The association between choice stepping reaction time and falls in older adults--a path analysis model

Can the Ordered Multi-Stepping Over Hoop test be useful for predicting fallers among older people? A preliminary 1 year cohort study

BACKGROUND AND AIMS

To prevent falls among older people, we developed a new fall-risk assessment, the "Ordered Multi-Stepping Over Hoop (OMO)" test. The aims of this study were preliminary: to investigate the association of the OMO with cognitive and physical function and to investigate whether the OMO could predict incidents of falling.

METHODS

Fifty-nine community-dwelling older people (mean age = 88.0 ± 0.87, female = 49) were recruited. We assessed cognitive and physical function including the OMO test at baseline and monitored the falls of participants during a 12-month follow-up period from the baseline. We investigated whether the OMO was associated with cognitive function, physical function, and incidents of falling. To investigate whether the OMO could predict incidents of falling, a receiver operating characteristic analysis was conducted.

RESULTS

The OMO time in fallers was significantly slower than for non-fallers. There were significant correlations between slower OMO times and lower physical functions and executive function. The area under the ROC curve in the OMO was 0.71 (p < 0.05). Times above 21.9 s for the OMO identified those more likely to fall.

CONCLUSIONS

The OMO time was correlated with cognitive function, physical function, and incidents of falling. Our preliminary study indicates that the OMO may help to make a distinction between fallers and non-fallers among older people as effectively as other tests.

A novel infrared laser device that measures multilateral parameters of stepping performance for assessment of fall risk in elderly individuals [corrected]

BACKGROUND AND AIMS

Avoiding falls requires fast and appropriate step responses in real-life situations. We developed a step-tracking device that uses an infrared laser sensor for convenient assessment of stepping performance, including concurrent assessment of temporal and spatial parameters. In the present study, we created a new index for assessment of fall risk that uses step speed and accuracy measurements. The purpose of this study was to determine whether the new index could discriminate between elderly individuals with different risks of falling.

METHODS

One hundred and fifty-two community-dwelling elderly individuals (73.9 ± 4.6 years) participated and performed stepping tasks as quickly as possible on a plus-shaped mat in response to optical cues. The step-tracking device with the infrared sensor detected the motion and position of both legs in the step field. The device recorded temporal and spatial parameters, foot-off and foot-contact time, step length, and the percentage of correctly executed steps. We used the coefficients of a logistic regression model to develop "stepping-response score" based on the weighted sum of these temporal and spatial parameters.

RESULTS

The faller group had significantly worse stepping-response score than the non-faller group (p < 0.001). A stepwise logistic regression analysis demonstrated that stepping-response score was independently associated with falling (odds ratio = 0.15; p < 0.001). The ROC curve had a moderate AUC (0.73) for stepping-response score (sensitivity 73.0 %; specificity 69.7 %).

CONCLUSIONS

This study indicates that the stepping-response score calculated from measurements obtained using the new step-tracking device can identify elderly individuals who are at a risk of falling.

Development of measurement system for task oriented step tracking using laser range finder

BACKGROUND

Avoiding a fall requires fast and appropriate step responses, stepping speed as a fall risk indicator has only been assessed in older adults. We have developed a new measurement system that applies a laser range finder to assess temporal and spatial parameters of stepping performance such as step speed, length, and accuracy. This measurement system has higher portability, lower cost, and can analyze a larger number of temporal and spatial parameters than existing measurement systems. The aim of this study was to quantify the system for measuring reaction time and stride duration by compared to that obtained using a force platform.

METHODS

Ten healthy young adults performed steps in response to visual cues. The measurement system applied a laser range finder to measure the position and velocity of the center of each leg and of both legs.We applied the developed measurement system to the rhythmic stepping exercise and measured reaction time and stride duration. In addition, the foot-off time and foot-contact time were quantified using the measurement system, and compared to the foot-off time and foot-contact time quantified using a force platform.

RESULTS

We confirmed that the measurement system can detect where a participant stood and measured reaction time and stride duration.Remarkable consistency was observed in the test-retest reliability of the foot-off time and foot-contact time quantified by the measurement system (p < 0.001). The foot-off time and foot-contact time quantified by the measurement system were highly correlated with the foot-off time and foot-contact time quantified by the force platform (reaction time: r = 0.997, stride duration: r = 0.879; p < 0.001).

CONCLUSIONS

The new measurement system provided a valid measure of temporal step parameters in young healthy adults.The validity of the system to measure reaction time and stride duration was evaluated, and confirmed by applying to the rhythmic stepping exercise.

Effects of visual interference on initial motor program errors and execution times in the choice step reaction

The purpose of this study was to examine whether visual interference has any effect on error in the initial direction of anticipatory postural adjustment (APA) prior to a step (indicating a motor program error) and response time during the choice step execution. Twenty healthy young participants were instructed to execute forward stepping as quickly and accurately as possible on the side indicated by a central arrow (←, left vs. →, right) of a visual cue in the neutral condition. In the flanker condition, they were additionally required to ignore the 2 flanking arrows on each side (→→→→→, congruent or →→←→→, incongruent). Errors in the direction of the initial weight transfer (APA errors) and the step execution times were measured from the vertical force data. In the incongruent condition, the percentage of APA errors and the step execution times were significantly greater than those in the neutral and congruent conditions. A linear mixed model revealed that the step execution time in trials with APA errors was longer than those in trials without APA errors. The visual interference effect of a flanker task may load selective attention and judgment processing during movement initiation, leading to increased initial motor program errors and prolonged step execution times even in healthy young adults.

