Search

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 10.6 hr per day and engaged in a median of 9 min 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 ≤1 min (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. [ABSTRACT FROM AUTHOR]

Previous research has explored the physical activity habits of people with dementia and their family carers separately, with little consideration of how physical habits are associated within dyads. In this observational study, we sought to explore the relationship between people with dementia and their carers' physical activity, at a group level and at a dyadic level. Twenty-six participant dyads (persons with dementia and their carer spouses) were asked to wear an accelerometer for 30 days continuously. Comparisons were made at a group level and a dyadic level. People with dementia did not participate in significantly more moderate to vigorous physical activity (M = 15.44 min/day; SD = 14.40) compared with carers (M = 17.95 min/day; SD = 17.01). Within dyads, there were moderately strong associations between daily moderate to vigorous physical activity (r =.48–.54), but not with overall activity levels (r =.24). Despite physical activity habits remaining relatively low within people with dementia and carers, respectively, moderate to vigorous physical activity levels appear to be correlated within dyads. Understanding mutual influence on physical activity levels within dyads is an important pathway to promote an active lifestyle. [ABSTRACT FROM AUTHOR]

We identified data-driven multidimensional physical activity (PA) profiles using several novel accelerometer-derived metrics. Participants aged 75, 80, and 85 (n = 441) wore triaxial accelerometers for 3–7 days. PA profiles were formed with k-means cluster analysis based on PA minutes, intensity, fragmentation, sit-to-stand transitions, and gait bouts for men and women. Associations with physical capacity and life-space mobility were examined using age-adjusted general linear models. Three profiles emerged: "Exercisers" and "actives" accumulated relatively high PA minutes, with actives engaging in lighter intensity PA. "Inactives" had the highest activity fragmentation and lowest PA volume, intensity, and gait bouts. Inactives showed lower scores in physical capacity and life-space mobility compared with exercisers and actives. Exercisers and actives had similar physical capacity and life-space mobility, except female exercisers had higher walking speed in the 6-min walk test. Our findings demonstrate the importance of assessing PA as multidimensional behavior rather than focusing on a single metric. [ABSTRACT FROM AUTHOR]

The aims of the current study were to analyze the association between the barriers to and changes in physical activity levels and sedentary behavior, as well as to examine whether these barriers change over time in patients with peripheral artery disease. In this longitudinal study, we assessed 72 patients (68% men; 65.7 ± 9.2 years). Physical activity was measured over a 7-day period using an accelerometer, and data were collected on time spent in sedentary activities, low-light physical activities, and moderate-to-vigorous physical activities. Personal and environmental barriers to physical activity were collected using yes or no questions. Assessments were repeated in the same patients after 27 months (95% confidence interval [26, 28] months). Most barriers remained stable in these patients; however, those who reported lack of money experienced an increase in sedentary behavior (β = 392.9 [159.7] min/week, p =.02) and a decrease in low-light physical activity (β = −372.4 [140.1] min/week, p =.02). These findings suggest that patients with symptomatic peripheral artery disease typically exhibit stable barriers over time, and individuals reporting lack of money demonstrated a decrease in low-light physical activity and an increase in sedentary behavior after 27 months. [ABSTRACT FROM AUTHOR]

The aim of this study was to quantify physical activity and sedentary behavior in older adults recovering from hip fracture and to identify groups based on movement patterns. In this cross-sectional cohort study, older adults (≥70 years) were included 3 months after surgery for proximal femoral fracture. Patients received an accelerometer for 7 days. Demographics and outcomes related to physical function, mobility, cognitive functions, quality of life, and hip fracture were assessed. In total, 43 patients with sufficient accelerometer wear time were included. Across all groups, participants engaged in very low levels of physical activity, spending an average of 11 hr/day in prolonged sedentary behavior. Based on the extracted components from a principal component analysis, three groups with substantial differences in levels of physical activity and sedentary behavior could be distinguished. [ABSTRACT FROM AUTHOR]

Purpose: To assess the association between the amount of recess provision and children's accelerometer-measured physical activity (PA) levels. Methods: Parents/guardians of 6- to 11-year-olds (n = 451) in the 2012 National Youth Fitness Survey reported recess provision, categorized as low (10–15 min; 31.9%), medium (16–30 min; 48.0%), or high (>30 min; 20.1%). Children wore a wrist-worn accelerometer for 7 days to estimate time spent sedentary, in light PA, and in moderate to vigorous PA using 2 different cut points for either activity counts or raw acceleration. Outcomes were compared between levels of recess provision while adjusting for covariates and the survey's multistage, probability sampling design. Results: Children with high recess provision spent less time sedentary, irrespective of type of day (week vs weekend) and engaged in more light or moderate to vigorous PA on weekdays than those with low recess provision. The magnitude and statistical significance of effects differed based on the cut points used to classify PA (eg, 4.7 vs 11.9 additional min·d−1 of moderate to vigorous PA). Conclusions: Providing children with >30 minutes of daily recess, which exceeds current recommendations of ≥20 minutes, is associated with more favorable PA levels and not just on school days. Identifying the optimal method for analyzing wrist-worn accelerometer data could clarify the magnitude of this effect. [ABSTRACT FROM AUTHOR]

Physical activity (PA) and physical function (PF) are modifiable risk factors for falls in older adults, but their ability to predict future fall incidence is unclear. The purpose of this study was to determine the predictive ability of baseline measures of PA, PF, and lower limb strength on future falls. A total of 104 participants underwent baseline assessments of PA, PF, and lower limb strength. Falls were monitored prospectively for 12 months. Eighteen participants fell at least once during the 12-month follow-up. Participants recorded almost exclusively sedentary levels of activity. PA, PF, and lower limb strength did not differ between fallers and nonfallers. Twelve participants, who reported a minor musculoskeletal injury in the past 6 months, experienced a fall. The results of this study suggest that in a cohort of highly functioning, sedentary older adults, PA does not distinguish fallers from nonfallers and that the presence of a recent musculoskeletal injury appears to be a possible risk factor for falling. [ABSTRACT FROM AUTHOR]

