Habitual Walking Research Articles

Associations Between Body Mass Index, Gait Biomechanics, and In Vivo Cartilage Function After Exercise in Those With Anterior Cruciate Ligament Reconstruction

Background: Both high body mass index (BMI) and anterior cruciate ligament reconstruction (ACLR) independently influence knee osteoarthritis risk. Preliminary evidence shows the combination of these risk factors leads to poorer recovery and altered biomechanical outcomes after ACLR, but few studies have directly evaluated early changes in cartilage health between normal-BMI and high-BMI groups in this population. Purpose: To evaluate ultrasound-based measures of cartilage strain and compositional changes (via echo-intensity [EI]) in response to an incline walking stress test between normal-BMI and high-BMI individuals with ACLR. A secondary evaluation was conducted of associations between habitual walking biomechanics (ie, ground-reaction forces, sagittal knee kinetics and kinematics) and cartilage strain and EI outcomes. Study Design: Controlled laboratory study. Methods: Gait biomechanics and femoral trochlear ultrasound analyses were evaluated in 64 participants with ACLR who had normal BMI (BMI < 27.0; n = 40) and high BMI (BMI ≥ 27.0; n = 24). Ultrasound images were collected bilaterally before and after an incline treadmill walk, and medial and lateral trochlear strain and EI changes pre-post exercise were used to compare BMI groups and limbs. Gait outcomes included ground-reaction forces, peak sagittal plane knee moments, angles, and excursions and were used to determine associations with cartilage outcomes in the entire cohort. Results: High-BMI individuals with ACLR exhibited greater medial trochlear cartilage strain in the ACLR limb compared with normal-BMI individuals (approximately 6%; P < .01). In those with high BMI, the ACLR limb exhibited greater medial trochlear strain relative to non-ACLR limbs (approximately 4%; P < .05), but between-limb differences were not observed in the normal-BMI group (P > .05). Medial trochlear EI changes were greater bilaterally in those with high BMI compared with normal-BMI ACLR counterparts (approximately 10%; P < .01). Last, individuals who walked with greater peak knee flexion angles exhibited less medial cartilage strain (ΔR2 = 0.06; P = .025). Conclusion: The data suggested that high BMI affects cartilage functional properties after ACLR, whereas smaller knee flexion angles were associated with larger medial cartilage strain. Clinical Relevance: High-BMI individuals with ACLR may represent a subset of patients exhibiting earlier declines in cartilage functional integrity in response to loading, necessitating additional or more targeted interventions to mitigate disease development.

Developing a battery of physical performance tests to predict functional disability in Japanese older adults: A longitudinal study from the Kasama study.

Preventing functional disability benefits the quality of life of older adults and mitigates the economic burden of an aging society. However, the most effective physical performance tests and optimal cut points for identifying older adults at risk of functional disability remain unclear, and Japan lacks physical function-based assessment tools. We aimed to identify the physical performance tests related to functional disability and to develop a predictive test battery for it. We included 975 older adults (mean 72.8 ± 5.2 years, 55.4% women) in Kasama City, Japan. Functional disability was defined as certification of care level 2 or above based on the long-term care insurance system. Cox proportional hazards analysis examined the association between physical performance tests and incident functional disability. During a mean follow-up of 8.6 years (maximum 14 years), 236 participants (24.2%) developed functional disability. After adjusting for covariates, higher performances in grip strength, single-leg balance with eyes open (SLB), timed up-and-go (TUG), five-repetition sit-to-stand (5-STS), and 5-m habitual walk were significantly associated with a lower risk of functional disability. In a stepwise model, SLB, TUG, and 5-STS were key predictors of functional disability. Receiver operating characteristic analysis determined optimal cut points of 32.6/32.7 s for SLB, 6.5/6.6 s for TUG, and 7.8/7.9 s for 5-STS. We developed a predictive battery combining these cut points (area under the curve = 0.78). The developed battery of physical performance tests predicts future functional disability and is useful for screening older adults at high risk. Geriatr Gerontol Int 2024; ••: ••-••.

Physical Activity, Sedentary Behavior, and Their Predictors Among Nursing Home Residents-Cross-Sectional Results of the BaSAlt Study.

