International / domestic magazine：International journal  

OBJECTIVES: This study aimed to investigate the additive effects of sarcopenia and low serum albumin level on the risk of incident disability in older adults. DESIGN: Prospective cohort study. SETTING: A Japanese community. PARTICIPANTS: Community-dwelling older adults aged ≥65 years, without disability at baseline (N = 4452). MEASURES: Sarcopenia was defined as the presence of both poor muscle function (low physical performance or muscle strength) and low muscle mass. Low serum albumin level was defined as ≤4.0 g/dL. Other potential confounding factors (demographics, medical history, depressive symptoms, and cognitive function) were also assessed. Incident disability was monitored based on Long-Term Care Insurance certification during follow-up. RESULTS: The median follow-up duration was 30 (interquartile range, 28-32) months. Participants were classified into mutually exclusive groups based on sarcopenia status and serum albumin levels: nonsarcopenia/normal serum albumin (n = 3719), low serum albumin alone (n = 552), sarcopenia alone (n = 132), and sarcopenia/low serum albumin (n = 49). A Cox hazards regression showed that the low serum albumin alone [hazard ratios (HR) = 1.71, 95% confidence interval (CI) = 1.26-2.33], sarcopenia alone (HR = 2.74, 95% CI = 1.58-4.77), and sarcopenia/low serum albumin groups (HR = 3.73, 95% CI = 1.87-7.44) had higher risk of disability than the nonsarcopenia/normal serum albumin group after adjusting for the covariates. CONCLUSIONS/IMPLICATIONS: Sarcopenia and low serum albumin level synergistically increase the risk of incident disability in older adults. Sarcopenia in older adults at risk of malnutrition should be detected early, and appropriate interventions should be implemented.

DOI： 10.1016/j.jamda.2018.06.011

PubMed

DOI： 10.1111/jgs.15458

PubMed

This study aimed to identify the learning requirements of nurses practicing diabetic foot care. Semi-constructive interviews were conducted with 15 nurses who had completed appropriate training in the teaching of diabetic foot lesion care and who were involved in the foot care of patients with diabetes at a medical institution. The obtained data were qualitatively and descriptively analyzed. Five categories of learning needs were generated: biomechanics-based foot care, assessment skills in foot care practice, techniques to facilitate multidisciplinary collaboration, direct foot care techniques performed on patients, and developing new educational tools to deepen learning. Our findings suggest learning needs that could not be fulfilled by conventional training programs alone. Thus, participants may feel a gap between the skills and abilities they acquired during training and those required in the field. Therefore, to address the complex and diverse needs of patients with diabetic foot lesions in the future, establishing an educational system that incorporates the perspectives of physical therapists, prosthetists, and other professionals, and also utilizes audiovisual aids and other educational materials is necessary.

DOI： 10.34466/jjsfcpm.4.2_100

International / domestic magazine：Domestic journal  

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.

DOI： 10.1298/ptr.R0027

PubMed

Publishing type：Research paper (scientific journal)  

Society today is facing a rapidly aging population. While various monitoring systems have been proposed for protecting elderly persons in their daily lives, concerns relating to privacy limit the effectiveness of these systems. In response to this issue, we investigate the use of Doppler radar images for monitoring the elderly, as these images are known to protect privacy very well. As the first step, we investigate the use of Doppler radar images for the gender classification of the elderly. We used sit-to-stand Doppler radar images of elderly persons, obtained eleven groups of images through image processing, and applied five state-of-the-art deep learning models to classify the gender. The classification results revealed a classification accuracy rate as high as 90%, which indicates that sit-to-stand Doppler radar images of the elderly can indeed reflect their gender to a certain extent.

DOI： 10.1007/s00779-020-01490-4

Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

BACKGROUND: Older adults, especially those with cognitive decline, often have poor gait performance, which results in poor clinical outcomes due to falls or decreased daily physical activity. The effects of various exercises on gait performance have been studied, whereas the short-term and long-term effects of different exercise modalities remain unknown. OBJECTIVE: To compare the short- and long-term effects of aerobic training (AT), resistance training (RT), and combined training (CT) on the gait performance of community-dwelling older adults with subjective cognitive decline (SCD). DESIGN: A four-arm, randomized controlled trial. SETTING AND SUBJECTS: 388 community-dwelling older adults with SCD (mean age, 72.3 years). METHODS: Participants attended an exercise or education class twice a week for 26 weeks. 10 gait performance parameters were examined at baseline, post-intervention (Week 26), and after 26 weeks of follow-up (Week 52) using an electronic walkway system. RESULTS: The mean adherence of exercise sessions was 82.5 to 85.9%. All exercise intervention induced an improvement in gait speed, stride time, cadence, stride length, and double-support time at Week 26 (p < .05), without significant intergroup differences among exercise interventions. However, only RT showed a significant effect on some spatiotemporal gait parameters at Week 52. The analyses for the gait variability parameters showed mild effects of all exercise interventions. CONCLUSION: All of the exercise programs examined had a positive short-term effect on spatiotemporal gait parameters of older adults with SCD, despite no effect on gait variability parameters. RT are most recommended when long-lasting effects are the primary aim.

DOI： 10.1016/j.exger.2021.111590

PubMed

International / domestic magazine：Domestic journal  

DOI： 10.1111/ggi.14281

PubMed

Publishing type：Research paper (scientific journal)   International / domestic magazine：Domestic journal  

AIM: We examined the effects of active learning education on arterial stiffness and physical activity of community-dwelling older adults with low health literacy. METHODS: This study is a secondary analysis of randomized controlled trial of 60 participants aged 65 and older with low health literacy. The intervention group (n=30) participated in a weekly 90-minute active learning program session for 24 weeks, which addressed health promotion in older age. The control group (n=30) attended a 90-minute health education class in a didactic manner. The outcomes were measured at baseline and in week 24. The degree of arterial stiffness was assessed based on the cardio-ankle vascular index (CAVI) using the VS-1500 device (Fukuda Denshi Co., Ltd., Tokyo, Japan). The shortened version of the self-reported International Physical Activity Questionnaire was used to assess the amount of total physical activity determined by the metabolic equivalent hours per week. We used analysis by intention-to-treat, with multiple imputation for missing data. RESULTS: Seven participants (11.7%) dropped out prior to the post-intervention assessment. The multiple imputation analysis revealed that the intervention group showed significant improvement in CAVI [between-groups difference (95% confidence interval)=-0.78 (-1.25 to -0.31), Cohen's d=0.82] and physical activity [32.5 (0.3 to 64.7), Cohen's d=0.57] as compared with the control group. The sensitivity analysis for the complete cases showed similar results. CONCLUSION: Active learning health education may be effective in improving arterial stiffness and physical activity in older adults with low health literacy.

DOI： 10.5551/jat.58354

PubMed

Publishing type：Research paper (scientific journal)  

To develop daily monitoring systems that can identify elderly people with cognitive functioning and health literacy impairments, this study examined elderly participants during the sit-to-stand (STS) movement by using a Doppler radar to gather kinematic information for assessing any associations between those data and factors related to both cognitive functioning and health literacy. More specifically, we used Doppler radar systems to measure kinematic parameters related to the STS movement among 170 community-dwelling elderly participants aged 65 years and older, who were classified into good or bad health literacy groups and cognitive-healthy or cognitive- impairment groups based on the results of conventional paper-based tests designed to assess health literacy and cognitive functioning, respectively. The Doppler radar measured kinematic parameters for not only velocity, acceleration, and jerk (the time derivative of acceleration), but also higher-order derivative parameters: snap (the time derivative of jerk) and crackle (the time derivative of snap). Intergroup differences between the measured kinematic parameters were then compared using Welch;s t-test. The results revealed that health literacy impairments were associated with velocity, acceleration, and jerk, while cognitive impairments were associated with the higher-order derivative parameters, snap and crackle. These findings show that the Doppler radar is an effective tool to distinguish impairments between health literacy and cognitive functioning based on the extraction of higher-order derivative parameters during the STS movement. The results should lead to the development of unconstrained monitoring systems that can detect early signs of impairments in both cognitive functioning and health literacy among the elderly.

DOI： 10.1109/JSEN.2021.3060050

Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

PURPOSE: This study addressed a two-part question. First, is cognitive decline associated with fear of falling (FoF)? Second, if this association is observed, is there also an association between FoF and physical activity (PA) independent of cognitive decline? METHODS: Participants in the study were community-dwelling Japanese residents between 65 and 85 years of age (N = 458, mean age = 72.4 ± 4.6, male = 53.7%). Step counts were recorded, as was objectively measured PA, divided into (1) low-intensity PA and (2) moderate- and vigorous-intensity PA. Three groups were determined based on FoF: low, moderate, and high. Neuropsychological tests were also conducted. RESULTS: Participants with high FoF had slower processing speed. low-intensity PA was associated with only high FoF, but after controlling for processing speed, the significance of this association was attenuated. Shorter time of moderate- and vigorous-intensity PA was associated with high FoF, even in the full model controlling for other factors. All FoF levels were associated with lower step counts. CONCLUSION: older community-dwelling adults with high FoF were found to have had declined cognitive speed/ Second, both moderate and high FoF were associated with moderate- and vigorous-intensity PA and step counts in older community-dwelling adults, with the high FoF group performing shorter time of moderate- and vigorous-intensity PA and fewer steps.

DOI： 10.1007/s41999-020-00410-2

PubMed

Publishing type：Research paper (scientific journal)  

<b>Aim: </b>To investigate the longitudinal association between health literacy and frailty status at two-year follow-up in community-dwelling older adults.

<b>Methods: </b>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).

<b>Results: </b>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.

<b>Conclusions: </b>Older adults with higher comprehensive health literacy are less likely to be frail at two-year follow-up than those with a lower literacy.

DOI： 10.3143/geriatrics.58.101

PubMed

CiNii Article

Publishing type：Research paper (scientific journal)  

This paper presents a Doppler radar apathy-screening technique applied to elderly people based on their basic daily activities of walking and movements of sit-to-stand and stand-to-sit (STS). Our Doppler radar system remotely measured the kinematic parameters of the movements of 78 community-dwelling elderly adults (27 apathetic participants and 51 non-apathetic ones). Subsequently, logistic regression models using the measured kinematic parameters of gait and sit-to-stand/stand-to-sit movements were constructed for screening. The experimental results verified that, although the model using gait parameters could screen an apathetic group with a sensitivity of 85.2% and a specificity of 58.8%, the model using the STS parameters achieved better screening accuracies with a sensitivity of 88.9% and a specificity of 76.5%. These results reveal that the kinematic information of STS movements is significantly more effective at detecting apathy than is the gait information, which is otherwise regarded to be effective in conventional epidemiological studies.

DOI： 10.1177/1460458221990051

Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

BACKGROUND: Physical exercise is suggested to be effective for preventing cognitive decline in older adults, but the relative efficacy of different types of exercise have yet to be clarified. OBJECTIVE: This single-blinded randomized controlled trial was designed to investigate the differential effects of aerobic exercise training (AT), resistance exercise training (RT), and combined exercise training (CT) on cognition in older adults with subjective memory complaints (SMC). METHODS: Community-dwelling older adults with SMC (n = 415; mean age = 72.3 years old) were randomly assigned to one of the four groups: AT, RT, CT, or control group. The study consisted of two phases: a 26-week intervention and a 26-week follow-up. The participants were evaluated at baseline, 26 weeks (postintervention), and 52 weeks (follow-up). The primary outcome of this study was memory function, which was assessed using the Logical Memory II subtest of the Wechsler Memory Scale-Revised (WMS-R) score. The secondary outcomes included global cognitive function, verbal fluency, working memory, processing speed, and executive functions. RESULTS: Intention-to-treat analysis by a mixed-effect model repeated measure showed that the AT group had significantly improved performance on the WMS-R Logical Memory II test (2.74 [1.82-3.66] points) than the control group (1.36 [0.44-2.28] points) at the postintervention assessment (p = 0.037). The effect was more pronounced in those without amnesia than those with amnesia. No significant improvement was observed in the RT and CT groups. CONCLUSION: This study suggests that AT intervention can improve delayed memory in community-dwelling older adults, particularly in individuals without objective memory decline.

DOI： 10.3233/JAD-210047

PubMed

Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

OBJECTIVES: Physical activity is associated with improvement in overall health and well-being, but robust evidence with comprehensive assessment of general health is lacking. This study aimed to clarify the effects of physical activity on intrinsic capacity among community-dwelling older adults with subjective memory concerns. DESIGN: A single-blind randomized controlled trial compared aerobic training (AT), resistance training (RT), and combined training (AT+RT) programs for improving general health evaluated by intrinsic capacity. SETTING: Toyota, Japan. PARTICIPANTS: Residents (65-85 years old) who screened positive for subjective memory concerns using the Kihon checklist were invited for eligibility assessment. In total, 415 community-dwelling older adults were enrolled and randomized into the AT, RT, AT+RT, and control groups. METHODS: 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. Intrinsic capacity (IC), constructed based on locomotion, cognition, psychological function, and vitality domains, was used to assess general health at baseline, week 26, and week 52. Between-group differences were exhibited with Z-score change in individual domain and combination of all domains. RESULTS: At baseline, mean age of all participants (47% women) was 72.3 ± 4.6 years, with a mean composited IC Z-score of -0.2 ± 0.5. Overall, AT and RT improved composite IC Z-scores by 0.17 (95% confidence interval [CI] 0.03-0.30) and 0.17 (95% CI 0.05-0.28) at week 26, respectively, but the beneficial effects waned at week 52. No significant differences in composite IC Z-scores were found in the AT+RT group at weeks 26 and 52. CONCLUSIONS AND IMPLICATIONS: Twenty-six-week AT with self-paced home training and RT with self-paced home training improve IC among community-dwelling older adults with subjective memory concerns, but the benefits waned subsequently. It will be required to develop optimal interventions that have a continuous beneficial effect on IC among community-dwelling older adults.

DOI： 10.1016/j.jamda.2020.06.048

PubMed

Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

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.

DOI： 10.1093/ageing/afaa086

PubMed

Publishing type：Research paper (scientific journal)  

DOI： 10.1587/COMEX.2019XBL0136

Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

Frailty has been established as a risk factor for falls, and prefrailty also seems a risk; however, few studies have focused on the association between falls and each of the five components of frailty proposed by Fried. In the present study, we sought to elucidate the association between prefrailty and falls, and moreover, the association of frailty component with falls. Participants were community-dwelling older people who had cognitive complaints but not dementia (N = 447, male 54.6%). Prefrailty was defined as exhibiting one or two of the five Fried criteria. Frail individuals were excluded. Background characteristics were compared between the prefrail and robust groups, and multiple regression analysis was performed to investigate the associations between fall history within the past year and factors that were significantly different between the groups. We also performed logistic regression analysis with adjustment for age, education and gender to assess associations with frailty components. We found that prefrailty was associated with fall history. Depressed mood was also significantly associated with fall history. Among the five frailty criteria, exhaustion was significantly associated with falls. Prefrailty, especially the criteria of exhaustion, and depressed mood were associated with fall history.

DOI： 10.1111/hsc.12845

PubMed

Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

This paper presents an evaluation technique for higher-level instrumental activities of daily living (HL-IADLs), which are defined as relatively complicated modern daily activities to perform independently, using micro-Doppler radar (MDR) signatures of sit-to-stand-to-sit (STSTS) movements. Because HL-IADLs are useful for evaluating the degree of disability and cognitive decline in daily life, this study aims to develop a system that enables the identification of individuals with HL-IADL impairments in an unconstrained manner. The study participants were elderly adults of age 65-74 years of rural communities in Japan, and their motion parameters in natural STSTS were extracted via a single 24-GHz MDR installed on the ceiling. Their HL-IADLs were evaluated using a questionnaire-based scale called the Japan Science and Technology Agency Index of Competence (JST-IC). The relationship between the HL-IADLs scaled with the JST-IC and the extracted STSTS parameters were statistically analyzed, and the results revealed that the extracted parameters were associated with the JST-IC score. Furthermore, an appropriately accurate screening method was verified for elderly adults with HL-IADL impairment using the extracted parameters.

DOI： 10.1109/JTEHM.2020.2964209

PubMed

Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

Apathy is a disease characterized by diminished motivation not attributable to a diminished level of consciousness, cognitive impairment, or emotional distress. It is a serious problem facing the elderly in today's society. The diagnosis of apathy needs to be done at a clinic, which is particularly inconvenient and difficult for elderly patients. In this work, we examine the possibility of using doppler radar imaging for the classification of apathy in the elderly. We recruited 178 elderly participants to help create a dataset by having them fill out a questionnaire and submit to doppler radar imaging while performing a walking action. We selected walking because it is one of the most common actions in daily life and potentially contains a variety of useful health information. We used radar imaging rather than an RGB camera due to the greater privacy protection it affords. Seven machine learning models, including our proposed one, which uses a neural network, were applied to apathy classification using the walking doppler radar images of the elderly. Before classification, we perform a simple image pre-processing for feature extraction. This pre-processing separates every walking doppler radar image into four parts on the vertical and horizontal axes and the number of feature points is then counted in every separated part after binarization to create eight features. In this binarization, the optimized threshold is obtained by experimentally sliding the threshold. We found that our proposed neural network achieved an accuracy of more than 75% in apathy classification. This accuracy is not as high as that of other object classification methods in current use, but as an initial research in this area, it demonstrates the potential of apathy classification using doppler radar images for the elderly. We will examine ways of increasing the accuracy in future work.

