Performance tests and disability: developing an objective index of mobility-related limitation in older populations

Five-Repetition Sit-to-Stand Test: Responsiveness and Minimal Important Difference in Idiopathic Pulmonary Fibrosis

Rationale: Standing from a sitting position is an important activity of daily living. The five-repetition sit-to-stand test (5STS) is a simple physical performance test that measures the fastest time taken to stand five times from a chair with arms folded. It can be measured in most healthcare settings and at home, where traditional field walking tests may not be possible. The 5STS has been validated in community-dwelling older adults and people with chronic obstructive pulmonary disease, but data in idiopathic pulmonary fibrosis (IPF) are limited.Objectives: The aims of this cohort study were to establish the construct validity, responsiveness to pulmonary rehabilitation (PR), and minimal important difference (MID) of the 5STS in IPF.Methods: In 149 people with IPF, we compared the 5STS with measures of lung function, exercise capacity, quadriceps strength, breathlessness, and health-related quality of life. Responsiveness and effect sizes were determined by measuring the 5STS before and after PR. The MID was estimated using anchor- and distribution-based methods.Results: The 5STS correlated significantly with incremental shuttle walk test (ISW) (r = -0.55), isometric quadriceps maximum voluntary contraction (QMVC) (r = -0.45), Medical Research Council dyspnea scale score (r = 0.40), Chronic Respiratory Questionnaire-Total (r = -0.21), and King's Brief Interstitial Lung Disease Questionnaire-Total (r = -0.21) but not forced vital capacity percentage predicted or quadriceps one-repetition maximum (1RM). There was a significant but very weak correlation between change in 5STS and changes in Medical Research Council (r = 0.18), ISW (r = -0.21), and Chronic Respiratory Questionnaire-Total (r = -0.26) but no significant correlation with change in 1RM (r = -0.12) or QMVC (r = -0.18). 5STS time improved with PR (median [25th percentile, 75th percentile] change, -1.97 [-3.47, -0.62] s; P < 0.001). The effect size for the 5STS was 0.66 and higher than quadriceps 1RM, QMVC, and ISW. The mean (range) MID estimate was -1.93 (-1.85 to -2.10) seconds.Conclusions: In people with IPF, the 5STS is a valid physical performance measure that is responsive to exercise-based interventions and suitable for use in most healthcare settings.

Assessment of fall-associated risk factors in the Muslim community-dwelling older adults of Peshawar, Khyber Pakhtunkhwa, Pakistan

BACKGROUND

Falls are the third-leading cause of disability among the elderly population worldwide. It is multifactorial, and the occurrence of falls depends on different factors, which can be different from context to context, and individual to individual. Therefore, regular assessment of fall risk factors is required to develop a strategy for fall prevention. The study aimed to identify fall-related risk factors in Pakistani healthy older adults at risk of developing physical disabilities. It also aimed to create a risk-predictive model for fall occurrence, offering evidence for preventive strategies.

METHODS

Data were collected from 140 Muslim older adults from two residential areas of Peshawar, Khyber Pakhtunkhwa, from July 2022 to August 25, 2022, after obtaining permission from the Zhengzhou University Ethical Review Board (ZZUIRB #202,254), and the District Health Department Office (DHO #14,207). Participants were informed, and consent was obtained before data collection. Data were collected using the Time Up and Go Test (TUGT) checklist, the Cognitive Screening Scores (CS-10) checklist, interviews regarding the prayer practice, fall history in the last six months, visual equity questions, and demographic variables.

RESULTS

Factors associated with falls were; age, gender, education, cognitive status, poor walking speed, lack of physical activity, poor vision, and history of falls in the last six months, with a significant P value of (P. < 0.05) in the Pearson correlation coefficient test. Poor cognition, low visual equity, poor walking speed, and lack of exercise increase the risk of falling in the future, with a prediction value of (P < 0.005) in Omnibus, Lemeshow score of (0.77).

CONCLUSION

Hence, our study provides a road map for future risk assessment of falls by adding the four mentioned risk factors in the proposed model to facilitate timely action to prevent fall-related infirmities in Pakistani healthy older adults.

Quality of life, self-esteem, self-efficacy and social participation of persons living with mobility-related disability using mobility aids devices within select Nigerian communities

BACKGROUND/PURPOSE

Disability has gained further global attention as a result of the integration of persons with disabilities into the societies. However, the association among quality of life (QoL), self-esteem (SE), self-efficacy (SEf) and social participation (SP) is inconclusive. This study was aimed to investigate the correlation among QoL, SE, SEf and SP in people living with mobility-related disability using mobility aid devices (MADs) in some selected communities of Enugu State.

METHODS

This cross-sectional survey involved 200 consenting participants (mean age = 37.47 ± 13.00 years) purposively recruited from four different sampled communities who have community-based rehabilitation (CBR) services. Quality of life (QoL), SE, SEf and SP of participants were explored using 36-item Short Form Survey, Rosenberg Self-Esteem Scale, General Self-Efficacy Scale and Participation Scale respectively. Data obtained was summarised using frequency counts, mean, standard deviation and analysed using spearman's Rank Order Correlation, Mann Whitney U and Kruskal-Wallis tests.

RESULTS

The mean QoL, SEf, SE, and SP of the participants are 55.06 ± 10.67, 25.00 ± 5.57, 16.36 ± 4.33 and 35.60 ± 13.50 respectively, which imply moderate QoL and SEf, high SE and severe restricted participation. QoL, SEf, SE, and SP significantly correlated with one another (p < 0.05). There was no significant influence of gender and occupational status of the participants on their QoL, SE, SEf and SP (p > 0.05).

CONCLUSION

Persons living with mobility-related disabilities have moderate QoL and SEf, high self-esteem and severe restriction in SP. QoL, SEf, SE, and SP correlated with one another. The possibility of improving other constructs by targeting one can be explored in disability rehabilitation.IMPLICATIONS FOR REHABILITATIONThe increasing prevalence of disability presented the need to study four constructs of well-being (Quality of Life, Self-esteem, Self-efficacy and Social participation).The perception of one's status and position in life can be negatively impacted upon by a mobility-related disability.Social participation may improve satisfaction and quality of life, which in turn could lead to better self-esteem and self-efficacy.

Analyzing the situation of older family caregivers with a focus on health-related quality of life and pain: a cross-sectional cohort study

Background

For a significant proportion of the older population, increasing age is associated with health problems and worsening health. Older family caregivers are largely responsible for care of next-of-kin living at home, which impacts their own physical and mental health both positively and negatively. However, evidence is insufficient regarding the health situation of older caregivers. The aim of this study was to investigate health-related quality of life (HRQoL) and pain, and their associations, among caregivers aged ≥60 years.