Little is known about physical activity (PA) and sedentary behavior (SB) among nursing home residents although PA is known as a health promoter. This study examined PA, SB, and their predictors among nursing home residents (n = 63). Dependent variables were accelerometry-based PA and SB. Predictor variables included in a path analysis were age, sex, body mass index, Barthel Index, cognitive status (Mini-Mental State Examination), physical performance (hand grip strength and habitual walking speed), and well-being (World Health Organization-5 well-being index). PA was very low (M steps per day = 2,433) and SB was high (M percentage of sedentary time = 89.4%). PA was significantly predicted by age (β = -0.27, p = .008), body mass index (β = -0.29, p = .002), Barthel Index (β = 0.24, p = .040), and hand grip strength (β = 0.30, p = .048). SB was significantly predicted by body mass index (β = 0.27, p = .008) and Barthel Index (β = -0.30, p = .012). Results might be helpful for everyday practice to identify individuals at high risk for low PA and high SB.

Association Of Habitual Walking Behaviors With Metabolic Health Outcomes In Elderly With Metabolic Syndrome

Association Of Habitual Walking Behaviors With Metabolic Health Outcomes In Elderly With Metabolic Syndrome

Velocity-Based-Training Frequency Impacts Changes in Muscle Morphology, Neuromuscular Performance, and Functional Capability in Persons With Parkinson's Disease.

Calaway, C, Walls, K, Levitt, H, Caplan, J, Mann, B, Martinez, K, Gastaldo, R, Haq, I, and Signorile, JF. Velocity-based-training frequency impacts changes in muscle morphology, neuromuscular performance, and functional capability in persons with Parkinson's disease. J Strength Cond Res XX(X): 000-000, 2024-Velocity-based training (VBT) positively impacts muscle morphology and performance in persons with Parkinson's disease (PD); however, optimal training frequencies for VBT in patients with PD remain undetermined. Changes in ultrasound-determined muscle thickness (MT) and echo intensity (EI)-derived muscle quality of the rectus femoris (RF) and vastus lateralis (VL), neuromuscular performance, and functional capacity were examined following 2 VBT frequencies (2-3 d·wk -1 ) using 30% velocity loss thresholds for 12 weeks. Neuromuscular performance was assessed using computerized pneumatic resistance machines. For each variable, 2 (time) × 2 (group) repeated-measures analyses of variance (ANOVA) were used to determine significant main effects and interactions. Significant time effects were seen for MT and EI of all muscles ( p < 0.05). Muscle thickness improvements included right VL (RVL) (0.171 ± 0.065 cm; p = 0.019), left VL (LVL) (0.214 ± 0.101 cm; p = 0.049), right RF (RRF) (0.194 ± 0.077 cm; p = 0.023), and left RF (LRF) (0.318 ± 0.109 cm; p = 0.010). For EI, improvements occurred in RVL (-18.688 ± 3.600; p = <0.001), LVL (-10.959 ± 4.894; p = 0.040), RRF (-9.516 ± 3.537; p = 0.016), and LRF (-9.018 ± 3.444; p = 0.019). Time effects were seen for leg-press 1-repetition maximum and peak power ( p < 0.01) and habitual walking speed ( p = 0.022), with a group by time interaction for maximal gait speed favoring the 3 d·wk -1 condition (∆0.15 m·s -1 , p = 0.002). The results indicate that VBT at 2 or 3 d·wk -1 can significantly improve muscle morphology, neuromuscular performance, and functional capability in patients with PD; however, improvements in maximal gait speed require 3 d·wk -1 . These findings provide flexibility when developing exercise prescriptions for patients with PD.

Peak vertical ground reaction force used to identify sub-groups of individuals with differing biomechanical gait profiles post-anterior cruciate ligament reconstruction.

