The effect of exercise referral schemes and self-management strategies on use of prescription analgesics among community-dwelling older adults: registry linkage with randomised controlled trials.

BACKGROUND AND OBJECTIVE: Exercise referral schemes and self-management strategies have shown positive effects on patient-reported and objectively measured outcomes, such as increased functional capacity and physical activity level. However, the impact of these interventions on analgesic use remains uncertain. We hypothesised that exercise referral schemes, either utilised alone or in combination with self-management strategies, is more effective in reducing use of prescription analgesics compared with a self-management strategy only. SUBJECTS AND METHODS: We utilised data from two completed randomised controlled trials, namely The Welfare Innovation in Primary Prevention (n = 121) and The SITLESS project (n = 338), and information from the national Danish health registries, including the National Prescription Registry. The two trials have investigated the effectiveness of interventions, which include exercise referral schemes and self-management strategies, on various aspects such as physical function and levels of physical activity among community-dwelling older adults. The studies were conducted in the period 2015-2020 and comprised older adults aged 65+ years, living in three different Danish municipalities. Participants were recruited through nationally regulated preventive home-visits. To estimate changes in use of prescription analgesics over time, a linear fixed effects regression model was applied. The outcome measure was the mean total yearly defined daily dose of analgesics. RESULTS: All intervention groups showed a within-group increase in overall analgesic use, though not statistically significantly different from zero. There were no differences in estimated changes in mean total yearly defined daily dose when comparing the intervention groups to the group receiving the least extensive intervention (self-management strategies/control). The findings indicated that exercise referral schemes and self-management strategies, whether administrated individually or in combination, did not result in a reduction in analgesic use over time.

Feasibility and acceptability of a cohort study baseline data collection of device-measured physical behaviors and cardiometabolic health in Saudi Arabia: expanding the Prospective Physical Activity, Sitting and Sleep consortium (ProPASS) in the Middle East.

BACKGROUND: Physical behaviors such physical activity, sedentary behavior, and sleep are associated with mortality, but there is a lack of epidemiological data and knowledge using device-measured physical behaviors. PURPOSE: To assess the feasibility of baseline data collection using the Prospective Physical Activity, Sitting, and Sleep consortium (ProPASS) protocols in the specific context of Saudi Arabia. ProPASS is a recently developed global platform for collaborative research that aims to harmonize retrospective and prospective data on device-measured behaviors and health. Using ProPASS methods for collecting data to perform such studies in Saudi Arabia will provide standardized data from underrepresented countries. METHOD: This study explored the feasibility of baseline data collection in Saudi Arabia between November and December 2022 with a target recruitment of 50 participants aged ≥ 30 years. Established ProPASS methods were used to measure anthropometrics, measure blood pressure, collect blood samples, carry out physical function test, and measure health status and context of physical behaviors using questionnaires. The ActivPal™ device was used to assess physical behaviors and the participants were asked to attend two sessions at (LHRC). The feasibility of the current study was assessed by evaluating recruitment capability, acceptability, suitability of study procedures, and resources and abilities to manage and implement the study. Exit interviews were conducted with all participants. RESULT: A total of 75 participants expressed an interest in the study, out of whom 54 initially agreed to participate. Ultimately, 48 participants were recruited in the study (recruitment rate: 64%). The study completion rate was 87.5% of the recruited participants; 95% participants were satisfied with their participation in the study and 90% reported no negative feelings related to participating in the study. One participant reported experiencing moderate skin irritation related to placement of the accelerometer. Additionally, 96% of participants expressed their willingness to participate in the study again. CONCLUSION: Based on successful methodology, data collection results, and participants' acceptability, the ProPASS protocols are feasible to administer in Saudi Arabia. These findings are promising for establishing a prospective cohort in Saudi Arabia.

Prevalence of low protein intake in 80+-year-old community-dwelling adults and association with dietary patterns and modifiable risk factors: a cross-sectional study.