Methods

The participants (n = 3444) were recruited from the Swedish National Study on Aging and Care-Blekinge and Good Aging in Skåne during 2001–2004. Participants aged ≥60 years were selected randomly and underwent cognitive tests, with demographic information obtained through questionnaires. The response rate was 60%. A predefined research protocol was used. HRQoL was measured with the Short-Form Health Survey, dimension mental health. Logistic regression models were used to investigate the associations between HRQoL and pain as well as control factors.

Results

Family caregiving was reported by 395 (11.5%) of the participants, and 56.7% of the caregivers reported pain. Family caregivers reported lower pain intensity on the Visual Analogue Scale and were younger, on median, than non-caregivers. Irrespective of caregiver status, pain was associated with mental HRQoL. Concerns about personal health and financial status had the strongest associations with mental HRQOL in both groups, but the levels were higher among caregivers.

Conclusion

Pain was one factor associated with low HRQoL regardless of family caregiver status and remained important when controlling for factors related to advanced age. This finding remained among family caregivers, though they reported lower pain intensity. Factors other than pain were shown to be important to mental HRQoL and should also be taken into consideration when discussing actions for family caregivers to maintain and improve health and HRQoL.

Trial registration number

Not applicable.

Impacto da dor musculoesquelética na incapacidade funcional

RESUMO O objetivo foi estimar a prevalência de incapacidade para realizar tarefas de vida diária e identificar associação com dor e fatores sociodemográficos. Trata-se de um estudo transversal, com amostra de conveniência, composta por indivíduos que buscaram ativamente assistência à saúde em um município de pequeno porte com queixas de dor musculoesquelética e dificuldades na realização de atividades de vida diária. Compuseram a amostra 766 indivíduos. Foram aplicados questionários para avaliar o grau de dificuldade de realização de atividades de vida diária e dor (Questionário Nórdico de Queixas Musculoesqueléticas e Escala Numérica de Dor). Foram estimadas as prevalências de incapacidade e dor, bem como foram construídos cinco modelos de regressão logística para incapacidade considerando sexo, idade, ocupação e presença e características da dor. Os dados encontrados mostraram que a prevalência de alguma dificuldade para realizar atividades de vida diária foi de 87,6%, de muita dificuldade 66,1%; a de dor musculoesquelética foi de 67,5%. Os indivíduos apresentaram incapacidade para realização de 3,6 atividades de vida diária em média. A dor foi o principal fator de associação para explicá-la (OR 9,9; IC95% 5,9-16,5), seguida da idade. A dificuldade na execução de atividades de vida diária foi associada à dor em membros inferiores, com frequência maior que quatro dias na semana, início há mais de cinco anos e intensidade forte ou insuportável nos episódios de crise. As prevalências de incapacidade e dores foram altas. A dor musculoesquelética e a idade impactaram na incapacidade funcional. Este estudo contribui para direcionar a construção de ações de cuidado que visem minimizar e prevenir dificuldades para realizar tarefas do dia a dia.

Air Pollution and Performance-Based Physical Functioning in Dutch Older Adults

BACKGROUND

Functional limitations are a major cause for needing care and institutionalization among older adults. Exposure to air pollution has been suggested to be associated with increased functional limitations in older people.

OBJECTIVE

Our objective was to assess the association between air pollution and physical functioning in Dutch older adults.

METHODS

We analyzed data on performance-based (walking speed, ability to rise from a chair, putting on and taking off a cardigan, balance test) and self-reported physical functioning for 1,762 participants of the Longitudinal Aging Study Amsterdam, who participated in measurement cycles performed in 2005/2006, 2008/2009, and 2011/2012. Annual average outdoor air pollution concentrations [nitrogen dioxide (NO₂), nitrogen oxides (NO_x), particulate matter with diameters ≤2.5μm (PM_2.5), ≤10μm (PM₁₀), and 2.5-10μm (PM_coarse), and PM_2.5 absorbance] at the home address at the start of the first measurement cycle were estimated using land-use regression models. Analyses were performed using mixed models with random participant intercepts adjusting for potential confounders.

RESULTS

Exposure to most air pollutants was associated with reduced performance-based physical functioning; for example, an interquartile range increase in NO₂ exposure was associated with a 0.22 (95% confidence interval: 0.03, 0.42) lower performance test score in fully adjusted models, equivalent to the difference in performance score between participants who differed by 9 mo in age. Exposure to air pollution was generally not statistically significantly associated with self-reported functional limitations, and not associated with a faster decline in performance-based physical functioning over the study period.

CONCLUSION

This study suggests that exposure to air pollution may adversely affect physical performance of older adults in the Netherlands. https://doi.org/10.1289/EHP2239.

Association of lower extremity range of motion and muscle strength with physical performance of community-dwelling older women

BACKGROUND

Reduced lower extremity range of motion (ROM) and muscle strength are related to functional disability in older adults who cannot perform one or more activities of daily living (ADL) independently. The purpose of this study was to determine which factors of seven lower extremity ROMs and two muscle strengths play dominant roles in the physical performance of community-dwelling older women.

METHODS

Ninety-five community-dwelling older women (mean age ± SD, 70.7 ± 4.7 years; age range, 65-83 years) were enrolled in this study. Seven lower extremity ROMs (hip flexion, hip extension, knee flexion, internal and external hip rotation, ankle dorsiflexion, and ankle plantar flexion) and two muscle strengths (knee extension and flexion) were measured. Physical performance tests, including functional reach test (FRT), 5 m gait test, four square step test (FSST), timed up and go test (TUGT), and five times sit-to-stand test (FTSST) were performed.

RESULTS

Stepwise regression models for each of the physical performance tests revealed that hip extension ROM and knee flexion strength were important explanatory variables for FRT, FSST, and FTSST. Furthermore, ankle plantar flexion ROM and knee extension strength were significant explanatory variables for the 5 m gait test and TUGT. However, ankle dorsiflexion ROM was a significant explanatory variable for FRT alone. The amount of variance on stepwise multiple regression for the five physical performance tests ranged from 25 (FSST) to 47% (TUGT).

CONCLUSIONS

Hip extension, ankle dorsiflexion, and ankle plantar flexion ROMs, as well as knee extension and flexion strengths may play primary roles in the physical performance of community-dwelling older women. Further studies should assess whether specific intervention programs targeting older women may achieve improvements in lower extremity ROM and muscle strength, and thereby play an important role in the prevention of dependence on daily activities and loss of physical function, particularly focusing on hip extension, ankle dorsiflexion, and ankle plantar flexion ROMs as well as knee extension and flexion strength.