Purpose: There are important methodological considerations for translating wearable-based gait-monitoring data to field settings. This study investigated different devices' sampling rates, signal lengths, and testing frequencies for athlete monitoring using dynamical systems variables. Methods: Secondary analysis of previous wearables data (N = 10 runners) from a 5-week intensive training intervention investigated impacts of sampling rate (100–2000 Hz) and signal length (100–300 strides) on detection of gait changes caused by intensive training. Primary analysis of data from 13 separate runners during 1 week of field-based testing determined day-to-day stability of outcomes using single-session data and mean data from 2 sessions. Stride-interval long-range correlation coefficient α from detrended fluctuation analysis was the gait outcome variable. Results: Stride-interval α reduced at 100- and 200- versus 300- to 2000-Hz sampling rates (mean difference: −.02 to −.08; P ≤.045) and at 100- compared to 200- to 300-stride signal lengths (mean difference: −.05 to −.07; P <.010). Effects of intensive training were detected at 100, 200, and 400 to 2000 Hz (P ≤.043) but not 300 Hz (P =.069). Within-athlete α variability was lower using 2-session mean versus single-session data (smallest detectable change:.13 and.22, respectively). Conclusions: Detecting altered gait following intensive training was possible using 200 to 300 strides and a 100-Hz sampling rate, although 100 and 200 Hz underestimated α compared to higher rates. Using 2-session mean data lowers smallest detectable change values by nearly half compared to single-session data. Coaches, runners, and researchers can use these findings to integrate wearable-device gait monitoring into practice using dynamic systems variables. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the validity of the Physical Activity Questionnaire for Older Children (PAQ-C) to assess the moderate- to vigorous-intensity physical activity (MVPA) level of children and adolescents diagnosed with HIV and propose cut-points, with accelerometer measures as the reference method. Method: Children and adolescents, aged 8–14 years (mean age = 12.21 y, SD = 2.09), diagnosed with HIV by vertical transmission, participated in the study. MVPA was investigated through the PAQ-C and triaxial accelerometer (ActiGraph GT3X+). Receiver operating characteristic curve and sensitivity and specificity values were used to identify a cut-point for PAQ-C to distinguish participants meeting MVPA guidelines. Results: Fifty-six children and adolescents participated in the study. Among those, 16 met MVPA guidelines. The PAQ-C score was significantly related to accelerometry-derived MVPA (ρ =.506, P <.001). The PAQ-C score cut-point of 2.151 (sensitivity = 0.625, specificity = 0.875) was able to discriminate between those who met MVPA guidelines and those that did not (area under the curve = 0.751, 95% confidence interval, 0.616–0.886). Conclusion: The PAQ-C was useful to investigate MVPA among children and adolescents diagnosed with HIV and to identify those who meet MVPA guidelines. [ABSTRACT FROM AUTHOR]

Assessing bone's response to physical activity interventions is challenging. This randomized controlled trial investigates if changes in bone turnover markers can offer an early evaluation of a physical activity intervention's effectiveness in improving bone mineral density (BMD) in premenopausal women. Participants in the intervention group (n = 27, with 24 completing the trial) were instructed to walk at least 10,000 steps every day on a brisk walk and to execute 60 jumps daily, each surpassing 4g of acceleration, using an accelerometer-based wearable device. Meanwhile, the control group (n = 26, with 18 completing the trial) continued with their usual lifestyle. Bone turnover markers, comprising of C-terminal telopeptide of Type I collagen, procollagen Type 1 N-terminal propeptide, and total osteocalcin (carboxylated and undercarboxylated) were measured at baseline and midway through the intervention (3 months). Dual-energy X-ray absorptiometry scans of the hip and lumbar spine were conducted at baseline and the end of the intervention (6 months) to estimate BMD. Analysis of covariance exhibited significant differences between groups in procollagen Type 1 N-terminal propeptide (−6.74 μg/L, p =.023) and C-terminal telopeptide of Type I collagen (−83 ng/L, p =.043) after 3 months, and in femoral neck BMD (+0.024 g/cm2, p =.016), total hip BMD (+0.036 g/cm2, p =.004), and lumbar spine BMD (+0.026 g/cm2, p =.020) after 6 months. A significant correlation (r = −.73; p <.001) was detected between reductions in C-terminal telopeptide of Type I collagen and increases in femoral neck BMD. In conclusion, this intervention improved BMD in premenopausal women, with bone turnover markers potentially useful for early intervention assessment, though further research is needed. [ABSTRACT FROM AUTHOR]

The aim of this investigation was to quantify professional rugby union player activity profiles after the most intense (peak) passages of matches. Movement data were collected from 30 elite and 30 subelite professional rugby union athletes across respective competitive seasons. Accelerometer-derived PlayerLoad and global navigation satellite system–derived measures of mean speed and metabolic power were analyzed using a rolling-average method to identify the most intense 5- to 600-second passages (ie, worst-case scenarios) within matches. Player activity profiles immediately post their peak 5- to 600-second match intensity were identified using 5 epoch duration-matched intervals. Mean speed, metabolic power, and PlayerLoad declined sharply (∼29%–86%) after the most intense 5 to 600 seconds of matches. Following the most intense periods of rugby matches, exercise intensity declined below the average match-half intensity 81% of the time and seldom returned to or exceeded it, likely due to a host of individual physical and physiological characteristics, transient and/or accumulative fatigue, contextual factors, and pacing strategies. Typically, player exercise intensities after the most intense passages of matches were similar between match halves, positional groups, and levels of rugby competition. Accurate identification of the peak exercise intensities of matches and movement thereafter using novel methodologies has improved the limited understanding of professional rugby union player activity profiles following the worst-case scenarios of matches. Findings of the present study may inform match-representative training prescription, monitoring, and tactical match decisions (eg, substitutions and positional changes). [ABSTRACT FROM AUTHOR]

This prospective cohort study aimed to investigate the association between physical activity (PA) as measured using accelerometers, and functional improvement measured using a short physical performance battery in older patients undergoing rehabilitation. After admission to the rehabilitation hospital, patients were categorized into quartile groups based on their level of PA measured using accelerometers. The primary outcome was physical function measured using the short physical performance battery at hospital discharge. A total of 204 patients were included in the analysis. After adjusting for confounding factors, light-intensity PA (p <.001) and moderate-to-vigorous-intensity PA (p <.001) were associated with a short physical performance battery at hospital discharge. In conclusion, PA at admission is positively associated with functional improvement in older patients undergoing hospital rehabilitation. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the long-term effect of body composition, physical activity, and cardiorespiratory fitness (CRF) from puberty on arterial health in late adolescent males. Methods: The cumulative burden of physical activity (measured with accelerometer), CRF (VO2peak0.82), and body composition (body mass index, fat mass, and fat percentage) from puberty to late adolescence (sum of 4 time points from 12 to 18 y) was assessed in 102 males. Additional analysis on the first (T1) and last (T4) time points was performed. Intima-media thickness (IMT), carotid-femoral pulse wave velocity, and augmentation index adjusted to heart rate of 75 beats per minute (bpm) as dependent variables were measured at T4 and analyzed in multivariable regression models adjusted for known risk factors including maturation, blood pressure, and smoking habits. Results: T1 and cumulative body composition measures were independently associated with IMT, while cumulative (β = −0.011, P =.036) and T4 (β = −0.0.031, P =.001) CRF revealed independent associations with IMT. Individuals with moderate to vigorous physical activity >60 minutes per day at T1 showed relationship (β = −1.091, P =.026) with IMT independently of late adolescent physical activity. No significant relationship was present for arterial function. Conclusion: Arterial structure in adolescent males is associated with physical activity at 12 years while relationship with CRF can be seen in late adolescence and cumulatively from puberty to late adolescence. [ABSTRACT FROM AUTHOR]

