Modeling recovery from stumbles: preliminary data on variable selection and classification efficacy.

Abstract

OBJECTIVE: The primary purpose of this preliminary investigation was to determine the functional relationship between selected information processing time and response execution variables and measures of postural stability in elderly women. A secondary purpose was to explore the efficacy of a neuromotor model using selected variables to retrospectively identify subjects with a self-reported history of falling. DESIGN: Descriptive, retrospective, cohort. SETTING: General community. SUBJECTS: Convenience sample of 17 community-dwelling females with a mean age of 72.2 years. MAIN OUTCOME MEASURES: Postural stability variables included the amplitude and frequency of postural sway during static vision-aided no-vision conditions. Information processing and response execution variables were collected using a simple-choice reaction time paradigm for an isometric knee extension task. RESULTS: Postural stability and information processing variables were functionally independent. Based upon significant intergroup differences, simple and choice pre-motor reaction time and non-vision aided anterior posterior sway amplitude were selected for inclusion in a discriminant analysis. The resulting discriminant function was significant (P = 0.01), correctly categorizing all of the subjects with a self-reported history of falling and identifying six out of seven of the non-fallers. CONCLUSIONS: These preliminary results suggest that it is feasible to identify a predisposition to falling by detecting an inability to respond successfully to a postural disturbance.