Self-reported and test-based mobility limitations in a representative sample of Finns aged 30+

Aims: The object of the present study was to acquire a comprehensive and accurate picture of mobility limitations in the Finnish adult population. Methods: A nationally representative sample of 8,028 persons aged 30+ with high participation was interviewed and examined in the Health 2000 Survey conducted in 2000—01. Mobility limitations were measured by self-reports and performance tests. Results: Perceived running difficulties were already common among persons in middle age, while difficulties in moving about indoors were frequent only among persons aged 75+. A third of women and a fifth of men aged 55+ could not reach a walking speed of 1.2 m/s. Working-aged women were more limited than men only in physically demanding tasks, but in the elderly the gender difference was evident in most mobility tasks. A substantial disagreement was found between the self-reported and test-based indicators in stair climbing. Supplementary data collection, carried out to increase participation in the health examination, as well as inclusion of institutionalized persons, provided a more complete estimate of the prevalence of mobility limitations among the elderly. Conclusions: Both self-reported and performance-based indicators are needed to achieve a comprehensive view of disability and its variation between population groups. Exclusion of institutionalized persons and low participation lead to underestimation of the occurrence of limitations. The number of persons suffering from mobility problems will increase with ageing of the population, which accentuates the importance of early intervention to maintain functional ability, especially in women.

The Coach2Move Approach: Development and Acceptability of an Individually Tailored Physical Therapy Strategy to Increase Activity Levels in Older Adults With Mobility Problems

BACKGROUND AND PURPOSE

Despite the positive effects of physical activity on numerous aspects of health, many older adults remain sedentary even after participating in physical activity interventions. Standardized exercise programs do not necessarily bring about the behavioral change that is necessary. Therefore, a patient-centered approach is needed. The purpose of this study was to develop and assess the acceptability and potential effectiveness of the Coach2Move strategy; a physical therapy (PT) approach aimed at improving the long-term level of physical activity in mobility-limited older adults.

METHODS

The Coach2Move strategy was developed on the basis of 2 systematic literature studies and expert consultations. Multiple focus group meetings and a Delphi procedure were organized to gain consensus on the Coach2Move strategy. Acceptability and potential effectiveness were studied in a pilot study with a pre-/postdesign in which 2 physical therapists and 12 patients participated. To assess acceptability, patients were interviewed, discussion were held with the involved physical therapists was held, and health records were studied. Potential effectiveness was tested measuring the level of physical activity, frailty, quality of life, and mobility before and after treatment.

RESULTS

On the basis of the literature study and expert consultations, an algorithm based on the Hypothesis Oriented Algorithm for Clinicians Part II was developed: the Coach2Move approach. Key elements of the Coach2Move approach include an extensive intake using motivational interviewing, clinical reasoning, coaching to increase physical activity and self-management, focusing on meaningful activities, and working according to 3 patient-tailored intervention profiles with a predefined number of sessions. The pilot study showed high appraisal of the strategy by both physical therapists and patients. Moreover, a potential effect on the level of physical activity, frailty, quality of life, and mobility was observed.

DISCUSSION AND CONCLUSION

Because the pilot study was not randomized or controlled and included a small sample, no conclusions can be drawn about the effectiveness of the Coach2Move strategy. However, all suggestions made in this study were implemented in an ongoing, randomized controlled trial in which the Coach2Move strategy will be compared to usual care PT. In conclusion, the Coach2Move strategy can be considered acceptable in PT practice and showed potential benefits. The results on the (cost-)effectiveness of this strategy based on a large, randomized, controlled trial are expected in 2014.

Functional disability of adults in Brazil: prevalence and associated factors

OBJECTIVE

To estimate the prevalence and factors associated with functional disability in adults in Brazil.

METHODS

We used information from the health supplement of the National Household Sample Survey in 2008. The dependent variable was the functional disability among adults of 18 to 65 years, measured by the difficulty of walking about 100 meters; independent variables were: health plan membership, region of residence, state of domicile, education level, household income, economic activity, self-perception of health, hospitalization, chronic diseases, age group, sex, and color. We calculated the gross odds ratios (OR), and their respective confidence intervals (95%), and adjusted them for variables of study by ordinal logistic regression, following hierarchical model. Sample weights were considered in all calculations.

RESULTS

We included 18,745 subjects, 74.0% of whom were women. More than a third of adults reported having functional disability. The disability was significantly higher among men (OR = 1.17; 95%CI 1.09;1.27), people from 35 to 49 years (OR = 1.30; 95%CI 1.17;1.45) and 50 to 65 years (OR = 1.38; 95%CI 1.24;1.54); economically inactive individuals (OR = 2.21; 95%CI 1.65;2.96); adults who reported heart disease (OR = 1.13; 95%CI 1.03;1.24), diabetes mellitus (OR = 1.16; 95%CI 1.05;1.29), arterial systemic hypertension (OR = 1.10; 95%CI 1.02;1.18), and arthritis/rheumatism (OR = 1.24; 95%CI 1.15;1.34); and participants who were admitted in the last 12 months (OR = 2.35; 95%CI 1.73;3.2).

CONCLUSIONS

Functional disability is common among Brazilian adults. Hospitalization is the most strongly associated factor, followed by economic activity, and chronic diseases. Sex, age, education, and income are also associated. Results indicate specific targets for actions that address the main factors associated with functional disabilities and contribute to the projection of interventions for the improvement of the well-being and promotion of adults' quality of life.

High short-term and long-term excess mortality in geriatric patients after hip fracture: a prospective cohort study in Taiwan

BACKGROUND

Hip fracture has a high mortality rate, but the actual level of long-term excess mortality and its impact on population-wide mortality remains controversial. The present prospective study investigated short- and long-term excess mortality after hip fractures with adjustment of other risk factors. We calculated the population attributable risk proportion (PARP) to assess the impact of each risk factor on excess mortality.

METHODS

We recruited 217 elders with hip fractures and 215 age- and sex-matched patients without fractures from the geriatric department of the same hospital. The mean follow-up time was 46.1 months (range: 35 to 57 months). We recorded data on 55 covariates, including baseline details about health, function, and bone mineral density. We used the multivariate Cox proportional hazards model to analyze hazard ratios (HRs) of short-term (<12 months follow-up) and long-term (≧ 2 months follow-up) excess mortality for each covariate and calculated their PARP.

RESULTS

Patients with hip fractures had a higher short-term mortality than non-fractured patients, and the long-term excess mortality associated with hip fracture remained high. The significant risk factors for short-term mortality were hip fracture, comorbidities, and lower (below cutoff) Mini Mental State Examination score with HRs of 2.4, 2.3, and 2.3, respectively. Their PARPs were 44.7%, 38.1%, and 34.3%, respectively. The significant risk factors for long-term mortality were hip fracture (HR: 2.7; PARP: 48.0%), lower T-score (HR: 3.3; PARP: 36.2%), lower body mass index (HR: 2.5; PARP: 42.8%), comorbidities (HR: 2.1; PARP: 34.8%), difficulty in activities of daily living (HR: 1.9; PARP: 31.8%), and smoking (HR: 2.5; PARP: 19.2%).