Low protein intake may accelerate age-related loss of lean mass and physical function. We investigated the prevalence of low protein intake (<1·0 g/kg/day) and the associations between dietary patterns, modifiable risk factors and low protein intake in self-reliant community-dwelling adults ≥ 80 years. This cross-sectional study consisted of two home visits. Data collection consisted of physical measurements (e.g. physical function, physical activity) and self-report of nutritional intake (4-d food records), appetite, eating symptoms and medical conditions. Binary analyses were performed to compare participants with low and normal protein intake. Multiple logistic regression analyses were performed to investigate associations between low protein intake, dietary patterns and modifiable risk factors adjusted for age, sex, BMI categories and diseases. One hundred twenty-six were included in the study. Prevalence of low protein intake was 54 %. A greater day-to-day variation in protein intake was associated with low protein intake (adjusted OR 2·5; 95 % CI 1·14, 5·48). Participants with low protein intake had a higher prevalence of nausea, diarrhoea and mouth dryness. Reduced appetite, mouth dryness and pain increased odds of low protein intake (adjusted OR 3·06, 95 % CI 1·23, 7·63; OR 3·41, 95 % CI 1·51, 7·7; OR 1·54, 95 % CI 1·00, 2·36, respectively). There was a high prevalence of low protein intake in community-dwelling adults aged ≥ 80 years. Day-to-day variability, appetite, mouth dryness and pain may be potentially modifiable risk factors. Targeting dietary patterns and risk factors in primary prevention strategies may potentially improve intake of protein and minimise risk of physical frailty.

Community-based exercise enhanced by a self-management programme to promote independent living in older adults: a pragmatic randomised controlled trial.

BACKGROUND: older adults face several modifiable barriers for engaging in physical activity (PA) programmes such as incontinence, loneliness and fear of falling. Enhancing PA programmes with behavioural components to support self-management of such barriers may increase the effectiveness to preserve functional capacity and independent living. OBJECTIVE: this study aimed at assessing the effects of a complex active lifestyle intervention (CALSTI) on objective and self-report measures of functional capacity and disability in community-dwelling older adults. SUBJECTS AND METHODS: about 215 older adults (79.9 ± 0.4 years) at increased risk of functional decline were randomly allocated to (i) CALSTI consisting of 12-weeks progressive explosive resistance training (24 sessions) enhanced by a 24-week multi-factorial self-management programme (8 sessions), or (ii) an extended version of the self-management intervention (SEMAI; 12 sessions) to reflect a reinforcement of usual care. The interventions were embedded in a nationally regulated preventive care pathway. Blinded assessors collected primary (the Short Physical Performance Battery; SPPB) and secondary outcome data (self-reported difficulty in activities of daily living, the short version of the Late-Life Function and Disability Index, and the EQ-health VAS scale) at baseline and after 12 and 24 weeks. RESULTS: after 24 weeks, CALSTI led to a clinically superior increase in SPPB compared with SEMAI (+0.77 points, P < 0.01), and the CALSTI group also demonstrated improvements in selected self-reported outcomes. CONCLUSIONS: a novel complex exercise and multi-factorial self-management intervention embedded in preventive care practice had large and clinically meaningful effects on a key measure of functional capacity and predictor of disability.

Cost-effectiveness of a programme to address sedentary behaviour in older adults: results from the SITLESS RCT.

