Step Time Research Articles

Influence of enzymatic extraction on the properties of corn starch

Corn starch played an important role in the food industries, while traditional extraction method involved using sulfur dioxide that could easily cause environmental pollution and equipment corrosion. Based on these drawbacks, the main objective of this study was to develop a feasible two-step enzymatic extraction method that could isolate starch from corn kernels and evaluate the properties of corn starch. The physicochemical components of steep liquor during enzymatic extraction were researched, the single-factor experiments and response surface methodology were used to optimize the steeping conditions. As a result, optimized steeping parameters of which the first step time was 30 h, the lactic acid solution concentration was 0.45%, the protease content was 480 U/g, the l-cysteine content was 0.45 g, and the second step time was 4 h. The corn starch yield (65.18%) with enzymatic extraction was higher than that of traditional extraction (54.73%). The solubility and swelling power of all starch samples were raised with the temperature increasing. The starch extracted using the enzymatic method had a higher amylose content (35.18%) and mean diameter (30.99 μm). Compared with commercial corn starch, the starch samples presented nearly identical FT-IR spectra, the same A-type crystalline pattern and morphology, furthermore, a higher resistant starch content was detected in corn starch obtained through extraction methods. This finding will provide useful information to food industries for extraction of corn starch.

Unravelling upright events: a descriptive epidemiology of the behavioural composition and temporal distribution of upright events in participants from the 1970 British Cohort Study

BackgroundContinued proliferation of accelerometers in physical activity research has opened new avenues for understanding activity behaviours beyond simple aggregate measures of frequency and duration. This study explores the standing and stepping composition, and the temporal distribution, of upright events, and investigates their associations with sociodemographic and health factors.MethodsParticipants from the 1970 British Cohort Study wore activPAL3 accelerometers for seven days. Event-based analysis was used to extract a time series of upright, standing, and stepping events. Derived metrics included daily number of upright and stepping events, total upright and stepping time, the burstiness of upright events and burstiness of sedentary events (burstiness refers to the pattern of how physical activity and sedentary behaviour are distributed throughout a given time period), within-event stepping proportion, within-event step count, and stepping cadence. Generalized linear regression models, adjusted for total step count, were employed to explore associations between derived metrics and sociodemographic and health-related factors.ResultsA total of 4527 participants, provided 30992 valid days (≥ 10 h of waking wear) and 1.64 million upright events. Upright event composition and temporal distribution varied across a range of sociodemographic and health-related factors. Females had more upright events than males (4.39 [3.41,5.38] n), spent more time upright, and exhibited burstier patterns of upright events (0.05 [0.04,0.05] Bn). Individuals with higher BMI had fewer upright events and a lower daily step count, but their temporal distribution of upright events was less bursty (overweight -0.02 [-0.02,-0.01] Bn; obese -0.03 [-0.04,-0.02] Bn), and upright events had a higher step count. People in active occupations were upright for longer, displayed burstier patterns of upright events (standing 0.04 [0.03,0.05] Bn; physical work 0.05 [0.04,0.05] Bn; heavy manual 0.06 [0.04,0.07] Bn), with more variable durations and shorter, slower paced stepping events compared with sedentary occupations.ConclusionsThis study has revealed novel phenotypes of standing and sitting that go beyond simple aggregate measures of total steps, step event duration or time between events. People with the same volume of stepping and frequency of gaps between upright events can accumulate their steps in very different ways. These differences and associations with population sub-groups, which persisted after adjustment for total stepping volume, may have important relations with functional and health outcomes. The findings lay the groundwork for future studies to investigate how different sitting and standing phenotypes can add to our understanding of the relationship between physical activity and health.

