boshra hatef phd candidate, physical therapy department, medical school, tarbiat modares university, tehran, iran. saeed talebian professor, physical therapy department, rehabilitation faculty, tehran university of medical sciences and health services, tehran, iran fahimeh hashemirad akhavan rehabilitation, educational and research center, university of social welfare and sciences, tehran, iran majid ghaffarpour professor of neurology, iranian center of neurological research, emam khomeyni hospital, keshavarz boulevard, tehran, iran