Dynamic compaction is a soil improvement technique which involves the repeated application of an impact load to a contact area of the soil surface induced by heavy weights. Experimental measurements were prepared for evaluation of the ground wave propagation induced by the rapid impact compaction. Influence of increase of subsoil stiffness during compaction and terrain configuration were investigated. When the shear strength of soil is exceeded during the penetration of the compaction footing, increase of peak particle velocities is slower but still clearly visible along the measurement line. The peak particle velocity is damped by the subsoil below 5 mm s−1 within 40–50 m from the source of excitation. Attenuation radius is affected by the terrain configuration, when terrain elevations cause the increase of acceleration amplitudes. Rigid bodies in the ground, such as foundation structures, could have similar influence. Dominant frequencies are in the interval from 20 to 40 Hz regardless the distance from the source of excitation or the density of the treated subsoil. Obtained results are preferably related to the given boundary conditions. However, wave propagation pattern and change of its characteristics during densification of the subsoil are applicable at another construction sites considering their particularities. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study is to explore the feasibility of using machine learning approaches to objectively differentiate the mobilization patterns, measured via accelerometer sensors, of patients pre- and post-intervention. Methods: The intervention tested the implementation of a Frailty Care Bundle to improve mobilization, nutrition and cognition in older orthopedic patients. The study recruited 120 participants, a sub-group analysis was undertaken on 113 patients with accelerometer data (57 pre-intervention and 56 post-intervention), the median age was 78 years and the majority were female. Physical activity data from an ankle-worn accelerometer (StepWatch 4) was collected for each patient during their hospital stay. These data contained daily aggregated gait variables. Data preprocessing included the standardization of step counts and feature computation. Subsequently, a binary classification model was trained. A systematic hyperparameter optimization approach was applied, and feature selection was performed. Two classifier models, logistic regression and Random Forest, were investigated and Shapley values were used to explain model predictions. Results: The Random Forest classifier demonstrated an average balanced accuracy of 82.3% (± 1.7%) during training and 74.7% (± 8.2%) for the test set. In comparison, the logistic regression classifier achieved a training accuracy of 79.7% (± 1.9%) and a test accuracy of 77.6% (± 5.5%). The logistic regression model demonstrated less overfitting compared to the Random Forest model and better performance on the hold-out test set. Stride length was consistently chosen as a key feature in all iterations for both models, along with features related to stride velocity, gait speed, and Lyapunov exponent, indicating their significance in the classification. Conclusion: The best performing classifier was able to distinguish between patients pre- and post-intervention with greater than 75% accuracy. The intervention showed a correlation with higher gait speed and reduced stride length. However, the question of whether these alterations are part of an adaptive process that leads to improved outcomes over time remains. [ABSTRACT FROM AUTHOR]

Step cadence‐based and machine‐learning (ML) methods have been used to classify physical activity (PA) intensity in health‐related research. This study examined the association of intensity‐specific PA duration with all‐cause (ACM) and CVD mortality using the cadence‐based and ML methods in 68 561 UK Biobank participants wearing wrist‐worn accelerometers. The two‐stage‐ML method categorized activity type and then intensity. The one‐level‐cadence‐method (1LC) derived intensity‐specific duration using all detected steps (including standing utilitarian steps) and cadence thresholds of ≥100 steps/min (moderate intensity) and ≥130 steps/min (vigorous intensity). The two‐level‐cadence‐method (2LC) detected ambulatory steps (i.e., walking and running) and then applied the same cadence thresholds. The 2LC exhibited the most pronounced association at the lower end of duration spectrum. For example, the 2LC showed the smallest minimum moderate‐to‐vigorous‐PA (MVPA) duration (amount associated with 50% of optimal risk reduction) with similar corresponding ACM hazard ratio (HR) to other methods (2LC: 2.8 min/day [95% CI: 2.6, 2.8], HR: 0.83 [95% CI: 0.78, 0.88]; 1LC, 11.1[10.8, 11.4], 0.80 [0.76, 0.85]; ML, 14.9 [14.6, 15.2], 0.82 [0.76, 0.87]). The ML elicited the greatest mortality risk reduction. For example, the medians and corresponding HR in VPA‐ACM association: 2LC, 2.0 min/day [95% CI: 2.0, 2.0], HR, 0.69 [95% CI: 0.61, 0.79]; 1LC, 6.9 [6.9, 7.0], 0.68 [0.60, 0.77]; ML, 3.2 [3.2, 3.2], 0.53 [0.44, 0.64]. After standardizing durations, the ML exhibited the most pronounced associations. For example, the standardized minimum durations in MPA‐CVD mortality association were: 2LC, −0.77; 1LC, −0.85; ML, −0.94; with corresponding HR of 0.82 [0.72, 0.92], 0.79 [0.69, 0.90], and 0.77 [0.69, 0.85], respectively. The 2LC exhibited the most pronounced association with all‐cause and CVD mortality at the lower end of the duration spectrum. The ML method provided the most pronounced association with all‐cause and CVD mortality, thus might be appropriate for estimating health benefits of moderate and vigorous intensity PA in observational studies. [ABSTRACT FROM AUTHOR]

