Local measures of fluctuations in inhomogeneous liquids: statistical mechanics and illustrative applications.

We show in detail how three one-body fluctuation profiles, namely the local compressibility, the local thermal susceptibility, and the reduced density, can be obtained from a statistical mechanical many-body description of classical particle-based systems. We present several different and equivalent routes to the definition of each fluctuation profile, facilitating their explicit numerical calculation in inhomogeneous equilibrium systems. This underlying framework is used for the derivation of further properties such as hard wall contact theorems and novel types of inhomogeneous one-body Ornstein-Zernike equations. The practical accessibility of all three fluctuation profiles is exemplified by grand canonical Monte Carlo simulations that we present for hard sphere, Gaussian core and Lennard-Jones fluids in confinement.

Effect of sample height and particle elongation in the sedimentation of colloidal rods.

We study theoretically the effect of a gravitational field on the equilibrium behaviour of a colloidal suspension of rods with different length-to-width aspect ratios. The bulk phases of the system are described with analytical equations of state. The gravitational field is then incorporated via sedimentation path theory, which assumes a local equilibrium condition at each altitude of the sample. The bulk phenomenology is significantly enriched by the presence of the gravitational field. In a suspension of elongated rods with five stable phases in bulk, the gravitational field stabilizes up to fifteen different stacking sequences. The sample height has a non-trivial effect on the stable stacking sequence. New layers of distinct bulk phases appear either at the top, at the bottom, or simultaneously at the top and the bottom when increasing the sample height at constant colloidal concentration. We also study sedimentation in a mass-polydisperse suspension in which all rods have the same shape but different buoyant masses.

Sedimentation path theory for mass-polydisperse colloidal systems.

Both polydispersity and the presence of a gravitational field are inherent to essentially any colloidal experiment. While several theoretical works have focused on the effect of polydispersity on the bulk phase behavior of a colloidal system, little is known about the effect of a gravitational field on a polydisperse colloidal suspension. We extend here the sedimentation path theory to study sedimentation-diffusion-equilibrium of a mass-polydisperse colloidal system: the particles possess different buoyant masses but they are otherwise identical. The model helps to understand the interplay between gravity and polydispersity on sedimentation experiments. Since the theory can be applied to any parent distribution of buoyant masses, it can also be used to study the sedimentation of monodisperse colloidal systems. We find that mass-polydispersity has a strong influence in colloidal systems near density matching for which the bare density of the colloidal particles equals the solvent density. To illustrate the theory, we study crystallization in sedimentation-diffusion-equilibrium of a suspension of mass-polydisperse hard spheres.

Development, implementation and formative evaluation of a motivational-volitional intervention to promote sustainable physical activity in breast cancer survivors.

OBJECTIVE: The aim of the current project was the development, implementation and evaluation of the programme, Motivational-Volitional Intervention-Movement After Breast Cancer (Mo-Vo-BnB), an intervention for the sustainable promotion of physical activity of breast cancer survivors. METHODS: In a multi-stage interdisciplinary development process, the pedagogical-didactic, psychological and physical evidence-based programme was developed and implemented for women after breast cancer who were approved for medical rehabilitation and were minimally, physically active (<60 min/week). Train-the-trainer seminars were carried out for the implementation. Four sessions were implemented in two German clinics. The training quality, didactic methods and accompanying material were evaluated 6 weeks and 12 months after implementation by patients, trainers and project members (n = 127 evaluations). RESULTS: The standardised and published MoVo-BnB programme can provide practical and quality training. Content and methods can be implemented according to the manual. Training quality, didactic methods, and accompanying materials were evaluated positively. CONCLUSION: The results suggest that MoVo-BnB is a useful standardised intervention for promoting the physical activity of breast cancer survivors. The demonstrated process is also suitable for other projects. CLINICAL TRIAL REGISTRATION: German Clinical Trials Register (DRKS): DRKS00011122; Trial registration date: 2016 October 13.

Effects of a Home-Based Physical Training and Activity Promotion Program in Community-Dwelling Older Persons with Cognitive Impairment after Discharge from Rehabilitation: A Randomized Controlled Trial.