BACKGROUND: This study details the within-trial economic evaluation and long-term economic model of SITLESS, a multi-country, three-armed randomized controlled trial comparing a combined intervention of exercise referral schemes (ERS) enhanced by self-management strategies (SMS) against ERS alone and usual care (UC). METHODS: A cost-utility analysis, conducted from the base-case perspective of the National Health Service and personal and social services, estimated the incremental cost per incremental quality-adjusted life year (QALY) and years in full capability (YFC). A secondary analysis combined the costs with a broad set of outcomes within a cost-consequence framework, from a societal perspective. A Markov-type decision-analytic model was developed to project short-term changes in physical activity to long-term outcomes and costs, over a 5- and 15-year time horizon. RESULTS: The results of the within-trial analysis show that SMS+ERS is highly likely to be cost-effective compared to ERS alone (ICER €4270/QALY), but not compared to UC. Participants allocated to the SMS+ERS group also showed an improvement in YFC compared to ERS alone and UC. The long-term analysis revealed that SMS+ERS is likely to be a cost-effective option compared to ERS and UC over a 5-year, but not with a 15-year horizon, being then dominated by ERS alone. CONCLUSION: This research provides new evidence that SMS is a cost-effective add-on to ERS strategies. This economic evaluation informs the case for further, cost-effective, refinement of lifestyle change programmes targeted to older adults, with the aim of ultimately reducing the impact of non-communicable diseases in this population.

Associations of sedentary behavior bouts with community-dwelling older adults' physical function.

The study aim was to explore associations between sedentary behavior (SB) bouts and physical function in 1360 community-dwelling older adults (≥65 years old). SB was measured using an ActiGraph wGT3X + accelerometer for seven consecutive days at the dominant hip and processed accordingly. Various SB bout lengths were assessed including: 1- to 9-minutes; 10- to 29-minutes; 30- to 59-minutes; and ≥60-minutes, as well as maximum time spent in a SB bout. Total SB time was adjusted for within the SB bout variables used (percentage SB time in the SB bout length and number of SB bouts per total SB hour). Physical function was assessed using the 2-minute walk test (2MWT), 5-times sit-to-stand (chair stand) test, and unipedal stance test (UST). Hierarchical linear regression models were utilized. Covariates such as moderate-vigorous physical activity (MVPA), demographic and health characteristics were controlled for. Lower percentage time spent in ≥60-minute SB bouts was significantly (P < .05) associated with longer 2MWT distance while lower numbers of ≥60-minute SB bouts were associated with longer 2MWT distance, shorter chair stand time and longer UST time. There were mixed associations with physical function for 10- to 29-minute SB bouts. In a large cohort of European older adults, prolonged SB bouts lasting ≥60-minutes appear to be associated with reduced physical function after controlling for MVPA and numerous other important covariates. Besides reducing SB levels, these findings suggest there is a need to regularly interrupt prolonged SB to improve physical function in older adults.

Associations between objectively measured physical activity, sedentary behaviour and time in bed among 75+ community-dwelling Danish older adults.

BACKGROUND: Older adults are recommended to sleep 7-8 h/day. Time in bed (TIB) differs from sleep duration and includes also the time of lying in bed without sleeping. Long TIB (≥9 h) are associated with self-reported sedentary behavior, but the association between objectively measured physical activity, sedentary behavior and TIB is unknown. METHODS: This study was based on cross-sectional analysis of the Healthy Ageing Network of Competence (HANC Study). Physical activity and sedentary behaviour were measured by a tri-axial accelerometer (ActiGraph) placed on the dominant wrist for 7 days. Sedentary behavior was classified as < 2303 counts per minute (cpm) in vector magnitude and physical activity intensities were categorized, as 2303-4999 and ≥ 5000 cpm in vector magnitude. TIB was recorded in self-reported diaries. Participants were categorized as UTIB (usually having TIB 7-9 h/night: ≥80% of measurement days), STIB (sometimes having TIB 7-9 h/night: 20-79% of measurement days), and RTIB (rarely having TIB 7-9 h/night: < 20% of measurement days). Multinominal regression models were used to calculate the relative risk ratios (RRR) of being RTIB and STIB by daily levels of physical activity and SB, with UTIB as the reference group. The models were adjusted for age, sex, average daily nap length and physical function. RESULTS: Three hundred and fourty-one older adults (median age 81 (IQR 5), 62% women) were included with median TIB of 8 h 21 min (1 h 10 min)/day, physical activity level of 2054 (864) CPM with 64 (15) % of waking hours in sedentary behavior. Those with average CPM within the highest tertile had a lower RRR (0.33 (0.15-0.71), p = 0.005) for being RTIB compared to those within the lowest tertile of average CPM. Accumulating physical activity in intensities 2303-4999 and ≥ 5000 cpm/day did not affect the RRR of being RTIB. RRR of being RTIB among highly sedentary participants (≥10 h/day of sedentary behavior) more than tripled compared to those who were less sedentary (3.21 (1.50-6.88), p = 0.003). CONCLUSIONS: For older adults, being physically active and less sedentary was associated with being in bed for 7-9 h/night for most nights (≥80%). Future longitudinal studies are warranted to explore the causal relationship sbetween physical activity and sleep duration.