Validation of portable in-clinic video-based gait analysis for prosthesis users

Despite the common focus of gait in rehabilitation, there are few tools that allow quantitatively characterizing gait in the clinic. We recently described an algorithm, trained on a large dataset from our clinical gait analysis laboratory, which produces accurate cycle-by-cycle estimates of spatiotemporal gait parameters including step timing and walking velocity. Here, we demonstrate this system generalizes well to clinical care with a validation study on prosthetic users seen in therapy and outpatient clinics. Specifically, estimated walking velocity was similar to annotated 10-m walking velocities, and cadence and foot contact times closely mirrored our wearable sensor measurements. Additionally, we found that a 2D keypoint detector pretrained on largely able-bodied individuals struggles to localize prosthetic joints, particularly for those individuals with more proximal or bilateral amputations, but after training a prosthetic-specific joint detector video-based gait analysis also works on these individuals. Further work is required to validate the other outputs from our algorithm including sagittal plane joint angles and step length. Code for the gait transformer and the trained weights are available at https://github.com/peabody124/GaitTransformer.

A Transferable Lidar-Based Method to Conduct Contactless Assessments of Gait Parameters in Diverse Home-like Environments.

Gait abnormalities in older adults are linked to increased risks of falls, institutionalization, and mortality, necessitating accurate and frequent gait assessments beyond traditional clinical settings. Current methods, such as pressure-sensitive walkways, often lack the continuous natural environment monitoring needed to understand an individual's gait fully during their daily activities. To address this gap, we present a Lidar-based method capable of unobtrusively and continuously tracking human leg movements in diverse home-like environments, aiming to match the accuracy of a clinical reference measurement system. We developed a calibration-free step extraction algorithm based on mathematical morphology to realize Lidar-based gait analysis. Clinical gait parameters of 45 healthy individuals were measured using Lidar and reference systems (a pressure-sensitive walkway and a video recording system). Each participant participated in three predefined ambulation experiments by walking over the walkway. We observed linear relationships with strong positive correlations (R2>0.9) between the values of the gait parameters (step and stride length, step and stride time, cadence, and velocity) measured with the Lidar sensors and the pressure-sensitive walkway reference system. Moreover, the lower and upper 95% confidence intervals of all gait parameters were tight. The proposed algorithm can accurately derive gait parameters from Lidar data captured in home-like environments, with a performance not significantly less accurate than clinical reference systems.

Associations of Neurological Biomarkers in Serum With Gait Measures: The Cardiovascular Health Study.

Gait impairment leads to increased mobility decline and may have neurological contributions. This study explores how neurological biomarkers are related to gait in older adults. We studied participants in the Cardiovascular Health Study, a population-based cohort of older Americans, who underwent a serum biomarker assessment from samples collected in 1996-1997 for neurofilament light chain (NfL), glial fibrillary acidic protein, ubiquitin carboxy-terminal hydrolase L1, and total tau (n = 1959, mean age = 78.0 years, 60.8% female). In a subsample (n = 380), cross-sectional associations with quantitative gait measures were explored. This subsample was assessed on a mat for gait speed, step length, double support time, step time, step length variability, and step time variability. Gait speed was also measured over a 15-ft walkway annually from 1996-1997 to 1998-1999 for longitudinal analyses. Linear regression models assessed cross-sectional associations of biomarkers with gait measures, whereas mixed effects models assessed longitudinal gait speed change from baseline to 1998-1999. Neurofilament light chain was significantly associated with annual gait speed decline (standardized β = -0.64 m/s, 95% CI: [-1.23, -0.06]) after adjustment for demographic and health factors. Among gait mat-assessed phenotypes, NfL was also cross-sectionally associated with gait speed (β = 0.001 m/s [0.0003, 0.002]) but not with other gait measures. None of the remaining biomarkers were significantly related to gait in either longitudinal or cross-sectional analyses. Higher NfL levels were related to greater annual gait speed decline. Gait speed decline may be related to axonal degeneration. The clinical utility of NfL should be explored.

Flipping Tradition on Its Head: A Single-Institution Study on United States Medical Licensing Examination Step Order.