A randomized controlled pilot study of home-based step training in older people using videogame technology

Background

Stepping impairments are associated with physical and cognitive decline in older adults and increased fall risk. Exercise interventions can reduce fall risk, but adherence is often low. A new exergame involving step training may provide an enjoyable exercise alternative for preventing falls in older people.

Purpose

To assess the feasibility and safety of unsupervised, home-based step pad training and determine the effectiveness of this intervention on stepping performance and associated fall risk in older people.

Design

Single-blinded two-arm randomized controlled trial comparing step pad training with control (no-intervention).

Setting/Participants

Thirty-seven older adults residing in independent-living units of a retirement village in Sydney, Australia.

Intervention

Intervention group (IG) participants were provided with a computerized step pad system connected to their TVs and played a step game as often as they liked (with a recommended dose of 2–3 sessions per week for 15–20 minutes each) for eight weeks. In addition, IG participants were asked to complete a choice stepping reaction time (CSRT) task once each week.

Main Outcome Measures

CSRT, the Physiological Profile Assessment (PPA), neuropsychological and functional mobility measures were assessed at baseline and eight week follow-up.

Results

Thirty-two participants completed the study (86.5%). IG participants played a median 2.75 sessions/week and no adverse events were reported. Compared to the control group, the IG significantly improved their CSRT (F_31,1 = 18.203, p<.001), PPA composite scores (F_31,1 = 12.706, p = 0.001), as well as the postural sway (F_31,1 = 4.226, p = 0.049) and contrast sensitivity (F_31,1 = 4.415, p = 0.044) PPA sub-component scores. In addition, the IG improved significantly in their dual-task ability as assessed by a timed up and go test/verbal fluency task (F_31,1 = 4.226, p = 0.049).

Conclusions

Step pad training can be safely undertaken at home to improve physical and cognitive parameters of fall risk in older people without major cognitive and physical impairments.

Trial Registration

Australian New Zealand Clinical Trials Registry ACTRN12611001081909.

Step Training System: an ICT solution to measure and reduce fall risk in older adults

Falls in older adults are a significant public heath issue with over 1/3 community-dwelling people aged 65 and over falling each year, many of them multiple times. We have developed and evaluated a set top box PC solution for delivering both fall risk assessment and fall risk reduction programs into the home. Preliminary field tests show that older adults engage with the system but that barriers to maintained use of the system do exist.

Examining the relationship between specific cognitive processes and falls risk in older adults: a systematic review

This systematic review aims to establish which cognitive domains are associated with falls or falls risk. Recent evidence suggests that impaired cognition increases seniors' risk of falling. The purpose of this review was to identify the cognitive domains that are significantly associated with falls or falls risk in older adults. We conducted a systematic review of peer-reviewed journal articles published from 1948 to present, focusing on studies investigating different domains of cognitive function and their association with falls or falls risk in adults aged 60 years or older. In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we completed a comprehensive search of MEDLINE, PubMed, and EMBASE databases to identify studies examining the association between cognitive function and falls or falls risk. With an expert in the field, we developed a quality assessment questionnaire to rate the quality of the studies included in this systematic review. Twenty-five studies were included in the review. We categorized studies based on two related but distinct cognitive domains: (1) executive functions or (2) dual-task ability. Twelve studies reported a significant association between executive functions and falls risk. Thirteen studies reported that dual-task performance is a predictor of falls or falls risk in older adults. Three studies did not report an association between cognition and falls risk. Consistent evidence demonstrated that executive functions and dual-task performance were highly associated with falls or falls risk. The results from this review will aid healthcare professionals and researchers in developing innovative screening and treatment strategies for mitigating falls risk by targeting specific cognitive domains.

The use of exercise-based videogames for training and rehabilitation of physical function in older adults: current practice and guidelines for future research

Declines in physical or cognitive function are associated with age-related impairments to overall health. Functional impairment resulting from injury or disease contribute to parallel declines in self-confidence, social interactions and community involvement. Fear of a major incident such as a stroke or a bone-breaking fall can lead to the decision to move into a supported environment, which can be viewed as a major step in the loss of independence and quality of life. Novel use of videogame console technologies are beginning to be explored as a commercially available means for delivering training and rehabilitation programs to older adults in their own homes. We provide an overview of the main videogame console systems (Nintendo Wii™, Sony Playstation® and Microsoft Xbox®) and discuss some scenarios where they have been used for rehabilitation, assessment and training of functional ability in older adults. In particular, we focus on two issues that significantly impact functional independence in older adults, injury and disability resulting from stroke and falls.

White matter hyperintensities and impaired choice stepping reaction time in older people

White matter hyperintensities (WMHs) are associated with impaired mobility in older people, but no studies have identified neuropsychological and sensorimotor mediating factors for this association. Our objective was to determine whether neuropsychological and sensorimotor functions mediate the association of WMHs and choice stepping reaction time (CSRT) under standard and dual-task conditions using structural equation modeling. Two hundred fifty-four older community dwellers (77.8 ± 4.5 years) underwent structural magnetic resonance imaging, CSRT tests, neuropsychological and sensorimotor assessments. WMH volumes were quantified using an automated method. WMH volumes were significantly associated with neuropsychological tests and dual task CSRT performance. All neuropsychological and sensorimotor variables were also significantly associated with standard and dual task CSRT. The structural equation modeling revealed that impaired sensorimotor function was the only factor influencing impaired stepping performances in the standard condition. In the dual task condition, the association between WMHs and CSRT was mediated through slowed cognitive processing and not through reduced sensorimotor functioning. The conclusion was that WMHs are associated with slowed performance on a dual task CSRT task and this relationship is explained primarily by underlying neuropsychological impairments.