Does physical performance and muscle strength predict future personal and nursing care services in community-dwelling older adults aged 75+?

AIM: The objective of this study was to investigate if grip strength or the short physical performance battery could predict the rate of receiving two different types of home care services: (a) personal care and (b) home nursing care for community-dwelling older adults aged 75+ years. METHODS: A secondary data analysis of a prospective cohort study including 323 community-dwelling older adults. Measures of grip strength and the short physical performance battery were incorporated in a nationally regulated preventive home visit programme. Referral to personal and home nursing care were obtained from an administrative database with an average follow-up of 4.1 years. The rate of receiving the individual home care services and the study measures were determined using multivariable Cox proportional hazards models controlling for a priori selected covariates (age, sex, living status, obesity, smoking and prior use of home care). RESULTS: The mean age was 81.7 years with 58.8% being women. The rate of receiving personal care differed between the short physical performance battery groups but not between the grip strength groups after adjusting for all covariates with hazard ratios (95% confidence intervals) of 1.90 (1.29-2.81) and 1.41 (0.95-2.08), respectively. The rate of receiving home nursing care differed between both the short physical performance battery and grip strength groups after adjusting for all covariates with hazard ratios of 2.03 (1.41-2.94) and 1.48 (1.01-2.16), respectively. CONCLUSIONS: The short physical performance battery was associated with the rate of receiving both personal care and home nursing care. The short physical performance battery can be used to predict home care needs of community-dwelling older adults aged 75+ years.

An Optimal Self-Report Physical Activity Measure for Older Adults: Does Physical Function Matter?

The authors compared two self-report measures of physical activity, the Physical Activity Scale for the Elderly (PASE) and the Community Healthy Activities Model Program for Seniors (CHAMPS), against the device-derived SenseWear Armband (SWA), to identify a recommended self-report tool to measure physical activity in older adults across physical function levels. A total of 65 community-dwelling older adults completed the PASE, CHAMPS, and seven full days of SWA wear. The authors measured physical function using the modified short physical performance battery (SPPB) and a usual-paced 6-m walk. Age- and sex-adjusted Spearman correlations showed that CHAMPS and SWA were correlated in higher functioning participants (SPPB: ρ = .33, p = .03; gait speed: ρ = .40, p = .006) and also correlated in lower functioning participants for SPPB (ρ = .70, p = .003) only. PASE and SWA were not significantly correlated across physical function. When an objective measure of physical activity is not practical, the CHAMPS questionnaire appears to capture physical activity for older adults across physical function levels.

The Mediating Role of Self-Regulation and Self-Efficacy on Physical Activity Change in Community-Dwelling Older Adults (≥65 Years): An Experimental Cross-Lagged Analysis Using Data From SITLESS.

Improving the capacity for physical activity interventions to maintain behavior change is a key public health concern and an important strategy for the health and independence of older adults. Ways of ensuring effective maintenance of physical activity levels in older adults are unclear. This study includes the objective measure of moderate-to-vigorous physical activity (MVPA); self-reported self-efficacy; and self-regulation at four timepoints (baseline, intervention completion at 4 months, 12-, and 18-month follow-up) from the SITLESS study, a clinical trial conducted with a cohort of community-dwelling older adults (≥65 years) from Denmark, Germany, Spain, and the United Kingdom. A cross-lagged analysis found that self-regulation and self-efficacy may be key determinants of MVPA behavior in community-dwelling older adults. More specifically, the use of behavioral support strategies represents an important correlate of MVPA behavior, and its association with MVPA may be mediated by self-regulation and self-efficacy in older adults in the short and long term.