CONCLUSIONS

After comprehensive adjustment, hip fracture was a significant risk factor and contributed the most to long-term as well as short-term excess mortality. Its adequate prevention and treatment should be targeted.

Geriatric multidimensional assessment for elderly patients with acute respiratory diseases

The case of an 87-year-old woman who falls at home and is admitted to the Emergency Department of an acute hospital with delirium exemplify a common situation that physicians face in their everyday clinical practice. We describe the typical context of frailty in which acute illnesses frequently present in frail elderly patients and, in particular, the relationship between comorbidity, disability and frailty. We also report the current knowledge about frailty theories and we focus on the "atypical" presentation of many acute illnesses. Major attention is devoted on delirium and on mobility impairment, two of the most common atypical symptoms of elderly frail subjects. Finally we describe the evidence on the comprehensive geriatric assessment, i.e., the method that is required to identify and understand the ultimate needs of elderly complex subjects.

Smoking and alcohol consumption patterns among elderly Canadians with mobility disabilities

BACKGROUND

Mobility disability is a major adverse health outcome associated with aging and an impediment to older adults' well-being and behaviors in social and leisure activities. It has been shown that lifestyle factors, including smoking and alcohol consumption, have been used as coping strategies to deal with the negative impact of disability. The aim of this study was to determine the prevalence of smoking and alcohol consumption among older Canadians with different levels of mobility disabilities and to examine factors associated with these two lifestyle patterns among those with disabilities.

METHODS

Secondary data analysis was performed using individuals (n = 6,038) aged 65 years and older from both the 2001 Participation and Activity Limitation Survey and the 2003 Canadian Community Health Survey. Multivariate logistic regressions examined the relationship between disability severity and smoking as well as alcohol consumption while controlling for potential confounding socioeconomic factors.

RESULTS

The proportion of current smokers among seniors with less-severe and more-severe mobility disabilities and those in the general population was comparable with 12.55%, 11.57% and 11.93%, respectively. Forty-eight percent of seniors in the general population consumed alcohol regularly, compared to only 12.85% with more-severe mobility disabilities. No significant association was shown between the severity level of mobility disabilities and smoking (odds ratio = 0.90, 95% confidence interval: 0.75, 1.08). However, seniors having more-severe disability were less likely to consume alcohol regularly (odds ratio = 0.76, 95% confidence interval: 0.65, 0.89). Other variables including age, gender, income, living status, and social participation also impacted these lifestyle patterns among the study population.

CONCLUSIONS

Smoking and alcohol patterns present different associations with the severity level of mobility disabilities. Compared with the general population, elderly Canadians with mobility disabilities had similar smoking prevalence but differ significantly in terms of alcohol consumption. Results from this research will be relevant to decision makers involved in program planning, health education, and policy development as it pertains to the prevention and management of age-related disability.

Respiratory impairment and the aging lung: a novel paradigm for assessing pulmonary function

BACKGROUND

Older persons have an increased risk of developing respiratory impairment because the aging lung is likely to have experienced exposures to environmental toxins as well as reductions in physiological capacity.

METHODS

Systematic review of risk factors and measures of pulmonary function that are most often considered when defining respiratory impairment in aging populations.

RESULTS

Across the adult life span, there are frequent exposures to environmental toxins, including tobacco smoke, respiratory infections, air pollution, and occupational dusts. Concurrently, there are reductions in physiological capacity that may adversely affect ventilatory control, respiratory muscle strength, respiratory mechanics, and gas exchange. Recent work has provided a strong rationale for defining respiratory impairment as an age-adjusted reduction in spirometric measures of pulmonary function that are independently associated with adverse health outcomes. Specifically, establishing respiratory impairment based on spirometric Z-scores has been shown to be strongly associated with respiratory symptoms, frailty, and mortality. Alternatively, respiratory impairment may be defined by the peak expiratory flow, as measured by a peak flow meter. The peak expiratory flow, when expressed as a Z-score, has been shown to be strongly associated with disability and mortality. However, because it has a reduced diagnostic accuracy, peak expiratory flow should only define respiratory impairment when spirometry is not readily available or an older person cannot adequately perform spirometry.

CONCLUSIONS

Aging is associated with an increased risk of developing respiratory impairment, which is best defined by spirometric Z-scores. Alternatively, in selected cases, respiratory impairment may be defined by peak expiratory flow, also expressed as a Z-score.

Effects of physical exercise therapy on mobility, physical functioning, physical activity and quality of life in community-dwelling older adults with impaired mobility, physical disability and/or multi-morbidity: a meta-analysis

This is the first meta-analysis focusing on elderly patients with mobility problems, physical disability and/or multi-morbidity. The aim of this study is to assess the effect of physical exercise therapy on mobility, physical functioning, physical activity and quality of life. A broad systematic literature search was performed in the databases PubMed, CINAHL, Embase, PEDro and The Cochrane Library. Relevant study characteristics were reviewed and meta-analyses using standardized mean differences (SMDs) were performed. The results show that physical exercise therapy has a positive effect on mobility (SMD final value: 0.18; 95% CI: 0.05, 0.30; SMD change value: 0.82; 95% CI: 0.54, 1.10) and physical functioning (SMD final value: 0.27; 95% CI: 0.08, 0.46; SMD change value: 2.93; 95% CI: 2.50, 3.36). High-intensity exercise interventions seem to be somewhat more effective in improving physical functioning than low-intensity exercise interventions (SMD final value: 0.22; 95% CI: -0.17, 0.62; SMD change value: 0.38; 95% CI: -0.48, 1.25). These positive effects are of great value for older adults who are already physically impaired. The effect on physical activity and quality of life was not evident and no definite conclusions on the most effective type of physical exercise therapy intervention can be drawn.

