Mobility Impairment Research Center, Babol University of Medical Sciences, Babol, Iran; Clinical Research Developmemt Unit, Rouhani Hospital, Babol University of Medical Sciences, Babol, Iran. Electronic address: bheidari6@gmail.com. Department of Biostatic and Epidemiology, Babol University of Medical Sciences, Babol, Iran. Clinical Research Developmemt Unit, Rouhani Hospital, Babol University of Medical Sciences, Babol, Iran; Department of Medicine Division of Rheumatology, Rouhani Hospital, Babol University of Medical Sciences, Babol, Iran.