Active Learning Through Video Conferencing to Maintain Physical Activity Among Older Adults: A Pilot Randomized Controlled Trial.

This randomized pilot trial investigated the feasibility of an active learning physical activity intervention through video conferencing and its preliminary effects. Participants comprised community-dwelling older adults who could use e-mail. The intervention group underwent a 12-week active learning intervention via video conferencing to promote a healthy lifestyle, particularly physical activity. The control group received information via e-mail once per week. The amount of physical activity and sedentary behavior was measured using an accelerometer at baseline, postintervention, and 24-week postintervention (36 weeks). Of the 31 participants, 29 were eligible and randomized into two groups (15 for the intervention and 14 for the control). Adherence to the intervention was 83%-100% (mean, 97%). Compared with the control group, the intervention group showed moderate maintenance effects on total physical activity and sedentary behavior at 36 weeks. Active learning physical activity intervention through video conferencing was found to be feasible and contributed to the prevention of physical activity decline in older adults.

Association between community-level health literacy and frailty in community-dwelling older adults.

AIMS: We aimed to investigate whether high community-level health literacy, beyond individual-level health literacy, is associated with a low prevalence of frailty among community-dwelling older adults. METHODS: A large cross-sectional questionnaire survey was conducted among citizens in Maizuru City, Kyoto, Japan, aged 65 years or older who were not certified as "support" or "care" level according to Japan's public long-term care insurance system, who could perform basic activities of daily living, and who did not have dementia or Parkinson's disease. Frailty status was assessed using the Kihon Checklist, with a score ≥ 8 indicating frailty. Health literacy was assessed using the Communicative and Critical Health Literacy Scale. The mean health literacy score of 20 school districts was used as the community-level health literacy index. We investigated demographic data and other potential confounding factors, including education, living arrangement, body mass index, comorbidity, smoking status, depressive symptoms, social networks, and community-level covariates. RESULTS: The primary analysis included 6230 individuals (mean age = 74.3 years [SD = 6.1]). In each school district, the prevalence of frailty was 21.2-34.2% (mean: 26.2%), and community-level health literacy index was 3.1-3.5 (mean: 3.4). Multilevel logistic regression model including school district as random effect showed that the community-level health literacy was significantly associated with frailty (odds ratio [95% confidence interval] = 0.28 [0.08 to 0.96]) after adjusting for the covariates. CONCLUSIONS: Not only high individual-level health literacy but also high community-level health literacy is associated with a low prevalence of frailty in community-dwelling older adults.

Objectively-measured out-of-home behavior and physical activity in rural older adults.

This cross-sectional study investigated the association of out-of-home behavior measured by global positioning system (GPS) and amounts of physical activity. Rural older adults aged ≥ 65 years (n = 133) participated in this study. Daily step count and physical activity level were measured using an accelerometer. We monitored out-of-home behavior using a GPS sensor and calculated two indicators: out-of-home time and number of nodes (places) visited per day. In results, only the number of nodes visited was significantly associated with step count (B coefficient = 1,324; 95% CI = 622 to 2,026) and physical activity level (B coefficient = 0.05; 95% CI = 0.02 to 0.09) in the fully-adjusted model, while out-of-home time was not. A greater number of nodes visited, rather than out-of-home time, was associated with higher amounts of physical activity in older adults.

The Effectiveness of an Active Learning Program in Promoting a Healthy Lifestyle among Older Adults with Low Health Literacy: A Randomized Controlled Trial.