BACKGROUND: Older people with cognitive impairment (CI) are at high risk for mobility limitations and adverse outcomes after discharge from geriatric rehabilitation settings. The aim was to estimate the effects of a specifically designed home-based physical training and activity promotion program on physical capacity, different aspects of physical activity (PA), and psychosocial status. METHODS: Patients with mild to moderate CI (Mini-Mental State Examination [MMSE]: 17-26 points) discharged home after rehabilitation were included in this randomized, double-blind, placebo-controlled trial with a 12-week intervention and 12-week follow-up period. The intervention group performed a CI-specific, autonomous, home-based strength, balance, and walking training supported by tailored motivational strategies to foster training adherence and promote PA. The control group participated in an unspecific motor placebo activity. Primary outcomes were physical capacity (Short Physical Performance Battery [SPPB]) and PA (sensor-based activity time). RESULTS: Among 118 randomized participants (82.3 ± 6.0 years) with CI (MMSE: 23.3 ± 2.4) and high levels of multimorbidity, those participants undergoing home-based training demonstrated superior outcomes to the control group in SPPB (mean difference between groups 1.9 points; 95% CI: 1.0-2.8; p < .001), with persistent benefits over the follow-up (1.3 points; 95% CI: 0.4-2.2; p < .001). There were no differences in PA across any time points. Among secondary outcomes, fear of falling and activity avoidance behavior were reduced in the intervention group at all time points, life-space mobility improved short-term. CONCLUSIONS: The results demonstrate clinically important benefits of an individually tailored autonomous physical training and activity promotion program on physical capacity and secondary outcomes in different domains in a vulnerable, multimorbid population. CLINICAL TRIAL REGISTRATION: ISRCTN82378327.

Sensor-based fall risk assessment in older adults with or without cognitive impairment: a systematic review.

BACKGROUND: Higher age and cognitive impairment are associated with a higher risk of falling. Wearable sensor technology may be useful in objectively assessing motor fall risk factors to improve physical exercise interventions for fall prevention. This systematic review aims at providing an updated overview of the current research on wearable sensors for fall risk assessment in older adults with or without cognitive impairment. Therefore, we addressed two specific research questions: 1) Can wearable sensors provide accurate data on motor performance that may be used to assess risk of falling, e.g., by distinguishing between faller and non-faller in a sample of older adults with or without cognitive impairment?; and 2) Which practical recommendations can be given for the application of sensor-based fall risk assessment in individuals with CI? A systematic literature search (July 2019, update July 2020) was conducted using PubMed, Scopus and Web of Science databases. Community-based studies or studies conducted in a geriatric setting that examine fall risk factors in older adults (aged ≥60 years) with or without cognitive impairment were included. Predefined inclusion criteria yielded 16 cross-sectional, 10 prospective and 2 studies with a mixed design. RESULTS: Overall, sensor-based data was mainly collected during walking tests in a lab setting. The main sensor location was the lower back to provide wearing comfort and avoid disturbance of participants. The most accurate fall risk classification model included data from sit-to-walk and walk-to-sit transitions collected over three days of daily life (mean accuracy = 88.0%). Nine out of 28 included studies revealed information about sensor use in older adults with possible cognitive impairment, but classification models performed slightly worse than those for older adults without cognitive impairment (mean accuracy = 79.0%). CONCLUSION: Fall risk assessment using wearable sensors is feasible in older adults regardless of their cognitive status. Accuracy may vary depending on sensor location, sensor attachment and type of assessment chosen for the recording of sensor data. More research on the use of sensors for objective fall risk assessment in older adults is needed, particularly in older adults with cognitive impairment. TRIAL REGISTRATION: This systematic review is registered in PROSPERO ( CRD42020171118 ).

[A Motivational-Volitional Program for Women after Breast Cancer Increases Physical Activity 12 Months Post Rehabilitation - Results of a Prospective Controlled Trial]. / Ein motivational-volitionales Programm für Frauen nach Brustkrebs verbessert die sportliche Aktivität 12 Monate nach der Rehabilitation ­ Ergebnisse einer prospektiven kontrollierten Studie.