Effects of a 10-week inspiratory muscle training program on lower-extremity mobility in people with multiple sclerosis: a randomized controlled trial

Pulmonary muscle weakness is common in ambulatory people with multiple sclerosis (MS) and may lead to deficits in mobility function. The purpose of this study was to examine the effect of a 10-week home-based exercise program using an inspiratory muscle threshold trainer (IMT) on the results of four lower-extremity physical performance tests in people with MS. The study design was a two-group (experimental-control), pretest-posttest study. Outcome measures consisted of pulmonary function measures including maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), and maximal voluntary ventilation (MVV), and the following lower-extremity physical performance measures: the 6-Minute Walk (6MW) distance, gait velocity (GV), the Sit-to-Stand Test (SST), the Functional Stair Test (FST), and a balance test (BAL). A total of 46 ambulatory participants (Expanded Disability Status Scale [EDSS] score, 2.0-6.5) with MS were randomly assigned to an intervention group (mean EDSS score, 4.1) that received 10 weeks of home-based inspiratory muscle training or a nontreatment control group (mean EDSS score, 3.2). Of the original 46 participants, 20 intervention group participants and 19 control group participants completed the study. Compared with the control group, the intervention group made significantly greater gains in inspiratory muscle strength (P = .003) and timed balance scores (P = .008). A nonsignificant improvement in 6MW distance (P = .086) was also noted in the IMT-trained group as compared with the control group. This is the first study directly linking improvement in respiratory function to improvement in physical performance function in people with mild-to-moderate disability due to MS.

Mobility, functional ability and health-related quality of life among people of 60 years or older

BACKGROUND AND AIMS

Knowledge about Health-Related Quality of Life (HRQoL) in advanced age is sparse. This study investigated to what extent mobility factors explained older people's HRQoL when age, gender and functional ability (ADL) were controlled for.

METHODS

Subjects were 1128 people aged 60-96 participating in a Swedish longitudinal multi-center cohort study. Besides descriptive and correlation statistics, a three-tier multiple logistic regression analysis was performed, which included the ADL scale, mobility tests and items, with physical and mental HRQoL as outcome variables.

RESULTS

In the models containing the control variables, functional ability was found to be associated with both physical and mental HRQoL. In the models including both functional ability and mobility factors, the importance of functional ability remained for mental but not for physical HRQoL. The mobility factors were found to have a stronger negative influence on HRQoL, i.e., physical and mental, than functional ability in itself.

CONCLUSIONS

For optimal identification of various types of disabilities and their impact on older people's HRQoL, the ADL scale should be used together with more targetspecific tests of disabilities. However, in certain situations, it appears that one mobility factor alone - the ability to walk - has the capacity to pick up changes in both physical and mental HRQoL. Thus, it is important that healthcare professionals should focus activities toward maintaining older people's mobility as a means of enhancing their HRQoL.

Risk factors for hip fracture in older adults: a case-control study in Taiwan

We conducted a matched case-control study of hip fracture in older adults. Our findings suggest that hip fracture risk was determined by multiple factors. Older women characterized by low consumption of milk, peak flow rate, grip strength, and bone mineral density (BMD) had increased risk of hip fracture. Older men with impaired cognitive function and low BMD were also at higher risk of hip fracture.

INTRODUCTION

Multiple factors contribute to low-trauma hip fracture in older adults. The aim of this study was to determine important characteristics of hip fracture in older population.

METHODS

A total of 228 patients with first low-trauma hip fracture were matched with 497 controls. All 77 potential risk factors of hip fracture organized into 13 groups were analyzed using conditional logistic regression.

RESULTS

Low milk intake, peak flow rate, hand grip strength, and bone mineral density in women and low mini-mental state examination score and bone mineral density in men were further identified to be independently associated with elevated hip fracture risk.

CONCLUSIONS

The factors found in our study may help understand the etiology of hip fracture and be further adopted to evaluate the risk of hip fracture in community and clinical setting.

Pulmonary function, muscle strength, and incident mobility disability in elders

Muscle strength, including leg strength and respiratory muscle strength, are relatively independently associated with mobility disability in elders. However, the factors linking muscle strength with mobility disability are unknown. To test the hypothesis that pulmonary function mediates the association of muscle strength with the development of mobility disability in elders, we used data from a longitudinal cohort study of 844 ambulatory elders without dementia participating in the Rush Memory and Aging Project with a mean follow-up of 4.0 years (SD = 1.39). A composite measure of pulmonary function was based on spirometric measures of forced vital capacity, forced expiratory volume, and peak expiratory flow. Respiratory muscle strength was based on maximal inspiratory pressure and expiratory pressure and leg strength based on hand-held dynamometry. Mobility disability was defined as a gait speed less than or equal to 0.55 m/s based on annual assessment of timed walk. Secondary analyses considered time to loss of the ability to ambulate. In separate proportional hazards models which controlled for age, sex, and education, composite measures of pulmonary function, respiratory muscle strength, and leg strength were each associated with incident mobility disability (all P values < 0.001). Further, all three were related to the development of incident mobility disability when considered together in a single model (pulmonary function: hazard ratio [HR], 0.721; 95% confidence interval [CI], 0.577, 0.902; respiratory muscle strength: HR, 0.732; 95% CI, 0.593, 0.905; leg strength: HR, 0.791; 95% CI, 0.640, 0.976). Secondary analyses examining incident loss of the ability to ambulate revealed similar findings. Overall, these findings suggest that lower levels of pulmonary function and muscle strength are relatively independently associated with the development of mobility disability in the elderly.

Validation of lower extremity performance tests for determining the mobility limitation levels in community-dwelling older women

BACKGROUND AND AIMS

Assessment of mobility status among community-dwelling older people is important for preventing further deterioration of mobility and identifying changes in mobility as early as possible. We attempted to identify the optimal cut-off values for eight lower extremity performance (LEP) tests in community-dwelling older women with mobility limitation (ML) levels.

METHODS

The ML levels of 433 community-dwelling older women, mean age 73.2 years (SD 5.7, range 65-93) were classified according to selfreports. ML levels were identified by face-to-face interviews and according to self-reported difficulty in walking one-quarter of a mile or climbing 10 steps without resting. The LEP tests comprised one-legged stance, tandem stance, functional reach, tandem walk, alternate step, five chair sit-to-stands, timed up-and-go (TUG) and usual gait speed. Receiver-operating characteristic curves were obtained for all scales to assess optimal cut-off values.

RESULTS

The optimal cut-off value of 6.52 (s) for the TUG test was shown by the highest sensitivity (74%) and specificity (71%) in the discrimination of no ML from moderate ML, whereas the optimal cut-off value of 1.05 (m/s) in the usual gait speed test showed the highest sensitivity (73%) and specificity (67%) in the discrimination of moderate ML from severe ML.

CONCLUSIONS

Among community-dwelling older women, TUG and usual gait speed had the highest sensitivity and specificity in discriminating ML levels.