BACKGROUND: Older adults often have a greater need for health information and health care services because access to these helps them manage their health and the chronic conditions of aging. Therefore, low health literacy bears a special significance for the population of older adults. OBJECTIVES: The aim of this study was to examine the effects of an active learning program on health literacy, lifestyle behaviors, physical function, and mental health among community-dwelling older adults with low health literacy. METHODS: This single-blind, randomized controlled trial involved 60 participants aged ≥65 years with a low health literacy who were randomly assigned to an intervention (n = 30) or control (n = 30) group. Across 24 weeks, the intervention group attended weekly 90-min active learning program sessions, which involved exploratory learning, group work, and the self-planning of behavior changes that promote a healthy lifestyle. The control group attended a 90-min class, which was taught in accordance with the didactic teaching method. For both groups, the programs focused on the role of exercise, diet/nutrition, and cognitive activity for promoting health among older adults. The outcome measures were administered at baseline and week 24. Comprehensive health literacy (i.e., primary outcome) was assessed using the Health Literacy Scale-14. Lifestyle factors (i.e., physical activity, dietary variety, life-space mobility, and social network size), physical function, and depressive symptoms were measured. We used a linear mixed model to estimate the intervention effects in accordance with the intention-to-treat approach. RESULTS: When compared to the control group, the intervention group demonstrated a significant improvement in communicative health literacy, step count, engagement in moderate-to-vigorous physical activity, dietary variety, life-space mobility, social network size, grip strength, gait speed, and depressive symptoms. CONCLUSIONS: The active learning program can promote a healthy lifestyle and prevent functional decline among older adults who lack the confidence to engage in health communication.

[Effects of health literacy on frailty status at two-year follow-up in older adults: A prospective cohort study].

AIM: To investigate the longitudinal association between health literacy and frailty status at two-year follow-up in community-dwelling older adults. METHODS: A total of 218 older adults (mean age, 72.5±4.9 [range 65-86] years old; men, n=81) without frailty at baseline participated in this study. Functional health literacy was assessed using the Newest Vital Sign (NVS). Comprehensive health literacy was assessed using the 47-item European Health Literacy Survey Questionnaire (HLS-EU-Q47). Comprehensive health literacy indices are constructed as a general health literacy index comprising all items along with the three sub-indices of health care, disease prevention, and health promotion domains. Demographic data and other potential confounding factors were also assessed. The total Kihon checklist score was used to monitor the presence of frailty based on a score of ≥8 at the 2-year follow-up (postal survey). RESULTS: Of the 253 participants in the follow-up survey, 226 responded (response rate: 89.3%). Excluding the 8 participants with missing values, 25 (11.5%) of the 218 were reported to be frail. A multiple logistic regression analysis indicated that comprehensive health literacy (total score of HLS-EU-Q47) was independently associated with a lower risk of frailty (odds ratio per standard deviation = 0.54, 95% confidence interval = 0.33-0.87) after adjusting for the covariates (age, gender, education, body mass index, gait speed, cognitive function, and comorbidities). The health care and disease prevention domain scores of the HLS-EU-Q47 were also independently associated with a lower risk of frailty. Functional health literacy (NVS score) was not associated with frailty. CONCLUSIONS: Older adults with higher comprehensive health literacy are less likely to be frail at two-year follow-up than those with a lower literacy.

Effect of various exercises on frailty among older adults with subjective cognitive concerns: a randomised controlled trial.

BACKGROUND: Physical exercise has been linked to reduced frailty, but there is insufficient evidence of beneficial effects in community-dwelling older adults with subjective cognitive concerns. OBJECTIVE: This study aimed to clarify the effects of physical exercise in this population. DESIGN: Single-blind randomised controlled trial. SETTING: Community sports centres. PARTICIPANTS: Residents aged 65-85 years were screened using the Kihon checklist; those with subjective cognitive concerns were invited for eligibility assessment. In total, 415 community-dwelling older adults were enrolled and randomised. METHODS: This trial investigated the effects of aerobic training (AT), resistance training (RT) and combined training (AT+RT) programs on reducing frailty. All participants were randomised into one of the three intervention groups or the control group. Participants in the intervention groups underwent a group training program and self-paced home training for 26 weeks. The control group received lectures about health promotion. A 95-item frailty index (FI) was utilised to determine the effects of training. Participants were followed up at weeks 26 and 52. RESULTS: At baseline, mean age of all participants (47% women) was 72.3 ± 4.6 years, with a mean FI score of 0.3 ± 0.1. Compared with control group, AT improved total FI by 0.020 (CI -0.039 to -0.001, effect size -0.275) and the depression and anxiety component of FI by 0.051 (CI -0.084 to -0.018, effect size -0.469) at week 26, but the effects waned at week 52. No significant differences in FI were found in RT and AT+RT groups at weeks 26 and 52. CONCLUSIONS: A 26-week AT reduced frailty modestly, especially in the depression and anxiety component, in older adults with subjective cognitive concerns.