Migraine is one of the most common neurological disorders, characterized by moderate-to-severe headache episodes. Autonomic nervous system (ANS) alterations can occur at phases of migraine attack. This study investigates patterns of ANS changes during the pre-ictal night of migraine, utilizing wearable biosensor technology in ten individuals. Various physiological, activity-based, and signal processing metrics were examined to train predictive models and understand the relationship between specific features and migraine occurrences. Data were filtered based on specified criteria for nocturnal sleep, and analysis frames ranging from 5 to 120 min were used to improve the diversity of the training sample and investigate the impact of analysis frame duration on feature significance and migraine prediction. Several models, including XGBoost (Extreme Gradient Boosting), HistGradientBoosting (Histogram-Based Gradient Boosting), Random Forest, SVM, and KNN, were trained on unbalanced data and using cost-sensitive learning with a 5:1 ratio. To evaluate the changes in features during pre-migraine nights and nights before migraine-free days, an analysis of variance (ANOVA) was performed. The results showed that the features of electrodermal activity, skin temperature, and accelerometer exhibited the highest F-statistic values and the most significant p-values in the 5 and 10 min frames, which makes them particularly useful for the early detection of migraines. The generalized prediction model using XGBoost and a 5 min analysis frame achieved 0.806 for accuracy, 0.638 for precision, 0.595 for recall, and 0.607 for F1-score. Despite identifying distinguishing features between pre-migraine and migraine-free nights, the performance of the current model suggests the need for further improvements for clinical application. [ABSTRACT FROM AUTHOR]

Accurately estimating single-axis rotational angle changes is crucial in many high-tech domains. However, traditional angle measurement techniques are often constrained by sensor limitations and environmental interferences, resulting in significant deficiencies in precision and stability. Moreover, current methodologies typically rely on fixed-axis rotation models, leading to substantial discrepancies between measured and actual angles due to axis misalignment. To address these issues, this paper proposes an innovative method for single-axis rotational angle estimation. It introduces a calibration technique for installation errors between inertial measurement units and the overall measurement system, effectively translating dynamic rotational inertial outputs to system enclosure outputs. Subsequently, the method employs triaxial accelerometers combined with zero-velocity detection technology to estimate the rotation axis position. Finally, it delves into analyzing the relationship between quaternion and axis–angle, aimed at reducing noise interference for precise rotational angle estimation. Based on this proposed methodology, a Low-Cost, a High Accuracy Measurement System (HAMS) integrating sensor fusion was designed and implemented. Experimental results demonstrate static measurement errors below ±0.15° and dynamic measurement errors below ±0.5° within a ±180° range. [ABSTRACT FROM AUTHOR]

A MEMS piezoresistive sensor for measuring accelerations greater than 100,000 g (about 106 m/s2) is described in this work. To enhance the performance of the sensor, specifically widening its measurement range and natural frequency, a cross-beam construction with a center block was devised, and a Wheatstone bridge was formed by placing four piezoresistors at the ends of the fixed beams to convert acceleration into electricity. The location of the varistor was determined using the finite element approach, which yielded the optimal sensitivity. Additionally, a reliable Pt-Ti-Pt-Au electrode was designed to solve the issue of the electrode failing under high impact and enhancing the stability of the ohmic contact. The accelerometer was fabricated using MEMS technology, and the experiment with a Hopkinson pressure bar and hammering was conducted, and the bias stability was measured. It had a sensitivity of 1.06 μV/g with good linearity. The simulated natural frequency was 633 kHz The test result revealed that the accelerometer can successfully measure an acceleration of 100,000 g. [ABSTRACT FROM AUTHOR]

The commercial value of cookies is easily lost when they break due to mechanical stress, such as shock, during distribution. Therefore, it is important to prevent shock by incorporating a cushioning design into cookie packaging. To optimize packaging, we must first understand the type of breakage caused by shock. During distribution, fatigue failure due to repetitive shocks might be the main factor involved in breakage of cookies because events related to shock stress usually occur more than once. Accordingly, we investigated the relationships between acceleration, shock frequency, and the occurrence of breakage in two types of packaged cookies (soft and hard). A drop test was performed at heights of 0.15–0.45 m. The results suggest that both types of cookies are broken by repetitive shocks, and the relationship between the number of shocks, acceleration (related to drop height), and the occurrence of breakage can be expressed as power approximation curves. Generally, the breakage of cookies due to mechanical stress is known to be a result of brittle fractures. However, our results suggest that the visible breakage of packaged cookies due to repetitive shock may be the result of fatigue failure. In addition, we propose a simple method that uses a small accelerometer to simulate breakage during transportation. The results of this study contribute to the development of new cushioning packaging designs to reduce the breakage of cookies during transportation. [ABSTRACT FROM AUTHOR]

It has been hypothesized that key lifestyle behaviors of physical activity and sleep worsened in response to the Coronavirus disease (COVID-19) pandemic. However, there have been inconsistencies in findings of changes in these key lifestyle behaviors across populations likely due to the wide variety of assessment methods. The purpose of the study was to compare physical activity and sleep before and after the COVID-19 pandemic using accelerometers and self-reported behaviors. A longitudinal follow-up was conducted on students, faculty, and staff at a university campus in the United States. In the periods before March 2020 (covering the academic years of 2018-2019 or 2019-2020) and again in April-June 2021, participants completed surveys to evaluate their physical activity and sleep behaviors and wore an accelerometer. A total of 44 participants completed the survey at both timepoints and 32 completed accelerometer assessment at both timepoints. Fifty-seven percent of participants reported a perceived decline in physical activity, while 30% reported a worsening in sleep. From self-reported data, overall physical activity did not change, but there was a decrease in active transport (p < 0.001) and increase in domestic physical activity (p = 0.012). Sleep quality decreased as evidenced by an increase in Pittsburgh Sleep Quality Index scores (p = 0.045). There were no changes in accelerometer measured physical activity or sleep. There were no changes in physical or mental health. While perceptions of physical activity declined from prior to the COVID-19 pandemic, there were no changes in device-measured physical activity, and changes in self-reported physical activity differed by domain. [ABSTRACT FROM AUTHOR]

Maintenance of mechanical elements is considered to be the most crucial task in industry and affects the economics, predominantly. There are many techniques available for fault diagnosis and condition monitoring of rotatory machine elements and one of the popular tools is vibration monitoring. Analyzing vibrations would be useful in supervising equipment/machine components in an attempt to detect the significant change which is the cause of growing failures or faults. Broadly speaking, it comes under prognostics and health monitoring (PHM) and prevents unexpected failure and costly repair. Proficient predictive monitoring and on-board recognition of failures is a need of the Fourth Industrial Revolution. Several types of vibration analyzers and sensors are commercially available, however, their total budget is not affordable. This motivates reviewing the suitability of low-cost sensors for vibration monitoring. An inclusive review of a variety of applications wherein microelectromechanical system (MEMS)-based accelerometer is used is presented in this paper. This would support an open-design movement for creating open. [ABSTRACT FROM AUTHOR]