The effectiveness and complexity of interventions targeting sedentary behaviour across the lifespan: a systematic review and meta-analysis.

BACKGROUND: Evidence suggests that sedentary behaviour (SB) is associated with poor health outcomes. SB at any age may have significant consequences for health and well-being and interventions targeting SB are accumulating. Therefore, the need to review the effects of multicomponent, complex interventions that incorporate effective strategies to reduce SB are essential. METHODS: A systematic review and meta-analysis were conducted investigating the impact of interventions targeting SB across the lifespan. Six databases were searched and two review authors independently screened studies for eligibility, completed data extraction and assessed the risk of bias and complexity of each of the included studies. RESULTS: A total of 77 adult studies (n=62, RCTs) and 84 studies (n=62, RCTs) in children were included. The findings demonstrated that interventions in adults when compared to active controls resulted in non-significant reductions in SB, although when compared to inactive controls significant reductions were found in both the short (MD -56.86; 95%CI -74.10, -39.63; n=4632; I2 83%) and medium-to-long term (MD -20.14; 95%CI -34.13, -6.16; n=4537; I2 65%). The findings demonstrated that interventions in children when compared to active controls may lead to relevant reductions in daily sedentary time in the short-term (MD -59.90; 95%CI -102.16, -17.65; n=267; I2 86%), while interventions in children when compared to inactive controls may lead to relevant reductions in the short-term (MD -25.86; 95%CI -40.77, -10.96; n=9480; I2 98%) and medium-to-long term (MD -14.02; 95%CI -19.49, -8.55; n=41,138; I2 98%). The assessment of complexity suggested that interventions may need to be suitably complex to address the challenges of a complex behaviour such as SB, but demonstrated that a higher complexity score is not necessarily associated with better outcomes in terms of sustained long-term changes. CONCLUSIONS: Interventions targeting reductions in SB have been shown to be successful, especially environmental interventions in both children and adults. More needs to be known about how best to optimise intervention effects. Future intervention studies should apply more rigorous methods to improve research quality, considering larger sample sizes, randomised controlled designs and valid and reliable measures of SB.

Consequences of physical inactivity in older adults: A systematic review of reviews and meta-analyses.

BACKGROUND: Globally, populations are ageing. Typically, physical activity levels decline and health worsens as we age; however, estimates of the impact of physical inactivity for population health often fail to specifically focus on older adults. METHODS: Multiple databases were searched for systematic reviews and/or meta-analyses of longitudinal observational studies, investigating the relationship between physical activity and any physical or mental health outcome in adults aged ≥60 years. Quality of included reviews was assessed using AMSTAR. RESULTS: Twenty-four systematic reviews and meta-analyses were included. The majority of reviews were of moderate or high methodological quality. Physically active older adults (≥60 years) are at a reduced risk of all-cause and cardiovascular mortality, breast and prostate cancer, fractures, recurrent falls, ADL disability and functional limitation and cognitive decline, dementia, Alzheimer's disease, and depression. They also experience healthier ageing trajectories, better quality of life and improved cognitive functioning. CONCLUSION: This review of reviews provides a comprehensive and systematic overview of epidemiological evidence from previously conducted research to assess the associations of physical activity with physical and mental health outcomes in older adults.

Sedentary behavior, physical activity, and mental health in older adults: An isotemporal substitution model.