PURPOSE: To assess the effectiveness of a motivational-volitional program for women after breast cancer (MoVo-BnB) who engage less than 60 minutes per week in physical activity. METHODS: This is a non-randomised, prospective bi-centered controlled trial in 2 in-patient medical rehabilitation centers. Data are assessed at 4 measurement points: at admission, discharge, 6 and 12 months post discharge. The control group (CG; n=266) has received the standard rehabilitation, and the intervention group (IG; n=279) attended additionally the group program (4 sessions lead by physiotherapeutic and health pedagogic personnel). The primary outcome is self-reported physical activity (BSA-F); secondary outcomes are health related quality of life (QLQ-C30), breast cancer specific quality of health (QLQ-BR23) and program acceptance. Analysis of change are performed by ANCOVA for each follow-up, adjusting for baseline values. RESULTS: At 12 months follow up, the level of exercise in the intervention group is 22 min/week higher than in the control group (95% CI: 2,6 to 41.5; p=0.02). Further, 49.1% of the intervention group exercises for at least 60 min/week compared to 37.6% of the control group (p≤0.01). We have observed no significant differences between the groups for quality of life. The participants' evaluation of the intervention is positive and does not differ substantially between the 2 clinics (p=0.3). CONCLUSION: Our findings demonstrate that a cognitive-behavioral program based on the motivation-volitional model can lead to long-term improvement in exercise behavior in breast cancer patients, who is initially minimally active. Physical activity should be encouraged after breast cancer diagnosis. The results suggest that practitioners working in cancer aftercare might like to consider using a motivational-volitional program for improving and maintaining physical activity behavior for physical sedentary target groups.

Comparison of Self-Reported and Device-Based Measured Physical Activity Using Measures of Stability, Reliability, and Validity in Adults and Children.

Quantification of physical activity (PA) depends on the type of measurement and analysis method making it difficult to compare adherence to PA guidelines. Therefore, test-retest reliability, validity, and stability for self-reported (i.e., questionnaire and diary) and device-based measured (i.e., accelerometry with 10/60 s epochs) PA was compared in 32 adults and 32 children from the SMARTFAMILY study to examine if differences in these measurement tools are systematic. PA was collected during two separate measurement weeks and the relationship for each quality criteria was analyzed using Spearman correlation. Results showed the highest PA values for questionnaires followed by 10-s and 60-s epochs measured by accelerometers. Levels of PA were lowest when measured by diary. Only accelerometry demonstrated reliable, valid, and stable results for the two measurement weeks, the questionnaire yielded mixed results and the diary showed only a few significant correlations. Overall, higher correlations for the quality criteria were found for moderate than for vigorous PA and the results differed between children and adults. Since the differences were not found to be systematic, the choice of measurement tools should be carefully considered by anyone working with PA outcomes, especially if vigorous PA is the parameter of interest.

Cost-Effectiveness and Cost-Utility of a Home-Based Exercise Program in Geriatric Patients with Cognitive Impairment.