Mass-spring is one of the most used structures in sensors and actuators of MEMS technology, including accelerometers, gyroscopes, harvesters, etc. Some of the major design parameters of the structure are natural frequency and displacement sensitivity. The limitations of microfabrication processes should be considered in the design process. The optimized geometry topology can reduce the area occupied by the structure in the fabrication and increases the number of possible structures per wafer. This study aims to provide a novel systematic design and optimization of a MEMS mass-spring system by using a dimensionless design flowchart. Based on the dimensionless design, this algorithm provides the designer with the optimized dimensions of the mass-spring by following the provided dimensionless diagrams, taking into account stress, displacement sensitivity, natural frequency, and fabrication limitations. Also, the optimized dimensions of the mass-spring system are obtained using the dimensionless design flowchart with respect to the desired natural frequency and displacement sensitivity. In addition, genetic algorithms and dimensionless diagrams present a procedure to minimize the footprint of the structure while keeping the desired natural frequency and displacement sensitivity. Results demonstrate that up to a 3% change in both natural frequency and displacement sensitivity, leads to a 45% reduction in the structure area compared to the related literature of MEMS accelerometers. [ABSTRACT FROM AUTHOR]

Purpose: The Functional Ambulation Categories (FAC) is a measurement tool used to classify walking ability according to the amount of physical support required. In this study, the FAC is translated into Danish and the reliability and validity of the FAC are established in a population of patients with acquired brain injury (ABI). Methods: The study took place in a neuro-rehabilitation setting. The translation process followed an accepted forward–backward translation method in six steps. For the assessment of clinometric properties a cross-sectional study design was applied. Interrater reliability was assessed with weighted Cohen's kappa. Construct validity of the FAC was assessed with Spearman's rho by correlating the FAC to walking velocity assessed with the 10-meter walk test and to the number of daily steps assessed with accelerometers. Results: The FAC was successfully translated into Danish. For the assessment of clinometric properties, 53 patients were included. Almost perfect interrater reliability was found (κ = 0.92, p < 0.0001). Construct validity was high between FAC and walking velocity (r2 = 0.87, p < 0.0001) and moderate between FAC and the number of daily steps (r2 = 0.62, p < 0.0001). Conclusion: The Danish version of the FAC was found reliable and valid for use in-patients with ABI. IMPLICATIONS FOR REHABILITATION: The Functional Ambulation Categories (FAC) has been translated into Danish and is available for use by researchers and clinicians in Denmark. Steps to ensure high reliability are described and can be replicated in other settings and these steps include developing a practice scoring sheet with a patient case for each FAC score. The reliability and validity of the FAC have been established, and the results are generalizable to similar populations of patients with acquired brain injury. [ABSTRACT FROM AUTHOR]

Affect is known to be predictive of and enhanced by higher physical activity (PA) levels in the general population. This secondary analysis aimed to increase the understanding of the bi-directional relationship between PA and core affect (i.e. valence, energetic arousal, and calmness) among adults with higher body weight. Affect and PA were assessed in naturalistic settings via ecological momentary assessment using a mixed sampling scheme from 157 participants (body mass index: 32.99 ± 3.78 kg/m2). Multilevel models revealed that being more physically active in the 15 minutes prior to the assessment predicted an increase in energetic arousal and a decrease in calmness. Subsequently, feeling more energetic and agitated was associated with increased PA within the following 15 minutes. Valence (i.e. pleasure–displeasure) was not associated with PA nor predictive of subsequent PA. Digital PA interventions may target the enhancement of feelings of energy and present psychoeducation about these distinct psychological benefits. [ABSTRACT FROM AUTHOR]

Traditional measurements of gait are typically performed in clinical or laboratory settings where functional assessments are used to collect episodic data, which may not reflect naturalistic gait and activity patterns. The emergence of digital health technologies has enabled reliable and continuous representation of gait and activity in free-living environments. To provide further evidence for naturalistic gait characterization, we designed a master protocol to validate and evaluate the performance of a method for measuring gait derived from a single lumbar-worn accelerometer with respect to reference methods. This evaluation included distinguishing between participants' self-perceived different gait speed levels, and effects of different floor surfaces such as carpet and tile on walking performance, and performance under different bouts, speed, and duration of walking during a wide range of simulated daily activities. Using data from 20 healthy adult participants, we found different self-paced walking speeds and floor surface effects can be accurately characterized. Furthermore, we showed accurate representation of gait and activity during simulated daily living activities and longer bouts of outside walking. Participants in general found that the devices were comfortable. These results extend our previous validation of the method to more naturalistic setting and increases confidence of implementation at-home. [ABSTRACT FROM AUTHOR]

Background: Children have alarmingly low levels of competency in fundamental motor skills (FMS) and high levels of physical inactivity. e:health interventions, interventions delivered electronically, are useful tools for intervention in the home through parents, but less is known about the effects of these interventions in early childhood education centers or settings. Therefore, we created the Motor skills At Playtime (MAP) e:health intervention (e:MAP) to be delivered in an early childhood education setting. The goals of this pilot study on e:MAP are to (1) determine the intervention effects on children's FMS and physical activity and (2) explore the teachers' perceptions and ability to facilitate e:MAP. Methods: This pilot study uses a pretest/posttest randomized cluster control design. We will recruit at least 64 children (3.5–5 years of age) enrolled in a single early childhood education center. Children will be randomly assigned at the level of the classroom to an e:MAP group (n~30) or a control group (n~30). Children in classrooms assigned to e:MAP will complete an 8-week intervention. We will collect measures of child FMS and physical activity, and teacher's perceptions of the program before (pretest) and after the intervention (posttest). FMS measures include process (Test of Gross Motor Development-3rd Edition) and product-oriented scores. Physical activity will be assessed using a 7-day accelerometer wear protocol. Teachers' perceptions will be assessed through a brief survey. Lastly, we will collect data on teachers' ability to facilitate e:MAP through a daily survey. Potential significance: This study will yield novel insights into the effectiveness and feasibility of a health intervention in an early childhood education setting. Results from this work will expand our knowledge of how to harness e:health modalities, which have the potential to significantly expand the distribution and scalability of FMS interventions. [ABSTRACT FROM AUTHOR]

This research aims to develop and validate a fiber Bragg grating (FBG) accelerometer, designed with a bearing and flexure hinge structure, to accurately measure medium‐ and high‐frequency vibrations caused by wheel‐rail excitation. The structural parameters of the accelerometer are optimized through theoretical mechanics analysis, and its dynamic characteristics are verified by experimental vibration testing and compared with the finite element simulated results. Key findings reveal that the proposed sensor has a wide operational frequency range of 10–1200 Hz and a high acceleration sensitivity of 3 pm/m·s−2, in addition to excellent linearity and repeatability. Moreover, the sensor demonstrates immunity to temperature variations, making it suitable for use in fluctuating temperature environments. Laboratory model experiment tests of high‐speed train tracks show that the FBG accelerometer effectively identifies medium‐ to high‐frequency vibration signals caused by wheel‐rail excitation, corroborated by traditional piezoelectric accelerometers. The results confirm the sensor's ability to capture vertical axle box vibration acceleration (ABVA) and its potential for assessing axle box structural dynamics in high‐speed railway applications. [ABSTRACT FROM AUTHOR]