DOI： 10.3389/fbioe.2020.553847

PubMed

【目的】介護予防を目的としたアクティブ・ラーニング型健康教育介入を地域で実践し、実行可能性と介入効果を検証することとした。【方法】対象は地域在住高齢者25名とし、週1回90分、12週間の教育介入を行い、調査学習などを通じて健康行動を促進した。事前に作成したテキストに沿って学習を進め、教室の進行はファシリテーターとして養成された高齢者が担当した。効果判定指標として、身体・認知機能、身体活動量、ヘルスリテラシーを評価した。【結果】22名(88%)が介入を完遂し、出席率は中央値91.7%で、全員が内容に「満足」または「大変満足」と回答した。歩行速度、認知機能(処理速度・言語流暢性)、平均歩数、機能的ヘルスリテラシー得点に有意な改善が認められた(p<0.05)。【結論】住民主体によるアクティブ・ラーニング型教育介入の実行可能性は良好であり、生活習慣や心身機能の改善に有効であることが示唆された。(著者抄録)

Other URL： https://search-tp.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2019&ichushi_jid=J01747&link_issn=&doc_id=20190829420008&doc_link_id=%2Fcb3physi%2F2019%2F004604%2F008%2F0275-0282%26dl%3D0&url=https%3A%2F%2Fwww.medicalonline.jp%2Fjamas.php%3FGoodsID%3D%2Fcb3physi%2F2019%2F004604%2F008%2F0275-0282%26dl%3D0&type=MedicalOnline&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00004_2.gif

Publishing type：Research paper (scientific journal)  

DOI： 10.1111/ggi.13651

PubMed

Other URL： https://onlinelibrary.wiley.com/doi/full-xml/10.1111/ggi.13651

&lt;p&gt;&lt;b&gt;Purpose&lt;/b&gt;: To investigate the association between bioelectrical impedance analysis (BIA) derived-phase angle and physical activity level in community-dwelling older adults.&lt;/p&gt;&lt;p&gt;&lt;b&gt;Methods&lt;/b&gt;: A total of 295 older adults (mean age, 72.5 years, men, n=98) participated in this study. Phase angle and muscle mass were examined using a multi-frequency BIA. A tri-axial accelerometer was used to obtain daily physical activity data for 2 weeks. The average number of steps and physical activity level (PAL) were measured. Grip strength and gait speed were also assessed as potential confounding factors. A linear regression model was used to determine whether physical activity was independently associated with phase angle after adjusting for confounding factors.&lt;/p&gt;&lt;p&gt;&lt;b&gt;Results&lt;/b&gt;: In the multivariate linear regression model, PAL was significantly positively correlated with phase angle after adjusting for age, muscle mass, grip strength, and gait speed in both male (&lt;i&gt;β&lt;/i&gt; = 0.21) and female subjects (&lt;i&gt;β &lt;/i&gt;= 0.21), whereas the average number of steps was significantly positively correlated with phase angle only in female subjects (&lt;i&gt;β&lt;/i&gt; = 0.15).&lt;/p&gt;&lt;p&gt;&lt;b&gt;Conclusions&lt;/b&gt;: Older adults with higher PAL are more likely to have higher phase angle, indicating greater cellularity, cell membrane integrity, and function.&lt;/p&gt;

CiNii Article

本論文では、マイクロドップラーレーダを用いた健常な若年者と高齢者の歩容判別法を提案する。レーダ信号から抽出される両被験者群間の有意差を示す歩行速度パラメータを選択し、Support Vector Machine(SVM)を用いる方法により、両群を高精度で判別できることを実証した。(著者抄録)

Publishing type：Research paper (scientific journal)  

DOI： 10.1109/ACCESS.2019.2900303

&lt;p&gt;&lt;b&gt;Aim: &lt;/b&gt;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.&lt;/p&gt;&lt;p&gt;&lt;b&gt;Methods: &lt;/b&gt;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.&lt;/p&gt;&lt;p&gt;&lt;b&gt;Results: &lt;/b&gt;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&lt;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]).&lt;/p&gt;&lt;p&gt;&lt;b&gt;Conclusions: &lt;/b&gt;Older adults with limited health literacy might be at a higher risk of arterial stiffness after accounting for confounding factors.&lt;/p&gt;

CiNii Article

Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

AIMS: The main objective of this study was to determine the association between objectively measured physical activity (PA) and cardiometabolic risk factors, particularly insulin resistance (IR), in Japanese community-dwelling older adults without diabetes mellitus. METHODS: Daily PA was measured by accelerometers in 388 community-dwelling older adults. IR was determined using homeostasis model assessment of insulin resistance (HOMA-IR). Regression analyses adjusted by age and sex were performed to determine the association of light-intensity PA (LPA), moderate-to-vigorous PA (MVPA), or total steps per day with cardiometabolic risk factors. Then, multiple regression analysis was performed with HOMA-IR as an independent variable and those factors with p < 10% in the regression analysis as explanatory variables. RESULTS: Objectively measured LPA was negatively associated with systolic blood pressure, diastolic blood pressure, waist circumference, body mass index, and triglyceride (TG) and positively associated with high-density lipoprotein cholesterol (HDL-C). LPA was also negatively associated with IR. Total steps per day also had significant association with IR. MVPA was associated with TG, HDL-C, and IR. Multiple regression analysis showed that the association between LPA and IR was independent of other covariates, whereas that between MVPA and IR was lost after adjustment for other covariates. CONCLUSION: IR was associated with LPA or total steps, but not with MVPA, in community-dwelling older adults without diabetes mellitus.

DOI： 10.1016/j.diabres.2018.07.022

PubMed

【目的】アクティブ・ラーニング型教育介入のフレイル予防に向けた効果を検証することとした。【方法】対象は地域在住高齢者84名とし、介入群と対照群にランダムに割りつけた。介入群には、週1回90分、24週間の教育介入を行い、調査学習などを通じて健康行動を促進した。効果判定指標は、メンタルヘルス、身体機能、ライフスタイル関連要因、プレフレイルの有無とした。【結果】脱落を除く79名を分析対象とした。Apathy Scale、歩行速度、5回椅子立ち座りテスト、身体活動量、食品摂取多様性得点、健康管理に対するセルフエフィカシー得点に時間と群の有意な交互作用が認められ(p&lt;0.05)、介入群では対照群に比較して改善した。また、介入群でのみ、プレフレイルの割合が有意に減少した。【結論】アクティブ・ラーニング型教育介入は、意欲向上、ライフスタイル変容、および身体機能改善に有効であり、フレイル予防に寄与することが示唆された。(著者抄録)

International / domestic magazine：International journal  

OBJECTIVES: Whether sarcopenia predicts incident homebound status remains unclear. This prospective cohort study aimed to determine the impact of sarcopenia on the incidence of homebound status in community-dwelling older adults. METHODS: The study included 3958 community-dwelling elderly people aged ≥65 years who were not homebound at baseline. Sarcopenia was defined as the presence of both poor muscle function (low physical performance or low muscle strength) and low muscle mass. Potential confounding factors, such as physical status, mental status, and level of social participation, were also assessed. Fifteen months after the baseline measurements, data regarding the incidence of homebound status were obtained using a postal survey. RESULTS: In the 15-month follow-up survey, 83 participants (2.1%, 95% confidence interval = 1.6-2.5) were reported to have become homebound. A multiple logistic regression analysis indicated that age (odds ratio = 1.06, 95% confidence interval = 1.02-1.10), sarcopenia (1.98, 1.04-3.77), and limited contact with friends (1.82, 1.03-3.23) were independently associated with an increased risk of becoming homebound. In a stratified analysis for age group, a significant odds ratio for low level of social role (2.50, 1.06-5.91) was observed in young-old subjects (aged 65-74 years), whereas significant odds ratios for sarcopenia (2.80, 1.33-5.91) and physical inactivity (2.85, 1.28-6.37) were observed in old-old subjects (aged 75 years and over). CONCLUSION: Sarcopenia had a strong impact on the risk of becoming homebound. Particularly in old-old subjects, sarcopenia and physical inactivity may impair people's ability to engage in activities outside the home much more than either their mental status or their level of social participation.

DOI： 10.1016/j.maturitas.2018.03.007

PubMed

Publishing type：Research paper (scientific journal)   International / domestic magazine：Domestic journal  

AIM: Physical activity (PA) and cognition have reportedly been associated with each other. However, it remains to be elucidated what intensities of PA are most strongly associated with cognition. In the current study, we aimed to determine the association between the intensities of objectively measured PA and cognitive function. METHODS: The present study was a cross-sectional analysis of the data obtained at registration in a randomized control trial in Toyota, Japan. Participants were community-dwelling older adults who had cognitive complaints. A battery of neuropsychological and physical assessments was carried out. Daily PA data were collected with the activity monitor. PA was categorized into one of three activity levels defined as light (<3.0 metabolic equivalents; LPA), moderate and vigorous (3.0 metabolic equivalents) activity. Partial correlation analysis was used to investigate the correlation between PA and cognition, with adjustments for age, sex and school years. We then carried out a multiple regression analysis to investigate the association of cognitive performance with PA, adjusting for insulin resistance or depressive mood. RESULTS: Partial correlation adjusted for age, sex and schooling years showed that LPA was significantly correlated with the Digit Symbol Substitution test, Trail Making Test (TMT) part A and TMT-B, whereas moderate and vigorous activity showed no correlations. Multiple regression analysis with several models with different adjustments showed that LPA was associated with the Digit Symbol Substitution test, TMT-A and TMT-B independently from insulin resistance or depressive mood. CONCLUSIONS: In the current study, we found that LPA was significantly associated with the performance of executive functional assessments. Geriatr Gerontol Int 2018; 18: 922-928.

DOI： 10.1111/ggi.13284

PubMed

International / domestic magazine：International journal  

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.

DOI： 10.1002/gps.4776

PubMed

International / domestic magazine：International journal  

BACKGROUND: The aim of this study was to describe the age-dependent changes in the parameters of physical performance and body composition in Japanese older adults who are independently dwelling in the community. We also examined whether the age-dependent changes differ among physical performance and body composition parameters. METHODS: Cross-sectional data from 10 092 community-dwelling older adults (mean age 73.6 years; 5296 women) were analyzed. The measures of physical performance included hand-grip strength, the five-times-sit-to-stand test, and walking speed. Body composition parameters (body weight, fat mass, and appendicular skeletal muscle mass) were measured with a bioelectrical impedance analyser. Correlations between age and the physical performance and body composition parameters were tested. The T-scores of physical performance and body composition measurements were calculated and presented according to 5-year age groups to examine the differences in age-dependent changes in physical performance and body composition parameters. RESULTS: All physical performance measures significantly decreased with aging. The cumulative mean T-scores according to age group showed different age-dependent changes between body mass index (BMI) and appendicular skeletal muscle mass index (ASMI) (cumulative mean T-score change of BMI and ASMI of -5.7 to -2.9 and -12.7 to -12.1, respectively). The slope declines in age-associated changes were greater in grip strength (β = -0.77, 95% confidence interval = -0.82 to -0.76) for men and in walking speed (β = -0.95, 95% confidence interval = -0.99 to -0.90) for women. CONCLUSIONS: The patterns of age-dependent decreases in physical performance measures differed among parameters and between sexes. There is a possibility of a difference in the age-related slope patterns among parameters; decreases in grip strength in men and walking speed in women may be more prominent with advancing age. Furthermore, the decrease in ASMI with age is more striking than that of BMI.

DOI： 10.1002/jcsm.12197

PubMed

Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

Insulin resistance (IR), diabetes mellitus (DM), sarcopenia, and cognitive dysfunction are thought to be mutually associated. We conducted a comprehensive assessment of the relationships among IR, gait speed, hyperglycemia, and DM by cross-sectionally analyzing the baseline data of an interventional study for cognitive preservation with physical exercise (the TOyota Preventional Intervention for Cognitive decline and Sarcopenia [TOPICS]). The participants (n = 444) were relatively healthy older individuals who had mild cognitive impairment without dementia, and 61 of the participants had DM. Slow gait speed and hyperglycemia were associated with cognitive dysfunction, mainly in the executive function domain, whereas IR was associated with memory impairment. The participants with DM had lower general cognition and executive function. Executive dysfunction in the DM participants seemed to be partly explained by hyperglycemia and/or slow gait speed. Our findings confirmed that IR, DM, sarcopenia, and cognitive dysfunction are mutually associated in complex ways. Understanding the mechanisms underlying these associations will lead to effective strategies to prevent and treat cognitive dysfunction in older individuals.

DOI： 10.3389/fnagi.2017.00072

PubMed

International / domestic magazine：Domestic journal  

AIM: Memory dysfunction is a major component of age-related cognitive decline, and is a marker of cognitive impairment. Emerging evidence suggests that the prefrontal cortex is required for maintenance of memory functions. The purpose of the present study was to elucidate age-related changes in prefrontal oxygenation during memory encoding and retrieval using near-infrared spectroscopy. METHODS: We examined 21 young (mean age 24.3 years), 52 young-old (mean age 69.7 years) and 50 old-old (mean age 79.5 years) participants. The concentration of oxyhemoglobin, which is a reliable biomarker of changes in regional cerebral blood flow, in the right and left prefrontal cortex was measured during encoding and delayed retrieval of a list of 10 target words. The average number of correct answers in the retrieval task was used as a measure of task performance. RESULTS: During encoding, oxyhemoglobin was significantly and bilaterally lower in young-old and old-old participants compared with young participants. Meanwhile, during retrieval, only old-old participants showed significantly decreased oxyhemoglobin compared with young and young-old participants. The old-old participants showed fewer correct answers in the retrieval period than the young and young-old participants. CONCLUSIONS: Old-old participants showed reduced prefrontal oxygenation during both encoding and retrieval, and decreased memory performance compared with younger participants. It is necessary for the clinical application of near-infrared spectroscopy to consider the effects of demographic variables on cerebral oxygenation. Geriatr Gerontol Int 2016; 16: 1296-1304.

DOI： 10.1111/ggi.12642

PubMed

International / domestic magazine：International journal  

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.

DOI： 10.1002/gps.4363

PubMed

International / domestic magazine：International journal  

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.

DOI： 10.1007/s00421-015-3221-x

PubMed

International / domestic magazine：Domestic journal  

AIM: Self-reported exhaustion (SE) is a clinical complaint that is associated with a wide range of chronic diseases. However, the association of SE with physical activity, physical function or cognitive function among the older adult Japanese population is unclear. The present study aimed to determine the prevalence of SE, as well as whether physical function, cognitive function and physical activity were significant covariates. METHODS: A total of 4607 adults (mean age 71 years) were considered eligible for participation based on the study criteria. SE was evaluated using the Study of Osteoporotic Fracture Index. We also evaluated physical activity, physical function (grip strength, Timed Up & Go) and cognitive function (Mini-Mental State Examination, Trail Making Test part A and B, Symbol Digit Substitution Task). RESULTS: The prevalence of SE ranged from 40.9% to 55.0%, and significantly increased with age. The results of the multiple logistic regression analyses showed that in the adjusted model of the 65-69 years age group, physical activity, Timed Up & Go and Symbol Digit Substitution Task were independently associated with SE. In the 70-79 years age group, physical activity, Timed Up & Go, Trail Making Test part A and B and Symbol Digit Substitution Task were independently associated with exhaustion. Only physical activity was associated with exhaustion in the ≥80 years age group. CONCLUSIONS: The prevalence of SE increased with age in the older adult Japanese population. Exhaustion was strongly associated with reduced daily physical activity, especially in those aged ≥80 years. Further studies should be carried out to determine if physical activity causes SE. Geriatr Gerontol Int 2016; 16: 625-630.

DOI： 10.1111/ggi.12528

PubMed

International / domestic magazine：Domestic journal  

AIM: Cognitive impairment can negatively affect driving performance and increase the risk of driving errors, leading to vehicle crashes. We used a population-based survey to identify the prevalence of cognitive impairments in older drivers. METHODS: A total of 10,073 older adults were enrolled in the National Center for Geriatrics and Gerontology - Study of Geriatric Syndromes. We characterized general cognitive impairment using the Mini-Mental State Examination (MMSE). We also used the National Center for Geriatrics and Gerontology-Functional Assessment Tool, which includes six tasks to assess word list memory, logical memory, attention and executive function, processing speed, and visuospatial skill. RESULTS: Just 15% of older women with moderate cognitive decline (MMSE ≤20) drove, whereas 61% of older men with moderate cognitive decline drove. Cognitively normal participants (MMSE score 27 and over) scored significantly better on six cognitive tests compared with those with mild (MMSE score 21-26) or moderate cognitive decline, and those in the mild cognitive decline group scored significantly better on six cognitive tests than those in the moderate cognitive decline group. CONCLUSION: A total of 61% of older men with moderate cognitive decline did not cease driving. These older drivers showed poor cognitive performance in multiple domains compared with those with normal and mild cognitive decline. Further studies are required to clarify the relationships between cognitive decline and car crashes in these high-risk populations.