Lesser peak vertical ground reaction force (vGRF) has been widely reported among individuals with anterior cruciate ligament reconstruction (ACLR). Peak vGRF remains less than uninjured controls and relatively stable during the first year following ACLR. However, it is unknown whether there are subgroups of individuals exhibiting consistently greater peak vGRF in the first 6-months following ACLR and if individuals with consistently greater peak vGRF exhibit kinematic and kinetic gait differences compared to individuals with low vGRF. The purpose of this study was to determine if distinct clusters exist based upon magnitude of peak vGRF 2- and 6-months post-ACLR. Subsequently, we explored between cluster differences in vGRF, knee flexion angle, and sagittal and frontal plane knee kinetics throughout stance between clusters. Forty-three individuals (58.1%female, 21.4 ± 4.4 years-old, 95.3% patellar-tendon autograft) completed five gait trials at their habitual walking speed 2- and 6-months post-ACLR. A single K-means cluster analysis was used to identify clusters of individuals based on peak vGRF at 2- and 6-months post-ACLR. Functional waveform analyses were used to compare gait outcomes between clusters with and without controlling for gait speed and age. We identified two clusters that included a subgroup with high vGRF (n = 16) and low vGRF (n = 27). The cluster with high vGRF demonstrated greater vGRFs, knee flexion angles, and knee extension moments during early stance as compared to the low vGRF cluster 2- and 6-months post-ACLR. Individuals with peak vGRF ≥1.02 times body-weight 2-months post-ACLR had 35.4 times greater odds of being assigned to the high vGRF cluster.

Aerobic Fitness of Elderly Community and Non-Community Individuals After Chronic Stroke

Introduction: Stroke commonly causes low aerobic fitness and walking speed. Objective: To compare the estimated aerobic fitness of the community and non-community elderly individuals after chronic stroke. Investigate the association between walking speed and aerobic fitness. Methods: Elderly people after stroke classified as community walkers or limited community walkers, according to their walking speed (10-m walk test), in m/s, were assessed with The Human Activity Profile (HAP). The Lifestyle Energy Consumption (LEC) score of the HAP was used to estimate aerobic fitness through the peak oxygen uptake (V̇o2peak). Results: Aerobic fitness of elderly individuals after stroke classified as community walkers was on average 17.3 (6.0) mL kg−1 min−1, while for non-community walkers, it was on average 10.2 (5.6) mL kg−1 min−1. There was a significant difference between groups (−7.05, 95% CI −10.98 to −3.12; P &lt; .001). A statistically significant (P &lt; .001) association with moderate magnitude (r = 0.587) was observed between the LEC and the habitual walking speed. Conclusions: Individuals with lower walking speed have lower aerobic fitness.

Mendelian randomisation and mediation analysis of self-reported walking pace and coronary artery disease.

The aim of this study was to assess the causal relationship between habitual walking pace and cardiovascular disease risk using a Mendelian randomisation approach. We performed both one- and two-sample Mendelian randomisation analyses in a sample of 340,000 European ancestry participants from UK Biobank, applying a range of sensitivity analyses to assess pleiotropy and reverse causality. We used a latent variable framework throughout to model walking pace as a continuous exposure, despite being measured in discrete categories, which provided more robust and interpretable causal effect estimates. Using one-sample Mendelian randomisation, we estimated that a 1mph (i.e., 1.6kph) increase in self-reported habitual walking pace corresponds to a 63% (hazard ratio (HR) = 0.37, 95% confidence interval (CI), 0.25-0.55, P = 2.0 × 10-6) reduction in coronary artery disease risk. Using conditional analyses, we also estimated that the proportion of the total effect on coronary artery disease mediated through BMI was 45% (95% CI 16-70%). We further validated findings from UK Biobank using two-sample Mendelian randomisation with outcome data from the CARDIoGRAMplusC4D consortium. Our findings suggest that interventions that seek to encourage individuals to walk more briskly should lead to protective effects on cardiovascular disease risk.

Twenty-four hour physical activity, sedentary behaviour and sleep profiles in adults living with rheumatoid arthritis: a cross-sectional latent class analysis

