morteza nazifi department of educational sciences and exceptional children, semnan university, semnan, ir iran hamidreza mokarami department of ergonomics, school of health, shiraz university of medical sciences, shiraz, ir iran; research center for modeling in health, institute for futures studies in health, kerman university of medical sciences, kerman, ir iran; research center for modeling in health, institute for futures studies in health, kerman university of medical sciences, kerman, ir iran. tel: +98-2182883585, fax: +98-2182884555 aliakbar akbaritabar department of social welfare, allameh tabatabaei university, tehran, ir iran haji omid kalte department of occupational health engineering, faculty of medical sciences, tarbiat modares university, tehran, ir iran amid rahi student research committee, kerman university of medical sciences, kerman, ir iran

C A King S H Katz N Ghaziuddin E Brand E Hill L McGovern