Given the recent change in Step 1 grading, medical students are faced with decisions surrounding the optimal Step examination order and timing. There is a current lack of guidance outside commonly used United States Medical Licensing Examination study blogs. The aim of this study was to characterize current practices in Step examination order and understand the factors influencing student examination preference. To gather data, we used a 24-item survey and electronically distributed it through three separate email requests to medical students. Participants included medical students (MS1-4) attending a single institution, interested in a surgical residency. In total, 56 students responded to the survey (response rate of 20%). Most students (63.6%) opted to take Step 2 before Step 1. Justifications included the perceived importance of Step 2 for residency applications (33.3%), the change to pass/fail grading (27.0%), the relevance of Step 2 after rotations (27.0%), and a desire to obtain a Step 2 score earlier (7.9%). Step examination order did not lead to differences in Step 2 score (P = 0.459), time used to prepare for Step 1 (P = 0.396), or time used to prepare for Step 2 (P = 0.078). Due to the perceived importance of Step 2, most medical students at our institution who are interested in pursuing a surgical residency are reversing the traditional Step examination order. As this may represent a national trend, additional work needs to be done to provide guidance to medical students and identify the optimal step examination testing strategy.

High yield and wide lateral size growth of α-Mo2C: exploring the boundaries of CVD growth of bare MXene analogues

Synthesis of Mo2C bare MXenes, without surface terminations groups, via chemical vapor deposition (CVD) on metal foils is scientifically a very intriguing crystal growth process, and there are still challenges and limited fundamental understanding to overcome to obtain high yield and wide crystal size lateral growth. Achieving large area coverage via direct growth is scientifically vital to utilize the full potential of their unique properties in different applications. In this study, we sought to expand the boundaries of the current CVD growth approach for Mo2C MXenes and gain insights into the possibilities and limitations of large area growth, with a particular focus on controlling Mo concentration. We report a facile modification of their typical CVD growth protocol and show its influence on the Mo2C synthesis, with growth times spanning up to 3 h. Specifically, prior to initiating the CVD growth process, we introduced a holding step in temperature at 1095 °C. This proved to be beneficial in increasing the Mo concentration on the liquid Cu growth surface. We achieved an average Mo2C crystals coverage of approximately 50% of the growth substrate area, increased tendency of coalescence and merging of individual flakes, and lateral flake sizes up to 170 μm wide. To gain deeper understanding into their CVD growth behavior, we conducted a systematic investigation of the effect of several factors, including (i) a holding step time on Mo diffusion rate through molten Cu, (ii) the Cu foil thickness over the Mo foil, and (iii) the CVD growth time. Phase, chemical and microstructural characterization by x-ray diffraction, x-ray photon spectroscopy, SEM and scanning/transmission electron microscopy revealed that the grown crystals are single phase α-Mo2C. Furthermore, insights gained from this study sheds light on crucial factors and inherent limitations that are essential to consider and may help guide future research progress in CVD growth of bare MXenes.

Automated Software Process Discovery and Real-Time Monitoring

Process monitoring is the concept based on managing the state of a business processes executed in an enterprise software. The named status and execution time are two important parameters to infer the state of a process in real-time. An execution of the process end to end is called as process instance. This paper covers monitoring process instances in real-time based on the data metric generated from event logs, where data metrics of a Business Process Models (BPM) – a Weighted Directed Acyclic Graph (WDAG) represents process model with its heuristics such as complete execution time of process, execution time between steps/activities and the status. Firstly, the process model is discovered either by manually or automatically from the events that are recorded from the logs using unsupervised learning techniques and heuristics of different steps of a process are modeled using statistical methods. Both process model and its heuristics are deployed to help process engineers to understand the path of executions of a business process, its state and performance in real-time. Path of executions involves most successful path, longest and shortest paths, error state if the process instances abruptly ends in between, state of failure etc., On the performance front the range of time taken to complete the process, for each step, most and least time consuming, identifying the steps taking more time than usual etc., Process engineers/users are notified if abnormalities are observed. KEY WORDS Process Mining, Process Monitoring, BPM, PM4PY, Standard Deviation (SD)

Rapid IDH1-R132 genotyping panel utilizing locked nucleic acid loop-mediated isothermal amplification.