BackgroundRheumatoid Arthritis (RA), an autoimmune systemic inflammatory disease, affects more than 17 million people globally. People with RA have higher risk of premature mortality; often experience chronic fatigue, pain and disrupted sleep; and are less physically active and more sedentary than healthy counterparts. It remains unclear how people with RA may balance sleep and awake movement activities over 24-hours, or how differences in 24-hour behaviours may be associated with determinants of health, or alignment with published activity guidelines.MethodsCross-sectional exploration of objective measures of 24-hour sleep-wake activities in 203 people with RA. Latent Class Analysis (LCA) derived classes from time, by tertile, in six sleep-awake activities over 24 h. Comparisons of model fit statistics, class separation and interpretability defined best fit for number of classes. Variations in sleep-awake behaviour across classes and association of profile allocation with determinants of health, quality metrics for sleep, sitting and walking and alignment with published guidelines were explored. Multinomial logistic regression identified factors associated with likelihood of profile allocation.ResultsLCA identified 2 to 6 classes and a 4-class model was determined as best fit for 24-hour sleep-awake behaviour profiles. One profile (26%) presented with more balanced 24-hour sleep, sitting and walking behaviours. The other three profiles demonstrated progressively less balanced 24-hour behaviours including: having low (< 7 h), high (> 8 h), or recommended (7–8 h) sleep duration in respective combination with high sitting (> 10 h), limited walking (< 3 h) or both when awake. Age, existing sitting and walking habit strength and fatigue were associated with likelihood of belonging to different profiles. More balanced 24-hour behaviour was aligned with better quality metrics for sleep, sitting and walking and published guidelines.DiscussionFor people living with RA it is important to understand the ‘whole person’ and their ‘whole day’ to define who may benefit from support to modify 24-hour sleep-awake behaviours and which behaviours to modify. Supports should be informed by an understanding of personal or health-related factors that could act as barriers or facilitators for behavioural change, including exploring existing habitual sitting and walking behaviours.Trial registrationsClinicalTrials.gov ID: NCT02554474 (2015-09-16) and ClinicalTrials.gov ID: NCT03404245 (2018-01-11)

Biomechanical Threshold Values for Identifying Clinically Significant Knee-Related Symptoms Six Months Following Anterior Cruciate Ligament Reconstruction.

Slower habitual walking speed and aberrant gait biomechanics are linked to clinically significant knee-related symptoms and articular cartilage composition changes linked to posttraumatic osteoarthritis (PTOA) following anterior cruciate ligament reconstruction (ACLR). To determine specific gait biomechanical variables that can accurately identify individuals with clinically significant knee-related symptoms post-ACLR, and the corresponding threshold values, sensitivity, specificity, and odds ratios for each biomechanical variable. Cross-sectional analysis. Laboratory. Seventy-one individuals (n=38 female; age=21±4 years; height=1.76±0.11 m; mass=75.38±13.79 kg) who were 6 months post-primary unilateral ACLR (6.2±0.4 months). 3D motion capture of 5 overground walking trials was used to calculate discrete gait biomechanical variables of interest during stance phase (1st and 2nd peak vertical ground reaction force [vGRF]; midstance minimum vGRF; peak internal knee abduction and extension moments; and peak knee flexion angle), along with habitual walking speed. Knee Injury and Osteoarthritis Outcome Scores (KOOS) was used to dichotomize patients as symptomatic (n=51) or asymptomatic (n=20) using the Englund et al. 2003 KOOS guidelines for defining clinically significant knee-related symptoms. Separate receiver operating characteristic (ROC) curves and respective areas under the curve (AUC) were used to evaluate the capability of each biomechanical variable of interest for identifying individuals with clinically significant knee-related symptoms. Habitual walking speed (AUC=0.66), vGRF at midstance (AUC=0.69), and 2nd peak vGRF (AUC=0.76), demonstrated low-to-moderate accuracy for identifying individuals with clinically significant knee-related symptoms. Individuals who exhibited habitual walking speeds ≤1.27 m/s, midstance vGRF ≥0.82 BW, and 2nd peak vGRF ≤1.11 BW, demonstrated 3.13, 6.36, and 9.57 times higher odds of experiencing clinically significant knee-related symptoms, respectively. Critical thresholds for gait variables may be utilized to identify individuals with increased odds of clinically significant knee-related symptoms and potential targets for future interventions.

Increasing habitual walking in mobility-limited older adults through a personalized GIS-based intervention

Background&#x0D; Ample evidence supports the health benefits of low-intensity physical activity such as walking, which is universally accessible and impacted by neighbourhood environmental factors like green spaces and availability of local amenities.&#x0D; Aim&#x0D; The MOBITEC-Routes project will investigate the effects of an individualized GIS-based walking intervention on physical and psychosocial functioning in mobility-limited older adults.&#x0D; Methods&#x0D; A randomized controlled trial to promote habitual walking will take place. The sample will include 130 inactive, chronically ill, mobility-limited older adults. The intervention will combine professional consultations with map-based planning and behaviour change techniques derived from the Health Action Process Approach.&#x0D; Results&#x0D; Expected outcomes include increase in participants’ daily step count, physical activity levels, physical function, life space mobility, self-efficacy, social participation, and quality of life.&#x0D; Conclusion&#x0D; MOBITEC-Routes is poised to offer new insights into personalized GIS-based interventions’ effectiveness in improving mobility and overall well-being in older adults with mobility impairments.