INTRODUCTION: Regular moderate-to-vigorous physical activity (MVPA) is associated with improved mental health, but the evidence for the effect of reducing sedentary behavior (SB) or increasing light PA (LPA) in older adults is lacking. Using isotemporal substitution (IS) models, the aim of this paper was to investigate the effect of substituting SB with LPA or MVPA on associations with mental health in older adults. METHODS: Data from 1360 older adults (mean age 75.18 years) in four countries were utilized. PA and SB was measured using ActiGraph wGT3X-BT + accelerometers worn for 7 days. Self-rated mental health was measured using the Hospital and Anxiety Depression Scale (HADS). IS models estimated cross-sectional associations when 30 minutes of one behavior was substituted with another. Models were adjusted for age, sex, marital status, and educational attainment. RESULTS: Substituting 30 minutes of SB with LPA (ß -.37; 95% CI -0.42, -0.32) or MVPA (ß -.14; 95% CI -0.21, -0.07) and substituting LPA with MVPA (ß -.11; 95% CI -0.18, -0.04) were associated with improvements in anxiety. However, substituting 30 minutes of SB with LPA (ß .55; 95% CI 0.49, 0.62) was associated with increased depression. CONCLUSION: Replacing 30 minutes of SB with LPA or MVPA was associated with improved anxiety symptoms in older adults. Greater benefits were observed when shifting SB and LPA to MVPA.

Associations between novel jump test measures, grip strength, and physical performance: the Osteoporotic Fractures in Men (MrOS) Study.

BACKGROUND/AIMS: Weight-bearing jump tests measure lower extremity muscle power, velocity, and force, and may be more strongly related to physical performance than grip strength. However, these relationships are not well described in older adults. METHODS: Participants were 1242 older men (mean age 84 ± 4 years) in the Osteoporotic Fractures in Men (MrOS) Study. Jump peak power (Watts/kg body weight), force (Newton/kg body weight) at peak power, and velocity (m/s) at peak power were measured by jump tests on a force plate. Grip strength (kg/kg body weight) was assessed by hand-held dynamometry. Physical performance included 400 m walk time (s), 6 m usual gait speed (m/s), and 5-repeated chair stands speed (#/s). RESULTS: In adjusted Pearson correlations, power/kg and velocity moderately correlated with all performance measures (range r = 0.41-0.51; all p < 0.001), while correlations for force/kg and grip strength/kg were weaker (range r = 0.20-0.33; all p < 0.001). Grip strength/kg moderately correlated with power/kg (r = 0.44; p < 0.001) but not velocity or force/kg. In adjusted linear regression with standardized ßs, 1 SD lower power/kg was associated with worse: 400 m walk time (ß = 0.47), gait speed (ß = 0.42), and chair stands speed (ß = 0.43) (all p < 0.05). Associations with velocity were similar (400 m walk time: ß = 0.42; gait speed: ß = 0.38; chair stands speed: ß = 0.37; all p < 0.05). Force/kg and grip strength/kg were more weakly associated with performance (range ß = 0.18-0.28; all p < 0.05). CONCLUSIONS/DISCUSSION: Jump power and velocity had stronger associations with physical performance than jump force or grip strength. This suggests lower extremity power and velocity may be more strongly related to physical performance than lower extremity force or upper extremity strength in older men.

Is Sedentary Behavior or Physical Activity Associated With Loneliness in Older Adults? Results of the European-Wide SITLESS Study.

Research has found that social relationships are central to the health and well-being of an aging population. Evidence exploring the association between physical activity (PA) and sedentary behavior (SB) with social isolation and loneliness is limited. This study uses objectively measured PA and SB (ActiGraph®) and self-reported measures of loneliness (the De Jong Gierveld Loneliness Scale) and social engagement (the Lubben Social Network Scale) from the SITLESS study, a European-wide study of community-dwelling older adults. Social isolation was associated with SB where higher levels of SB were associated with an increase in the level of social isolation, controlling for age, sex, living arrangements, employment status, body mass index, educational background, marital status, and self-reported general health. In contrast, PA was not associated with social isolation, and neither SB nor PA was a statistically significant predictor of loneliness. SB may be linked to social isolation in older adults, but PA and SB are not necessarily linked to loneliness in older community-dwelling adults.

Copenhagen Consensus statement 2019: physical activity and ageing.