While the detection of single-nucleotide variants (SNVs) is important for evaluating human health and disease, most genotyping methods require a nucleic acid extraction step and lengthy analytical times. Here, we present a protocol which utilizes the integration of locked nucleic acids (LNAs) into self-annealing loop primers for the allelic discrimination of five isocitrate dehydrogenase 1 R132 (IDH1-R132) variants using loop-mediated isothermal amplification (LAMP). This genotyping panel was initially evaluated using purified synthetic DNA to show proof of specific SNV discrimination. Additional evaluation using glioma tumor lysates with known IDH1-R132 mutational status demonstrated specificity in approximately 35 min without the need for a nucleic acid extraction purification step. This LNA-LAMP-based genotyping assay can detect single base differences in purified nucleic acids or tissue homogenates, including instances where the variant of interest is present in an excess of background wild-type DNA. The pH-based colorimetric indicator of LNA-LAMP facilitates convenient visual interpretation of reactions, and we demonstrate successful translation to an end-point format using absorbance ratio, allowing for an alternative and objective approach for differentiating between positive and negative reactions. Importantly, the LNA-LAMP genotyping panel is highly reproducible, with no false-positive or false-negative results observed.

Effects of Rhythmic Auditory Stimulation on Step Times and Trunk Acceleration while Walking

Effects of Rhythmic Auditory Stimulation on Step Times and Trunk Acceleration while Walking

Gait Analysis in Patients with Adolescent Idiopathic Scoliosis

The study describes changes in gait parameters (temporal-spatial parameters, kinematic parameters represented by the global Gait Deviation Index) of individuals with Adolescent Idiopathic Scoliosis (AIS) compared to the healthy population. The hypothesis assumed a difference in the observed parameters between the two mentioned groups. In a retrospective study, the temporal-spatial parameters and Gait Deviation Index (GDI) of a cohort of 45 AIS patients (36 girls and 9 boys with the mean age of 15.2 years, the mean Cobb angle of the thoracic curve of 47.3° and the lumbar curve of 51.8°) were compared to a typically developing population of 12 healthy individuals with no musculoskeletal pathology. The difference of followed-up parameters in patients with AIS compared to normal values was assessed by one-sample Student's T-test at the significance level of p = 0.05. The gait analysis shows significant deviations in the gait stereotype of patients with AIS compared to the healthy population. Statistically significant differences within temporal-spatial parameters were confirmed for cadence, walking speed, step time, stride time for left leg, step length, stride length and step width. The mean GDI of the cohort reached the value of 91.07 that indicates a slight alteration of gait, however, even this change is statistically significant. In our cohort of patients with AIS, we identified a significantly reduced walking speed (on average 15.4% compared to normal values. At the same time, a reduction in cadence (by an average of 7.5%) and an increase of the stride time (by an average of 12%) were recorded. Our mean GDI values were 91.07, which is consistent with the results reported in the literature for comparable groups of AIS patients. Our study demonstrated that AIS significantly affects gait stereotype. The differences compared to the group of healthy individuals within temporal-spatial parameters were confirmed for cadence, walking speed, duration and length of step and stride, and step width. The kinematic analysis of gait using the global (GDI) index in patients with AIS demonstrated its slight alteration. A better understanding of the change in movement stereotypes and gait in patients with AIS can bring wider possibilities for individualizing conservative treatment and also can help prevent secondary changes in the locomotor system. adolescent idiopathic scoliosis, AIS, gait analysis, Gait Deviation Index, GDI.