[Socio-demographic differentials in the functional decline among the elderly in Brazil]

There is a positive reversion in the expectations regarding the health condition of the elderly population, possibly due to the progresses in medical technology; behavioural changes; development of special programmes for the elderly; improvements in the socio-economic status; decrease of infectious diseases. This study aims analyzing differentials in the prevalence rates of mobility disability among elderly people in Brazil. The data used were from 'The 1998 and 2003 National Household Survey (PNAD)', conducted by the Brazilian Institute of Geographic and Statistics (IBGE). The two samples were nationally representative, including approximately 30 thousand individuals aged 60 years or more respectively. "Difficulty to walk more than 100 meters" was the variable selected as the indicator of disability. Socio-demographic status measures were sex, age group, region of residence and family income per capita. Comparison of the PNAD results of 1998 and 2003 showed that over that period in Brazil the elderly disability rates decreased among all socio-demographic groups considered. Public policies directed to the elderly must focus on reducing mobility disability.

Reductions in disability prevalence among the highest income groups of older Brazilians

OBJECTIVES

We sought to identify the income-disability prevalence relationship among older Brazilians.

METHODS

Data were from 63,985 individuals 60 years and older from the 1998 and 2003 Brazilian National Household Surveys. Generalized additive logistic models with cubic regression splines were used to estimate the disability-income relationships.

RESULTS

There was a strong linear relationship between increased income and reduced disability prevalence for most of the income distribution. Benefits were still present above the 90th percentile of income but were more modest. Because incomes among the wealthiest few are disproportionately large, odds ratios of disability nevertheless showed marked improvements, even across the very highest income groups.

CONCLUSIONS

Among older Brazilians, reduced disability is associated with higher income, and these associations are present even above the 90th percentile of income. In addition to understanding mechanisms of disability reduction among impoverished individuals, work is needed to understand these mechanisms in middle- and high-income groups.

At the tipping point: predicting severe mobility difficulty in vulnerable older women

OBJECTIVES

To identify clinical measures that aid detection of impending severe mobility difficulty in older women.

DESIGN

Cross-sectional and longitudinal cohort study.

SETTING

Urban community in Baltimore, Maryland.

PARTICIPANTS

One thousand two community-dwelling, moderate to severely disabled women aged 65 and older in the Women's Health and Aging Study I.

MEASUREMENTS

Self-report and performance measures representing six domains necessary for mobility: central and peripheral nervous systems, muscles, bones and joints, perception, and energy. Severe mobility difficulty was defined as usual gait of 0.5 m/s or less, any reported difficulty walking across a small room, or dependence on a walking aid during a 4-m walking test.

RESULTS

Four hundred sixty-seven out of 984 (47%) had severe mobility difficulty at baseline, and 104/474 (22%) developed it within 12 months. Baseline mobility difficulty was correlated with poor vision, knee pain, feelings of helplessness, inability to stand with feet side by side for 10 seconds, difficulty keeping balance while dressing or walking, inability to rise from a chair five times, and cognitive impairment. Of these, knee pain (odds ratio (OR)=1.74, 95% confidence interval (CI)=1.05-2.89), helplessness (OR=1.87, 95% CI=1.10-3.24), poor vision (OR=2.03, 95% CI=1.06-3.89), inability to rise from a chair five times (OR=2.50, 95% CI=1.15-5.41), and cognitive impairment (OR=4.75, 95% CI=1.67-13.48) predicted incident severe mobility difficulty within 12 months, independent of age.

CONCLUSION

Five simple measures may aid identification of disabled older women at high risk of severe mobility difficulty. Further studies should determine generalizability to men and higher-functioning individuals.

Physical performance characteristics of assisted living residents and risk for adverse health outcomes

PURPOSE

Researchers know little about the physical performance ability of residential care/assisted living (RC/AL) residents and its relationship to adverse outcomes such as fracture, nursing home placement, functional decline, and death. The purposes of this article are to (a) describe the functional characteristics of RC/AL residents, (b) examine the relationships between resident- and facility-level characteristics and physical performance, and (c) determine the predictive value of physical performance for adverse outcomes.

DESIGN AND METHODS

Data came from 1,791 residents in 189 RC/AL facilities participating in the Collaborative Studies of Long-Term Care. At baseline, residents were tested on four performance measures (grip strength, chair rise, balance, and walking speed), and other resident- and facility-level information was collected. Adverse outcomes were measured over 1 year.

RESULTS

Average grip strength was 14 +/- 7 kg, 61% of residents walked <0.6 m/s (M = 0.41 m/s), 26% could perform five chair rises, and only 19% could perform a tandem stand for a least 1 s. Multivariable analyses showed that more cognitive and functional impairment, depressive symptoms and comorbid conditions, and for-profit ownership were associated with poorer physical performance. Controlling for individual characteristics, we found that better performance on the four physical performance measures was associated with a reduced risk of nursing home placement, fracture, and decline in function over 1 year.

IMPLICATIONS

Simple performance measures identify modifiable functional deficits and suggest targeted interventions to prolong independent mobility and aging in place in RC/AL facilities.

Neighbourhood deprivation and incident mobility disability in older adults

OBJECTIVE

to assess whether incident mobility disability and neighbourhood deprivation in older people are associated independent of the effects of individual socio-economic status, health behaviours and health status.

METHODS

prospective cohort study with a 2-year follow-up.

SETTING

the English Longitudinal Study of Ageing (ELSA), a national probability sample of non-institutionalised older people.

PARTICIPANTS

4,148 participants aged 60 years and over.

MEASUREMENTS

exposure was a census-based index of neighbourhood deprivation [the Index of Multiple Deprivation (IMD)]; outcomes were measured and self-reported incident mobility difficulties.

RESULTS

neighbourhood deprivation had a statistically significant effect on physical function following adjustment for individual socio-economic factors, health behaviours and health status. Compared to those living in the least deprived 20% of neighbourhoods, those in the most deprived neighbourhoods had a risk ratio (RR) of incident self-reported mobility difficulties of 1.75 (95% CI 1.14-2.70) and RR of incident-impaired gait speed of 1.63 (95% CI 1.01-2.62). In adjusted models, 4.0 per 100 (95% CI 3.0-5.4) older adults in neighbourhoods in the least deprived 20% had incident mobility difficulties over a 2-year period, whereas 13.6 per 100 (95% CI 10.5-17.4) older adults had incident mobility difficulties in neighbourhoods in the most deprived 20%.

CONCLUSIONS

older people living in deprived neighbourhoods are significantly more likely to experience incident mobility difficulties than those in less-deprived neighbourhoods. The mechanisms underlying this relationship are unclear and research to identify mechanisms and appropriate interventions is needed.

Peak expiratory flow as a predictor of subsequent disability and death in community-living older persons

OBJECTIVES

To determine whether peak expiratory flow (PEF), when expressed by a validated method using standardized residual (SR) percentile, is associated with subsequent disability and death in older persons.

DESIGN

Prospective cohort study.

SETTING

New Haven, Connecticut.