INTRODUCTION: There is a substantial lack of home-based exercise programs in the highly vulnerable group of geriatric patients with cognitive impairment (CI) after discharge from ward rehabilitation. Beyond clinical effectiveness, the cost-effectiveness of intervention programs to enhance physical performance is not well investigated in this target group. OBJECTIVE: The aim of the study was to determine the cost-effectiveness of a 12-week home-based exercise intervention following discharge from ward rehabilitation compared to unspecified flexibility training for geriatric patients with CI from a societal perspective. METHODS: This cost-effectiveness study was conducted alongside a randomized placebo-controlled trial. A total of 118 geriatric patients with CI (Mini-Mental State Examination score: 17-26) were randomized either to the intervention group (IG, n = 63) or control group (CG, n = 55). Participants in the IG received a home-based individually tailored exercise program to increase physical performance, while participants in the CG received unspecific flexibility training (placebo control). Healthcare service use, physical performance (Short Physical Performance Battery, SPPB), and quality of life (EQ-5D-3L) were measured over 24 weeks. The net monetary benefit (NMB) approach was applied to calculate incremental cost-effectiveness of the exercise intervention compared to the CG with respect to improvement of (a) physical performance on the SPPB and (b) quality-adjusted life years (QALYs). RESULTS: Physical performance was significantly improved in the IG compared to the CG (mean difference at 24 weeks: 1.3 points; 95% confidence interval [95% CI] = 0.5-2.2; p = 0.003), while health-related quality of life did not significantly differ between the groups at 24 weeks (mean difference: 0.08; 95% CI = -0.05 to 0.21; p = 0.218). Mean costs to implement the home-based exercise intervention were EUR 284 per patient. The probability of a positive incremental NMB of the intervention reached a maximum of 92% at a willingness to pay (WTP) of EUR 500 per point on the SPPB. The probability of cost-utility referring to QALYs was 85% at a WTP of EUR 5,000 per QALY. CONCLUSION: The home-based exercise intervention demonstrated high probability of cost-effectiveness in terms of improved physical performance in older adults with CI following discharge from ward rehabilitation, but not in terms of quality of life.

Psychometric properties of the German version of the Fear of Falling Questionnaire-revised (FFQ-R) in a sample of older adults after hip or pelvic fracture.

BACKGROUND: Identifying patients with maladaptive fear of falling (FOF) is important in the rehabilitation phase after serious fall. The 6-item Fear of Falling Questionnaire-revised (FFQ-R) was seen as promising measurement instrument as it evaluates FOF in a broader way than the one-item-question and independent of physical activities. AIM: The purpose of the analysis was to evaluate the psychometric properties of the translated German FFQ-R. METHODS: Back-translation method was applied. Confirmatory factor analysis (CFA) with diagonally weighted least square estimation was used to verify the two-factor structure. Data were collected during inpatient rehabilitation from hip and pelvic fracture patients [age 84.3 ± 6.2, Mini-Mental State Examination (MMSE) scores > 23] participating in an RCT (N = 112) and a cross-sectional survey (N = 40). RESULTS: Internal consistency was 0.78 (Cronbach´s alpha). No floor or ceiling effects were found. Discriminatory power on item level was moderate to good (r = 0.43-0.65). CFA revealed a good model fit and confirmed the two-factor structure. The German FFQ-R was moderately correlated (r = 0.51) with the Short Falls Efficacy Scale-International (Short FES-I) used as a proxy measure for FOF. Missing rates up to 9% for specific items were because some individuals, independent of cognitive level or age, had problems to rate items with conditional statements on possible negative consequences of a fall. CONCLUSIONS: Results demonstrated moderate to good psychometric properties similar to the original English version in a comparable sample of fracture patients.

Increasing Life-Space Mobility in Community-Dwelling Older Persons With Cognitive Impairment Following Rehabilitation: A Randomized Controlled Trial.

BACKGROUND: Community-dwelling older persons with cognitive impairment (CI) following discharge from geriatric rehabilitation are at high risk of losing life-space mobility (LSM). Interventions to improve their LSM are, however, still lacking. The aim of this study was to evaluate the effects of a CI-specific, home-based physical training and activity promotion program on LSM. METHODS: Older persons with mild-to-moderate CI (Mini-Mental State Examination: 17-26 points) discharged home from rehabilitation were included in this double-blinded, randomized, placebo-controlled trial with a 12-week intervention period and 12-week follow-up period. The intervention group received a CI-specific, home-based strength, balance, and walking training supported by tailored motivational strategies. The control group received a placebo activity. LSM was evaluated by the Life-Space Assessment in Persons with Cognitive Impairment, including a composite score for LSM and 3 subscores for maximal, equipment-assisted, and independent life space. Mixed-model repeated-measures analyses were used. RESULTS: One hundred eighteen participants (82.3 ± 6.0 years) with CI (Mini-Mental State Examination: 23.3 ± 2.4) were randomized. After the intervention, the home-based training program resulted in a significant benefit in the Life-Space Assessment in Persons with Cognitive Impairment composite scores (b = 8.15; 95% confidence interval: 2.89-13.41; p = .003) and independent life-space subscores (b = 0.39; 95% confidence interval: 0.00-0.78; p = .048) in the intervention group (n = 63) compared to control group (n = 55). Other subscores and follow-up results were not significantly different. CONCLUSIONS: The home-based training program improved LSM and independent life space significantly in this vulnerable population. Effects were not sustained over the follow-up. The program may represent a model for improved transition from rehabilitation to the community to prevent high risk of LSM restriction.