Improving Walking Performance in Prosthetic Leg Users: The Role of Virtual Reality and Audio Feedback

Virtual reality (VR) has emerged as a promising technology for enhancing the rehabilitation process and improving the life quality for lower limb prosthetic user. The integration of audio within VR environments can significantly impact the performance of lower limb prosthetic user, improve their gait patterns, enhance balance control, and avoid user from falling. This research paper investigates the effectiveness of VR and audio stimuli in improving gait in amputees wearing prosthetic legs. A VR-based training system is developed, utilizing a head-mounted display (HMD) and audio cues synchronized with footsteps or slowed down. Thirteen transfemoral prosthetic leg users participate in the study, assessing the impact on gait parameters. Participants were asked to walk in 3 conditions: without audio (WA), with audio (A), and slow tempo audio (SA). Results demonstrate significant enhancements in step length, stride length, and step time, achieving balance between the prosthetic and normal limbs. The integration of audio stimuli proves advantageous in enhancing walking performance and addressing asymmetries. The findings suggest that VR with slow-tempo audio cues holds promise for improving rehabilitation outcomes for prosthetic leg users. Future research should focus on optimizing training methods and exploring full potential of audio-integrated VR for gait rehabilitation in amputees.

Dynamics of Center of Pressure Trajectory in Gait: Unilateral Transfemoral Amputees Versus Non-Disabled Individuals.

The primary goal of rehabilitation for individuals with lower limb amputation, particularly those with unilateral transfemoral amputation (uTFA), is to restore their ability to walk independently. Effective control of the center of pressure (COP) during gait is vital for maintaining balance and stability, yet it poses a significant challenge for individuals with uTFA. This study aims to study the COP during gait in individuals with uTFA and elucidate their unique compensatory strategies. This study involved 12 uTFA participants and age-matched non-disabled controls, with gait and COP trajectory data collected using an instrumented treadmill. Gait and COP parameters between the control limb (CL), prosthetic limb (PL), and intact limb (IL) were compared. Notably, the mediolateral displacement of COP in PL exhibited significant lateral displacement compared to the CL from 30% to 60% of the stance. In 20% to 45% of the stance, the COP forward speed of PL was significantly higher than that of the IL. Furthermore, during the initial 20% of the stance, the vertical ground reaction force of PL was significantly lower than that of IL. Additionally, individuals with uTFA exhibited a distinct gait pattern with altered duration of loading response, single limb support, pre-swing and swing phases, and step time. These findings indicate the adaptability of individuals with uTFA in weight transfer, balance control, and pressure distribution on gait stability. In conclusion, this study provides valuable insights into the unique gait dynamics and balance strategies of uTFA patients, highlighting the importance of optimizing prosthetic design, alignment procedures, and rehabilitation programs to enhance gait patterns and reduce the risk of injuries due to compensatory movements.

Can Manual Lymph Drainage Be Considered as a Passive Recovery Strategy?

The aim of this study was to investigate the acute effects of Swedish massage and manual lymph drainage (MLD) on performance parameters related to jumping, walking, and blood lactic acid levels after Nordic hamstring exercises. This study was designed as a controlled crossover study. The study included 16 young trained men. Participants' lactic acid levels, gait-related parameters, and jumping performance were assessed. Assessments were performed at baseline, after Nordic hamstring exercises, and after 3 different passive recovery strategies: resting, Swedish massage, and MLD for 3weeks. As a result of the study, it was observed that lactic acid levels after the MLD and massage intervention were significantly lower in both MLD and massage conditions compared with the control condition (P < .05). There was no within- and between-conditions difference in jumping parameters after the MLD and massage interventions (P > .05). Walking speed in the MLD condition was statistically higher following the intervention compared with both before and after exercise (P < .05). Step time in the massage condition was statistically lower after the intervention compared with after Nordic hamstring exercise (P < .05). Although MLD and massage interventions have positive effects on lactic acid levels and walking and jumping parameters, they are not superior to each other. MLD can be used as a passive recovery technique after exercise.

Facilitation of motor adaptation using multiple gait rehabilitation interventions.