Introduction: The effect of displayed step count in smartwatches on the accuracy of daily step-count estimation and the potential underlying psychological factors have not been revealed. The study aimed for the following: (i) To investigate whether the counting and reporting of daily steps by a smartwatch increases the daily step-count estimation accuracy and (ii) to elucidating underlying psychological factors. Methods: A total of 34 healthy men and women participants wore smartwatches for 4 weeks. In week 1 (baseline), 3 (follow-up 1), and 8 (followup 2), the number of smartwatch displayed steps was blinded for each participant. In week 2 (Intervention), the number of steps was not blinded. During baseline and follow-ups 1 and 2, the participants were instructed to estimate their number of steps four times per day. During the 4-week washout period between follow-ups 1 and 2, no feedback was provided. The Body Awareness Questionnaire and the Body Responsiveness Questionnaire (BRQ) were used to elucidate the psychological facets of the assumed estimation accuracy. Results: The mean absolute percentage error between the participants' steps count estimations and measured steps counts were 29.49% (at baseline), 0.54% (intervention), 11.89% (follow-up 1), and 15.14% (follow-up 2), respectively. There was a significant effect between baseline and follow-up 1 [t (61.7) = 3.433, p < 0.001] but not between follow-up 1 and followup 2 [t (60.3) = -0.288, p = 0.774]. Only the BRQ subscale "Suppression of Bodily Sensations" appeared to be significant at the Baseline (p = 0.012; Bonferroni adjusted p = 0.048) as a factor influencing step-count estimation accuracy. Conclusion: The counting and reporting of daily steps with a smartwatch allows improving the subjective estimation accuracy of daily step counts, with a stabilizing effect for at least 6 weeks. Especially individuals who tend to suppress their bodily sensations are less accurate in their daily step-count estimation before the intervention. [ABSTRACT FROM AUTHOR]

Background: Greater public transport use has been linked to higher physical activity levels. However, neither the amount of physical activity associated with each daily public transport trip performed, nor the potential total physical activity gain associated with an increase in trips/day, has been determined. Using objective measures, we aimed to quantify the association between public transport use, physical activity and sedentary time. Methods: A longitudinal study of Australian adults living in Hobart, Tasmania, who were infrequent bus users (≥ 18 years; used bus ≤ 2 times/week). The number of bus trips performed each day was determined from objective smartcard data provided by the public transportation (bus) provider across a 36-week study timeframe. Accelerometer measured steps/day (primary outcome), moderate-to-vigorous physical activity (min/day), and sedentary time (min/day) were assessed across four separate one-week periods. Results: Among 73 participants across 1483 day-level observations, on days that public transport was used, participants achieved significantly more steps (β = 2147.48; 95%CI = 1465.94, 2829.03), moderate to vigorous physical activity (β = 22.79; 95% CI = 14.33, 31.26), and sedentary time (β = 37.00; 95% CI = 19.80, 54.21) compared to days where no public transport trips were made. The largest increase in steps per day associated with a one-trip increase was observed when the number of trips performed each day increased from zero to one (β = 1761.63; 95%CI = 821.38, 2701.87). The increase in the number of steps per day was smaller and non-significant when the number of trips performed increased from one to two (β = 596.93; 95%CI=-585.16, 1779.01), and two to three or more (β = 632.39; 95%CI=-1331.45, 2596.24) trips per day. Significant increases in sedentary time were observed when the number of trips performed increased from zero to one (β = 39.38; 95%CI = 14.38, 64.39) and one to two (β = 48.76; 95%CI = 25.39, 72.12); but not when bus trips increased from two to three or more (β=-27.81; 95%CI=-76.00, 20.37). Conclusions: Greater public transport use was associated with higher physical activity and sedentary behaviour. Bus use may yield cumulative increases in steps that amount to 15–30% of the daily recommended physical activity target. A policy and public health focus on intersectoral action to promote public transport may yield meaningful increases in physical activity and subsequent health benefits. [ABSTRACT FROM AUTHOR]

The renowned Moors and Christians celebrations held in Alicante (specifically in Villajoyosa), are widely appreciated for their authentic recreations of historical events and battles that took place during the sixteenth century. Moreover, Villajoyosa is famous for its excellent state of conservation of architectonic elements such as walls, facades, watchtowers, churches, or fortifications. However, due to the poor information, these events have been moved to different places to the ones where the original battles happened. Hence, this study presents a practical examination aimed at cataloging and characterizing the impact of pyrotechnics and firing weapons in close proximity to these architectural elements. In order to gather these data, multiple sound‐level meters and accelerometers were strategically positioned on the building. Six arquebusiers fire their weapons to emulate the effect of this festival. Thanks to the obtained results, we have been able to propose some recommendations to move these events to the original emplacement at the time of protecting our heritage. [ABSTRACT FROM AUTHOR]

Individuals working in the field of dentistry have a high prevalence of musculoskeletal disorders (MSDs) owing to monotonous and one-sided physical exertion. Inertial measurement units (IMU) are increasingly shifting into focus for assessing postural risk at work. Therefore, the present study aimed to evaluate the effects of an ergonomic lecture and training intervention on postural risk and MSDs in dental assistant students using inertial sensor-based motion capture (MoCap). Eighteen female dental assistant students (age: 19.44 ± 6.83 years; height: 164.59 ± 5.32 cm; weight: 64.88 ± 16.52 kg; BMI: 19.70 ± 4.89 kg/m2), randomly divided into intervention (n = 9) and control (n = 9) groups, participated in the present study. The participants completed the Nordic Questionnaire on MSD prevalence, after which a 90 s MoCap with Xsens IMU was performed. A lecture on ergonomics was provided, followed by a five-week intervention for the intervention group. Follow-up assessments were performed, and 5- and 18-week follow-up MSD questionnaires were administered. Mixed analysis of variance (MANOVA) showed a significant difference in the Rapid Upper Limb Assessment (RULA) and part-scores of the upper arm and wrist. Despite a reduction in MSDs, no significant differences in the time of measurement and groups were detected after the five-week training intervention and the 18-week follow-up questionnaire. A targeted ergonomics lecture was effective for dental assistant students, and technologies such as IMU improved workplace ergonomics in dentists. Further studies with a longer measurement periods, follow-up, and larger sample sizes are recommended. [ABSTRACT FROM AUTHOR]