A Comparison of Dynamic Gait Stability between the Young and Elderly Female Populations Using the Zero-Moment Point Method

A compromised stability in the elderly population is considered a major factor for fall risk assessment. The dynamic stability of human gait with various mathematical metrics has been extensively studied to find a prediction index and fall prevention strategies that can be embedded in a wearable monitoring sensor. In this study, the zero-moment point method (ZMP) was utilized for analyzing the gait stability of young and elderly female populations. Participants in the young and elderly female groups with no musculoskeletal disorders and fall experience were asked to walk at a habitual speed on 10 m flat ground. Dynamic instability is defined by the percentage of the ZMP values that fall outside the base of support during one gait cycle. The ZMP trajectory between the left and right leg swing was not symmetrical considering flat-ground walking. Also, there was no statistical difference in the dynamic stability in the anterior–posterior direction (71.3 ± 7.9% for the young group and 73.6 ± 7.6% for the elderly group), but walking in the medial–lateral direction was more stable in the elderly group (53.9 ± 8.6%) than in the young group (44.1 ± 11.2%) because the habitual walking speed decreased in the elderly group.

Investigating the social and environmental contexts of habitual walking ACTIVities in older adult DYADs: A mixed methods protocol for the ActivDyad study

AbstractBackgroundMobility‐related ambulatory activity (e.g., walking) is essential to healthy cognitive and functional ageing. Wearable technology (e.g., accelerometers/inertial measurement units; IMUs) allows us to objectively and continuously capture digital mobility outcomes (DMOs), e.g. volume, pattern and variability of walking activities. Continuous digital mobility assessment has been shown as feasible and acceptable to older adults with and without dementia. However, interpretation of DMOs is limited as we do not yet understand the impact of different social and environmental contexts on walking activity. For example, DMOs may be influenced by the volume of walking that one’s partner participates in, or by the walkability of their local area. Understanding the impact of social and environmental contexts on DMOs will support development of socio‐ecological strategies to support mobility in ageing. We aim to conduct a feasibility study in older adults with the following objectives: (1). Objectively assess DMOs in older adult dyads using digital mobility tools (i.e., IMUs/GPS); (2). Identify key social and environmental influences on DMOs through mixed‐methods exploration; (3). Develop a novel analytical approach combining DMOs with GPS data to assess independence/interdependence in dyads’ walking activities.MethodWe will recruit 20 older adult dyads in North‐East England for an observational cross‐sectional study. Walking activities will be recorded continuously for seven days using an IMU attached to participants’ lower backs. DMOs include volume (e.g., daily steps), pattern (e.g. mean bout length) and variability (of bout length) of walking activities. Simultaneously, participants will carry a GPS device (i.e., smartphone) to monitor excursions outside the home. Questionnaires will capture information on cognition, function, falls risk, exercise motivation, wellbeing, relationship mutuality, spatial navigation, and walkability of local area. Participants will complete a “mobility diary” for the assessment period (e.g., daily journeys, motivations/perceptions/familiarity of journeys).ResultPreliminary results will be presented regarding associations between social/environmental contexts with DMOs via flexible Bayesian statistical models and thematic qualitative analysis.ConclusionThis study will assess the feasibility of the protocol and analysis strategies, with intentions of developing further research to examine the impact of social and environmental influences on DMOs in people with dementia and their carers.

Investigating the social and environmental contexts of habitual walking ACTIVities in older adult DYADs: A mixed methods protocol for the ActivDyad study