DOI： 10.1111/ggi.12504

PubMed

International / domestic magazine：International journal  

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.

DOI： 10.1002/gps.4308

PubMed

International / domestic magazine：Domestic journal  

AIMS: Identifying the risk factors of cognitive impairment is essential for implementing effective prevention strategies for dementia. Previous studies have shown that the frequency of going outdoors is inversely associated with cognitive decline. Little research has examined whether the relationship between going outdoors and cognitive decline varies with physical functioning in older adults. The aim of the present study was to examine the relationship between going outdoors and cognitive function in older adults with and without physical function limitations. METHODS: The present study analyzed the data of 4450 individuals (aged 65 years or older) who participated in the Obu Study of Health Promotion for the Elderly. The measures were the Mini-Mental State Examination (MMSE), going outdoors (at least once a week or not), self-reported physical function limitations (with or without), and demographic and health-related factors as potential confounders. RESULTS: Analysis of covariance and post-hoc comparisons showed that although going outdoors at least once a week was associated with higher MMSE scores among older adults with limited physical function, it was not significantly associated with the MMSE scores among older adults without limited physical function. Similarly, logistic regression analyses, stratified by physical function, showed a significant association between going outdoors and MMSE (<24 points or not) among older adults with limited physical function. CONCLUSIONS: The results show that going outdoors less than once a week is associated with decreased cognitive function among older adults with limited physical function, but it is not associated with cognitive function among older adults without limited physical function.

DOI： 10.1111/ggi.12437

PubMed

Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

OBJECTIVES: The aim of this study was to determine whether mild cognitive impairment (MCI) affects the development of fear of falling (FoF) in older adults. DESIGN: Prospective cohort study. SETTING: The Obu Study for Health Promotion in the Elderly, Japan. PARTICIPANTS: A total of 1700 community-dwelling people aged 65 years or older without FoF at baseline participated. MEASUREMENTS: FoF and related variables, such as physical function, self-rated health, depression, and total number of medication doses, were investigated at baseline. Participants also underwent cognitive tests and were divided into cognitive healthy and MCI. Fifteen months after the baseline measurements, we collected information about the status of FoF and fall incidence during the 15-month follow-up. RESULTS: At the 15-month follow-up survey, 452 participants (26.5%) reported the development of FoF. Logistic regression analysis showed that MCI (odds ratio [95% CI] = 1.41 [1.07-1.87]) and a fall incident (3.00 [2.23-4.07]) during follow-up independently predicted the development of FoF, after controlling for demographic factors, physical function, self-rated health, and depression. The odds ratio for the development of FoF in participants with both MCI and a fall incident compared with those without them was 7.34 (4.06-13.3), after controlling for confounding factors. CONCLUSION: MCI predicts the new onset of FoF in older adults, especially when they have experience with falling. Aside from the risk of falling, it is suggested that individuals with MCI are an at-risk population for FoF and related negative consequences in terms of postfall syndrome.

DOI： 10.1016/j.jamda.2015.09.014

PubMed

International / domestic magazine：Domestic journal  

AIM: To examine the association of the combination of slow gait and mild cognitive impairment (MCI) with cognitive function and falling in community-dwelling older people. METHODS: Participants were selected from the Obu Study of Health Promotion for the Elderly (n = 3400), and underwent gait examination and a battery of neuropsychological examinations, including the Mini-Mental State Examination and the National Center for Geriatrics and Gerontology Functional Assessment Tool (tablet version of Trail Making Test Part A and B, Symbol Digit Substitution Task, Figure selection task, Word memory and Story memory), and were interviewed with a series of questionnaires including medical history, physical activity, geriatric depression scale and fall history. RESULTS: Participants were classified into control (n = 2281), slow gait speed (SG; n = 278), MCI (n = 673) and MCI with SG (MCI+SG; n = 168) groups. All cognitive functions were significantly affected by the group factor, even adjusting for participant characteristics as covariates (P < 0.001). Post-hoc analysis showed that the control group had better performance than the other groups, and the MCI+SG group had worse performance than the other groups in all cognitive functions (all P < 0.05). In multiple logistic regression analysis, SG and MCI were independently associated with falling (all P < 0.05), and MCI+SG had a higher odds ratio for falling (adjusted OR 1.99, 95% CI 1.08-3.65). CONCLUSIONS: Our findings support the idea that slow gait and MCI were related, and concurrently associated with falling. Motor function among MCI subjects should be focused on to assess profile risks.

DOI： 10.1111/ggi.12407

PubMed

International / domestic magazine：International journal  

OBJECTIVE: To examine the relationships between smoking status and various domains of cognitive function in community-dwelling elderly subjects. METHODS: Participants (N = 4348) were asked about smoking status, demographic variables, and lifestyle factors, and underwent multidimensional neurocognitive tests. RESULTS: All analyses were conducted separately by sex. Women never smokers exhibited significantly better scores than past and/or current smokers in some neurocognitive tests. Among men, never smokers had significantly higher scores, such as in the Symbol Digit Substitution Test. Multiple linear regression analysis showed that pack-years (history of smoking) were significantly associated with the Symbol Digit Substitution Test in men. CONCLUSIONS: Smoking status may be associated with a decline in processing speed, and this decline varies by sex.

DOI： 10.5993/AJHB.39.3.1

PubMed

International / domestic magazine：Domestic journal  

AIM: Mild cognitive impairment (MCI) is conceptualized as prodromal of Alzheimer's disease (AD). Declined physical function is one of the risk factors for progression to AD, whereas genetic factors, especially the apolipoprotein E ε4 allele (APOE4), also contribute to the risk of AD and affect the risk factors. However, the association between APOE4 and physical function in MCI is still unclear. To elucidate the association, we carried out the present study to compare physical function between APOE4 carriers and non-carriers in MCI. METHODS: The study included 386 MCI patients (mean age 71.6 years) who were classified into APOE4 carrier and non-carrier groups. The participants' characteristics were assessed by face-to-face interviews. Grip strength, five chair stand test, walking speed and 6-min walking test were measured as physical functions. RESULTS: In univariate analysis, the APOE4 carrier group had decreased walking speed compared with the non-carrier group (P < 0.05), but other measures of physical function were not significantly different between the groups. The linear regression model showed a significant association between walking speed and APOE4 after adjusting for covariates (P < 0.05). CONCLUSIONS: The present study showed that APOE4 carrier participants with MCI had decreased walking speed compared with non-carrier participants. Thus, APOE4 genotypes should be considered as a potential mediator when the measure of walking speed is used as a risk factor of dementia in older adults with MCI. Further studies using prospective data are required to clarify the relationship between physical function and genetic factors in MCI.

DOI： 10.1111/ggi.12291

PubMed

International / domestic magazine：International journal  

BACKGROUND: Greater physical activity (PA) is associated with better memory performance and greater hippocampal volume in older adults. However, most studies to date assessed PA via questionnaires and thereby lacked objective characterization of PA (eg, intensity, duration, etc.). Thus, we currently do not have a comprehensive understanding of PA characteristics that are important for neuroprotection, especially among older adults with mild cognitive impairment (MCI). Thus, using triaxial accelerometers, we examined the association between light- and moderate-intensity PA, total duration of PA, hippocampal volume, and memory in older adults with MCI. METHODS: This cross-sectional study involved 310 older adults with MCI who completed neuropsychological tests of memory, and structural magnetic resonance imaging. Participants were instructed to wear the accelerometer on an elastic band on their hip at all times for 2 weeks. Average daily duration of light, moderate, and total PA (min/day) was calculated. RESULTS: Moderate PA was associated with hippocampal volume (β = .167, p = .003) after controlling for age, but light PA (β = -.021, p = .713) and total PA (β = .011, p = .844) were not. Both light and moderate PAs were not associated with memory performance. Structural equation modeling demonstrated that moderate PA was not directly associated with memory but significantly contributed to hippocampal volume; hippocampal volume loss was significantly and directly associated with poor memory performance. CONCLUSIONS: Our results suggest that the benefits of moderate PA on memory among older adults with MCI are mediated by hippocampal volume. Furthermore, light PA may not reduce dementia risk among older adults with MCI.

DOI： 10.1093/gerona/glu136

PubMed

International / domestic magazine：International journal  

OBJECTIVE: The purpose of this study was to determine whether frailty is an important and independent predictor of incident depressive symptoms in elderly people without depressive symptoms at baseline. DESIGN: Fifteen-month prospective study. SETTING: General community in Japan. PARTICIPANTS: A total of 3025 community-dwelling elderly people aged 65 years or over without depressive symptoms at baseline. MEASUREMENTS: The self-rated 15-item Geriatric Depression Scale was used to assess symptoms of depression with a score of 6 or more at baseline and 15-month follow-up. Participants underwent a structural interview designed to obtain demographic factors and frailty status, and completed cognitive testing with the Mini-Mental State Examination and physical performance testing with the Short Physical Performance Battery as potential predictors. RESULTS: At a 15-month follow-up survey, 226 participants (7.5%) reported the development of depressive symptoms. We found that frailty and poor self-rated general health (adjusted odds ratio 1.86, 95% confidence interval 1.30-2.66, P < .01) were independent predictors of incident depressive symptoms. The odds ratio for depressive symptoms in participants with frailty compared with robust participants was 1.86 (95% confidence interval 1.05-3.28, P = .03) after adjusting for demographic factors, self-rated general health, behavior, living arrangements, Mini-Mental State Examination, Short Physical Performance Battery, and Geriatric Depression Scale scores at baseline. CONCLUSIONS: Our findings suggested that frailty and poor self-rated general health were independent predictors of depressive symptoms in community-dwelling elderly people.

DOI： 10.1016/j.jamda.2014.08.017

PubMed

【目的】勤労者における抑うつ症状の関連要因の関係性を、パス解析を用いてモデル化し、全体像を明らかにすることを目的とした。【方法】勤労者346名を対象に、Self-rating Depression Scale(以下、SDS)を用いて抑うつ症状を評価した。労働条件、心理・社会的要因、睡眠時間、身体活動習慣、筋骨格系疼痛を調査し、SDSとの関連性の仮説を立てた後、パス解析を用いて修正および改良した。【結果】修正モデルの適合性は十分に高かった(x2=21、p=0.14、GFI=0.99)。直接的な関係性に加え、人間関係への気掛かりと筋骨格系疼痛は仕事のやりがいやストレスを介して、余暇身体活動は筋骨格系疼痛を介して抑うつに関連していた。【結論】勤労者の抑うつには心理社会的要因に加えて、筋骨格系疼痛と余暇身体活動が直接的もしくは間接的に影響を与えていることが示唆された。(著者抄録)

Publishing type：Research paper (scientific journal)  

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. (C) 2015 S. Karger AG, Basel

DOI： 10.1159/000375408

PubMed

International / domestic magazine：Domestic journal  

[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.

DOI： 10.1589/jpts.26.1979

PubMed

Publishing type：Research paper (scientific journal)  

Growing evidence supports the relationships between depressive symptoms, cognitive decline, and brain structural changes in older adults. The purpose of this study was to determine whether depressive symptoms are related to cerebral oxygenation during cognitive tasks in older adults. In this study, 80 elderly subjects (73.9 +/- 5.4 years, 34 males) were evaluated using multi-channel Near-infrared spectroscopy. Concentration changes (mmol cm/l) in oxy-hemoglobin (oxy-Hb), as the most reliable available indicator of changes in regional cerebral blood flow, in the right and left prefrontal cortex were measured during the Trail Making Test Part B (TMT-B). Depressive symptoms were assessed using the short Geriatric Depression Scale (GDS). Subjects were divided into a depressive group (GDS greater than or equal to 6) and non-depressive group (GDS lower than 6). In results, Oxy-Hb activation during the TMT-B was significantly smaller in the depressive group (n = 13) than in the non-depressive group (n = 67) in both the right and left prefrontal cortex. In the multivariate analysis, GDS scores were significantly negatively correlated with oxy-Hb activation after adjusting for age, gender and educational history (right, beta = -0.32, p = 0.002; left, beta = -0.25, p = 0.02). Less prefrontal activation in older adults with depressive symptoms may account for decline in executive function. Further studies are needed to investigate the influence of the less brain activation associated with depressive symptoms on future cognitive decline and structural brain changes in older adults. (C) 2014 Elsevier Ireland Ltd. All rights reserved.

DOI： 10.1016/j.archger.2014.07.003

PubMed

Publishing type：Research paper (scientific journal)  

The purpose of this study was to examine whether the combined factors of physical performance, depressive symptoms and cognitive status are significantly associated with a history of falling in community-dwelling elderly. We performed a cross-sectional community-based survey, the OSHPE, from August 2011 to February 2012. In total, 5104 community-dwelling older adults aged 65 years and older (mean age 72.0) participated in the OSHPE. Participants underwent a grip strength (GS) test, chair stand test (CST), Timed Up & Go (TUG) test, Geriatric Depression Scale (GDS), and Mini-Mental State Examination (MMSE). Of the 4481 participants who met our requirements, 645 (14.4%) participants reported falling at least once in the past year. In a signal detection analysis (SDA), we found that the combination of GDS (&gt;= 6 points) and TUG (&gt;= 10.6 s) had the highest fall rate (36.4%), and the combination of GDS (&lt;6 points) and CST (&lt;11.1 s) had the lowest fall rate (11.7%). The highest fall rate group had a significantly higher odds ratio (OR) compared with the lowest fall rate group after adjusting for other potentially confounding variables [OR 3.12 (95% confidence interval (CI) 2.08-4.68) p &lt; 0.001]. The combination of depressive symptoms, TUG, and CST performance was strongly associated with a history of falling in community-dwelling elderly. (C) 2014 Elsevier Ireland Ltd. All rights reserved.

DOI： 10.1016/j.archger.2014.01.001

PubMed

International / domestic magazine：International journal  

OBJECTIVES: Few studies have reported the relationship between fear of falling (FoF) and mild and global cognitive impairment in community-dwelling older adults. We aimed to determine whether the status of cognitive impairment affects the prevalence of FoF in community-dwelling older adults. STUDY DESIGN: Cross-sectional study among 4474 community-dwelling older adults who participated in the Obu Study of Health Promotion for the Elderly. MAIN OUTCOME MEASURES: Participants underwent cognitive tests and were divided into three groups: cognitive healthy, mild cognitive impairment (MCI), and global cognitive impairment (GCI). FoF and related variables, such as fall history, physical function, and depression, were also investigated. RESULTS: The prevalence of FoF was significantly different by group (p<0.001; healthy: 43.6%, MCI: 50.6%, GCI: 40.6%). Logistic regression analysis showed that GCI (odds ratio=0.63; 95% confidence interval=0.526-0.76) was independently associated with FoF, after controlling for confounding factors. Older adults with GCI showed the lowest prevalence of FoF, although they had the lowest physical function comparing with the other groups (p<0.001). CONCLUSION: MCI and GCI in community-dwelling older adults affect the prevalence of FoF in a completely different manner. Further study is required to determine whether insensitivity to FoF with GCI increases the risk of falling in older adults.

DOI： 10.1016/j.maturitas.2014.02.018

PubMed

International / domestic magazine：International journal  

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.

DOI： 10.1186/1471-2377-14-67

PubMed

International / domestic magazine：Domestic journal  

AIM: Several operative definitions and screening methods for sarcopenia have been proposed in previous studies; however, the opinions of researchers still differ. We compared the prevalence of sarcopenia using two different algorithms: (i) the European working group on sarcopenia in older people (EWGSOP)-suggested algorithm using gait speed as the first step; and (ii) the muscle mass and strength algorithm. METHODS: A population-based, cross-sectional survey of adults aged over 65 years was carried out. Data on a total of 4811 participants were available for analysis. Gait speed, grip strength and appendicular skeletal muscle mass were assessed to determine sarcopenia. Appendicular skeletal muscle mass was estimated from bioimpedance analysis measurements and expressed as skeletal muscle mass index. Grip strength and skeletal muscle mass index were considered to be low if they fell below the threshold of the lowest 20% of values measured in a subset of healthy subjects. We compared the prevalence rates of sarcopenia determined by the two algorithms. RESULTS: The prevalence rate of sarcopenia in a representative sample of older Japanese adults was 8.2% for men and 6.8% for women based on the EWGSOP algorithm. The two algorithms identified the same participants as sarcopenic, the only difference being the EWGSOP algorithm classified an additional seven participants (0.15%) into sarcopenia compared with the muscle mass and strength algorithm. CONCLUSION: It is debatable whether inclusion of gait speed is necessary when screening for sarcopenia in community-dwelling older adults. Future research should examine the necessity of including gait speed in algorithms and the validity of cut-off values.

DOI： 10.1111/ggi.12210

PubMed

International / domestic magazine：International journal  

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.