Background: Opt2Move is a theory-guided moderate and vigorous physical activity (MVPA) promotion trial that uses multiphase optimization strategy (MOST) methodology to evaluate the individual and combined effects of four intervention components in a full factorial experiment among young adult cancer survivors (YACS; N = 304). All participants will receive the core mHealth MVPA intervention, which includes a Fitbit and standard self-monitoring Opt2Move smartphone application. YACS will be randomized to one of 16 conditions to receive between zero and four additional components each with two levels (yes v. no): E-Coach, buddy, general mindfulness, and MVPA-specific mindfulness. Objective: The primary aim is to determine the individual and combined effects of the components on MVPA post-intervention (12-weeks) and at 24-week follow-up. The secondary aim is to examine how changes in MVPA are associated with patient-reported outcomes, light-intensity activity, sedentary time, and sleep duration and quality. Potential mediators and moderators of component effects will also be examined. Results: Results will support the selection of a package of intervention components optimized to maximize MVPA to be tested in a randomized controlled trial. Conclusion: Opt2Move represents the first systematic effort to use MOST to design an optimized, scalable mHealth MVPA intervention for YACS and will lead to an improved understanding of how to effectively change YACS' MVPA and ultimately, improve health and disease outcomes. [ABSTRACT FROM AUTHOR]

Background: Among elementary-aged children (5-12yrs), summer vacation is associated with accelerated gains in Body Mass Index (BMI). A key behavioral driver of BMI gain is a lack of physical activity (PA). Previous studies indicate PA decreases during summer, compared to the school year but whether this difference is consistent among boys and girls, across age, and by income status remains unclear. This study examined differences in school and summer movement behaviors in a diverse cohort of children across three years. Methods: Children (N = 1,203, age range 5–14 years, 48% girls) wore wrist-placed accelerometers for a 14-day wear-period during school (April/May) and summer (July) in 2021 to 2023, for a total of 6 timepoints. Mixed-effects models examined changes in school vs. summer movement behaviors (moderate-to-vigorous physical activity [MVPA], sedentary) for boys and girls, separately, and by age and household income groups (low, middle, and upper based on income-to-poverty ratio). Results: Children provided a total of 35,435 valid days of accelerometry. Overall, boys (+ 9.1 min/day, 95CI 8.1 to 10.2) and girls (+ 6.2 min/day, 95CI 5.4 to 7.0) accumulated more MVPA during school compared to summer. Boys accumulated less time sedentary (-9.9 min/day, 95CI -13.0 to -6.9) during school, while there was no difference in sedentary time (-2.7 min/day, 95CI -5.7 to 0.4) for girls. Different patterns emerged across ages and income groups. Accumulation of MVPA was consistently greater during school compared to summer across ages and income groups. Generally, the difference between school and summer widened with increasing age, except for girls from middle-income households. Accumulation of sedentary time was higher during school for younger children (5-9yrs), whereas for older children (10-14yrs), sedentary time was greater during summer for the middle- and upper-income groups. For boys from low-income households and girls from middle-income households, sedentary time was consistently greater during summer compared to school across ages. Conclusions: Children are less active and more sedentary during summer compared to school, which may contribute to accelerated BMI gain. However, this differs by biological sex, age, and income. These findings highlight the complex factors influencing movement behaviors between school and summer. [ABSTRACT FROM AUTHOR]

Young children's physical activity (PA) has been decreasing while their sports participation has been increasing. Therefore, the aim of this research was to longitudinally examine whether and, if so, how organised and non‐organised PA participation by early childhood education and care (ECEC)‐aged children (T1; 3–8 years) predicted their accelerometer‐measured PA at primary school age (T2; 7–11 years). Secondarily, changes in organised and non‐organised PA participation over time were investigated. The cluster‐randomised study participants comprised 501 Finnish children (52.3% girls: T1, Mage = 5.57 ± 1.06; T2, Mage = 8.80 ± 1.07). PA participation was queried via guardian questionnaire at T1 and T2. Organised PA participation was operationalised as non‐participation, participation in one sport or multisport (two or more) participation; non‐organised PA was operationalised as time spent outdoors on weekdays and on weekend days. PA at T2 was measured using accelerometers. The primary outcome was tested using linear regressions, while a paired sample t‐test and Mann–Whitney U test assessed differences between T1 and T2. The results showed outdoor time and organised sports participation increased from T1 to T2. Moreover, outdoor time at T1 predicted more moderate‐to‐vigorous PA (MVPA) and less sedentary time at T2, while multisport participation predicted significantly more MVPA and less sedentary time at T2. Overall, being outdoors and multisport participation at younger ages appear to have predicted Finnish children's later (MV) PA and sedentary behaviour. Highlights: Outdoor time and multisports in early childhood positively predicted subsequent physical activity (PA) in middle childhood.Spending more than 30 min a day outdoors of ECEC hours predicted higher subsequent MVPA and lower sedentary time at school age.Adults promoting outdoor activities and multisports support children to adopt a physically active lifestyle. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate sleep‐wake behavior and gain insights into perceived impairment (sleep, fatigue, and cognitive function) of athletes competing in two international multi‐day adventure races. Twenty‐four athletes took part across two independent adventure races: Queensland, Australia and Alaska, USA. Individual sleep periods were determined via actigraphy, and racers self‐reported their perceived sleep disturbances, sleep impairment, fatigue and cognitive function. Each of these indices was calculated for pre‐, during‐ and post‐race periods. Sleep was severely restricted during the race period compared to pre‐race (Queensland, 7:46 [0:29] vs. 2:50 [1:01]; Alaska, 7:39 [0:58] vs. 2:45 [2:05]; mean [SD], hh:mm). As a result, there was a large cumulative sleep debt at race completion, which was not 'reversed' in the post‐race period (up to 1 week). The deterioration in all four self‐reported scales of perceived impairment during the race period was largely restored in the post‐race period. This is the first study to document objective sleep‐wake behaviors and subjective impairment of adventure racers, in the context of two geographically diverse, multi‐day, international adventure races. Measures of sleep deprivation indicate that sleep debt was extreme and did not recover to pre‐race levels within 1 week following each race. Despite this objective debt continuing, perceived impairment returned to pre‐race levels quickly post‐race. Therefore, further examination of actual and perceived sleep recovery is warranted. Adventure racing presents a unique scenario to examine sleep, performance and recovery. Highlights: Adventure, or expedition, racing is an ultra‐endurance sport, carried out over multiple days, which presents an extreme test of athletic performance under conditions of severe sleep restriction and deprivation. However, limited research has been conducted to examine sleep and perceived impairment of athletes who choose this sport.Using actigraphy, the team‐based nature of adventure racing was evident with severe sleep restriction synchronized between team members during the race.There was significant sleep debt accumulated across the race and was not recovered by the end of the measurement period. Furthermore, perceived impairment returned to pre‐race levels quickly after race completion, despite the remaining sleep debt objectively observed.This study posits that adventure racing presents a unique context to study sleep, performance, and recovery. [ABSTRACT FROM AUTHOR]

