Tehran University of Medical Sciences Journal of Modern Rehabilitation 2538-385X 13 1 2019 11 27 59 64 Saina Aliabadi Department of Physiotherapy, School of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran. Roya Khanmohammadi Department of Physiotherapy, School of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran. Gholamrezareza Olyaei Department of Physiotherapy, School of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran. Nastaran Ghotbi Department of Physiotherapy, School of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran. Saeed Talebian Department of Physiotherapy, School of Rehabilitation, Tehran University of Medical Sciences, Tehran, Iran. Abdolreza Naser Moghadasi Multiple Sclerosis Research Center, Sina Hospital, Tehran University of Medical Sciences, Tehran, Iran. 2019 11 27 Introduction: Position sense, one of the most accurate senses in the body, makes everyone aware of the state of the body in space. This sense is an essential ability in maintaining physical health and avoiding injury. Deficits in position sense cause balance impairments in people with mild Multiple Sclerosis (MS). Position sense requires instant and coordinated communication between the central nervous system and peripheral nervous system, while in patients with MS, communication between the brain and other parts of the body is disrupted. This study aims to compare the position sense of knee joint in people with MS and healthy subjects. Materials and Methods: Ten healthy subjects with the Mean±SD age of 27.6±3.71 years and 10 persons with MS disease and the Mean±SD age of 31.40±3.50 years participated in this study. For evaluating their position sense of knee joint, they flexed their knees (from 90 to 45 degrees) four times, and then a software calculated their repositioning errors. Results: No significant changes in repositioning errors (constant, variable, absolute) were observed in MS patients, and the control group (P˃0.05). Conclusion: The results indicate that mild MS disease cannot disturb the position sense of knee joint. https://jmr.tums.ac.ir/index.php/jmr/article/view/230 https://jmr.tums.ac.ir/index.php/jmr/article/download/230/133