DOI： 10.1093/chemse/bjt052

PubMed

International / domestic magazine：International journal  

OBJECTIVE: The clinical relationship between brain-derived neurotrophic factor (BDNF) and cognitive function or mild cognitive impairment (MCI) is not well-understood. The purpose of this study was to identify the relationship between serum BDNF and cognitive function and MCI, and determine whether serum BDNF level might be a useful biomarker for assessing risk for MCI in older people. MATERIALS AND METHODS: A total of 4463 individuals aged 65 years or older (mean age 72 years) participating in the study. We measured performance in a battery of neuropsychological and cognitive function tests; serum BDNF concentration. RESULTS: Eight hundred twenty-seven participants (18.8%) had MCI. After adjustment for sex, age, education level, diabetes, and current smoking, serum BDNF was associated with poorer performance in the story memory, and digit symbol substitution task scores. Serum BDNF was marginally associated with the presence of MCI (odds ratio, 95% confidence interval: 1.41, 1.00-1.99) when BDNF was 1.5 SD lower than the mean value standardized for sex and age, education level, diabetes, and current smoking. CONCLUSION: Low serum BDNF was associated with lower cognitive test scores and MCI. Future prospective studies should establish the discriminative value of serum BDNF for the risk of MCI.

DOI： 10.3389/fnagi.2014.00069

PubMed

Publishing type：Research paper (scientific journal)  

The purpose of this study is to examine the effects of a speed or accuracy strategy on response interference control during choice step execution. Eighteen healthy young participants were instructed to execute forward stepping on the side indicated by a central arrow (&lt;-, left vs. -&gt;, right) under task instructions that either emphasized speed or accuracy of response in the neutral condition. In the flanker condition, they were additionally required to ignore the 2 flanking arrows on each side (-&gt;-&gt;-&gt;-&gt;-&gt;, congruent or -&gt;-&gt;&lt;--&gt;-&gt;, incongruent). Errors in the direction of the initial weight transfer (APA errors) and the step execution times were measured from the vertical force data. APA error was increased in response to the flanker task and step execution time was shortened with a speed strategy compared to an accuracy strategy. Furthermore, in response to the visual interference of the flanker task, speed instructions in particular increased APA errors more than other instructions. It may be important to manipulate the level of the speed-accuracy trade-off to improve efficiency and safety. Further research is needed to explore the effects of advancing age and disability on choice step reaction in a speed or accuracy strategy. (C) 2013 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.humov.2013.07.007

PubMed

International / domestic magazine：International journal  

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.

DOI： 10.1007/s40520-013-0119-5

PubMed

International / domestic magazine：Domestic journal  

AIM: This study sought to confirm the test-retest reliability and validity of the National Center for Geriatrics and Gerontology functional assessment tool (NCGG-FAT), a newly developed assessment of multidimensional neurocognitive function using a tablet personal computer (PC). METHODS: This study included 20 community-dwelling older adults (9 females, aged 65-81 years). Participants were administered the NCGG-FAT twice, separated by approximately 30 days to determine test-retest reliability. To test the validity of the measure, participants underwent established neurocognitive measurements, including memory, attention, executive function, processing speed and visuospatial function within a week from the first administration of the NCGG-FAT. RESULTS: Test-retest reliability was in an acceptable range for each component of the NCGG-FAT, with intraclass correlation coefficients ranging from 0.764 to 0.942. Each task in the NCGG-FAT showed a moderate to high correlation with scores on widely-used conventional neurocognitive tests (r = 0.496 to 0.842). CONCLUSION: We found that the NCGG-FAT using a tablet PC was reliable in a sample of community-dwelling older adults. The NCGG-FAT might be useful for cognitive screening in population-based samples and outcomes, enabling assessment of the effects of intervention on multidimensional cognitive function among older adults.

DOI： 10.1111/ggi.12014

PubMed

International / domestic magazine：International journal  

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.

DOI： 10.1186/1471-2377-13-102

PubMed

International / domestic magazine：International journal  

OBJECTIVE: Preventive strategies for frailty and mild cognitive impairment (MCI) are important for avoiding future functional decline and dementia in older adults. The purpose of this study was to use a population-based survey to ascertain the single and combined prevalence of frailty and MCI and to identify the relationships between frailty and MCI in older Japanese adults. DESIGN: Cross-sectional study. SETTING: General community. PARTICIPANTS: A total of 5104 older adults (aged 65 years or older, mean age 71 years) who were enrolled in the Obu Study of Health Promotion for the Elderly (OSHPE). MEASUREMENTS: Each participant underwent detailed physical and cognitive testing to assess frailty and MCI. We considered the frailty phenotype to be characterized by limitations in 3 or more of the following 5 domains: mobility, strength, endurance, physical activity, and nutrition. Screening for MCI included a standardized personal interview, the Mini-Mental State Examination, and the National Center for Geriatrics and Gerontology-Functional Assessment Tool (NCGG-FAT), which included 8 tasks used to assess logical memory (immediate and delayed recognition), word list memory (immediate and delayed recall), attention and executive function (tablet version of Trail Making Test-part A and B), processing speed (tablet version of digit symbol substitution test), and visuospatial skill (figure selection). RESULTS: The overall prevalence of frailty, MCI, and frailty and MCI combined was 11.3%, 18.8%, and 2.7%, respectively. We found significant relationships between frailty and MCI (the odds ratio adjusted for age, sex, and education was 2.0 (95% confidence interval 1.5-2.5). CONCLUSIONS: Using the OSHPE criteria, we found more participants with MCI than with frailty. The prevalence of frailty and MCI combined was 2.7% in our population. Future investigation is necessary to determine whether this population is at increased risk for disability or mortality.

DOI： 10.1016/j.jamda.2013.03.010

PubMed

Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

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.

DOI： 10.1007/s40520-013-0042-9

PubMed

International / domestic magazine：International journal  

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.

DOI： 10.1186/1743-0003-10-47

PubMed

Publishing type：Research paper (scientific journal)  

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. © 2012 Elsevier B.V.

DOI： 10.1016/j.gaitpost.2012.10.016

PubMed

【目的】日本語版-改訂Gait Efficacy Scale(mGES)の信頼性と妥当性を検証することを目的とした。【方法】地域在住高齢者240名を対象とした。そのうちの31名については、自記式による日本語版mGESの評価を2回実施した(評価間隔14〜20日間)。日本語版mGESの妥当性を検証するために、運動機能(chair-stand test、片脚立位時間、通常歩行速度、6分間歩行距離)、生活空間、転倒恐怖感との関連を調べた。【結果】日本語版mGESは高い再検査信頼性を示し(級内相関係数[2,1]=0.945、95%信頼区間0.891〜0.973)、すべての運動機能および生活空間と有意な相関関係を認めた。従属変数を転倒恐怖感の有無、独立変数を性別、各運動機能、生活空間、日本語版mGES得点としたロジスティック回帰分析の結果、転倒恐怖感と有意な関連を認めた項目は、性別(女性)、通常歩行速度、日本語版mGES得点であった。【結論】高齢者における歩行状態の自信の程度を把握する指標として、日本語版mGESは良好な信頼性および妥当性を有する評価であることが確認された。(著者抄録)

Publishing type：Research paper (scientific journal)  

Recently, several studies have reported that muscle coactivation during static postural control increases with aging. Although greater muscle coactivation during quiet standing enhances joint stability, it may reduce dynamic postural control. The purpose of this study was to investigate the effect of muscle coactivation during quiet standing on dynamic postural control. Seventy older adults (81.1 +/- 7.2 years) participated in this study. Static postural control was evaluated by postural sway during quiet standing, whereas dynamic postural control was evaluated by the functional reach and functional stability boundary tests. Electromyography of the soleus (SOL) and tibialis anterior (TA) was recorded during quiet standing, then coactivation was evaluated using the co-contraction index (CI). We used multiple regression analysis to identify the effect of muscle coactivation during standing on each dynamic postural control variable using age, body mass index (BMI), gender, timed up and go (TUG) tests, postural sway area and CI during quiet standing as independent variables. TUG tests were added to the model to evaluate the effect of functional mobility on dynamic postural control with a fixed base. The multiple regression analysis revealed that CI during standing was significantly related to all of the dynamic postural control tasks. The functional reach distance was significantly associated with CI during standing, age and TUG (p &lt; 0.05). The functional stability boundary for forward and backward were associated only with CI during standing (p &lt; 0.05). This study revealed that muscle coactivation during quiet standing is independently associated with dynamic postural control abilities. (C) 2012 Elsevier Ireland Ltd. All rights reserved.

DOI： 10.1016/j.archger.2012.08.009

PubMed

Publishing type：Research paper (scientific journal)  

This study sought to investigate the relationship between going outdoor daily and prefrontal cortex activation during execution of the VFT using near-infrared spectroscopy (NIRS) in community-dwelling older adults. Blood oxygenation changes in left and right prefrontal cortices were measured in twenty older adults (mean age 76.1 +/- 6.7 years) by NIRS during VFT performance. In this task, participants were required to pronounce as many nouns as possible beginning with the letters "Shi," "I," and "Re." Changes in oxygenated hemoglobin (oxy-Hb) levels during the VFT were compared between two groups defined by the frequency of going outdoors: daily or non-daily within a week. Participants in both groups exhibited significantly increased oxy-Hb levels in the left and right prefrontal cortices during the VFT compared to a resting baseline condition. After controlling for age and gender, there were significant group-by-condition interactions on oxy-Hb levels with less activation during the execution of the VFT over both cortices in the non-daily group (left: F = 4.76, p = 0.04; right: F = 6.32, p = 0.02). These findings indicate that going outdoors daily is associated with increased activation in the prefrontal cortices during VFT performance in community-dwelling older adults. (C) 2012 Elsevier Ireland Ltd. All rights reserved.

DOI： 10.1016/j.archger.2012.08.017

PubMed

International / domestic magazine：Domestic journal  

AIM: Restriction of life-space is associated with physical performance and functional decline in older adults. Little is known about the factors associated with life-space in older adults with amnestic mild cognitive impairment (aMCI). The purpose of this study was to identify factors associated with life-space in older adults with aMCI. METHODS: The study participants were 69 older adults (mean age 74.5 years, males 56.5%) who were identified with aMCI. Life-space mobility was measured using a Japanese translation of the life-space assessment (LSA). Age, sex, cognitive function (general function, executive function and processing speed), physical performance, instrumental activities of daily living status (IADL) and fear of falling (FoF) were measured as potential relevant factors. RESULTS: Univariate analysis showed that the LSA was associated with FoF, sex, physical performance, processing speed and IADL. In the stepwise regression analysis, FoF, processing speed and IADL maintained a significant association with the LSA scores, although sex and physical performance did not reach significance. CONCLUSION: The results suggest that the restrictions of life-space in older adults with aMCI were more affected by the FoF, slower processing speed and restricted IADL than sex or physical performance.

DOI： 10.1111/j.1447-0594.2012.00878.x

PubMed

International / domestic magazine：International journal  

AIMS: This study aimed to identify differences in the implementation of cognitive activities and instrumental activities of daily living (IADLs) between healthy individuals and subjects with mild cognitive impairment (MCI). METHODS: The study included 2,498 cognitively healthy subjects (mean age, 71.2 ± 5.1 years) and 809 MCI subjects (mean age, 71.8 ± 5.4 years). The subjects were interviewed regarding their participation in cognitive activities and the implementation of IADLs. RESULTS: We found a significant association between participation in any cognitive activities (p < 0.001), using a bus or a train (p < 0.001), and MCI. After adjusting for covariates, cognitive activity of any type remained significantly associated with MCI (p < 0.005) but not with the implementation of IADLs. CONCLUSIONS: Our study revealed that greater participation in cognitive activity was associated with lower odds of MCI. Participation in cognitive activities may reflect differences between healthy and MCI subjects. To clarify the causal relationship between cognitive activities and MCI, further studies are required.

DOI： 10.1159/000355553

PubMed

International / domestic magazine：International journal  

OBJECTIVES: To identify appropriate clinical tests for determining the demand for personal care in older Japanese people. DESIGN: Cross-sectional observation study. SETTING: Obu Study of Health Promotion for the Elderly (Obu, Aichi) and Tsukui Ordered Useful Care for Health (241 day-care centres) cohorts in Japan. PARTICIPANTS: A total of 10 351 individuals aged 65 years or older (6791 with personal care and 3560 without personal care) participated in the study. MEASURES: Physical performance tests included grip strength, the chair stand test, walking speed at a comfortable pace, and the timed up-and-go test. Personal care was defined as participants who had been certified in the national social long-term care insurance in Japan. RESULTS: Individuals who received personal care showed a significantly poorer performance than those without personal care for all physical performance tests (p<0.001). Gait speed was the most useful of the physical performance tests to determine the demand for personal care (receiver operating characteristic curve statistics: men, 0.92; women, 0.94; sensitivity: men, 86; women, 90; specificity: men, 85; women, 85). After adjustment for age, sex, cognitive impairment and other physical tests, all physical performance tests were individually associated with the demand for personal care. A slow gait speed (<1 m/s) was more strongly correlated with the demand for personal care than other performance measures (gait speed OR: 5.9; 95% CI: 5.0 to 6.9). CONCLUSIONS: Clinical tests of physical performance are associated with the demand for personal care in older people. Preventive strategies to maintain physical independence may be required in older adults who show a gait speed slower than 1 m/s. Further research is necessary to confirm these preliminary results.

DOI： 10.1136/bmjopen-2012-002424

PubMed

International / domestic magazine：International journal  

BACKGROUND: Although much evidence supports the hypothesis that cognitive function and physical function are interrelated, it is unclear whether cognitive decline with mild cognitive impairment influences trainability of physical performance in exercise intervention. The purpose of this study was to examine the association between cognitive function at baseline and change in physical performance after exercise intervention in older adults with mild cognitive impairment. METHODS: Forty-four older adults diagnosed with mild cognitive impairment based on the Peterson criteria (mean age 74.8 years) consented to and completed a 6-month twice weekly exercise intervention. The Timed Up and Go (TUG) test was used as a measure of physical performance. The Mini-Mental State Examination (MMSE), Trail Making Test Part B, Geriatric Depression Scale, baseline muscle strength of knee extension, and attendance rate of intervention, were measured as factors for predicting trainability. RESULTS: In the correlation analysis, the change in TUG showed modest correlations with attendance rate in the exercise program (r = -0.354, P = 0.027) and MMSE at baseline (r = -0.321, P = 0.034). A multiple regression analysis revealed that change in TUG was independently associated with attendance rate (β = -0.322, P = 0.026) and MMSE score (β = -0.295, P = 0.041), controlling for age and gender. CONCLUSION: General cognitive function was associated with improvements in physical performance after exercise intervention in subjects with mild cognitive impairment. Further research is needed to examine the effects of exercise programs designed to address cognitive obstacles in older adults with mild cognitive impairment.

DOI： 10.2147/CIA.S39434

PubMed

International / domestic magazine：International journal  

BACKGROUND AND AIMS: There has been much interest in exercise interventions as a primary behavioral prevention strategy against cognitive decline. The aim of this study was to evaluate the effect of a multicomponent exercise program on physical and dual-task performances in community-dwelling older adults with amnestic mild cognitive impairment (aMCI). METHODS: Fifty older adults (23 women) with aMCI (mean age, 76 years) were randomized to an intervention (n=25) or a control group (n=25). The intervention group received a multicomponent exercise program for 90 minutes/day, 2 days/week, or 40 times over six months. The multicomponent exercises included aerobic exercise, muscle strength training and postural balance retraining, which was conducted under multi-task conditions to stimulate attention and memory. Participants in the control group attended two health promotion education classes within six months. Physical and dual-task performances were measured before randomization and after six months. Dual-task performances using reaction times with balance and cognitive demands were measured. RESULTS: The improvement effects on dual-task performances with both balance and cognitive demands were not statistically significant: reaction time with balance demand F1,45=3.3, p=0.07, and cognitive demand F1,45=2.6, p=0.12. However, there was a significant group-by-time interaction on maximal walking speed, which decreased significantly in the control group (F1,45=5.9, p=0.02). CONCLUSION: This six-month multicomponent exercise program improved maximal walking speed in older adults with aMCI; however, it did not improve dual-task performances assessed by reaction times.

DOI： 10.3275/8760

PubMed

International / domestic magazine：International journal  

UNLABELLED: BACKGROUND: To examine the effects of a multicomponent exercise program on the cognitive function of older adults with amnestic mild cognitive impairment (aMCI). METHODS: DESIGN: Twelve months, randomized controlled trial; SETTING: Community center in Japan; PARTICIPANTS: Fifty older adults (27 men) with aMCI ranging in age from 65 to 93 years (mean age, 75 years); INTERVENTION: Subjects were randomized into either a multicomponent exercise (n = 25) or an education control group (n = 25). Subjects in the multicomponent exercise group exercised under the supervision of physiotherapists for 90 min/d, 2 d/wk, for a total of 80 times over 12 months. The exercises included aerobic exercises, muscle strength training, and postural balance retraining, and were conducted using multiple conditions to stimulate cognitive functions. Subjects in the control group attended three education classes regarding health during the 12-month period. MEASUREMENTS were administered before, after the 6-month, and after the 12-month intervention period; MEASUREMENTS: The performance measures included the mini-mental state examination, logical memory subtest of the Wechsler memory scale-revised, digit symbol coding test, letter and categorical verbal fluency test, and the Stroop color word test. RESULTS: The mean adherence to the exercise program was 79.2%. Improvements of cognitive function following multicomponent exercise were superior at treatment end (group × time interactions for the mini-mental state examination (P = 0.04), logical memory of immediate recall (P = 0.03), and letter verbal fluency test (P = 0.02)). The logical memory of delayed recall, digit symbol coding, and Stroop color word test showed main effects of time, although there were no group × time interactions. CONCLUSIONS: This study indicates that exercise improves or supports, at least partly, cognitive performance in older adults with aMCI.