From 19th to 22nd November 2018, 26 researchers representing nine countries and a variety of academic disciplines met in Snekkersten, Denmark, to reach evidence-based consensus about physical activity and older adults. It was recognised that the term 'older adults' represents a highly heterogeneous population. It encompasses those that remain highly active and healthy throughout the life-course with a high intrinsic capacity to the very old and frail with low intrinsic capacity. The consensus is drawn from a wide range of research methodologies within epidemiology, medicine, physiology, neuroscience, psychology and sociology, recognising the strength and limitations of each of the methods. Much of the evidence presented in the statements is based on longitudinal associations from observational and randomised controlled intervention studies, as well as quantitative and qualitative social studies in relatively healthy community-dwelling older adults. Nevertheless, we also considered research with frail older adults and those with age-associated neurodegenerative diseases, such as Alzheimer's and Parkinson's disease, and in a few cases molecular and cellular outcome measures from animal studies. The consensus statements distinguish between physical activity and exercise. Physical activity is used as an umbrella term that includes both structured and unstructured forms of leisure, transport, domestic and work-related activities. Physical activity entails body movement that increases energy expenditure relative to rest, and is often characterised in terms of intensity from light, to moderate to vigorous. Exercise is defined as a subset of structured physical activities that are more specifically designed to improve cardiorespiratory fitness, cognitive function, flexibility balance, strength and/or power. This statement presents the consensus on the effects of physical activity on older adults' fitness, health, cognitive functioning, functional capacity, engagement, motivation, psychological well-being and social inclusion. It also covers the consensus on physical activity implementation strategies. While it is recognised that adverse events can occur during exercise, the risk can be minimised by carefully choosing the type of activity undertaken and by consultation with the individual's physician when warranted, for example, when the individual is frail, has a number of co-morbidities, or has exercise-related symptoms, such as chest pain, heart arrhythmia or dizziness. The consensus was obtained through an iterative process that began with the presentation of the state-of-the-science in each domain, followed by group and plenary discussions. Ultimately, the participants reached agreement on the 30-item consensus statements.

Dynamic sitting: Measurement and associations with metabolic health.

Dynamic sitting, such as fidgeting and desk work, might be associated with health, but remains difficult to identify out of accelerometry data. We examined, in a laboratory study, whether dynamic sitting can be identified out of triaxial activity counts. Among 18 participants (56% men, 27.3 ± 6.5 years), up to 236 counts per minute were recorded in the anteroposterior and mediolateral axes during dynamic sitting using a hip-worn accelerometer. Subsequently, we examined in 621 participants (38% men, 80.0 ± 4.7 years) from the AGES-Reykjavik Study whether dynamic sitting was associated with cardio-metabolic health. Compared to participants who recorded the fewest dynamic sitting minutes (Q1), those with more dynamic sitting minutes had a lower BMI (Q2 = -1.39 (95%CI = -2.33;-0.46); Q3 = -1.87 (-2.82;-0.92); Q4 = -3.38 (-4.32;-2.45)), a smaller waist circumference (Q2 = -2.95 (-5.44;-0.46); Q3 = -3.47 (-6.01;-0.93); Q4 = -8.21 (-10.72;-5.71)), and a lower odds for the metabolic syndrome (Q2 = 0.74 [0.45;1.20] Q3 = 0.58 [0.36;0.95]; Q4 = 0.36 [0.22;0.59]). Our findings suggest that dynamic sitting might be identified using accelerometry and that this behaviour was associated with health. This might be important given the large amounts of time people spend sitting. Future studies with a focus on validation, causation and physiological pathways are needed to further examine the possible relevance of dynamic sitting.

Impact of musculoskeletal pain on balance and concerns of falling in mobility-limited, community-dwelling Danes over 75 years of age: a cross-sectional study.

