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

M D Grabiner; D W Jahnigen

doi:10.1111/j.1532-5415.1992.tb01989.x

Home/Archive/PubMed

PubMed · 1512388

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

M D Grabiner·D W Jahnigen

View original source ↗Export metadata ↓

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.

Explore related subjects

Accidental Falls Aged Biomechanical Phenomena Cognition Female Geriatric Assessment Humans Models, Neurological Motor Activity Postural Balance Posture Reaction Time Retrospective Studies Journal Article

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

M D Grabiner, D W Jahnigen. 1992. Modeling recovery from stumbles: preliminary data on variable selection and classification efficacy.. https://doi.org/10.1111/j.1532-5415.1992.tb01989.x

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2003

Effects of age-related gait changes on the biomechanics of slips and falls.

A laboratory study was conducted to examine gait changes associated with aging and the effect of these changes on initiation of slips and frequency of falls utilizing newly defined biomechanical parameters of slips and falls. Twenty-eight participants from two age groups (young and old) walked around a circular track at a comfortable pace wearing a safety harness. A slippery floor surface was placed on the walking track over the force plate at random time intervals without the participants' awareness. Synchronized kinetic and kinematic measurements were obtained on both slippery and non-slippery walking surfaces. The results indicated that older participants' horizontal heel contact velocity was significantly faster, step length was significantly shorter, and transitional acceleration of the whole body centre-of-mass (COM) was significantly slower than younger participants. Older participants' initial friction demand, as measured by required coefficient of friction (RCOF), was not significantly different than their younger counterparts. Additionally, older participants slipped longer and faster, and fell more often than younger participants. A comparison of horizontal heel contact velocity for participants who fell with participants who did not fall indicated that, in general, fallers' horizontal heel contact velocity was faster than non-fallers. However, a comparison of RCOF for participants who fell with participants who did not fall suggested that RCOF was not a totally deterministic factor influencing actual fall events. These findings suggest that gait changes associated with aging (especially higher horizontal heel contact velocity and slower transition of the whole body COM) affect initiation of slip-induced falls.

Accidental Falls↗

PubMed2003

Sizing and fit of fall-protection harnesses.

Full-body fall-protection harnesses have been a critical work-practice control technology for reducing the number of fall-related injuries and fatalities among construction workers; yet, very little is known about the fit of these harnesses to the population that wears them. This study evaluated the fit and sizing efficacy of a harness system. Seventy-two male and 26 female construction workers participated in the study. Their body size-and-shape information was measured while they were suspended (with a harness) and standing (with and without a harness), using a 3-D full-body laser scanner and traditional anthropometric calipers. Fisher's discriminant analysis results did not point to the need for a change in the current sizing selection scheme by body height and weight for end users. However, an integrated redesign of harness components is needed because 40% of subjects did not pass fit-performance criteria in either the standing or suspended condition. A multivariate accommodation analysis has identified 15 representative body models for the 'standard-size' harness design. These models can serve as a useful population to test harness design until a larger survey of the nation's construction workers can be done. Finally, further developments in 3-D shape quantification methods are recommended to improve the harness design process; the point-to-point anthropometric information currently used seems to be insufficient for harness design.

Accidental Falls↗

PubMed2003

Health status and functional capacity in a group of successfully ageing 65-85-year-olds.

PURPOSE: To examine health behaviours of older people, comparing people aged 65-74 years with those aged 75-85 years. METHOD: Seventy-five men (45%) and women (55%) aged between 65 and 85 years were recruited from a sample of convenience. Participants completed three questionnaires which documented health status, exercise patterns, levels of physical capacity, independence in daily living and involvement in activities. Tests of physical ability were then conducted related to walking, upper extremity function, ability on tram steps, and grip strength. RESULTS: The sampling method delivered a biased sample with most participants rating their health as excellent or very good for their age. While many participants reported chronic medical conditions, or more than one fall in the last year, the level of physical activity was strikingly high. Men were more active than women, and physical activity declined minimally after the age of 75. Anecdotally, the sample was also active in social and intellectual activities, with women involved in these activities more than physical pursuits. CONCLUSIONS: The role of activity is important in the study of successful ageing. This study reported gender and age group differences in the activities chosen, demonstrating that the inclusion of a cross-section of daily activities is essential in the study of health status and well-being.

Accidental Falls↗