Will We Do If We Can? Habitual Qualitative and Quantitative Physical Activity in Multi-Morbid, Older Persons with Cognitive Impairment.

This study aimed to identify determinants of quantitative dimensions of physical activity (PA; duration, frequency, and intensity) in community-dwelling, multi-morbid, older persons with cognitive impairment (CI). In addition, qualitative and quantitative aspects of habitual PA have been described. Quantitative PA and qualitative gait characteristics while walking straight and while walking turns were documented by a validated, sensor-based activity monitor. Univariate and multiple linear regression analyses were performed to delineate associations of quantitative PA dimensions with qualitative characteristics of gait performance and further potential influencing factors (motor capacity measures, demographic, and health-related parameters). In 94 multi-morbid, older adults (82.3 ± 5.9 years) with CI (Mini-Mental State Examination score: 23.3 ± 2.4), analyses of quantitative and qualitative PA documented highly inactive behavior (89.6% inactivity) and a high incidence of gait deficits, respectively. The multiple regression models (adjusted R2 = 0.395-0.679, all p < 0.001) identified specific qualitative gait characteristics as independent determinants for all quantitative PA dimensions, whereas motor capacity was an independent determinant only for the PA dimension duration. Demographic and health-related parameters were not identified as independent determinants. High associations between innovative, qualitative, and established, quantitative PA performances may suggest gait quality as a potential target to increase quantity of PA in multi-morbid, older persons.

Effects of a Collective Family-Based Mobile Health Intervention Called "SMARTFAMILY" on Promoting Physical Activity and Healthy Eating: Protocol for a Randomized Controlled Trial.

BACKGROUND: Numerous smartphone apps are targeting physical activity and healthy eating, but empirical evidence on their effectiveness for initialization and maintenance of behavior change, especially in children and adolescents, is still limited. OBJECTIVE: The aim of this study was to conceptualize a theory-based and evidence-based mHealth intervention called SMARTFAMILY (SF) that targets physical activity and healthy eating in a collective family-based setting. Subsequently, the app will be refined and re-evaluated to analyze additional effects of just-in-time adaptive interventions (JITAIs) and gamification features. METHODS: A smartphone app based on behavior change theories and behavior change techniques was developed and implemented and will be evaluated with family members individually and cooperatively (SF trial). Existing evidence and gained results were used to refine and will be used to re-evaluate the app (SF2.0 trial). Both trials are cluster randomized controlled trials with 3 measurement occasions. The intervention group uses the app for 3 consecutive weeks, whereas the control group receives no treatment. Baseline measurements (T0) and postintervention measurements (T1) include physical activity (ie, self-reported and accelerometry) and healthy eating measurements (ie, self-reported fruit and vegetable intake) as the primary outcomes. The secondary outcomes (ie, self-reported) are intrinsic motivation, behavior-specific self-efficacy, and the family health climate, complemented by an intentional measure in SF2.0. Four weeks following T1, a follow-up assessment (T2) is completed by the participants, consisting of all questionnaire items to assess the stability of the intervention effects. Mixed-method analysis of covariance will be used to calculate the primary intervention effects (ie, physical activity, fruit and vegetable intake) while controlling for covariates, including family health climate, behavior-specific self-efficacy, and intrinsic motivation. RESULTS: This study is funded by the German Federal Ministry of Education and Research and ethically approved by the Karlsruhe Institute of Technology. For both trials, it is hypothesized that the apps will positively influence physical activity and healthy eating in the whole family. Furthermore, SF2.0 is expected to produce stronger effects (ie, higher effect sizes) compared to SF. SF app development and piloting are completed. Data acquisition for the SF trial is terminated and discontinued due to the COVID-19 pandemic. SF2.0 app development and piloting are completed, while data acquisition is ongoing. Participant recruitment for the SF 2.0 trial started in February 2020. The results for SF are expected to be published in mid-2021, and the results of SF2.0 are expected to be published in mid-2022. CONCLUSIONS: In this study, it is hypothesized that targeting the whole family will facilitate behavior change at the individual level and the family level, as the implemented strategies address changes in daily family life. Furthermore, subsequent app development (SF2.0) with supplementary addition of motivation-enhancing features and a JITAI approach is expected to enhance positive intervention effects. TRIAL REGISTRATION: German Clinical Trials Register DRKS00010415; https://tinyurl.com/yyo87yyu. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/20534.