Behavioral protective factors of increased depressive symptoms in community-dwelling older adults: A prospective cohort study.

BACKGROUND: It remains unclear what kinds of behavior prevent the development of geriatric depression. This study aimed to elucidate behavioral predictors of increased depressive symptoms in older adults focusing on gender differences. METHODS: A total of 3106 community-dwelling older people aged older than or equal to 65 years without depressive symptoms at baseline participated. The 15-item Geriatric Depression Scale was used to assess depressive symptoms with a score of 6 or more at baseline and 15 month follow-up. Behavioral status was investigated by using dichotomous questions about the aspects of physical, cognitive, and social activities. Each category included 3 specific items. Demographic data and other potential confounding factors were also assessed. RESULTS: In the 15 month follow-up survey, 239 participants (7.7%) reported increased depressive symptoms. Multiple logistic regression analysis indicated that engagement in light physical exercise (odds ratio = 0.74, 95%, CI = 0.56-0.98), taking enrichment lessons (0.62, 0.46-0.85), using a personal computer (0.68, 0.48-0.97), participation in events at the community center (0.54, 0.40-0.72), and attending a community meeting (0.69, 0.52-0.92) were independently associated with lower risk of increased depressive symptoms. In a separate analysis for each gender, significant odds ratios of using a personal computer were observed in men, whereas significant odds ratios of light physical exercise, participation in events at the community center, and attending a community meeting were observed in women. CONCLUSIONS: Light physical exercise, taking lessons, usage of a computer, and participation in community events showed protective effects against depressive symptoms. However, the significance of each behavioral factor may vary according to gender.

[The association of limited health literacy and risk of arterial stiffness in community-dwelling older adults].

AIM: This study aimed to investigate the effects of limited health literacy on arterial stiffness measured by the cardio-ankle vascular index (CAVI) in community-dwelling older adults. METHODS: A total of 288 older adults (mean age, 72.4 years, men, n = 99) participated. The degree of arterial stiffness was assessed based on the CAVI using the VS-1500 device (Fukuda Denshi Co., Ltd., Tokyo, Japan). Arterial stiffness was defined according to a cut-off point of ≥9.0. Comprehensive health literacy was assessed using the 47-item European Health Literacy Survey Questionnaire (HLS-EU-Q47). Other potential confounding factors, such as demographics, number of prescribed medications, mini-mental state examination results, grip strength, gait speed, current smoking, alcohol consumption, and physical inactivity, were also assessed. An analysis of variance for continuous variables or chi-square test for categorical variables was used for group comparisons. A logistic regression analysis was performed to examine the association between quartiles of HLS-EU-Q47 and arterial stiffness in crude and multivariate models adjusted for age, gender, and other confounding factors. RESULTS: The first quartile with the lowest health literacy showed a significantly higher CAVI and prevalence of arterial stiffness than the fourth quartile with the highest health literacy (p<0.05). In logistic regression, the crude model showed that the third quartile (odds ratio [95% confidence interval] = 0.48 [0.24-0.93]) and fourth quartile (0.39 [0.19-0.77]) were significantly associated with arterial stiffness, while the multivariate model showed that to fourth quartile was significantly associated with arterial stiffness (0.44 [0.19-0.98]). CONCLUSIONS: Older adults with limited health literacy might be at a higher risk of arterial stiffness after accounting for confounding factors.

Performance on the flanker task predicts driving cessation in older adults.

OBJECTIVES: This study examined the predictive validity of flanker tasks on driving cessation in older drivers. The flanker task comprises a set of response inhibition tests used to assess the ability to suppress responses. METHODS: A total of 2805 older drivers aged ≥65 years at baseline participated in this study. We conducted several baseline assessments focused on physical and psychological health as well as cognitive performance. Fifteen months after the baseline measurements, we collected information about the current driving status of the participants. RESULTS: Forty-eight participants (1.7%) ceased driving during the 15-month period following the assessment. Logistic regression models identified the following as significant predictors of driving cessation: performance on the trail-making test (parts A and B), digit symbol substitution test scores, story memory, and flanker task scores for the total, congruent, and incongruent conditions. The flanker task scores for the total, congruent, and incongruent conditions were significant predictors in the fully adjusted logistic model. CONCLUSION: The flanker task was more important than assessments of general cognition, including memory, attention, executive control, and processing speed, in predicting driving cessation. The flanker task may be useful for identifying driving cessation in older adults.