AbstractBackgroundMobility‐related ambulatory activity (e.g., walking) is essential to healthy cognitive and functional ageing. Wearable technology (e.g., accelerometers/inertial measurement units; IMUs) allows us to objectively and continuously capture digital mobility outcomes (DMOs), e.g. volume, pattern and variability of walking activities. Continuous digital mobility assessment has been shown as feasible and acceptable to older adults with and without dementia. However, interpretation of DMOs is limited as we do not yet understand the impact of different social and environmental contexts on walking activity. For example, DMOs may be influenced by the volume of walking that one’s partner participates in, or by the walkability of their local area. Understanding the impact of social and environmental contexts on DMOs will support development of socio‐ecological strategies to support mobility in ageing. We aim to conduct a feasibility study in older adults with the following objectives: (1). Objectively assess DMOs in older adult dyads using digital mobility tools (i.e., IMUs/GPS); (2). Identify key social and environmental influences on DMOs through mixed‐methods exploration; (3). Develop a novel analytical approach combining DMOs with GPS data to assess independence/interdependence in dyads’ walking activities.MethodWe will recruit 20 older adult dyads in North‐East England for an observational cross‐sectional study. Walking activities will be recorded continuously for seven days using an IMU attached to participants’ lower backs. DMOs include volume (e.g., daily steps), pattern (e.g. mean bout length) and variability (of bout length) of walking activities. Simultaneously, participants will carry a GPS device (i.e., smartphone) to monitor excursions outside the home. Questionnaires will capture information on cognition, function, falls risk, exercise motivation, wellbeing, relationship mutuality, spatial navigation, and walkability of local area. Participants will complete a “mobility diary” for the assessment period (e.g., daily journeys, motivations/perceptions/familiarity of journeys).ResultPreliminary results will be presented regarding associations between social/environmental contexts with DMOs via flexible Bayesian statistical models and thematic qualitative analysis.ConclusionThis study will assess the feasibility of the protocol and analysis strategies, with intentions of developing further research to examine the impact of social and environmental influences on DMOs in people with dementia and their carers.

Are DOSE-RESPONSE RELATIONSHIPS OF RESISTANCE TRAINING reliable TO IMPROVE FUNCTIONAL PERFORMANCE IN FRAIL AND PRE-FRAIL OLDER ADULTS? A SYSTEMATIC REVIEW WITH META-ANALYSIS AND META-REGRESSION of randomized controlled trials.

This systematic review with meta-analyses investigates the impact of resistance training (RT), using meta-regressions, on functional performance in frail and pre-frail adults aged ≥ 65 years to determine the key variables of RT. Ten randomized controlled trials involving 1303 participants were analyzed. Five studies assessed habitual walking speed (HWS), three studies evaluated performance in the timed-up-and-go test (TUG), three studies evaluated performance in the Short Physical Performance Battery (SPPB), and three studies assessed performance in the sit-to-stand test (STS). RT alone improved STS time and SPPB scores in frail and pre-frail older adults. RT improved STS performance (Effect Size (ES):-0.536; 95% CI -0.874 to -0.199; p=.002) and led to a 2.261-point increase in SPPB performance (ES:1.682; 95% CI 0.579 to 2.786; p=.003). At least two weekly training sessions are required to increase SPPB scores, and three sessions seem to optimize the improvements. Higher training volume per exercise and volume per session reduce the gains in SPPB performance. We did not observe any association between different doses of RT and STS time improvements. RT alone positively influenced TUG performance only in community-dwelling older frail and pre-frail adults but not in institutionalized older individuals. RT alone did not improve the HWS compared to the non-active control group.

O.4.1-6 Multidimensional physical activity profiles and changes in physical function and self-reported walking ability among community-dwelling older adults – a 4-year follow-up

Abstract Purpose Physical activity (PA) is multidimensional but often assessed using single metrics. We studied how data-driven PA profiles predict changes in physical functioning and self-reported walking ability over time among older adults. Methods Participants (n = 318) were community-dwelling 75-, 80- and 85-year-olds who wore a thigh-mounted accelerometer for 3-7 days at baseline. PA intensity, fragmentation, absolute and relative PA minutes, sit-to-stand transitions, and gait bout characteristics were used in PA profiling using k-means cluster analysis. Physical function was assessed at baseline and at follow-up 4 years later. Substantial decline in physical function was operationalized as decline of at least 2 points in the Short Physical Performance Battery (SPPB, range 0-12) and at least 0.2 m/s decline in habitual 10-m walking speed. Change in self-reported walking ability during 2 km walk was assessed using a 5-point scale (decline vs. no change/improvement for all). Data were analyzed using logistic regression analysis. Results Three physical activity profiles were identified, and named as Exercisers, Actives and Inactives. Exercisers and Actives accumulated high PA minutes, but Actives engaged in predominantly light intensity PA that was accumulated in shorter bouts. The largest difference was observed in relative PA minutes (minutes exceeding participants’ preferred walking speed). Inactives accumulated the lowest PA minutes, intensity and highest activity fragmentation. During the follow-up period, 32% of participants experienced a substantial decline in walking speed, 24% in SPPB score and 21% in self-reported walking ability. Among women, Exercisers, but not Actives, had lower risk for a substantial decline in walking speed (OR 0.30, 95% CI 0.10-0.95) and SPPB score (0.33, 0.12-0.88) compared to Inactives after adjusting for age, depressive symptoms, comorbidity and baseline walking speed or SPPB score. Among women, Exercisers also had lower risk for decline in self-reported walking ability, but this was explained by differences in health. For men, the differences were not statistically significant. Conclusions Daily PA that is accumulated in longer bouts and at intensity exceeding one’s preferred walking speed may be especially beneficial for the maintenance of physical function with advancing age. Funding Source Academy of Finland, Finnish Ministry of Education &amp; Culture and European Research Council.