DOI： 10.1186/1471-2377-12-128

PubMed

Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

BACKGROUND: Recently, several studies have reported age-associated increases in muscle coactivation during postural control. A rigid posture induced by strong muscle coactivation reduces the degree of freedom to be organized by the postural control system. The purpose of this study was to clarify the effect of balance training on muscle coactivation during postural control in older adults. METHODS: Forty-eight subjects were randomized into an intervention (mean age: 81.0 ± 6.9 years) and a control group (mean age: 81.6 ± 6.4 years). The control group did not receive any intervention. Postural control ability (postural sway during quiet standing, functional reach, and functional stability boundary) was assessed before and after the intervention. A cocontraction index was measured during the postural control tasks to assess muscle coactivation. RESULTS: Cocontraction index values in the intervention group significantly decreased following the intervention phase for functional reach (p < .0125). Cocontraction index values had a tendency to decrease during functional stability boundary for forward and quiet standing tasks. Functional improvements were observed in some of the tasks after the intervention, that is, functional reach, functional stability boundary for forward, one-leg stance, and timed up and go (p < .05). CONCLUSIONS: Our study raised the possibility that balance training for older adults was associated with decreases in muscle coactivation during postural control. Postural control exercise could potentially lead older adults to develop more efficient postural control strategies without increasing muscle coactivation. Further research is needed to clarify in greater detail the effects of changes in muscle coactivation.

DOI： 10.1093/gerona/glr252

PubMed

International / domestic magazine：International journal  

BACKGROUND AND AIMS: For safe locomotion, visual attention must be directed toward not only the central visual field but also the peripheral visual field. This study explored the effect of stepping task on reaction time for the central and peripheral visual fields in young and older adults. METHODS: Nine older (mean age 83.8±6.8 years) and 11 young adults (mean age 22.9±1.3 years) participated in this study. Reaction times to press a handheld button in response to stimuli for the central and peripheral visual fields were measured in static standing and stepping task conditions. RESULTS: Vision angle and condition were significantly associated with reaction time in the older group (p=0.006), while reaction time in the young group was affected by vision angle only. Reaction times for visual stimulus at a 45° vision angle were significantly longer in the older group in stepping task conditions than in static standing conditions. CONCLUSIONS: Effective visual field may diminish during lightly loaded exercise in older adults.

PubMed

International / domestic magazine：International journal  

BACKGROUND AND AIMS: Impairment in visual-spatial attention can cause difficulties in planning and guiding movements, leading to falls in older adults .The purpose of this study was to investigate the relationship between visual-spatial attention during movement and the risk of falling in older adults. METHODS: Thirty-six elderly volunteers (mean age, 73.2±6.8 years) performed a rapid choice stepping task in response to flanker task stimuli. Step errors in congruent or incongruent conditions were recorded as a measure of the accuracy of choice stepping. Four clinical measurements were also assessed: 10-min walking time, timed up and go test, functional reach test and 5- chair stand test. RESULTS: High-risk (HR) participants showed a significantly higher rate of step errors in the incongruent condition than low-risk (LR) ones (HR: 55.5%, LR: 18.5%; p =0.032). Step error in the incongruent condition [odds ratio (OR)=5.5; p=0.041] was the only independent variable which remained significant in the final step of the logistic regression model. CONCLUSION: Impaired choice stepping in response to a visual-spatial attention-demanding task was associated with the risk of falling in older adults.

PubMed

Publishing type：Research paper (scientific journal)   International / domestic magazine：Domestic journal  

OBJECTIVES: The aim of the present study was to evaluate whether a complex course obstacle negotiation exercise (CC), a 24-week exercise program, can reduce falls and fractures in older adults, as compared with a simple course obstacle negotiation exercise (SC). METHODS: This trial was carried out on older adults, aged 75 years and above in Japan. In total, 157 participants were randomized into the CC group (n = 78) and the SC group (n = 79). Participants were enrolled in the exercise class using the CC program or the SC program for 24 weeks. The outcome measure was the number of falls and fracture rates in CC and SC groups for 12 months after the completion of the 24-week exercise class. RESULTS: Two participants (2.8%) in the CC group and 19 (26.0%) in the SC group experienced falls during 12 months. During the 12-month follow-up period after the intervention, the incidence rate ratio (IRR) of falls in the SC group against the CC group was 9.37 (95% CI = 2.26-38.77). One participant (1.4%) in the CC group and eight (10.9%) in the SC group had experienced fractures during 12 months after the exercise class. The IRR of fractures in the SC group compared with the CC group was 7.89 (95% CI = 1.01-61.49). CONCLUSIONS: The results of the present trial show that the participants who received individualized obstacle avoidance training under complex tasks combined with a traditional intervention had a lower incidence rate of falls and fractures during the 12 months after the intervention.

DOI： 10.1111/j.1447-0594.2011.00794.x

PubMed

国立長寿医療研究センターが保有する65歳以上のデータベースから重度脳卒中、心疾患の既往のある者、調査遂行ができない者を除く、調査協力が得られた対象者から手段的日常生活活動(IADL)が自立していない高齢者を除外した119名(男性59名、女性60名、平均75.7±7.2歳)を対象に、IADLが自立した地域在住高齢者の転倒恐怖感の存在率および関連要因について検討した。対象者の中で61名(51.3%)が転倒恐怖感を有していた。対象者は全員日常生活には影響ないと回答した。基本属性では年齢とBMIは群間において有意差はなかったが、性別では、なし群(34.5%)に比べ、あり群(65.6%)に有意に女性が多かった。健康状態では「3種類以上の服用あり」では有意差がなかったが、「過去1ヵ月に痛みあり」と「慢性疾患の既往歴あり」が転倒恐怖感あり群に有意に多く存在した。Timed UP&Go test(TUG)ではあり群の方が、なし群に比べ有意に遅く、開眼片足立ち保持時間ではあり群がなし群に比べ有意に短かった。ライフスペースアセスメント(LSA)ではあり群がなし群に比べ有意に低値を示した。

Other URL： https://search-tp.jamas.or.jp/index.php?module=Default&action=Link&pub_year=2012&ichushi_jid=J01214&link_issn=&doc_id=20120815240011&doc_link_id=1390282680001216384&url=https%3A%2F%2Fcir.nii.ac.jp%2Fcrid%2F1390282680001216384&type=CiNii&icon=https%3A%2F%2Fjk04.jamas.or.jp%2Ficon%2F00003_3.gif

[目的]高齢者とは65歳以上といった幅広い層を指す名称にもかかわらず,これまでの身体機能評価を用いた研究では「高齢者」と一括りにして報告されている.本研究では,高齢者を年齢層により分類し,各層における歩行機能を比較検討した.[対象・方法]対象は地域在住高齢者270名および若年者60名である.高齢者を前期高齢者,後期高齢者,超高齢者に分類し,若年者と合わせて4群間で,単一課題条件および二重課題条件での歩行速度および歩行周期時間の変動を比較検討した.[結果]どの評価項目においても高齢者の年齢層間で有意な差を認めたものの,若年者-前期高齢者間ではどの評価においても有意な差を認めなかった.また,歩行周期時間の変動では二重課題条件にすることで,単一課題条件では認められなかった年齢層間の差が認められた.[結語]高齢者の身体機能を評価する際には,年齢層に分類して評価する必要性が示唆された.(著者抄録)

International / domestic magazine：International journal  

BACKGROUND AND AIMS: The purpose of this study was to examine the center of pressure (COP) trajectory at gait initiation in single- and dualtask conditions between elderly Fallers and Non-fallers. METHODS: Seventy-one community-dwelling elderly people (mean age 80.5 ± 7.6 years) voluntarily participated in this study. Participants were categorized as Fallers or Non-fallers on the basis of previous fall experience. In single- and dual-task conditions, participants performed gait initiation trials from a starting position on a force platform while COP data were collected. Steady-state walking time on a 10-m straight walkway in single- and dual-task conditions was also measured. In the dual-task condition, participants performed individual tests with simultaneous backward counting. Maximum COP displacements and velocities were calculated in the anteroposterior and mediolateral directions. RESULTS: In the dual-task condition, Fallers had significantly smaller backward displacements and slower backward velocities of COP than Non-fallers, although there was no significant difference in these values in the single-task condition between groups. Steadystate walking time was also not significantly different in both single- and dual-task conditions between groups. CONCLUSIONS: Gait-initiation performance in dual-task conditions may be a good discriminator between Fallers and Non-fallers.

PubMed

Publishing type：Research paper (scientific journal)   International / domestic magazine：Domestic journal  

AIM: The purpose of this longitudinal study was to determine whether the rate of decline in community-dwelling older adults varies according to baseline locomotive function levels. METHODS: This longitudinal study was conducted in community-dwelling older adults in Kyoto, Japan. In addition to information about falls, physical performance was assessed using a series of tests, including 10-m walking time, timed up and go (TUG) test, functional reach, one-leg stand test, and five chair stand test. The outcomes for each patient were measured once in 2009 and then followed up 1 year later. The change in physical performance was then determined. We divided the participants into tertiles (T1, T2, and T3) according to timed up and go test results, and the differences among the three groups were compared. RESULTS: Of the 252 individuals who were enrolled in the study, 231 (91.6%) completed the 12-month follow-up: 77 in the T1 group; 78 in the T2 group; and 76 in the T3 group. The T1 group showed a significantly larger decrease than the T2 and T3 groups in the 10-m walking time and TUG tests (P < 0.05). However, there were no significant differences in functional reach, one-leg standing test, or five chair stand test among the three groups. In the T1 group, the number of falls and elderly who had developed fear of falling increased during the study period. CONCLUSIONS: This study demonstrated that elderly with the highest baseline performances were more likely to show a greater decline in locomotive performance than the other groups. Further study is required to elucidate the mechanism of faster physical functional decline in robust elderly.

DOI： 10.1111/j.1447-0594.2011.00757.x

PubMed

Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

BACKGROUND AND AIMS: Increased fear of falling is associated with greater muscular coactivation during standing postural control. Excessive muscular coactivation reduces the performance of agonist muscles. Although several recent studies have observed increased muscular coactivation during walking in older adults, little is known about the relationship between fear of falling and muscular coactivation during walking. The purpose of this study was to compare muscular coactivation during walking between older adults with fear of falling and older adults without fear of falling. METHODS: Thirty-eight healthy older adults (82.3 ± 6.8 years) participated in this study. Walking speed and step length were measured. Electromyography (EMG) data were collected from the tibialis anterior and soleus during walking to calculate the co-contraction index (CI). Subjects were divided into those with fear of falling and those without fear of falling, on the basis of a modified Falls Efficacy Scale (FES). Stepwise multiple regression analysis was used, with CI as the dependent variable, and fear of falling, experience of falling (during the past year), walking speed, step length, and age as independent variables. RESULTS: Mean values of CI during walking, walking speed, and step length were 51.9 ± 11.7%, 0.90 ± 0.40 m/s, and 0.43±0.11 m, respectively. Eight subjects (21.1%) had fallen within the past year, and 19 subjects (50.0%) had fear of falling. All subjects without fear of falling had FES scores of 10 (maximum score). Subjects with fear of falling had a median FES score of 17 (interquartile range, 13 to 25). Stepwise multiple regression analysis revealed that fear of falling remained significantly associated with CI (p<0.01): CIs for subjects with fear and those without fear were 59.5 ± 12.2% and 46.7 ± 8.5%, respectively. CONCLUSION: Individuals with a fear of falling have increased muscular co-activation at the ankle joint during walking, at least in a certain subgroup of older adults. Further research is needed to clarify negative and positive effects of muscular coactivation during walking in fearful subjects.

DOI： 10.3275/7716

PubMed

Publishing type：Research paper (scientific journal)  

Few studies have reported the effect of exercise intervention for improving postural control deficit in older adults at high risk of falling. We have developed a "Dual-task Switch Exercise (DSE)" program that focuses on gait initiation performance under the dual-task condition. The purpose of this study was to evaluate whether gait initiation performance could be improved by a specific exercise intervention. Eighteen participants were randomly assigned to either DSE or control groups. The DSE group received focused training to improve the ability to initiate movements quickly under the dual-task condition. The control group received steady-state walking training. After 30-min of seated training sessions, participants received 5-min individualized training sessions once a week for 24 weeks. In the pre- and post-training period, performance of the steady-state gait (10-m walking time) and gait initiation (reaction time, backward center of pressure (COP) displacement) were measured under the single-and dual-task conditions. The results of a randomized clinical trial showed that both groups showed improvement of steady-state walking time under the dual-task condition (main effect of time; p = 0.018). However, DSE was more effective in improving both the reaction time and backward COP displacement during gait initiation under the dual-task condition than control (interaction effect of time x group; reaction time, p = 0.015; COP displacement, p = 0.011). There were no significant differences in steady-state gait and gait initiation performance under the single-task condition between pre- and post-training in both groups. Only the specific exercise intervention improved gait initiation performance under the dual-task condition. (C) 2012 Elsevier Ireland Ltd. All rights reserved.

DOI： 10.1016/j.archger.2012.01.002

PubMed

Publishing type：Research paper (scientific journal)  

It was recently reported that the measurement of stepping accuracy while performing a new walking test, a multi-target stepping task (MTST), could contribute to identifying older individuals at high risk (HR) of falling. The present study was designed to identify factors leading HR older individuals to an impaired stepping performance in terms of frequency of maladaptive turning behavior (spin turn) and spatio-temporal patterns of fixations. Eleven HR (80.8 +/- 3.6 years), 26 low-risk (LR) (77.1 +/- 7.7 years) older individuals, and 20 younger individuals performed the MTST. For the MTST, stepping accuracy was measured with two types of failure (stepping target and avoiding distracters). The frequency of a spin turn (i.e., a crossover step) was compared among the groups. The location and duration of each fixation were also compared. The HR older and younger participants showed a higher rate of spin turns. Whereas the younger participants fixated approximately three steps ahead, the older participants directed their fixation closer toward the imminent footfall target, demonstrating their difficulty to use the visual information regarding the target in a feedforward manner. Such patterns of fixations were significantly associated with the frequency of stepping and avoidance failures. The higher rate of stepping and avoidance failures in the MTST were attributed to maladaptive turning behavior, which is potentially destabilizing, and the tendency to fixate on/around an imminent footfall target, which prevented older individuals from considering the locations of future footfall targets. (C) 2011 Elsevier Ireland Ltd. All rights reserved.

DOI： 10.1016/j.archger.2011.08.012

PubMed

International / domestic magazine：International journal  

Little is known about dynamic balance control under dual-task conditions in older adults with fear of falling (FoF). The purpose of this study was to examine the effect of FoF on anticipatory postural adjustment (APA) during gait initiation under dual-task conditions in older adults. Fifty-seven elderly volunteers (age, 79.2 [6.8] years) from the community participated in this study. Each participant was categorised into either the Fear (n=24) or No-fear (n=33) group on the basis of the presence or absence of FoF. Under single- and dual-task conditions, centre of pressure (COP) data were collected while the participants performed gait initiation trials from a starting position on a force platform. We also performed a 10-m walking test (WT), a timed up & go test (TUG), and a functional reach test (FR). The reaction and APA phases were measured from the COP data. The results showed that under the dual-task condition, the Fear group had significantly longer APA phases than the No-fear group, although no significant differences were observed between the 2 groups in the reaction and APA phases under the single-task condition and in any clinical measurements (WT, TUG, and FR). Our findings suggest that specific deficits in balance control occur in subjects with FoF during gait initiation while dual tasking, even if their physical functions are comparable to subjects without FoF.

DOI： 10.1016/j.gaitpost.2011.09.100

PubMed

International / domestic magazine：International journal  

AIMS: The purpose of this study is to clarify the effects of exercise intervention on vascular risk factors in older adults with mild cognitive impairment (MCI). METHODS: Community-dwelling older adults who met the definition of MCI using the Petersen criteria (n = 100; mean age = 75.3 years) were randomly allocated to the exercise (n = 50) or education control group (n = 50). Participants in the exercise group exercised under the supervision of physiotherapists for 90 min/day, 2 days/week, 80 times for 12 months. Anthropometric profiles, blood markers, blood pressure, and physical fitness (the 6-min walking test) were measured. Total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and TC/HDL-C risk ratio measurements were taken from blood samples. RESULTS: The exercise group showed significantly reduced TC and TC/HDL-C risk ratio after training compared with baseline levels (p < 0.001, p = 0.004). However, no significant reduction was found for the control group (p = 0.09, p = 0.09). Physical fitness also significantly improved after exercise intervention compared with the control group (p < 0.0001). CONCLUSION: Exercise intervention was associated with positive changes in important vascular risk factors related to cognitive decline and vascular disease in older adults with MCI.