PARTICIPANTS

Seven hundred fifty-four initially nondisabled, community-living persons aged 70 and older.

MEASUREMENTS

PEF was assessed at baseline along with chronic conditions and smoking history. The onset of persistent disability in activities of daily living (ADLs), continuous mobility disability, and death were ascertained during monthly interviews over a 5-year period.

RESULTS

Participants' mean age was 78.4, 63.7% had a smoking history, and 17.4% reported chronic lung disease. The incidence rates per 100 person-months were 1.00 (95% confidence interval (CI)=0.90-1.12) for ADL disability, 0.80 (95% CI=0.70-0.93) for mobility disability, and 0.44 (95% CI=0.38-0.51) for death. At a PEF less than 10(th) SR percentile, identifying nearly one-quarter of the cohort, hazard ratios (HRs) adjusted for multiple confounders, including age, smoking, and chronic lung disease, demonstrated a greater risk of ADL disability (HR=1.79, 95% CI=1.23-2.62), mobility disability (HR=1.89, 95% CI=1.15-3.10), and death (HR=2.31, 95% CI=1.29-4.12).

CONCLUSION

In an elderly cohort, it was found that low PEF, when expressed as an SR percentile, is independently associated with subsequent disability and death. These results support the use of PEF as a potentially valuable risk assessment tool in community-living older persons.

Ethnic differences in physical performance in older Americans: data from the Third National Health and Nutrition Examination Survey (1988-1994)

BACKGROUND AND AIMS

Impaired physical performance in older adults has been shown to vary by ethnic groups. The objective of this study is to examine ethnic differences in physical performance in older Americans.

METHODS

We conducted a cross-sectional analysis using a sample of 4456 non-institutionalized Americans aged 60 and above (2712 non- Hispanic Whites, 861 non-Hispanic Blacks and 883 Mexican Americans) from a large national representative survey (The Third National Health and Nutrition Examination Survey (NHANES III) conducted in 1988- 1994). Measurements included socio-demographic variables; self-reported physician diagnosed medical conditions, body mass index (BMI) and physical performance examination (tandem stand balance, timed chair stand, and timed 8-foot walk).

RESULTS

Of 4456 study participants, 60.9% (n=2712) subjects were non-Hispanic white, 19.3% (n=861) were non-Hispanic black, and 19.8% (n=883) were Mexican American. About 35% (n=1573) of subjects could not hold the tandem balance test for 10 seconds. Older age, diabetes, stroke and arthritis were significantly associated with decreased performance on the balance test. Older age, female gender, being Mexican American or non-Hispanic black, hip fracture and high BMI were significantly associated with decreased performance on 8- foot walking test, while older age, female gender, being non-Hispanic black, low education, stroke, cancer, arthritis and high BMI were significantly associated with decreased performance on the chair stand test.

CONCLUSIONS

With some ethnic variation, older age, female gender, being non-Hispanic black, being Mexican American, low education, high BMI, diabetes, stroke, cancer and arthritis were associated with decreased physical performance in elderly Americans.

Health-related fitness tests as predictors of difficulties in long-distance walking among high-functioning older adults

BACKGROUND AND AIMS

Health-related fitness (HRF) tests are valid predictors of self-reported mobility difficulties among high-functioning older adults. The aim of the present study was to identify optimal cut-off values for HRF tests predicting self-reported difficulties in walking 2 km (WD).

METHODS

Subjects were 55- to 69-year-old men and women who were free of WD at baseline. The HRF assessment in 1996 included seven test items, and postal questionnaires were used to assess occurrence of new WD in 2002. Analysis of covariance and receiver-operating characteristic analysis were used as statistical methods.

RESULTS

In a 1-km walk, the sensitivity and specificity at the optimal cut-off 10:15 (min:s) for men were 63% and 75%, and at the cut-off 10:47 for women 70% and 71%. In dynamic back extension, the sensitivity and specificity at the optimal cut-off 16.5 (repetitions) were 67% and 65% in men and 82% and 59% at cut-off 13.5 in women. Correspondingly, in backward walking, the sensitivity and specificity at the optimal cut-off 27.7 (seconds) were 65% and 69% in men and 74% and 61% at cutoff 35.0 in women.

CONCLUSIONS

The 1-km walk, dynamic back extension and backward walking tests had the best predictive value for WD. These tests, with identified cut-off values, can be used to screen individuals who are at increased risk of WD. Tests can also be used in physical activity counseling to target activity to those components of HRF that indicate poor fitness and are important for good walking ability.

Reporting peak expiratory flow in older persons

BACKGROUND

Peak expiratory flow ("peak flow") predicts important outcomes in older persons. Nevertheless, its clinical application is uncertain because prior strategies for reporting peak flow may not be valid. We thus determined the frequency distribution of peak flow by the conventional strategy of percent predicted (%predicted) and by an alternative method termed standardized residual (SR) percentile, and evaluated how these two metrics relate to health status in older persons.

METHODS

Participants included 754 community-dwelling persons aged >/= 70 years. Data included chronic conditions, frailty indicators, and peak flow.

RESULTS

Mean age was 78.4 years, with 63.7% reporting a smoking history, 17.4% chronic lung disease, and 77.1% having one or more frailty indicators. Peak flow >/= 80 %predicted was recorded in 67.5% of participants, whereas peak flow >/= 80th SR percentile was only noted in 15.9%. A graded relationship was observed between peak flow and health status, but %predicted yielded health risk at peak flows currently considered normal (80-100 %predicted), whereas SR percentile conferred health risk only at severely reduced peak flows (< 50th SR percentile).

CONCLUSIONS

Peak flow expressed as SR percentile attains a frequency distribution more consistent with the characteristics of our elderly cohort, and establishes health risk at more appropriate levels of reduced peak flow. These findings establish the need for longitudinal studies based on SR percentile to further evaluate the use of peak flow as a risk assessment tool in older persons and to determine if pulmonary function, in general, is better reported in older persons as SR percentile, rather than as %predicted.

Lower extremity strength and power are associated with 400-meter walk time in older adults: The InCHIANTI study

BACKGROUND

It has been suggested that lower extremity muscle power is more important for physical function in older adults compared to strength, and that there is a nonlinear relationship between power or strength and physical function that might be indicative of a threshold above which the association between muscle function and physical function is no longer evident. This study examined the association between lower extremity strength or power with the time to complete a 400-meter walk, and attempted to identify thresholds within the relationship.

METHODS

A cross-sectional analysis of a sample of 384 females and 336 males aged > or = 65 years from the InCHIANTI study ("Invecchiare in Chianti," i.e., Aging in the Chianti Area) was conducted. Measures included 400-meter walk time, lower extremity strength and power, comorbidities, and sociodemographic variables (age, gender, height, education, cognitive function, depression).