The rate of adjustment in a movement, driven by feedback error, is referred to as the adaptation rate, and the rate of recovery of a newly adapted movement to its unperturbed condition is called the de-adaptation rate. The rates of adaptation and de-adaptation are dependent on the training mechanism and intrinsic factors such as the participant's sensorimotor abilities. This study investigated the facilitation of the motor adaptation and de-adaptation processes for spatiotemporal features of an asymmetric gait pattern by sequentially applying split-belt treadmill (SBT) and asymmetric rhythmic auditory cueing (ARAC). Two sessions tested the individual gait characteristics of SBT and ARAC, and the remaining four sessions consisted of applying the two interventions sequentially during training. The adjustment process to the second intervention is referred to as "re-adaptation" and is driven by feedback error associated with the second intervention. Ten healthy individuals participated in the randomized six-session trial. Spatiotemporal asymmetries during the adaptation and post-adaptation (when intervention is removed) stages were fitted into a two-component exponential model that reflects the explicit and implicit adaptation processes. A double component was shown to fit better than a single-component model. The decay constants of the model were indicative of the corresponding timescales and compared between trials. Results revealed that the explicit (fast) component of adaptation to ARAC was reduced for step length and step time when applied after SBT. Contrarily, the explicit component of adaptation to SBT was increased when it was applied after ARAC for step length. Additionally, the implicit (slow) component of adaptation to SBT was inhibited when applied incongruently after ARAC for step time. These outcomes show that the role of working motor memory as a translational tool between different gait interventions is dependent on (i) the adaptation mechanisms associated with the interventions, (ii) the targeted motor outcome of the interventions; the effects of factors (i) and (ii) are specific to the explicit and implicit components of the adaptation processes; these effects are unique to spatial and temporal gait characteristics.

Impact of the COVID-19 pandemic on the complete rehabilitation journey of hip fracture patients in Italy: From surgical admission to rehabilitation facility discharge.

The COVID-19 pandemic led to a significant reorganization of health services, potentially affecting the quality of care for major public health concerns such as proximal femoral fractures. This study aimed to investigate potential changes in the timing of various steps in the patient journey after a hip fracture during the pandemic in Piedmont, a region in Northern Italy. A retrospective study was conducted on the discharge records of patients aged 65 or older who were admitted for hip surgery following a femur fracture in 2019 and 2020. The study examined four-time steps: duration from hospital admission to surgery, length of hospital stay, interval between hospital discharge and admission to the rehabilitation facility, and duration of stay at the rehabilitation facility. To mitigate biases linked to sex and age factors, groups well-balanced across 2019 and 2020 were created using propensity score estimation. The dataset consisted of two cohorts of 583 patients each for the years 2019 and 2020. The average duration from admission to surgery was approximately 1.9 days in both years, with 75% of patients undergoing surgery within 2 days of hospital admission. The average hospital stay reduced from 13.49 days in 2019 to 11.34 days in 2020. The gap between hospital discharge and admission to rehabilitation was approximately 10-12 days, and the average duration of stay at the rehabilitation facility was about 31.6 days. The study indicates that healthcare systems can exhibit resilience and adaptability, even during a global pandemic, to ensure high-quality and safe standards of care. However, further long-term studies are needed to fully understand the pandemic's impact on primary health outcomes following hip replacement surgery and subsequent rehabilitation. The potential role of telemedicine in reducing the time between steps also warrants further investigation.

A Novel Behavioral Intervention to Enhance Physical Activity for Older Veterans in a Skilled Nursing Facility.

Physical activity levels during skilled nursing facility (SNF) rehabilitation fall far below what is needed for successful community living and to prevent adverse events. This feasibility study's purpose was to evaluate the feasibility, acceptability, and preliminary effectiveness of an intervention designed to improve physical activity in patients admitted to SNFs for short-term rehabilitation. High-Intensity Rehabilitation plus Mobility combined a high-intensity (i.e.,high weight, low repetition), progressive (increasing in difficulty over time), and functional resistance rehabilitation intervention with a behavioral economics-based physical activity program. The behavioral economics component included five mobility sessions/week with structured goal setting, gamification, and loss aversion (the idea that people are more likely to change a behavior in response to a potential loss over a potential gain). SNF physical therapists, occupational therapists, and a mobility coach implemented the High-Intensity Rehabilitation plus Mobility protocol with older Veterans (n = 18) from a single SNF. Participants demonstrated high adherence to the mobility protocol and were highly satisfied with their rehabilitation. Treatment fidelity scores for clinicians were ≥95%. We did not observe a hypothesized 40% improvement in step counts or time spent upright. However, High-Intensity Rehabilitation plus Mobility participants made clinically important improvements in short physical performance battery scores and gait speed from admission to discharge that were qualitatively similar to or slightly higher than historical cohorts from the same SNF that had received usual care or high-intensity rehabilitation alone. These results suggest a structured physical activity program can be feasibly combined with high-intensity rehabilitation for SNF residents following a hospital stay.

