Mahoney FI, Barthel DW : Functional evaluation : the Barthel Index. Maryland State Med J 14 : pp61-653, 1965.
Lawton, M. P & Brody. E. M. Assessment of older people : Self Maintaining and instrumental activities of daily living. Gerontologist. 9 : pp179-168, 1969.
Nakamura K. A ”super-aged” society and the ”locomotive syndrome”. J Orthop Sci. 13(1): pp1-2, 2008.