RESULTS

Linear regression models showed that both lower extremity strength and power were significant predictors of 400-meter walk time, although power explained marginally more of the variance in 400-meter walk time. Quadratic models of lower extremity strength and power fit the data slightly better than the linear models. Regardless of gender, comorbidities, or normalization scheme for strength and power, the curvilinear form of the relationship between strength or power and 400-meter walk time remained the same.

CONCLUSIONS

Lower extremity muscle strength and power are both important predictors of the 400-meter walk time. Although curvilinear relationships existed between muscle strength and power and the 400-meter walk time, the data do not indicate a clear threshold for either strength or power above which the performance in the 400-meter walk test plateaus.

A prevalência de incapacidade funcional em idosos no Brasil

O processo de envelhecimento brasileiro tende a se intensificar nas próximas décadas, de tal forma que, em 2050, projeta-se um número absoluto de idosos em torno de 64 milhões. Considerando que os estudos internacionais vêm apontando redução do declínio funcional entre os idosos nos países desenvolvidos, este estudo tem por finalidade analisar como vêm ocorrendo as mudanças na incapacidade funcional dos idosos, no Brasil, segundo alguns indicadores sociodemográficos selecionados. Foram utilizadas as informações dos Suplementos de Saúde da Pesquisa Nacional por Amostra de Domicílios (PNAD), de 1998 e 2003, realizados pelo Instituto Brasileiro de Geografia e Estatística (IBGE). Os microdados, para o cálculo das taxas de prevalência de incapacidade funcional, foram processados usando o Banco Multidimensional Estatístico (BME/IBGE). Os resultados apontam que houve redução nas taxas de prevalência de incapacidade funcional dos idosos, embora diferenciada entre os grupos sociodemográficos.

Middle-aged and mobility-limited: prevalence of disability and symptom attributions in a national survey

BACKGROUND

Lower limb mobility disabilities are well understood in older people, but the causes in middle age have attracted little attention.

OBJECTIVES

To estimate the prevalence of mobility disabilities among noninstitutionalized adults in England and to compare the disabling symptoms reported by middle-aged and older people.

DESIGN

Cross-sectional data from the 2002 English Longitudinal Study of Ageing (ELSA). Mobility disability was identified by level of reported difficulty walking a quarter mile.

PARTICIPANTS

Eleven thousand two hundred sixteen respondents aged 50 years and older living in private households in 2002.

RESULTS

The prevalence of difficulty walking a quarter mile increases sharply with age, but even in the middle-aged (50 to 64 years age-group) 18% (95% confidence interval [CI]: 16% to 19%) of men and 19% (95% CI: 17% to 20%) of women reported some degree of difficulty. Of the 16 main symptoms reported as causing mobility disability in middle age, 2 dominated: pain in the leg or the foot (43%; 95% CI: 40% to 46%) and shortness of breath/dyspnea (21%; 95% CI: 18% to 23%). Fatigue or tiredness, and stability problems were cited by only 5% and 6%, respectively. These proportions were slightly different from those in the 65 to 79-year age group: 40%, 23%, 6%, and 8%, respectively.

CONCLUSIONS

Mobility (walking) disabilities in the middle-aged are relatively common. The symptoms reported as causes in this age group differ little from those reported by older groups, and are dominated by lower limb pain and shortness of breath. More clinical attention paid to disabling symptoms may lead to disability reductions in later life.

Clinical gait and stepping performance measures in older adults

Problems with ambulation and mobility are frequent problems in older adults. Each year, about one in 100 older adults develops new severe mobility disability. Assessment of abnormal gait constitutes a major component of clinical practice and may lead to fall reduction. Clinicians can benefit from simple gait and mobility assessment tools to be used in busy clinical settings. This review focuses on gait and stepping performance measures that can be used by the busy clinician to assess gait, mobility performance, balance, and falls risk in the older adult.

The apolipoprotein E e4 polymorphism is strongly associated with poor mobility performance test results but not self-reported limitation in older people

BACKGROUND

The apolipoprotein E (ApoE) e4 polymorphism is linked to increased mortality rates, Alzheimer's disease, and cardiovascular disease in older people, but previous studies have largely failed to detect an effect on self-reported mobility disability. We hypothesized that poor performance on mobility-related tests may provide a better measure of effects, and we aimed to estimate the extent to which the ApoE e4 allele increases risks of poor performance on measured mobility and self-reported mobility disability compared to e3/3, in a medium-sized population cohort.

METHODS

Data were from 1262 people at baseline older than 65 years from the Longitudinal Aging Study Amsterdam (LASA), followed up for 6 years. Age- and sex-adjusted logistic regression models were used to explore associations.

RESULTS

At baseline, those individuals with an e4 allele had an odds ratio of 2.26 (95% confidence interval, 1.31-3.90) for poor performance on gait speed testing (<0.4 m/s) and 1.94 (95% confidence interval, 1.19-3.16) for five chair stands (> or =20 s), compared to those with e3/3 status. At follow-up, associations between e4 status and incident poor performance on the chair stand test was significant. Associations with self-reported inability or need for help walking for 5 minutes or for climbing 15 steps were nonsignificant throughout.

CONCLUSIONS

The ApoE e4 polymorphism is associated with a substantial excess of mobility limitation. The impact is detectable by performance testing, but not by self-reports. Poor results on mobility performance tests may provide a phenotype of ageing.

Sequencing sit-to-stand and upright posture for mobility limitation assessment: determination of the timing of the task phases from force platform data

The identification of quantitative tools to assess an individual's mobility limitation is a complex and challenging task. Several motor tasks have been designated as potential indicators of mobility limitation. In this study, a multiple motor task obtained by sequencing sit-to-stand and upright posture was used. Algorithms based on data obtained exclusively from a single force platform were developed to detect the timing of the motor task phases (sit-to-stand, preparation to the upright posture and upright posture). To test these algorithms, an experimental protocol inducing predictable changes in the acquired signals was designed. Twenty-two young, able-bodied subjects performed the task in four different conditions: self-selected natural and high speed with feet kept together, and self-selected natural and high speed with feet pelvis-width apart. The proposed algorithms effectively detected the timing of the task phases, the duration of which was sensitive to the four different experimental conditions. As expected, the duration of the sit-to-stand was sensitive to the speed of the task and not to the foot position, while the duration of the preparation to the upright posture was sensitive to foot position but not to speed. In addition to providing a simple and effective description of the execution of the motor task, the correct timing of the studied multiple task could facilitate the accurate determination of variables descriptive of the single isolated phases, allowing for a more thorough description of the motor task and therefore could contribute to the development of effective quantitative functional evaluation tests.