The role of solution temperature in characteristics of TiO2 nanotube arrays prepared on Ti foil in acid solution.

The characteristics of TiO2 nanotube arrays (TNTs) prepared on Ti foil in sulfuric acid solution that contains Cl- under different temperatures are investigated by field emission scanning electron microscopy (FESEM), electrochemical impedance spectroscopy (EIS), Mott-Schottky measurement and Raman spectra. The solution temperature significantly affects the morphologies of TNTs, i.e., when solution temperature rises from -10 °C to 90 °C, the inner diameter of the nanotube increases and the barrier layer thickness decreases, and, as TNTs display n-type semiconductive properties, the donor density (ND) and corrosion protection decrease. Two types (types I and II) of pulse temperature are used to fabricate TNTs, in which type I is firstly anodized at a low temperature for time t, and then increases to a high temperature. While for type II, the solution temperature order is opposite to that of type I. The ND of TNTs in the case of type I is lower than ND of TNTs in the case of type II. ND decreases with the increased pulse step time for type I, while ND increases with the increased pulse step time for type II.

Association of Daily Physical Activity With Motivation in Prefrail and Frail Older Adults Living in Retirement Communities.

Older adults living in retirement communities are an understudied population, and the association between their motivation and daily physical activity is unknown. We recruited participants (n = 173) living in a retirement community who completed the Behavioral Regulation in Exercise Questionnaire-2 and wore an activPAL accelerometer to evaluate this relationship. Participants had a median age of 81years and demonstrated low levels of daily activity with an average step count of 3,637 (±1,965)steps per day and 52 (±25)min of daily stepping time. External motivation was negatively associated with the square root of daily step count (β = -4.57; p < .001) and square root of daily stepping time (β = -0.49; p < .001). Older adults living in retirement communities demonstrated low levels of daily activity, with a negative association between external motivation and daily activity. Strategies are needed to make an active lifestyle supportive and enticing for older adults in these communities.

Physical Activity Levels and Sedentary Behavior of People Living With Mild Cognitive Impairment: A Cross-Sectional Study Using Thigh-Worn Accelerometers.

Community-dwelling people with Mild Cognitive Impairment self-reporting not to be meeting recommended physical activity levels participated in this study to (a)determine compliance of wearing (thigh-worn) accelerometers, (b)describe physical activity levels and sedentary behavior, and (c)determine the validity of the Physical Activity Scale for the Elderly (PASE) compared with activPAL accelerometers. A total of 79 people had valid accelerometer data (median [interquartile range]: age, 71 [54-75]years). Compliance was 86.81%. Participants were sedentary for 10.6hr per day and engaged in a median of 9min per day of moderate-intensity physical activity. Fair correlations were found between the PASE and total stepping time per day (r = .35, p < .01), total number of steps per day (r = .36, p < .01), and number of steps in stepping activities completed for ≤1min (r = .42, p < .01). The PASE and Standing time (r = .04, p = .724) and PASE and Sitting time (r = .04, p = .699) had little to no relationship. The use of thigh-worn accelerometers for this population is achievable. People with Mild Cognitive Impairment have high levels of sedentary behavior and minimal engagement in moderate-intensity physical activity. The PASE has fair, positive criterion validity with activity-based outcomes measured by activPAL accelerometers but not with sedentary behavior, which is high for this population.