Eggermont LH, Gavett BE, Volkers KM, Blankevoort CG, Scherder EJ, Jefferson AL, Steinberg E, Nair A, Green RC, Stern RA. Lower-extremity function in cognitively healthy aging, mild cognitive impairment, and Alzheimer's disease. Objective: To examine differences in lower-extremity function in cognitive healthy older persons, older persons with mild cognitive impairment (MCI), and older persons with Alzheimer's disease (AD). Design: Descriptive study. Setting: University Alzheimer's disease clinical and research program. Participants: Older persons (N=66) were studied (mean age, 76.7y); 22 were cognitively normal, 22 were diagnosed with probable MCI, 22 were diagnosed with probable AD. Interventions: Not applicable. Main Outcome Measures: Lower-extremity function was assessed by the four-meter walk test (4MWT), Timed Up & Go (TUG) test, and sit-to-stand (STS) test. Results: Analysis of variance, adjusting for covariates, revealed that performance on the 4MWT was significantly lower in the MCI and AD groups as compared with controls. TUG test performance was worse in the AD group compared with controls. No significant group differences were found for STS performance. Conclusions: These results suggest an association between cognitive impairment and lower-limb function in older persons. Walking speed could be evaluated for its possible utility in screening older persons at risk for cognitive impairment and falls. © 2010 American Congress of Rehabilitation Medicine.