A short physical performance battery assessing lower extremity function: association with self-reported disability and prediction of mortality and nursing home admission. - Guralnik,J.M.; Simonsick,E.M.; Ferrucci,L.; Glynn,R.J.; Berkman,L.F.; Blazer,D.G.; Scherr,P.A.; Wallace,R.B. (J Geront, 1994)