Transition from inpatient rehabilitation to the home environment in cognitively impaired older persons after hip fracture.

OBJECTIVE: To investigate short-term changes in clinical characteristics in the transition period between geriatric inpatient rehabilitation and independent living at home in older patients with hip/pelvic fracture and cognitive impairment. DESIGN: Longitudinal observational study. SUBJECTS: A total of 127 multi-morbid, older patients with hip/pelvic fracture and cognitive impairment. METHODS: Physical performance, fall-related self-efficacy, fear of falling, depressive symptoms, quality of life, and pain were assessed before discharge from geriatric inpatient rehabilitation and at home. RESULTS: During the transition period (median 18.5 days; interquartile range 14-25 days), 25 participants dropped out due to admission to a nursing home (n = 11), withdrawal of consent (n = 8), death (n = 2), severe disease (n = 2), or other reasons (n = 2). Physical performance improved (p ≤ 0.001), while fall-related self-efficacy (p = 0.040) and fear of falling (p = 0.004) deteriorated. Depressive symptoms, quality of life, and pain did not change. Improvement in physical performance was associated with lower age, lower baseline physical performance, less baseline fear of falling, and living alone. CONCLUSION: While significant improvements in physical performance indicate a high potential for further enhancements in the majority of participants following inpatient rehabilitation, a considerable subgroup dropped out, partly indicating a negative trajectory in this vulnerable patient group. Sustained physical training or promotion of activity at home may further support rehabilitation in patients with hip/pelvic fracture and cognitive impairment.

Key facets to build up eHealth and mHealth interventions to enhance physical activity, sedentary behavior and nutrition in healthy subjects - an umbrella review.

BACKGROUND: Electronic (eHealth) and mobile (mHealth) health interventions can provide a large coverage, and are promising tools to change health behavior (i.e. physical activity, sedentary behavior and healthy eating). However, the determinants of intervention effectiveness in primary prevention has not been explored yet. Therefore, the objectives of this umbrella review were to evaluate intervention effectiveness, to explore the impact of pre-defined determinants of effectiveness (i.e. theoretical foundations, behavior change techniques, social contexts or just-in-time adaptive interventions), and to provide recommendations for future research and practice in the field of primary prevention delivered via e/mHealth technology. METHODS: PubMed, Scopus, Web of Science and the Cochrane Library were searched for systematic reviews and meta-analyses (reviews) published between January 1990 and May 2020. Reviews reporting on e/mHealth behavior change interventions in physical activity, sedentary behavior and/or healthy eating for healthy subjects (i.e. subjects without physical or physiological morbidities which would influence the realization of behaviors targeted by the respective interventions) were included if they also investigated respective theoretical foundations, behavior change techniques, social contexts or just-in-time adaptive interventions. Included studies were ranked concerning their methodological quality and qualitatively synthesized. RESULTS: The systematic search revealed 11 systematic reviews and meta-analyses of moderate quality. The majority of original research studies within the reviews found e/mHealth interventions to be effective, but the results showed a high heterogeneity concerning assessment methods and outcomes, making them difficult to compare. Whereas theoretical foundation and behavior change techniques were suggested to be potential positive determinants of effective interventions, the impact of social context remains unclear. None of the reviews included just-in-time adaptive interventions. CONCLUSION: Findings of this umbrella review support the use of e/mHealth to enhance physical activity and healthy eating and reduce sedentary behavior. The general lack of precise reporting and comparison of confounding variables in reviews and original research studies as well as the limited number of reviews for each health behavior constrains the generalization and interpretation of results. Further research is needed on study-level to investigate effects of versatile determinants of e/mHealth efficiency, using a theoretical foundation and additionally explore the impact of social contexts and more sophisticated approaches like just-in-time adaptive interventions. TRIAL REGISTRATION: The protocol for this umbrella review was a priori registered with PROSPERO: CRD42020147902 .