DOI： 10.1159/000343486

PubMed

International / domestic magazine：International journal  

BACKGROUND: In spite of a number of reports about various factors associated with the fear of falling (FoF) among older adults (such as age and physical function), the relationship between FoF and cognitive decline remains unclear. OBJECTIVE: To determine which cognitive function is related with the prevalence of FoF in older adults. METHODS: Participants were 101 older adults (mean age 75.1 years; 48.5% males). Of these, 54 older adults (53.4%) were classified as the fear group on the basis of the presence of FoF. Age, gender, the Timed Up and Go test (TUG), fall history, the Alzheimer's Disease Assessment Scale, the Wechsler Memory Scale-Revised-Logical Memory I (WMS-LM I), the delayed memory test, digit symbol coding, digit span and verbal fluency were measured as potential relevant factors. RESULTS: Logistic regression analysis revealed that TUG [odds ratio (OR) 1.43, 95% confidence interval (CI) 1.12-1.83; p = 0.004], WMS-LM I (OR 1.20, 95% CI 1.07-1.35; p = 0.002) and fall history (OR 4.38, 95% CI 1.53-12.51; p = 0.006) were independently associated with FoF. CONCLUSIONS: The results suggest that a lower prevalence of self-reported FoF is associated with memory decline among older adults. Insensitivity to FoF may be one of the characteristics of psychological change with memory decline.

DOI： 10.1159/000336988

PubMed

Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

OBJECTIVE: The purpose of this randomized control trial study was to evaluate the effectiveness of a digital video disc (DVD)-based seated dual-task (DT) stepping exercise to improve the DT walking capability in elderly people. In the DT exercise, participants were asked to perform a verbal fluency task while stepping as quickly as possible. METHODS: Eight clusters (n=93) randomized into a DVD group (4 clusters, n=48) and a nonexercise control group (4 clusters, n=45) participated in this trial. In the DVD group, participants received 20 min of group training twice a week for 24 weeks. The exercise class used an exercise DVD that included a 15-min basic exercise and a 5-min DT exercise. No exercise program was prescribed for the control group. The measurements were based on the difference in physical function, including DT walking, between the DVD and control groups. In the DT walking test, participants walked individually at a comfortable speed while carrying a ball on a tray. The relative DT lag was calculated by using simple walking as the comparison condition. The Timed Up and Go test and the 5-chair stand test were also performed. RESULTS: The median relative adherence to the study was 87.5% (25th-75th percentile, 83.3%-95.8%) in the DVD group. The outcome measurements, including the DT walking time and DT time lag (p<0.05), among participants in the DVD group were significantly improved. However, other outcome measurements were not significantly different between the two groups (p>0.05). CONCLUSION: The current study reports the effectiveness of a DVD-based exercise for the improvement of the DT walking capability. A larger study is needed to confirm the present results. Study of a Web-based exercise regime would be valuable to identify the most effective exercise for prevention of falls and fall-related fractures.

DOI： 10.1089/tmj.2011.0054

PubMed

Publishing type：Research paper (scientific journal)  

The purpose of this study was to clarify the difference in muscle coactivation during postural control between older and young adults and to identify the characteristics of postural control strategies in older adults by investigating the relationship between muscle coactivation and postural control ability. Forty-six healthy older adults (82.0 +/- 7.5 years) and 34 healthy young adults (22.1 +/- 2.3 years) participated. The postural tasks selected consisted of static standing, functional reach, functional stability boundary and gait. Coactivation of the ankle joint was recorded during each task via electromyography (EMG). The older adults showed significantly higher coactivation than the young adults during the tasks of standing, functional reach, functional stability boundary (forward), and gait (p &lt; 0.01). Postural sway area (rho = 0.42, p &lt; 0.05) and functional reach distance (rho = -0.52, p &lt; 0.05) significantly correlated with coactivation during the corresponding task in older adults, i.e., muscle coactivation was significantly higher in the elderly with low postural control ability than in the elderly with high balance ability. Increased muscle coactivation could be a necessary change to compensate for a deterioration in postural control accompanying healthy aging. Further research is needed to clarify in greater detail positive and negative effects of muscle coactivation on postural control. (C) 2011 Elsevier Ireland Ltd. All rights reserved.

DOI： 10.1016/j.archger.2011.01.003

PubMed

DOI： 10.1093/ageing/afr068

PubMed

Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

BACKGROUND: Elderly individuals who are at high risk for a fall generally exhibit increased gait variability, a decline in visuomotor control of foot movement, and cognitive impairment, particularly in executive functions. A new walking test, a multitarget stepping task, was developed in the present study to identify elderly individuals with impaired stepping performance on a walkway requiring the involvement of executive functions to find a footfall target. METHODS: Thirty-one high-risk (82.7 ± 6.4 years) and 87 low-risk (80.7 ± 7.9 years) elderly individuals performed the multitarget stepping task on 2 days with a 2-week interval. For the multitarget stepping task, they walked while stepping on squares with an assigned color as a footfall target continuously along the 15 lines while avoiding other colors (distracters). Two types of failure were measured: (a) failure to step precisely on the target (stepping failure) and (b) failure to avoid distracters (avoidance failure). The two groups' performance was compared. A logistic regression analysis was also performed to determine whether the measurements were independently associated with falling. RESULTS: The high-risk groups showed a significantly higher rate in stepping (64.5 vs 25.3% of participants in the group) and avoidance (54.8 vs 17.2%) failure than the low-risk groups. The test-retest analyses showed good agreement for both measurements. A logistic regression analysis demonstrated that the stepping failure was independently associated with falling (odds ratio = 19.365, 95% confidence interval = 3.28-113.95; p < .001). CONCLUSIONS: Measurements of stepping accuracy while performing the multitarget stepping task, particularly precise stepping failure, could contribute to identifying high-risk elderly individuals.

DOI： 10.1093/gerona/glr073

PubMed

Publishing type：Research paper (scientific journal)   International / domestic magazine：International journal  

BACKGROUND AND AIMS: The aim of the present study is to compare the gaze behavior between fallers and non-fallers during obstacle avoidance in dual-task conditions. METHODS: Nine older adults who had no experience of falling (mean age 79.9 ± 5.4) and 9 older adults with known experience of falling (83.4 ± 3.6) participated in the study. We examined their gaze behavior during obstacle avoidance in singletask (ST) and dual-task (DT) conditions. RESULTS: In the ST condition, compared with the faller group, the non-faller group showed no significant difference in timing of gaze transfer from the obstacle (faller: gaze transfer from obstacle when 1.6 ± 1.1 steps before; non-faller: 1.9 ± 0.7 steps before, p=0.493). In the DT condition, the faller group chose a transfer of gaze strategy significantly earlier than the non-faller group (faller: 2.7 ± 1.4 steps before; non-faller: 1.6 ± 0.5 steps before, p=0.008). CONCLUSION: Our findings suggest that fallers chose an early transfer of gaze strategy when challenged with an obstacle in DT conditions.

DOI： 10.3275/7258

PubMed

Publishing type：Research paper (scientific journal)  

Background. Obstacles are a common cause of falls among older adults. Anticipatory motor planning for obstacle negotiation must be completed during the precrossing phase in order to step over the obstacle safely. This cognitive load may affect anticipatory postural adjustments (APAs) in older adults at high risk of falling. This study explored the effect of obstacle negotiation on APA during gait initiation in older adults at high risk of falling.
Methods. Seventy-six elderly volunteers (mean age: 80.5 [7.6 years]) from the community participated in this study. Participants performed gait initiation tasks from a starting position on a force platform under the following two conditions: (1) unobstructed (smooth walkway) and (2) obstructed (walkway with an obstacle placed at 1 m from the initial position). The reaction and APA phases were measured from the data of center of pressure. Each participant was categorized as a high-risk or a low-risk individual according to the presence or absence of a fall experience within the past year.
Results. High-risk participants had significantly longer APA phases than low-risk participants under the obstructed condition even though there was no significant difference between groups under the unobstructed condition. Reaction phase was not significantly different between groups in either the unobstructed or the obstructed condition.
Conclusion. Motor performance deterioration occurred in high-risk participants in the beginning of the precrossing phase of obstacle negotiation. A slow and inefficient APA at the precrossing phase of obstacle negotiation might be one of the causes of accidental falls.

DOI： 10.1093/gerona/glr081

PubMed

Publishing type：Research paper (scientific journal)  

The purpose of this study was to examine whether the Nintendo Wii Fit program could be used for fall risk assessment in healthy, community-dwelling older adults. Forty-five community-dwelling older women participated in this study. The "Basic Step" and "Ski Slalom" modules were selected from the Wii Fit game program. The following 5 physical performance tests were performed: the 10-m walk test under single- and dual-task conditions, the Timed Up and Go test under single- and dual-task conditions, and the Functional Reach test. Compared with the faller group, the nonfaller group showed a significant difference in the Basic Step (P &lt; .001) and a nonsignificant difference in the Ski Slalom (P = .453). The discriminating criterion between the 2 groups was a score of 111 points on the Basic Step (P &lt; .001). The Basic Step showed statistically significant, moderate correlations between the dual-task lag of walking (r = .547) and the dual-task lag of the Timed Up and Go test (r = -.688). These results suggest that game-based fall risk assessment using the Basic Step has a high generality and is useful in community-dwelling older adults. (Geriatr Nurs 2011;32:188-194)

DOI： 10.1016/j.gerinurse.2011.02.002

PubMed

【目的】姿勢制御エクササイズの反復が足関節周囲筋の同時活動に及ぼす影響を明らかにすることを目的とした。【方法】対象は健常若年者22名とし、介入群(11名)と対照群(11名)に無作為に分類した。不安定板上で10秒間姿勢を保持する課題を行い、その際の筋活動を前脛骨筋、ヒラメ筋より導出した。介入群には不安定板上での反復エクササイズを行い、その後不安定板上での評価を再度実施した。得られた筋電図波形より、同時活動の指標であるco-contraction index(CI)を求めた。【結果】介入群のCIは、エクササイズ後に有意に減少し、介入前50.7±23.9%、介入後38.5±22.0%であった。一方、対照群のCIには変化が認められず、介入前58.7±23.9%、介入後60.9±23.1%であった(p<0.05)。【結論】不安定場面での同時活動は、姿勢制御エクササイズを行うことで減少する。このことは、姿勢制御エクササイズにより筋の過剰な同時活動が減少することを示唆している。(著者抄録)

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International / domestic magazine：International journal  

DOI： 10.1111/j.1532-5415.2010.03206.x

PubMed

Publishing type：Research paper (scientific journal)  

Background/Purpose: The purpose of this study was to determine whether or not daily activities determined by average daily steps are associated with age, gender, body mass index, fear of falling, and physical functions (locomotive function, balance function, and muscle power) in community-dwelling nonfrail and frail older adults. Methods: This is a cross-sectional study conducted in community-dwelling older adults in Japan. Based on the Timed Up and Go (TUG) test, 629 elderly adults were divided into two groups: 515 were grouped to nonfrail elderly (TUG time less than 13.5 seconds, mean age 77.0 ± 7.2 years) and 114 to frail elderly (TUG time of 13.5 seconds or more, mean age 76.1 ± 7.5 years). Daily physical activities were determined by average daily steps measured by pedometer and four other physical function tests (10-m walk test, single-leg standing, functional reach, and five-chair stand test) were performed along with the assessment of fear of falling. Results: Stepwise regression analysis revealed that age, gender, 10-m walk test, and single-leg standing were significant and independent determinants of the average step counts in the nonfrail elderly (R2 = 0.282, p &lt
0.001), whereas fear of falling was the only significant and independent determinant of the average step counts in the frail elderly (R2 = 0.119, p &lt
0.001). Conclusion: These results indicate that differential factors may be related to daily activities depending on the level of frailty in community-dwelling older adults. © 2011, Asia Pacific League of Clinical Gerontology &amp
Geriatrics. Published by Elsevier Taiwan LLC. All rights reserved.

DOI： 10.1016/j.jcgg.2011.02.004

1.高齢者における自己効力感の低下、活動制限や生活機能低下につながる悪循環をもたらす。2.転倒関連自己効力感は、レジスタンストレーニングなどの運動介入や認知行動療法によって改善が可能である。3.高齢者の身体活動に対する自己効力感は行動変容技法によって改善が可能であるが、若年者と異なり、高齢者では自己調整を促す手法が有効でない可能性がある。4.自己効力感のような心理的要素を、効果判定や介入プログラム作成のための判断材料として捉えた、包括的な理学療法アプローチの開発が望まれる。(著者抄録)

DOI： 10.11477/mf.1551200528

CiNii Article

DOI： 10.11477/mf.1551106632

CiNii Article

Presentation type：Public lecture, seminar, tutorial, course, or other speech  

【はじめに】 転倒は様々な因子が複雑に絡み合って発生する事故である。転倒を予防するためには、それらの因子を事前に把握し、その要因に対処することが重要である。歩行機能と転倒との関連については、速度や歩幅等の平均値が関係していると報告されているが、近年では平均値を観察するのではなく、これらの変動係数 (Coefficient of Variability: CV) に着目した報告が増えてきている。本研究では、加速度計を用いて計測した歩行周期時間のCV（歩行CV）と転倒との関連を明らかにすることを目的とした。また、副次的解析として、このCVと他の転倒関連項目との関係を比較検討した。【方法】 対象は、独歩あるいは歩行補助具を使用して自立して歩行可能であり、日常生活動作は全て自立して遂行可能な者191名（平均年齢80.7±7.9歳・女性161名）とした。評価項目は、快適歩行時の歩行CVと過去半年の転倒経験歴、Timed Up and Go test (TUG)、Functional Reach Test (FRT)、10m快適歩行時間、二重課題下(Dual Task: DT)10m歩行時間、5秒間立位ステッピング回数の計7項目とした。歩行CVは10m快適歩行時に3軸加速度計（ATR-Promotions社製）を両側外果に取り付け、中央8歩行周期を解析対象とした。加速度計のサンプリング周波数は200Hzとし、垂直成分の加速度信号より床接地時の特徴的波形が確認できることから、同成分の信号を解析対象とした。DTは副課題としてManual Taskを採用し、右手掌にお皿をのせ、その上にボールをのせた状態で測定した。また、ボールを落とす失敗は1度までは再評価を行い、2度失敗した者は課題が困難と判断し除外した。立位ステッピングは、ステッピング回数測定器（竹井機械工業製）を使用し、肩幅に開いた立位にて5秒間での最速足踏み回数を計測した。計測値は左右のステッピング回数の合計を用いた。統計解析は、対象者を過去半年間の転倒経験の有無により、転倒群と非転倒群の2群に分類した。連続変数の場合はshapiro-wilk検定にて正規性の検定を行い、パラメトリックであった場合には対応のないt-検定を、ノンパラメトリックであった場合にはWilcoxon rank sum検定を用いて2群間の比較を行った。カテゴリー変数の場合はχ二乗検定を用いて2群間の比較を行った。また、歩行CVをはじめとした転倒リスク関連評価項目の特性を分類するために因子分析を行った。因子の抽出には重み付けのない最小2乗法を用い、因子数の決定には累積寄与率が80％を超えるまでと規定した。因子数を決定した後にVarimax回転を行い、各因子について因子負荷量が0.400以上の因子項目を抽出した。なお、いずれの解析も有意水準は5％未満とした。【説明と同意】 対象者およびその家族に対して、本研究の趣旨を紙面および口頭にてインフォームドコンセントを行い署名にて同意を得た。【結果】 転倒群73名(38.2％)、非転倒群118名であった。歩行CVは、転倒群が4.7±2.3％、非転倒群が3.8±2.0％と転倒群が有意に大きな値を示した（p&lt;0.01）。その他の測定項目でも、TUG（転倒群vs非転倒群）14.3±6.1秒 vs 12.3±5.5秒（p=0.02）、FRT 17.3±8.5cm vs 20.2±7.5cm（p=0.02）、10m歩行時間 15.2±7.2秒 vs 12.3±4.5秒（p&lt;0.01）、DT10m歩行時間 17.1±8.9秒 vs 13.9±5.7秒（p&lt;0.01）、立位ステッピング 17.4±6.1回 vs 20.2±7.3回（p&lt;0.01）と、全ての項目において2群間に有意な差を認めた。因子分析では、3つの因子が抽出され、因子1を説明する変数には10m歩行時間、DT10m歩行時間、TUG、因子2にはTUG、FRT、立位ステッピング回数、因子3には歩行CVが該当した。【考察】 歩行CVが高齢者の転倒経験の有無により違いがあるかを比較検討した結果、転倒群は非転倒群に比して、有意に高い歩行CVを示した。先行研究からも歩行周期時間のバラツキが大きいと転倒リスクが高いと報告されており、本研究もその結果を支持する結果となった。因子分析の結果より、転倒に関連するとされる評価6項目を3つに分類することができた。因子1には10m歩行時間、DT10m歩行時間、TUGのような歩行を要す測定項目が該当し、因子2にはTUG、FRT、立位ステッピング回数のようにバランスを要す測定項目、そして因子3には、歩行CVのように歩行やバランスを要するだけでなく歩行リズムも必要とされる測定項目が該当した。つまり、歩行CVは他の評価要因では捉えることのできない要素で転倒リスクを評価できる指標であると考えられる。【理学療法研究としての意義】 疾病や障害の予防、健康増進の視点から見た理学療法の必要性が叫ばれる中、本研究は、近年注目されている歩行変動の有用性および高齢者の転倒予防の評価項目の共通因子が明らかとなり、今後の理学療法士の専門性を支える一助になりうる。