O.1.2-9 Sex-related differences in free-living estimates of physical activity energy expenditure between older men and women

Abstract Purpose Physical activity is often quantified as physical activity energy expenditure (PAEE), which may be affected by individual ability to sustain physical activity intensity. We examined if there is a true difference in physical activity between older women and men when their physical capacity is considered. Methods Out of the population-based sample of 1021 (75-85-year-old) adults (62 % women), 410 wore an accelerometer (100 Hz) and a single-channel ECG monitor (250 Hz) for at least 3 days in free-living. A treadmill walk calibration and previously validated equations were used to estimate PAEE from combined acceleration and heart rate sensing using branched equation modelling. Preferred walking speed in a six-minute walking test, fat free mass (FFM) using bioimpedance and isometric maximal leg extension strength scaled to FFM were measured. Independent t-test, Pearson correlation and hierarchical multiple regression were used for statistical analyses. Results PAEE was 41.4 (14.2) kJ/kg/day for men, which was significantly higher (p &amp;lt; 0.001) than the PAEE 34.8 (10.9) for women. Walking speed (1.2 (0.2) vs. 1.1 (0.2) m/s), FFM (56.9 (6.5) vs. 42.1 (4.8) kg) and maximal strength (7.4 (1.8) vs. 6.7 (1.8) N/kg) were higher in men than in women (all p &amp;lt; 0.001). PAEE was significantly associated with walking speed (r = 0.44, p &amp;lt; 0.001), FFM (r = 0.26, p &amp;lt; 0.001), and maximal strength (r = 0.26, p &amp;lt; 0.001). In the regression analysis, 22 % of the variation in PAEE was explained by walking speed, FFM and maximal strength combined (F = 37.8, p &amp;lt; 0.001), whereas adding sex did not improve the model (F = 28.9, p &amp;lt; 0.001). The strongest predictor of PAEE was preferred walking speed (standardized beta=0.35, p &amp;lt; 0.001). Conclusions The results indicate that the observed difference in physical activity volume between sexes was largely explained by physical characteristics, especially the faster preferred walking speed of men compared to women. Free-living physical activity is largely comprised of habitual walking especially in older people which makes walking speed a significant contributor of daily PAEE. Walking speed could be measured more widely in physical activity counselling and health care settings as a potential underlying factor of low physical activity in older people. Support/Funding Sources European Research Council, Academy of Finland and Yrjö Jahnsson Foundation.

S15-5 Executive and physical functions among community-dwelling older adults: results from the PASSWORD study

