times per week. The pre-test and post-test of Y test was done for two groups afterward. Independent and dependent t-test used to analyze the data. Results. Results showed significant differences in mean posterolateral and Posteromedial in the experimental group in post test (p≤0.05) but insignificant on anterior direction (p≤0.27). Conclusion. Core stabilization training program may improve the dynamic balance and can be used with other training programs. Key words: mental retardation, core stability, dynamic balance, Y test. Introduction Mental retardation (MR) causes important effects on children physical fitness, as well as cognitive activities during life span. Most research in the literature states that children with MR have poor level of physical fitness compared with their nondisabled peers. These studies found that children with MR have a low level of cardiovascular endurance, muscular strength, muscular endurance, running speed, balance and agility. It is well known that children with MR have isolation problems in society what leads to their physical inactivity. Some research reports indicate that children with MR achieves very low scores in cardiovascular fitness tests. In addition; several studies reported a significantly positive correlation between inactive lifestyles and cardiovascular disease. Therefore, physical activities should be established for children with MR, to develop their cardiovascular fitness (1). According to the American Association of Mental Retard (2006), the motor development of those children’s can present functional incapacities, limiting the execution of activities and restricting the participation of several situations of the real life. Therefore it is important to analyze the individuals' motor aspects with ID. One of the variables to be analyzed is the balance. That requires inputs from visual, somatosensory and vestibular inputs as well as their integration to reference the self within the environment and deficits in balance may result in delayed motor development because as postural control is generally presumed to be a precondition for the development of motor skills (2). However, current data regarding the effects of intellectual disability on balance performance are limited. Balance is an important component of daily activity and athletic performance (3). Balance plays a curtail role in almost all sport events. Either in shooting which requires the least amount of movements or dynamic sports such as gymnastics and wrestling, which require agility in conjunction with maximum balance, balance plays a critical role in success and failure (4). Specialists believe in the important role of posture control and balance in doing tasks such sitting, 2003