妊娠末期の産婦79名と出産経験者31名にアンケートを行い、「妊娠に伴う腰背部〜骨盤周囲の疼痛」の有無・程度・出現時期について調査するとともに、生活様式や運動習慣との関連性について検討した。その結果、疼痛の経験を有している人の割合は産婦で29%、出産経験者で23%であった。疼痛の出現時期は、妊娠初期よりも中期が多く、中期よりも後期が多かった。疼痛の程度は、妊娠初期よりも中期が強く、中期よりも後期が強かった。生活様式との関連では、柔らかい寝具を使用している群に比べて硬い寝具を使用している群で疼痛出現率が高い傾向にあった。運動習慣との関連では、妊娠中期の活動量が多い群に比べて少ない群で疼痛出現率が有意に高かった。

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【目的】&lt;BR&gt; 主動作筋と拮抗筋が同時に活動することを筋の同時活動(co-activation)という．一般に関節に生じる過剰な同時活動は「力み」として表現される．近年，高齢者では姿勢制御場面での同時活動が増大することが明らかになってきている．姿勢制御場面での同時活動の増大は，関節の固定性を高め，動作の安定性を向上させる一方，スムーズな動作遂行を阻害し，転倒発生を助長する可能性もあるとされる．&lt;BR&gt; 一方，姿勢制御エクササイズは高齢者の姿勢制御能力を向上させることが可能である．しかしながら，エクササイズを実施することで，高齢者の姿勢制御戦略の一つである同時活動がどのように変化するかは明らかにはなっていない．より同時活動を高める戦略をとることで姿勢制御能力の向上が獲得されるのか，反対に姿勢制御能力の向上に合わせて同時活動が減少するのか，そのメカニズムを明らかにすることは理学療法戦略を考えるうえで重要である．本研究では，高齢者に対し姿勢制御エクササイズを実施し，姿勢制御時の筋の同時活動がどのように変化しているのかを明らかにすることを目的とした．&lt;BR&gt;&lt;BR&gt;【方法】&lt;BR&gt; 対象は施設入所高齢者48名(81.6 ± 6.6歳)とした．層化ブロックランダム割り付けにより，対象者を介入群24名，対照群24名に分類した．なお，顕著な中枢神経障害を有する者，および重篤な認知機能障害を有するものは対象から除外した．運動プログラムは姿勢制御能力向上を目的としたエクササイズ(片脚立位，リーチエクササイズ，ステップエクササイズなど)からなり，1回当たり約40分のプログラムを，週2回の頻度で8週間，介入群に対して実施した．なお、姿勢制御エクササイズの際には主動作筋の働きを意識するよう指導した。介入期間中、対照群には通常通りの生活を送るように指示した。姿勢制御能力の測定項目は10m歩行時間，立位重心動揺，Functional reach(以下FR)，安定性限界（前・後），片脚立位，立位ステッピングとした．立位時の重心動揺，安定性限界の重心移動距離の測定には，床反力計( kistler社製)を使用した．なお，姿勢制御能力の測定項目のうち，立位，FR，安定性限界について，筋電図を用いた同時活動の測定を実施した．筋電図には表面筋電図測定装置(Noraxon社製)を用い，利き足の前脛骨筋とヒラメ筋の筋活動を導出した(サンプリング周波:1500Hz)．得られた筋電信号は，平滑化処理を行った後，それぞれの筋の最大等尺性収縮を100%とした正規化を行った．正規化された筋電図波形より，Falconerらの推奨する同時活動指標であるCo-contraction index を求めた．&lt;BR&gt; 統計解析には，姿勢制御能力，同時活動に関して，各群，介入前後を要因とした分割プロットデザインの二元配置分散分析を用いた．交互作用のみられた項目については，事後検定としてBonferroni補正を実施したWilcoxon検定，Mann-Whitney U検定を使用した．&lt;BR&gt;&lt;BR&gt;【説明と同意】&lt;BR&gt; 対象者には研究の内容を紙面上にて説明した上，同意書に署名を得た． 本研究は本学倫理委員会の承認を得た．&lt;BR&gt;&lt;BR&gt;【結果】&lt;BR&gt; 8名が脱落し，最終的に介入群20名(80.8 ± 6.7歳)，対照群20名(82.4 ± 6.3歳)となった．姿勢制御能力としては，FR，安定性限界前方において，介入群で有意な改善がみられた(交互作用: p&lt;0.05)．同時活動に関しては，FR，安定性限界前方において，介入群で有意に同時活動が減少していた(交互作用: p&lt;0.05)．立位姿勢，安定性限界後方には，交互作用，主効果とも認められなかった(p≧0.05)．筋活動量については，介入群においてFR時の前脛骨筋の活動が減少し，ヒラメ筋の活動が増大する傾向にあった．また，安定性限界前方時のヒラメ筋の筋活動が介入群で上昇していた．&lt;BR&gt;&lt;BR&gt;【考察】&lt;BR&gt; 本研究の結果，高齢者では，姿勢制御エクササイズによる姿勢制御能力の向上に伴い，筋の同時活動が減少することが明らかになった．このことは，エクササイズにより高齢者が姿勢制御能力を獲得していく際には，より効率の良い動作戦略を獲得しながらパフォーマンスを向上させていることを示唆している．動作時の同時活動の増大は，関節の固定性向上に寄与する反面，関節の自由度の低下をもたらすとされており，自由度の高い姿勢制御を行っていく上で障害となる可能性がある．同時活動を減少させることは，動作効率の向上に加え，さまざまな環境下で適切な姿勢制御を獲得していく上で重要であると考えられる．&lt;BR&gt;&lt;BR&gt;【理学療法学研究としての意義】&lt;BR&gt; 臨床場面では，高齢者に限らず，同時活動を過剰に増大させた姿勢制御戦略をとっている症例が多くみられる．これらの症例に対しては，適切な姿勢制御エクササイズを実施することで，過剰な同時活動を抑制し，より効率のよい姿勢制御戦略を獲得することが可能となると思われる．

【目的】主動作筋と拮抗筋が同時に活動することを筋の同時活動(co-activation)という．一般に関節に生じる過剰な同時活動は「力み」として表現される．これまで高齢者においては，最大筋力発揮時に主動作筋に対する拮抗筋の活動が増大していることが報告されており，筋出力低下の因子として説明されている．また，姿勢制御場面での同時活動としては，加齢による立位・歩行時の同時活動の増大が生じる可能性が示唆されている．特に歩行時の同時活動の増大は，関節の固定性を高め，動作の安定性を向上させる反面，歩行のエネルギー効率を低下させるとされている．また，同時活動の増大による歩行の力みは，スムーズな動作遂行を阻害し，高齢者の転倒発生を助長する可能性がある．一方，同時活動への心理面の影響として，転倒恐怖心が静的姿勢制御に影響し，姿勢を固める戦略に寄与することが報告されている．臨床場面において，歩行時に過剰な力みが生じている高齢者は散見されるが，歩行時における高齢者の同時活動の増大に関連する因子については明らかではない．本研究では，高齢者の歩行時の同時活動を測定し，転倒・転倒恐怖感の有無，年齢，歩行能力が歩行時の同時活動に及ぼす影響を明らかにすることを目的とした．&lt;BR&gt;【方法】対象は地域在住・施設入所高齢者38名(平均年齢82.3±6.8歳，身長150.8±6.3cm，体重52.1±6.7kg)とした．なお，整形外科的疾患，神経学的疾患を有するもの，重度の認知症症状を有する対象者は除外した．歩行時の同時活動の測定には表面筋電図(Telemyo2400: Noraxon社製)を用い，利き足の前脛骨筋とヒラメ筋の筋活動を導出した(サンプリング周波:1500Hz)．10m自由歩行の所要時間，および動作筋電図を測定した．動作筋電図の解析対象は，フットスイッチセンサーより同定した3歩行周期とした．筋電信号は全波整流化，50msecウインドウでのRoot mean squareによる平滑化処理を行った後，それぞれの筋の最大等尺性収縮を100%とした正規化を行った．正規化された筋電図波形より，Falconerらの推奨する同時活動指標であるCo-contraction index(CI)を用いて，歩行時のCo-contraction indexを算出した(歩行CI)．転倒経験については，過去一年間での転倒経験の有無を聴取した．転倒恐怖感は日本語版Fall Efficacy Scale(40点満点)を用いて評価し，40点満点を転倒恐怖感なし，39点以下を転倒恐怖感ありとした．統計解析として，従属変数を歩行CI，独立変数を転倒経験の有無，転倒恐怖感の有無，共変量を年齢，歩行速度とした共分散分析を用いた．なお，共分散分析の適応を確認するため，平行性の検定を行った．統計学的有意水準は5%未満とした．&lt;BR&gt;【説明と同意】対象者には研究の内容を紙面上にて説明した上，同意書に署名を得た．なお本研究は本学の倫理委員会の承認を得ている．&lt;BR&gt;【結果】歩行CIは51.9±11.7％，平均歩行時間は13.9±7.7秒であった．過去1年間に転倒経験を有した者は7名（18.4%），転倒恐怖感を有していたものは21名（55.2%）であった．共分散分析の結果，転倒恐怖感の有無が歩行CIを有意に説明する因子となった(F=6.173, p=0.018)．その他，年齢(F=0.68, p=0.68)，歩行時間(F=0.57, p=0.46)，転倒の有無(F=0.71, p=0.41)は歩行CIに対して有意な影響を認めなかった．なお，転倒恐怖感の有無による歩行CIの平均値は，あり群59.5±12.2%，なし群46.7±8.5%であった．&lt;BR&gt;【考察】本研究の結果，転倒恐怖感を有する高齢者は，年齢や歩行速度の影響とは無関係に，歩行時の足関節の同時活動が高まっていることが明らかになった．これは，転倒恐怖という情動が歩行動作時の姿勢制御戦略に関連していることを示唆している．この同時活動が増大した原因としては，動作の安定性を得るための代償的戦略を選択したことが考えられるまた、不安や緊張状態といった情動はγ運動ニューロンの興奮性を増大させることが報告されており，今回の結果に関連している可能性がある．この同時活動の増大は動作における安定性獲得というメリットがある反面，外乱刺激に対する適応能力を阻害するともいわれている．つまり、同時活動を高めた歩行戦略をとっている高齢者では運動の自由度が制限されるため，例えば実生活場面において、つまずきや滑りが生じた際に，適切な姿勢調整を瞬時に行う能力等が低下している可能性がある．&lt;BR&gt;【理学療法学研究としての意義】転倒に対する恐怖感を感じている高齢者は多く存在する．同時活動の増大は，場合によっては姿勢の安定性を確保する意味で有益なものとなるが，過剰な増大は動作の制限因子となりうる．また，転倒恐怖感は活動性やQOLに負の影響を与えるとされている．われわれ理学療法士が転倒恐怖感に対して適切なアプローチを行うことは，高齢者の過剰な同時活動を抑制し，適切な動作遂行能力の獲得につなげるためにも重要である．

【目的】&lt;BR&gt;主動作筋と拮抗筋が同時に活動することを筋の同時活動(co-activation)という．一般に関節に生じる過剰な同時活動は「力み」として表現される．これまで高齢者においては，最大筋力発揮時に主動作筋に対する拮抗筋の活動が増大していることが報告されており，筋出力低下の因子の一つとして説明されている．また，姿勢制御場面での同時活動としては，加齢による立位・歩行時の同時活動の増大が生じる可能性が示唆されている．&lt;BR&gt;姿勢制御場面での適切な同時活動の増大は、関節の固定性を高め，動作の安定性を向上させるというメリットがある反面、エネルギー効率を低下させるとされている．また，過剰な同時活動の増大は，スムーズな動作遂行を阻害し，例えば高齢者の転倒発生を助長する可能性があることから、同時活動を定量化し、姿勢制御能力の一つとして評価することは重要である。&lt;BR&gt;しかしながら、これらの同時活動と、姿勢制御能力との関連は明らかにされておらず、加齢に伴いどのような変化が生じているのかは不明である。本研究では，若年者と高齢者の姿勢制御時の同時活動を測定し、加齢による影響と、姿勢制御能力と同時活動の関連を明らかにすることを目的とした。&lt;BR&gt;&lt;BR&gt;【方法】&lt;BR&gt;対象は地域在住・施設入所高齢者46名(82.0±6.8歳)、健常若年者34人(22.1±2.3歳)とした．なお，整形外科的疾患，神経学的疾患を有するもの，重度の認知症症状を有する対象者は除外した．同時活動の測定には表面筋電図(Telemyo2400: Noraxon社製)を用い，利き足の前脛骨筋とヒラメ筋の筋活動を導出した(サンプリング周波:1500Hz)．測定動作は、静的姿勢制御として静止立位、動的姿勢制御として安定性限界（前・後）、ファンクショナルリーチ（以下FR）、自由歩行を測定した。筋電図の測定は、静止立位、安定性限界、FRについては安定した３秒間を、歩行については、フットスイッチセンサーより同定した3歩行周期とした．また、立位時の重心動揺、安定性限界の重心移動距離の測定には、床反力計(kistler 9286: kistler社製)を使用した。筋電信号は全波整流化，50msecウインドウでのRoot mean squareによる平滑化処理を行った後，それぞれの筋の最大等尺性収縮を100%とした正規化を行った．正規化された筋電図波形より，Falconerらの推奨する同時活動指標であるCo-contraction index(CI)を用いた．統計解析には、若年群と高齢群の姿勢制御能力、CIを比較するため、正規分布の確認できた変数についてはt検定、正規分布していない変数についてはMann Whitney U検定を使用した。また、各群の姿勢制御能力とCIの関係をSpeamanの順位相関係数を用いて分析した。統計学的有意水準は5%未満とした．&lt;BR&gt;&lt;BR&gt;【説明と同意】&lt;BR&gt;対象者には研究の内容を紙面上にて説明した上，同意書に署名を得た．なお本研究は本学の倫理委員会の承認を得ている．&lt;BR&gt;&lt;BR&gt;【結果】&lt;BR&gt;姿勢制御能力については、すべての項目で若年群が高齢群よりも優れた成績を示した(p&lt;0.001)。筋の同時活動については、安定性限界の後方以外のすべての項目において、高齢群の方が若年者よりも高い値を示した(p&lt;0.01)。姿勢制御能力と同時活動との関連では、高齢群において安静立位(r=0.42, p&lt;0.05)、FR(r=-0.52, p&lt;0.05)で、有意な相関を認めた。安定性限界の前方でも同様の傾向がみられた(r=-0.33, p=0.06)。若年群では、すべての項目で有意な相関を認めなかった。&lt;BR&gt;&lt;BR&gt;【考察】&lt;BR&gt;本研究の結果、高齢者は若年者よりも姿勢制御場面において高い同時活動を示すことが明らかになった。このことは、加齢に伴い、姿勢制御場面では同時活動を高めるという代償的戦略を用いることを示唆している。また、姿勢制御能力の低下した高齢者ほど、足関節の同時活動が高いという関係がみとめられた。このことは、姿勢制御能力の低下した高齢者ほど、同時活動を高める戦略をとっていることを示している。これら同時活動の増大は、関節の固定性を高めることで安定化を図るというポジティブな影響があると考えられる。しかし一方で、関節の自由度を制限することで、バランス能力を制限しているというネガティブな影響もある可能性がある。&lt;BR&gt;&lt;BR&gt;【理学療法研究としての意義】&lt;BR&gt;同時活動の増大は一種の適応反応であると考えられる。しかし、それが過剰になる、もしくはあらゆる状況で同時活動を高める姿勢制御戦しか選択できないとすると、同時活動を高める戦略では対応できない場面で、動作の制限や転倒リスクの増大につながる可能性が考えられる。臨床場面では、バランス能力の低下した患者に対してリハビリテーションを行う際には、適切な同時活動の獲得、過剰な同時活動の排除、環境に適応した同時活動戦略を選択する能力を獲得していくことが安定性の向上に重要であるかもしれない。