Abstract Purpose Cognitive and physical functions are key factors for safe walking. As these functions deteriorate with age walking may be compromised among older adults. However, cognitive and physical decline may be attenuated with cognitive and physical training. This study investigated the associations between cognitive, especially executive, and physical functions and sex differences in these associations in physically inactive older adults. Additionally, the role of participant characteristics in cognitive and physical training-induced change in executive functions was investigated Methods 314 older adults aged 70-85 were recruited and randomized to PTCT (N = 155) or PT (N = 159). PT included two supervised training sessions a week and home exercises. PTCT included PT and cognitive training. Measurements were organized at baseline, 6 and 12 months. Physical functions were assessed with 10-meter maximal walking speed, 6-minutes walking distance, dual-task cost in walking speed, habitual walking speed and Short Physical Performance Battery (SPPB). Core skills of executive functions were assessed with Stroop (inhibition), Trail Making Test B (set shifting) and Letter Verbal Fluency (updating). Training compliance was based on participation in supervised training sessions. The data was analyzed with multiple linear regression analyses and longitudinal two-group linear path models. Results Mean age of the participants was 74.5. Results showed that Verbal Fluency test was positively associated with faster maximal and habitual walking speed (β = 0.272, p&amp;lt;0.001, β = 0.184, p = 0.009 respectively), longer 6-min walking distance (β = 0.242, p&amp;lt;0.001) and higher scores in SPPB (β = 0.234, p&amp;lt;0.001), additionally, TMT B-A was positively associated with higher scores in SPPB (β=-0.236, p&amp;lt;0.001). No significant sex-differences were found. Additionally, Stroop improved significantly more in women and participants in the low compliance subgroup who received PTCT compared to participant receiving PT (difference -8.758, p = 0.001 and difference in -8.405, p = 0.010 respectively) No other significant associations were observed. Conclusion Executive and physical functions are positively associated in older adults. The association depends on the physical task and the executive subdomain. Physical and cognitive training improves older adults’ executive functions. Women and participants who only occasionally engaged in training may gain additional benefits for inhibition from physical and cognitive training compared to physical training. Funding Academy of Finland (Grant no. 296843).

Associations Between Local Area Deprivation and Physical Activity Participation in People with Cognitive Impairment in the North East of England.

Promoting physical activity, such as habitual walking behaviors, in people with cognitive impairment may support their ability to remain independent with a good quality of life for longer. However, people with cognitive impairment participate in less physical activity compared to cognitively unimpaired older adults. The local area in which people live may significantly impact abilities to participate in physical activity. For example, people who live in more deprived areas may have less safe and walkable routes. To examine this further, this study aimed to explore associations between local area deprivation and physical activity in people with cognitive impairment and cognitively unimpaired older adults (controls). 87 participants with cognitive impairment (mild cognitive impairment or dementia) and 27 older adult controls from the North East of England were included in this analysis. Participants wore a tri-axial wearable accelerometer (AX3, Axivity) on their lower backs continuously for seven days. The primary physical activity outcome was daily step count. Individuals' neighborhoods were linked to UK government area deprivation statistics. Hierarchical Bayesian models assessed the association between local area deprivation and daily step count in people with cognitive impairment and controls. Key findings indicated that there was no association between local area deprivation and daily step count in people with cognitive impairment, but higher deprivation was associated with lower daily steps for controls. These findings suggest that cognitive impairment may be associated with lower participation in physical activity which supersedes the influence of local area deprivation observed in normal aging.

Segmental extracellular-to-intracellular water resistance ratio and physical function in older adults

ObjectivesThis study aimed to investigate the association between whole-body (WB), arm, and leg extracellular-to-intracellular water resistance (Recw/Ricw) ratios and various physical functions of each segment and muscle mass using segmental multifrequency bioelectrical impedance analysis. MethodsIn total, 988 community-dwelling older adults were included in the analysis. Physical function was assessed using hand grip, 5-repetition sit-to-stand, 5-m habitual walk, Timed Up and Go, and single-leg balance with eyes open tests. Each segmental Recw/Ricw ratio and muscle mass were assessed at 5 and 250 kHz resistances using a segmental multifrequency bioelectrical impedance analysis device. Pearson's correlation between the segmental Recw/Ricw ratio and muscle mass and physical function was calculated, and the difference in correlation coefficients was tested using Bonferroni correction. Multiple linear regression analysis was conducted using physical function as the dependent variable and the segmental Recw/Ricw ratio as the independent variable, adjusting for sex, age, body mass index, and segmental muscle mass. ResultsWB and leg Recw/Ricw ratios were significantly positively correlated with good hand grip performance, gait speed, mobility, balance, and standing power (p < 0.05), after adjusting for sex, age, body mass index, and muscle mass. Furthermore, the leg Recw/Ricw ratio was positively associated with lower extremity physical function compared with WB and arm Recw/Ricw ratios and muscle mass (p < 0.01). Conversely, WB muscle mass was more strongly related to grip strength than WB, arm, and leg Recw/Ricw ratios (p < 0.01). ConclusionsThe Recw/Ricw ratio is useful for identifying older adults with worse physical function. The Recw/Ricw ratio allows for easy and timely screening of older adults with worse physical function in clinical settings.