Reduced prefrontal oxygenation in mild cognitive impairment during memory retrieval.

BACKGROUND: Memory impairment is considered a hallmark of amnestic mild cognitive impairment (aMCI) and dementia. Emerging evidence suggests that the prefrontal lobe is required to maintain memory functions. The purpose of this study was to clarify whether older adults with aMCI have decreased prefrontal oxygenation during memory encoding and retrieval compared with age-matched healthy older adults, using multi-channel near-infrared spectroscopy. METHODS: We examined 64 older adults with aMCI (mean 71.8 years) and 66 cognitively healthy control subjects comparable in age and gender (mean 71.7 years). The concentration of oxy-hemoglobin, which is a reliable biomarker of changes in regional cerebral blood flow, was measured in the prefrontal cortex during encoding and delayed retrieval of a list of 10 target words. Task performance was evaluated as average number of correct answers in the retrieval task. RESULTS: Subjects with aMCI showed reduced activation in the bilateral dorsolateral cortex (approximately Brodmann area 9) and provided fewer correct answers in the retrieval period than control subjects. There were no significant differences during encoding. CONCLUSIONS: Reduced activation in the dorsolateral cortex during retrieval may cause deficits in memory performance, which may be used as a marker of aMCI. Further studies are required to examine the predictive validity of this decreased activation pattern for the incidence of Alzheimer's disease.

Age differences in reactive strategies and execution time during choice stepping with visual interference.

PURPOSE: We aimed to explore the effects of visual interference from a flanker task on a reactive strategy and execution speed of choice stepping among young and older adults. METHODS: Twenty-two healthy young (21.9 ± 1.4 years) and 21 older participants (72.6 ± 4.9 years) 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 during a neutral condition. During a flanker condition, participants were additionally required to ignore flanker arrows on each side of the central arrow (→→→→→ congruent or incongruent →→←→→). Errors in the direction of the initial weight transfer [anticipatory postural adjustment (APA) errors], step execution time, and divided phases (reaction, APA, and swing phases) were measured from the data of vertical force. RESULTS: Incongruence had larger effects on step execution times and APA phase in older adults than in young adults, while incongruence had smaller effects on reaction phase in older adults than in young adults. Step execution times were prolonged for trials with APA errors relative to trials without those in both groups. Only older adults showed that step execution times during trials with APA errors increased prominently in the incongruent condition as compared to the other conditions. CONCLUSION: Older adults might have a tendency to make hastier judgments, and might be vulnerable to potential motor program errors caused by an interference effect. Composite measurement of inhibition and stepping in a functional context may increase discriminative ability for age-related deficits in postural control.

Analysis of Choice Stepping with Visual Interference Can Detect Prolonged Postural Preparation in Older Adults with Mild Cognitive Impairment at High Risk of Falling.

BACKGROUND/AIMS: We aimed to clarify postural control deficits in older adults with mild cognitive impairment (MCI) at high risk of falling by addressing the inhibitory process. METHODS: This study involved 376 community-dwelling older adults with MCI. Participants were instructed to execute forward stepping on the side indicated by the central arrow while ignoring the 2 flanking arrows on each side (→→→→→, congruent, or →→←→→, incongruent). Initial weight transfer direction errors [anticipatory postural adjustment (APA) errors], step execution times, and divided phases (reaction, APA, and swing phases) were measured from vertical force data. Participants were categorized as fallers (n = 37) and non-fallers (n = 339) based on fall experiences in the last 12 months. RESULTS: There were no differences in the step execution times, swing phases, step error rates, and APA error rates between groups, but fallers had a significantly longer APA phase relative to non-fallers in trials of the incongruent condition with APA errors (p = 0.005). Fallers also had a longer reaction phase in trials with the correct APA, regardless of the condition (p = 0.01). CONCLUSION: Analyses of choice stepping with visual interference can detect prolonged postural preparation as a specific falling-associated deficit in older adults with MCI.