【目的】&lt;BR&gt;転倒による骨折は、要介護の状態となる要因の上位に挙げられている。そのため、転倒の危険因子に関しては、世界中で調査が行われており、筋力低下や歩行速度低下などの運動機能に加えて認知機能や投薬状況、環境因子などが報告されている。一方、脊椎の後弯変形は、高齢者の代表的な形態学的変化であり、立位バランス能力低下や歩幅減少など、変形に直結する問題を生じさせるだけでなく、移動時のエネルギー効率低下や、視界の制限など二次的な影響を招くことも予想され、重大な転倒リスク要因となっている可能性がある。しかし、脊椎アライメント、歩行能力、バランス能力、筋力を、多変量的に解析し転倒との関連性について検討されたものは見当たらず、脊椎アライメントの変化がどの程度、転倒に寄与しているのかは不明である。本研究の目的は、高齢者における脊椎アライメントを加えた種々の運動機能が転倒に及ぼす影響について多変量的に検討することである。&lt;BR&gt;【方法】&lt;BR&gt;対象は、地域在住高齢者117名（平均年齢79.5±8.6歳）である。なお、神経学的疾患を有する者、重度認知症の者は対象から除外した。過去一年間の転倒歴を聴取し、脊椎アライメント、膝伸展筋力、10m歩行時間、timed up and go test（以下TUG）、開眼片足立位時間、functional reach test（以下FR）を測定した。脊椎アライメントは、スパイナルマウスを用いて静止立位・体幹屈曲位・体幹伸展位の3姿位での、胸椎後弯角度、腰椎前弯角度および前後屈可動域を立位にて測定した。膝伸展筋力は、膝関節90°屈曲位で等尺性筋力を測定した。得られた数値より関節トルクを算出し、体重で除してトルク体重比として正規化した。&lt;BR&gt;統計解析は、転倒歴を基に転倒群、非転倒群の2群に分類し、各測定項目の差を対応のないt検定で検討した。また、ピアソン相関係数を用いて、脊椎アライメントの関連性を検討した上で、転倒の有無を従属変数、年齢、静止立位時の腰椎前弯角度、膝伸展筋力、歩行速度、TUG、片足立位時間、FRを独立変数としたとしたロジステッィク回帰分析を行い、転倒に関連する因子を抽出した。なお、統計学的有意水準は5％未満とした。&lt;BR&gt;【説明と同意】&lt;BR&gt;対象者には、研究の趣旨について十分な説明を行い、研究参加の同意を得た。&lt;BR&gt;【結果】&lt;BR&gt;対象者のうち、過去一年間に転倒した者は40名（35％）であった。対応のないt検定によって、転倒群と非転倒群を比較した結果、脊椎アライメントでは静止立位時および体幹伸展時の腰椎前弯角度に有意差を認め、転倒群で腰椎前弯角度が減少していた（p&lt;0.01）。また、脊椎の可動域に関しては、腰椎屈曲可動域に有意差を認め、転倒群では屈曲可動域が減少していた。また、膝伸展筋力、FR、10m歩行時間およびTUGにも有意差を認め、転倒群では有意に筋力（p&lt;0.05）、動的な立位バランス（p&lt;0.05）および移動能力（p&lt;0.01）が低下していた。なお、片足立位保持時間には有意な差を認めなかった。脊椎アライメントの関連性については、静止立位時の腰椎前弯角度と体幹伸展時・屈曲時の腰椎前弯角度および屈曲可動域の間に有意な相関を認めた（r=0.89,r=0.63,r=-0.39,p&lt;0.01）。&lt;BR&gt;さらに、転倒の有無を従属変数、年齢、静止立位時の腰椎前弯角度、膝伸展筋力、歩行速度、TUG、片足立位時間、FRを独立変数としたロジスティック回帰分析による多変量解析の結果、転倒に影響を及ぼす因子として、TUG（95％信頼区間：1.006〜1.343）、膝伸展筋力（95％信頼区間：1.000〜1.018）、静止立位時の腰椎前弯角度（95％信頼区間：1.008〜1.067）が抽出された。&lt;BR&gt;【考察】&lt;BR&gt;転倒群、非転倒群との間に差を認めた項目は数多くあったものの、多変量的に解析した結果、TUG、膝伸展筋力、静止立位時の腰椎前弯角度が抽出され、転倒の危険性を高める要因になることが示唆された。TUGは、立ち上がりや方向転換等を含めた複合的な移動能力、膝伸展筋力は全身筋力、腰椎前弯角度は姿勢制御能力の指標として転倒予防を総合的に捉える上で重要な因子になると考えられる。しかし、腰椎前弯角度の減少が転倒に及ぼす影響については報告が少なく、今後さらに詳細に検討していく必要があると考えられる。&lt;BR&gt;【理学療法学研究としての意義】&lt;BR&gt;本研究の結果は、静止立位時の腰椎前弯角度の減少が転倒の危険性を高めることを示唆した。この結果は、高齢者の転倒を考える上で、脊椎アライメントの評価を行う必要があることを示しており、今後の高齢者の転倒予防事業において、適切な評価、介入のための有用な情報を提供するものと考える。

【目的】&lt;BR&gt; 日常生活は、複数の課題に囲まれた環境であり、安全に移動を行うためには、各々の課題に対して適切に注意を配分する必要がある。また、高齢者では屋内移動が多いため、歩行の開始と停止を頻回に繰り返して生活の大半を過ごしていると予想される。近年、高齢者の易転倒性に関して、二重課題(Dual Task:以下DT)条件下での動作遂行能力との関連が注目されている。その報告の多くはDT条件における定常歩行の速度を評価指標としているが、転倒との関係性の有無に関して一貫した知見は得られていない。これに対して歩行開始動作は定常歩行とは異なる複雑な姿勢調節のもとに行われており、足圧中心(以下COP)が一度後方・遊脚側へと移動することで重心との関係にずれが生じ、前方への推進力が生じる。その為、屋内で発生することが多い転倒を考えた場合、定常歩行のみでなく歩行開始動作を詳細に分析する必要があると考えた。本研究の目的はDTが高齢者の歩行開始動作に与える影響を明らかにするとともに、高齢者の転倒との関連を検証することである。&lt;BR&gt;&lt;BR&gt;【方法】&lt;BR&gt; 対象は65歳以上の高齢者71名(平均年齢80±7歳)とした。なお、著しい認知機能低下によって研究内容の理解が困難な場合、神経学的・整形外科的疾患等により左右の下肢の荷重比が著しく異なる場合は除外した。課題は静止立位(踵間距離6cm,足角10°)からの歩行開始動作とし、動作開始の合図は発光ダイオードによって行い、1歩目をできるだけ早く踏み出すように指示した。この課題を単一課題(Single task:以下ST)およびDTの2条件で実施した。DT条件では、数字を逆唱している状態で開始合図を行い、歩行開始後も逆唱を継続するように指示した。記録には床反力計(Kisler社製)を使用し、COPの初期位置を静止立位での1500msecの平均値と規定し、一歩目を踏み出そうとした際のCOPの最大側方(遊脚側)移動距離と、その時点でのCOPの後方移動距離を算出した。COPの移動距離は、それぞれ支持基底面の縦径と横径にて標準化した。また、開始合図からCOPの動き始め(初期位置から遊脚側に3SD以上変位した時点)までの時間(以下反応時間)を算出した。その他の運動機能評価として、10m自由歩行時間をSTおよびDT(数字の逆唱)の2条件で測定した。さらに過去1年間の転倒経験の有無を調査し、転倒群と非転倒群にグループ分けを行った。統計処理は、歩行開始動作の床反力解析,10m歩行時間については、群(転倒,非転倒)と条件(ST,DT)を要因とする二元配置分散分析を行い、交互作用がみられた場合にはTukey-Kramerの多重比較検定、みられなかった場合には対応のないt検定により各群,条件の比較を行った。有意水準は5%とした。&lt;BR&gt;&lt;BR&gt;【説明と同意】&lt;BR&gt; 対象者には研究内容について口頭にて十分な説明を行い、書面にて同意を得た。&lt;BR&gt;&lt;BR&gt;【結果】&lt;BR&gt; 転倒群(45名;79±8歳)・非転倒群(26名;81±7歳)で、年齢に有意差はみられなかった。COPの後方移動距離は交互作用がみられ(p&lt;.05)、DT条件において非転倒群(13.3±7.4%)に比較して転倒群(8.6±6.3%)で有意に低下していた(p&lt;.05)。COPの側方移動距離は、交互作用はみられなかった(p=.08)が、DT条件において、非転倒群(13.3±4.9%)に比較して転倒群(10.7±5.5%)で有意に低下していた(p&lt;.05)。反応時間は交互作用がみられ(p&lt;.05) 、DT条件において非転倒群(0.47±0.17sec)に比較して転倒群(0.62±0.22sec)で有意に延長していた(p&lt;.05)。10m歩行時間は交互作用がみられなかった。&lt;BR&gt;&lt;BR&gt;【考察】&lt;BR&gt; ST,DT条件での10m歩行時間には両群間に有意差がみられなかったが、転倒群ではDT条件での歩行開始におけるCOPの後方移動距離が非転倒群に比較して有意に低下しており、前方への加速力が低下していることが考えられた。DT条件では2つの課題への注意を適切に配分する必要があるが、高度に自動化した運動である定常歩行よりも、静止状態から随意的に前方への加速を生じる歩行開始のほうが必要とされる注意量が大きいと予想された。転倒高齢者は運動機能および注意機能の低下により、DT条件において、主課題である歩行開始への注意配分が適切に行えず、前方への加速力の低下が生じた可能性が考えられた。&lt;BR&gt;&lt;BR&gt;【理学療法学研究としての意義】&lt;BR&gt; 転倒高齢者はDT条件下での歩行開始において、COPの後方移動距離が低下しており、効率的に加速する能力が低下していることが考えられた。このことから高齢者の転倒予防には、DT条件における歩行開始などの静止と動作の変換期に着目した評価やトレーニングが有効である可能性を示唆した。

【目的】&lt;BR&gt;人は日常生活において活動する際に、二つ以上の課題を同時遂行することが求められる環境に置かれている。近年、このような二重課題条件下での課題遂行能力の低下が、高齢者における転倒リスクを高める要因となることが報告されている。&lt;BR&gt;これまでの報告によって、転倒高齢者では二重課題条件になることで歩行の不安定性が増加することが知られている。これは、換言すれば歩行リズムのバラツキを過度に大きくさせた状態であるといえる。しかし一方で、転倒高齢者では立位保持中に二重課題を課した場合には、逆に重心動揺が減少することも報告されている。バラツキを小さくすることは、この場合換言すれば不安定性を過度に減少させた状態であるといえる。歩行に於いて不安定性が過大になると、転倒リスクが高くなることが報告されている。しかし二重課題条件下での歩行に於いては、課題内容や周囲の状況に対応する必要性から、ある程度のバラツキが必要であると考える。不安定性が過小になり、バラツキが小さくなると、複数課題を遂行する際の状況に対応できなくなり、課題の同時遂行に支障をきたすのではないかと考える。&lt;BR&gt;歩行リズムのバラツキは、変動係数によって数値化されることが一般的である。CVとは標準偏差を平均値で除した値に100を乗じたものであり、この値が大きければバラツキが大きいことを示している。我々は、これまでにもCV値を用いた報告を行っており、CV値が大きい高齢者ではつまずき易いという現象を報告している。&lt;BR&gt;本研究の目的は、転倒経験の有無における二重課題条件下での歩行リズムのバラツキの変化を明らかにすることである。&lt;BR&gt;【方法】&lt;BR&gt;対象は歩行可能な地域在住高齢者185名（年齢：76.5±8.5歳、身長：156.0±9.6cm、体重：55.1±10.1kg）とした。このうち、要介護認定を受けた高齢者は96名含まれていた。対象者に15mの歩行を行わせ、その中央10mに要した時間、歩数、および重心加速度の計測を行った。これを快適歩行（ST）および二重課題歩行（DT）の二条件で計測した。二重課題の副次課題には、非利き手側もしくは、杖を使用していない側の掌にボールを載せた皿を置き、ボールを落とさないように歩行するというマニュアル課題を用いた。第3腰椎部に加速度センサを貼り付け、その加速度信号より歩行周期を同定した。さらに、それぞれの歩行周期に要した時間を算出し、計8歩行周期の時間変動係数（CV）を求めた。また、過去一年間の転倒経験を聴取した。&lt;BR&gt; 統計解析としては、歩行時間、歩数、CVのそれぞれの従属変数に対して、転倒の要因および歩行条件の要因による比較を行うため、二元配置分散分析を行った。&lt;BR&gt;【説明と同意】&lt;BR&gt;参加者には研究の目的、および方法などに関して十分な説明を行い、署名にて同意を得た。&lt;BR&gt;【結果】&lt;BR&gt;歩行時間および歩数を従属変数とした際には、歩行条件の違いによる主効果を認め（p&lt;0.05）、転倒経験の有無に関わらずDT条件下では歩行速度が遅延し歩数が増大していた。一方、CVを従属変数とした際には、交互作用を認め、ST条件のCV値は転倒群で有意に大きいものの、DT条件になることで逆転し、転倒群ではCV値を減少させる傾向にあったのに対し、非転倒群では増大するという結果になった（ST→DT、転倒群：4.5%→4.1%、非転倒群：3.8%→4.4%）。&lt;BR&gt;【考察】&lt;BR&gt;高齢者では、副次課題が課されることによって、歩幅を狭小化させて歩行速度を遅らせるという運動戦略を用いることが示唆された。さらに非転倒高齢者では、DT条件になることでCV値を増大させ、歩行リズムのバラツキを高めるような戦略を選択することで副次課題に対応していた。しかしながら、転倒高齢者ではDT条件下であっても、CV値を高めるような戦略は行うことができず、歩行リズムのバラツキという観点からは副次課題に対応するような戦略は用いていなかった。このように、歩行速度や歩幅という量的な因子には、転倒高齢者と非転倒高齢者の特性に違いは認められなかったものの、歩行リズムのバラツキという質的な因子に関しては顕著な違いが認められた。【理学療法学研究としての意義】&lt;BR&gt;転倒に関わるDT条件下での運動機能評価を行った報告の多くは、転倒高齢者における運動機能の変化に着眼するものが多かった。しかし本研究では、非転倒高齢者ではDT条件下でCV値を高めるという特徴的な現象を捉えることが可能であった。今後はこのような現象を考慮した理学療法および転倒予防介入を展開していくことが必要であるのではないかと考える。

【目的】&lt;BR&gt; 一般に高齢者の歩行では、下肢関節運動や推進力が減少し、速度も低下している．歩行中の推進力発揮には足部・足趾が重要な役割を持つが、高齢者では外反母趾などの変形を伴うことも多く、その機能が低下していると考える．本研究の目的は、高齢者に対して足部・足趾の機能発揮を補助する足底板を作成し、その適応や有効性を検証することである．&lt;BR&gt;【方法】&lt;BR&gt; 対象は明らかな疾患を有さず、研究への同意が得られた高齢者10名(年齢;83.4±6.7歳,男性4名,女性6名)とした．本研究で用いた足底板は被験者の足型に合わせて作製し、加工を施していないもの(N)、足趾部分を下降させたもの(F)、足底板の裏面の周囲(足趾以外の部分)に沿って約 2〜4mm高の縁をつけたもの(W)、FとWの両方を組み合わせたもの（FW）の4種類とした．課題は、4種類の足底板を各々装着した10mの自由歩行とし、速度、歩幅、歩行率を求めた．さらに床反力計(KISLER社)およびデジタルビデオカメラで自由歩行を3回測定し、動作解析ソフト(Frame-diasIV)により、1歩行周期での右側の股関節、膝関節、足関節の屈伸の最大角度、足関節底屈モーメントの最大値を求めた．解析には3試行の平均値を用いた．なお、各条件の測定順は無作為とした．加えて、 足底板の適応を判断するため、被験者の右足の外反母趾角を測定し、その中央値を求め、中央値未満の群をA群、中央値以上の群をB群としてグループ分けした．統計処理は一元配置反復測定分散分析と多重比較(Bonferroni法)により各条件の比較を行い、有意水準を5%とした．&lt;BR&gt;【結果】&lt;BR&gt; 足底板の種類によって速度、歩幅、歩行率、各関節の最大角度、足関節底屈モーメントの最大値に有意差はみられなかった．外反母趾角でグループ分けを行うと(A群5名,B群5名)、両群とも速度、歩幅、歩行率に有意差はみられなかったが、立脚終期から前遊脚期の足関節最大底屈角度がN(7.65±6.4°)に比較してFW(13.97±2.9°)で有意に増加した(p&lt;0.01)．B群ではFおよびWでもNに比較して最大底屈角度に増加傾向がみられたが有意差はみられなかった．足関節底屈モーメント最大値は、B群でのみ、N(1.09±0.24Nm/kg)に比較してFW(1.26±0.36Nm/kg)で増加傾向がみられたが、有意差はみられなかった．&lt;BR&gt;【考察】&lt;BR&gt; 足趾を下降させ、足部の周囲に縁をつけた足底板によって、B群の足関節最大底屈角度が増大した．外反母趾傾向にある場合、母趾による荷重支持・推進が困難となるが、足趾の下降と中足骨頭部の側方の安定化作用によって、よりスムーズな前足部への荷重の移行が可能になったことが推測される．本研究で作成した足底板により、 母趾による荷重支持・推進機能を補助できる可能性が示唆された．