Promoting physical activity in geriatric patients with cognitive impairment after discharge from ward-rehabilitation: a feasibility study.

The aim of the present study was to examine adherence and acceptance of a home-based program to promote physical activity (PA) in older persons with cognitive impairment (CI) following inpatient rehabilitation. Sixty-three older persons (≥ 65 years) with mild to moderate CI (Mini-Mental State Examination score 17-26), allocated to the intervention group of a randomized, controlled intervention trial underwent a 12-week home-based PA intervention including (1) physical training and outdoor walking to improve functional fitness and (2) motivational strategies (goal-setting, pedometer-based self-monitoring, social support delivered by home visits, phone calls) to promote PA. Training logs were used to assess adherence to physical training, outdoor walking and to motivational strategies (goal-setting, pedometer-based self-monitoring). Acceptance (subjective feasibility and effectiveness) of the program components was assessed by a standardized questionnaire. Mean adherence rates over the intervention period were 63.6% for physical training, 57.9% for outdoor walking, and between 40.1% (achievement of walking goals), and 60.1% (pedometer-based self-monitoring) for motivational strategies. Adherence rates significantly declined from baseline to the end of intervention (T1: 43.4-76.8%, T2: 36.1-51.5%, p values<.019). Most participants rated physical training, outdoor walking, goal-setting, and pedometer self-monitoring as feasible (68.2-83.0%) and effective (63.5-78.3%). Highest ratings of self-perceived effectiveness were found for home visits (90.6%) and phone calls (79.2%). The moderate to high adherence to self-performed physical training and motivational strategies proved the feasibility of the home-based PA program in older persons with CI following inpatient rehabilitation.

Ambulatory Assessment for Physical Activity Research: State of the Science, Best Practices and Future Directions.

Technological and digital progress benefits physical activity (PA) research. Here we compiled expert knowledge on how Ambulatory Assessment (AA) is utilized to advance PA research, i.e., we present results of the 2nd International CAPA Workshop 2019 "Physical Activity Assessment - State of the Science, Best Practices, Future Directions" where invited researchers with experience in PA assessment, evaluation, technology and application participated. First, we provide readers with the state of the AA science, then we give best practice recommendations on how to measure PA via AA and shed light on methodological frontiers, and we furthermore discuss future directions. AA encompasses a class of methods that allows the study of PA and its behavioral, biological and physiological correlates as they unfold in everyday life. AA includes monitoring of movement (e.g., via accelerometry), physiological function (e.g., via mobile electrocardiogram), contextual information (e.g., via geolocation-tracking), and ecological momentary assessment (EMA; e.g., electronic diaries) to capture self-reported information. The strengths of AA are data assessment that near realtime, which minimizes retrospective biases in real-world settings, consequentially enabling ecological valid findings. Importantly, AA enables multiple assessments across time within subjects resulting in intensive longitudinal data (ILD), which allows unraveling within-person determinants of PA in everyday life. In this paper, we show how AA methods such as triggered e-diaries and geolocation-tracking can be used to measure PA and its correlates, and furthermore how these findings may translate into real-life interventions. In sum, AA provides numerous possibilities for PA research, especially the opportunity to tackle within- subject antecedents, concomitants, and consequences of PA as they unfold in everyday life. In-depth insights on determinants of PA could help us design and deliver impactful interventions in real-world contexts, thus enabling us to solve critical health issues in the 21st century such as insufficient PA and high levels of sedentary behavior.

