The role of the pedunculopontine tegmental nucleus in relation to conditioned motor performance in the cat. II. Effects of reversible inactivation by intracerebral microinjections

OBJECTIVE: To describe lower-extremity functioning in community-dwelling older Mexican Americans and to examine its relationship with medical problems. DESIGN: Cross-sectional analyses of survey and performance-based data obtained in a population-based study employing area probability sampling. SETTING: Households within selected census tracts of five Southwestern states: Arizona, California, Colorado, New Mexico, and Texas. PARTICIPANTS: A total of 2873 Mexican Americans aged 65 years and older. MEASUREMENTS: A multidimensional questionnaire assessing demographic, sociocultural, and health variables. Standardized tests of lower-extremity physical functioning included measures of standing balance, repeated chair stands, walking, and an overall summary measure. RESULTS: Regression analyses revealed that being more than age 75 and female, having arthritis diabetes, visual impairments, or being obese or underweight were all significantly associated with performance on both individual and summary tests of lower-extremity functioning. In separate regression analyses, the total number of medical conditions was also associated with performance. CONCLUSIONS: The likelihood of predicting performance or inability to complete tests of lower-extremity functioning was greatest for those aged 80 and older, those with arthritis or diabetes, and those with three or more medical conditions. Because of the high prevalence of diabetes in Mexican Americans, documentation of the association of diabetes with performance-based tests of lower-extremity functioning may help guide early interventions targeted to prevent progression to more severe limitations or disability.