BACKGROUND: In older adults, musculoskeletal pain is associated with increased concerns of falling, reduced balance and increased occurrence of falls. In younger adults, the intensity of neck pain and low back pain is associated with increased postural sway. It is not known if pain further impairs balance and concerns of falling in mobility-limited older adults, and if so, whether this is associated with different intensities of pain. OBJECTIVE: This study examined whether mobility-limited older adults with mild or intense neck pain and/or low back pain have significantly increased postural sway as measured by centre of pressure (COP) changes and concerns of falling compared to those without pain. METHODS: 48 older adults with a gait speed of < 0.9 m/s from Odense, Denmark were recruited through the public health service. Self-reported neck pain, low back pain, and concerns of falling were recorded on questionnaires. Sway range, velocity and area were recorded on a force plate in a comfortable standing stance. Pain intensity was rated on an 11 point numerical rating scale (0-10). Participants were sub-grouped into mild (0-4) and intense (> 5) neck pain or low back pain. RESULTS: Intense neck pain was associated with increased anterior-posterior sway range and area of sway. Intense low back pain was associated with increased concerns of falling. CONCLUSION: Intense neck pain in mobility-limited older adults is associated with significant changes in postural balance, and intense low back pain is associated with significantly higher concerns of falling.

Movement prediction using accelerometers in a human population.

We introduce statistical methods for predicting the types of human activity at sub-second resolution using triaxial accelerometry data. The major innovation is that we use labeled activity data from some subjects to predict the activity labels of other subjects. To achieve this, we normalize the data across subjects by matching the standing up and lying down portions of triaxial accelerometry data. This is necessary to account for differences between the variability in the position of the device relative to gravity, which are induced by body shape and size as well as by the ambiguous definition of device placement. We also normalize the data at the device level to ensure that the magnitude of the signal at rest is similar across devices. After normalization we use overlapping movelets (segments of triaxial accelerometry time series) extracted from some of the subjects to predict the movement type of the other subjects. The problem was motivated by and is applied to a laboratory study of 20 older participants who performed different activities while wearing accelerometers at the hip. Prediction results based on other people's labeled dictionaries of activity performed almost as well as those obtained using their own labeled dictionaries. These findings indicate that prediction of activity types for data collected during natural activities of daily living may actually be possible.

Sensorimotor Peripheral Nerve Function and the Longitudinal Relationship With Endurance Walking in the Health, Aging and Body Composition Study.

OBJECTIVES: To determine whether lower extremity sensorimotor peripheral nerve deficits are associated with reduced walking endurance in older adults. DESIGN: Prospective cohort study with 6 years of follow-up. SETTING: Two university research clinics. PARTICIPANTS: Community-dwelling older adults enrolled in the Health, Aging and Body Composition Study from the 2000-2001 annual clinical examination (N=2393; mean age ± SD, 76.5±2.9y; 48.2% men; 38.2% black) and a subset with longitudinal data (n=1178). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Participants underwent peripheral nerve function examination in 2000-2001, including peroneal motor nerve conduction amplitude and velocity, vibration perception threshold, and monofilament testing. Symptoms of lower extremity peripheral neuropathy included numbness or tingling and sudden stabbing, burning, pain, or aches in the feet or legs. The Long Distance Corridor Walk (LDCW) (400 m) was administered in 2000-2001 and every 2 years afterward for 6 years to assess endurance walking performance over time. RESULTS: In separate, fully adjusted linear mixed models, poor vibration threshold (>130 µm), 10-g and 1.4-g monofilament insensitivity were each associated with a slower 400-m walk completion time (16.0 s, 14.4s, and 6.9 s slower, respectively; P<.05 for each). Poor motor amplitude (<1 mV), poor vibration perception threshold, and 10-g monofilament insensitivity were related to greater slowing per year (4.7, 4.2, and 3.8 additional seconds per year, respectively; P<.05), although poor motor amplitude was not associated with initial completion time. CONCLUSIONS: Poorer sensorimotor peripheral nerve function is related to slower endurance walking and greater slowing longitudinally. Interventions to reduce the burden of sensorimotor peripheral nerve function impairments should be considered to help older adults maintain walking endurance-a critical component for remaining independent in the community.