Fluctuation Profiles in Inhomogeneous Fluids.

Three one-body profiles that correspond to local fluctuations in energy, in entropy, and in particle number are used to describe the equilibrium properties of inhomogeneous classical many-body systems. Local fluctuations are obtained from thermodynamic differentiation of the density profile or equivalently from average microscopic covariances. The fluctuation profiles follow from functional generators and they satisfy Ornstein-Zernike relations. Computer simulations reveal markedly different fluctuations in confined fluids with Lennard-Jones, hard sphere, and Gaussian core interactions.

Correlates of fear of falling and falls efficacy in geriatric patients recovering from hip/pelvic fracture.

OBJECTIVE: To gain a better understanding about the nature of fear of falling, this study analyzed associations between psychological and physical aspects related to fear of falling and falls efficacy in hip/pelvic fracture patients. DESIGN: Baseline data of a randomized controlled trial. SETTING: Geriatric inpatient rehabilitation hospital. SUBJECTS: In all, 115 geriatric patients with hip/pelvic fracture (mean age: 82.5 years) reporting fear of falling within first week of inpatient rehabilitation. INTERVENTIONS: None. MAIN MEASURES: Falls efficacy (Short Falls Efficacy Scale-International; Perceived Ability to Manage Falls), fear of falling (one-item question), fall-related post-traumatic stress symptoms (six items based on Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV) criteria), physical performance (Short Physical Performance Battery) and psychological inflexibility (Acceptance and Action Questionnaire-II) were assessed. RESULTS: Path analyses demonstrated that low falls efficacy (Short Falls Efficacy Scale International) was significantly related to poor physical performance (ß* = -.277, P ⩽ .001), but not to psychological inflexibility and fall-related post-traumatic stress symptoms (P ⩾ .05.). Fear of falling was directly associated with fall-related post-traumatic stress symptoms (ß*= .270, P = .007) and indirectly with psychological inflexibility (ß*= .110, P = .022). Low perceived ability to manage falls was significantly related to previous falls (ß* = -.348, P ⩽ .001), psychological inflexibility (ß* = -.216, P = .022) and female gender (ß* = -.239, P ⩽ .01). CONCLUSION: Falls efficacy and fear of falling constitute distinct constructs. Falls efficacy measured with the Short Falls Efficacy Scale International reflects the appraisal of poor physical performance. Fear of falling measured by the single-item question constitutes a fall-specific psychological construct associated with psychological inflexibility and fall-related post-traumatic stress symptoms.

Validity, reliability, and feasibility of the uSense activity monitor to register physical activity and gait performance in habitual settings of geriatric patients.

OBJECTIVE: The aim of the study was to investigate the psychometric quality of a newly developed activity monitor (uSense) to document established physical activity parameters as well as innovative qualitative and quantitative gait characteristics in geriatric patients. APPROACH: Construct and concurrent validity, test-retest reliability, and feasibility of established as well as innovative characteristics for qualitative gait analysis were analyzed in multi-morbid, geriatric patients with cognitive impairment (CI) (n = 110), recently discharged from geriatric rehabilitation. MAIN RESULTS: Spearman correlations of established and innovative uSense parameters reflecting active behavior with clinically relevant construct parameters were on average moderate to high for motor performance and life-space and low to moderate for other parameters, while correlations with uSense parameters reflecting inactive behavior were predominantly low. Concurrent validity of established physical activity parameters showed consistently high correlations between the uSense and an established comparator system (PAMSys™), but the absolute agreement between both sensor systems was low. On average excellent test-retest reliability for all uSense parameters and good feasibility could be documented. SIGNIFICANCE: The uSense monitor allows the assessment of established and-for the first time-a semi-qualitative gait assessment of habitual activity behavior in older persons most affected by motor and CI and activity restrictions. On average moderate to good construct validity, high test-retest reliability, and good feasibility indicated a sound psychometric quality of most measures, while the results of concurrent validity as measured by a comparable system indicated high correlation but low absolute agreement based on different algorithms used.