Olfactory identification and cognitive performance in community-dwelling older adults with mild cognitive impairment.

Olfactory impairment constitutes one of the earliest signs of Alzheimer's disease in older adults with mild cognitive impairment. We investigated which aspects of neuropsychological measures are correlated with olfactory identification performance among older adults with mild cognitive impairment. Total of 220 participants with mild cognitive impairment (mean age 71.7 years) were examined. Odor identification was assessed using the Open Essence test. Participants underwent comprehensive neurocognitive evaluation, including measures of verbal memory, visual memory, working memory, attention/executive function, and processing speed. We examined associations between olfactory function and cognitive performance scores. Participants with severe hyposmia exhibited significantly poor verbal and visual memory performance, attention/executive function, and slower processing speed scores compared with those without severe hyposmia. In multivariable logistic regression models, better performance scores on verbal and visual memory were significantly associated with decreased likelihood of severe hyposmia after adjusting for age, sex, education, and other cognitive performance scores. These findings suggest that olfactory impairment might be more closely associated with memory loss compared with other aspects of cognitive functioning in mild cognitive impairment subjects.

Cognitive function and gait speed under normal and dual-task walking among older adults with mild cognitive impairment.

BACKGROUND: Gait ability and cognitive function are interrelated during both normal walking (NW) and dual-task walking (DTW), and gait ability is thus adversely affected by cognitive impairment in both situations. However, this association is insufficiently understood in people with mild cognitive impairment (MCI). Here, we conducted a study with MCI participants, to examine whether the association depends on walking conditions and MCI subtypes. METHODS: We classified 389 elderly adults into amnestic MCI (n = 191) and non-amnestic MCI (n = 198), assessed their cognitive functions, and administered gait experiments under NW and DTW conditions. Gait ability was defined as gait speed. Five aspects of cognitive function were assessed: processing speed, executive function, working memory, verbal memory, and visual memory. RESULTS: Regression analysis adjusted for covariates showed a significant association between cognitive functions and gait speed. Processing speed and executive function correlated with gait speed during both NW and DTW (p < .05). Gait speed during DTW was also significantly associated with working memory (p < .001). Visual memory was associated during NW and DTW, particularly for amnestic MCI participants (p < .05). CONCLUSIONS: Our findings support the idea that the association between gait speed and cognitive function depends on walking condition and MCI subtypes. Additional studies are necessary to determine the neural basis for the disruption in gait control in older adults with MCI.

Self-reported Exhaustion is Associated with Small Life Space in Older Adults with Mild Cognitive Impairment.

[Purpose] Older adults experience exhaustion-induced health problems, such as poor physical function and low physical activity levels. The associations between self-reported exhaustion and physical function and activity are not clear in older adults with mild cognitive impairment (MCI). The aim of this study was to investigate the relationships between self-reported exhaustion and physical function and activity in older adults with mild cognitive impairment. [Subjects] A total of 356 older adults with mild cognitive impairment (mean age = 71.6 ± 0.3 years, 50.8% women) were included in this study. [Methods] Self-reported exhaustion was identified by one item from the Study of Osteoporotic Fractures index. Gait speed, gait endurance, and life space were also assessed. [Results] Sixty-two participants reported having exhaustion, giving a 17.4% prevalence of self-reported exhaustion among these individuals. Logistic regression analysis showed that the Life-Space Assessment score was the only parameter significantly independently associated with exhaustion status (adjusted odds ratio 0.97, 95% confidence interval 0.95-0.99). [Conclusion] These results suggest that self-reported exhaustion is associated with life space. Future research is needed to identify ways for older people with MCI to improve their exhaustion status.

Poor balance and lower gray matter volume predict falls in older adults with mild cognitive impairment.

BACKGROUND: The risk of falling is associated with cognitive dysfunction. Older adults with mild cognitive impairment (MCI) exhibit an accelerated reduction of brain volume, and face an increased risk of falling. The current study examined the relationship between baseline physical performance, baseline gray matter volume and falls during a 12-month follow-up period among community-dwelling older adults with MCI. METHODS: Forty-two older adults with MCI (75.6 years, 43% women) underwent structural magnetic resonance imaging and baseline physical performance assessment, including knee-extension strength, one-legged standing time, and walking speed with normal pace. 'Fallers' were defined as people who had one or more falls during the 12-month follow-up period. RESULTS: Of the 42 participants, 26.2% (n = 11) experienced at least one fall during the 12-month follow-up period. Fallers exhibited slower walking speed and shorter one-legged standing time compared with non-fallers (both p < .01). One-legged standing time (sec) (standardized odds ratio [95% confidence interval]: 0.89 [0.81, 0.98], p = .02) was associated with a significantly lower rate of falls during the 12-month follow-up after adjusting for age, sex, body mass index, and history of falling in the past year at baseline. Voxel-based morphometry was used to examine differences in baseline gray matter volume between fallers and non-fallers, revealing that fallers exhibited a significantly greater reduction in the bilateral middle frontal gyrus and superior frontal gyrus. CONCLUSIONS: Poor balance predicts falls over 12 months, and baseline lower gray matter densities in the middle frontal gyrus and superior frontal gyrus were associated with falls in older adults with MCI. Maintaining physical function, especially balance, and brain structural changes through many sorts of prevention strategies in the early stage of cognitive decline may contribute to decreasing the risk of falls in older adults with MCI.

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.

Brain activation during dual-task walking and executive function among older adults with mild cognitive impairment: a fNIRS study.

BACKGROUND AND AIMS: Dual-task walking (DTW) is thought to involve activation of the prefrontal cortex in healthy adults and to be affected by cognitive impairment. However, it is unclear whether prefrontal cortex activation is involved in DTW in older adults with mild cognitive impairment. This study examined brain activation during DTW among older adults with mild cognitive impairment using functional near-infrared spectroscopy. METHODS: Sixteen older adults (aged 75.4 ± 7.2 years, women n = 6) performed gait experiments under normal walking and DTW conditions. We used a design with 60-s blocks consisting of a 10-s rest standing as pre-resting period, a 20-s walking task period, and a 30-s rest standing as post-resting period. Walking speed was measured during a 20-s walking task. Changes in oxy-hemoglobin were measured in the prefrontal area during gait experiments. RESULTS: Walking speed was slower during DTW compared with normal walking (p < 0.001). The oxy-hemoglobin level during DTW was higher than during normal walking (p < 0.001) and was correlated with executive function, as measured by Stroop interference (p < 0.05). CONCLUSION: Our findings indicate that DTW is associated with prefrontal activation among older adults with mild cognitive impairment. The brain activation during DTW was correlated with executive function. Additional studies are necessary to elucidate the effects of cognitive impairment on the association between prefrontal activity and walking under various conditions.

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.

Frailty and Environmental Attributes in Older Adults: Insight from an Ecological Model.

Many studies on frailty have primarily focused on individual-level risk factors such as demographics and lifestyle. While guidelines for frailty management recommend modifications to an individual's lifestyle, their lifestyle behaviors are significantly influenced by their surroundings. Recently, the association between frailty and environmental attributes has drawn attention as a result of the increase in evidence that multiple factors affect health conditions and behaviors associated with frailty. These findings can be organized based on an ecological model involving five nested levels that influence an individual's behaviors, namely, an intrapersonal/individual core (age, education, and attitude), an interpersonal level (persons and groups), an organizational/institutional level (organization and workplace), a community level (natural, built, and social environments), and a system/public policy level (public policies from local to national). This study reviewed possible factors associated with frailty from the onset and its progression at each level of the ecological model and their implications regarding frailty prevention. Additionally, we introduce a policy-level approach for frailty prevention in Japan-which encourages residents to engage in the local society by participating in community places or groups that are referred to as "Kayoi-no-ba"-and aggregate its status from a government report. This perspective on community building is consistent with the concept of an ecological model. However, few studies have verified the effects of policy- or system-level approaches on disability and frailty prevention. Further studies from an ecological perspective are needed to fulfill multilevel interventions for frailty prevention.