The elastic modulus of concrete is one of the most important parameters in the analysis and design of concrete structures. However, determining the elastic modulus in civil structures using core-drilled samples is time-consuming and labor-intensive. Additionally, the elastic modulus of Ultra-High Performance Concrete (UHPC) varies significantly depending on its composition. This paper proposes an improved, non-destructive application to identify the elastic modulus of UHPC materials in in-service structures. The elastic modulus is estimated through calibration between a numerical model and experimental UHPC plate vibration test results, using frequency and mode shapes. This calibration involves solving an inverse problem using optimization techniques such as Particle Swarm Optimization (PSO), Genetic Algorithm (GA), Cuckoo Search, and the YUKI algorithm. Updating the plate characteristics is made possible by the development of numerous iterations, where each iteration updates the elastic modulus, thickness, and width values in the term to find the best solution. The highest accuracies compared to experimental data natural frequency values were found in models updated by GA, PSO, YUKI, and Cuckoo algorithms, with errors of 10.77%, 6.58%, 6.87%, and 6.87%, respectively. An experimental sample was tested to determine the elastic modulus of the UHPC, and the proposed application showed a 0.55% error compared to the experimental value. Thus, the estimated elastic modulus value is highly accurate. [ABSTRACT FROM AUTHOR]

We propose a novel approach for predicting stress severity by measuring sleep phasic heart rate variability (HRV) using a smart device. This device can potentially be applied for stress self‐screening in large populations. Using a Holter electrocardiogram (ECG) and a Huawei smart device, we conducted 24‐h dual recordings of 159 medical workers working regular shifts. Based on photoplethysmography (PPG) and accelerometer signals acquired by the Huawei smart device, we sorted episodes of cyclic alternating pattern (CAP; unstable sleep), non‐cyclic alternating pattern (NCAP; stable sleep), wakefulness, and rapid eye movement (REM) sleep based on cardiopulmonary coupling (CPC) algorithms. We further calculated the HRV indices during NCAP, CAP and REM sleep episodes using both the Holter ECG and smart‐device PPG signals. We later developed a machine learning model to predict stress severity based only on the smart device data obtained from the participants along with a clinical evaluation of emotion and stress conditions. Sleep phasic HRV indices predict individual stress severity with better performance in CAP or REM sleep than in NCAP. Using the smart device data only, the optimal machine learning‐based stress prediction model exhibited accuracy of 80.3 %, sensitivity 87.2 %, and 63.9 % for specificity. Sleep phasic heart rate variability can be accurately evaluated using a smart device and subsequently can be used for stress predication. [ABSTRACT FROM AUTHOR]

Athlete load monitoring using upper back-mounted global navigation satellite system (GNSS) player tracking is common within many team sports. However, accelerometer-based load monitoring may provide information that cannot be achieved with GNSS alone. This review focuses on the accelerometer-based metrics quantifying the accumulation of accelerations as an estimation of athlete training load, appraising the validity and reliability of accelerometer use in upper back-mounted GNSS player tracking systems, the accelerometer-based metrics, and their potential for application within athlete monitoring. Reliability of GNSS-housed accelerometers and accelerometer-based metrics are dependent on the equipment model, signal processing methods, and the activity being monitored. Furthermore, GNSS unit placement on the upper back may be suboptimal for accelerometer-based estimation of mechanical load. Because there are currently no feasible gold standard comparisons for field-based whole-body biomechanical load, the validity of accelerometer-based load metrics has largely been considered in relation to other measures of training load and exercise intensity. In terms of convergent validity, accelerometer-based metrics (e.g., Play- erLoad, Dynamic Stress Load, Body Load) have correlated, albeit with varying magnitudes and certainty, with measures of internal physiological load, exercise intensity, total distance, collisions and impacts, fatigue, and injury risk and incidence. Currently, comparisons of these metrics should not be made between athletes because of mass or technique differences or between manufacturers because of processing variations. Notable areas for further study include the associations between accelerometer- based metrics and other parts of biomechanical load-adaptation pathways of interest, such as internal biomechanical loads or methods of manipulating these metrics through effective training design. [ABSTRACT FROM AUTHOR]

The quantification of training loads (TLs) is essential for optimizing jump performance and reducing the occurrence of injuries. This study aimed to (a) propose a new method for quantifying TLs in explosive exercises, (b) determine the nature of the relationship between TLs dynamics and injury occurrence, and (c) assess a TLcritical for training schedule purposes, above which the risk of injury occurrence becomes unacceptable. This study was conducted with 11 male volleyball players on a national team during a 5-month international competitive period. The proposed new method for quantifying TLs is based on a weighting factor applied to relative jumping intensities, determined by the number of sustainable jumps and their intensities measured by G-Vert accelerometer. The relationship between TLs dynamics and injury occurrence was assessed using a variable dose-response model. A high coefficient of determination was found between the maximum number of jumps possible and their intensities (r² = 0.94 ± 0.14, p < 0.001), indicating a strong physiological relationship between jumping intensities and the constraints imposed. The occurrence of injury was dependent on TLs dynamics for 2 players (r² = 0.26 ± 0.01; p < 0.001). The TLcritical corresponded to 11 jumps over 80% of maximum jump height during games and approximately 130 jumps at <80% of maximal jump height. The present study proposes a new approach for quantifying supramaximal exercises and provides tools for training schedules and the prevention of volleyball injuries. [ABSTRACT FROM AUTHOR]

This article addresses the important problem of tilt measurement and stabilization. This is particularly important in the case of drone stabilization and navigation in underwater environments, multibeam sonar mapping, aerial photogrammetry in densely urbanized areas, etc. The tilt measurement process involves the fusion of information from at least two different sensors. Inertial sensors (IMUs) are unique in this context because they are both autonomous and passive at the same time and are therefore very attractive. Their calibration and systematic errors or bias are known problems, briefly discussed in the article due to their importance, and are relatively simple to solve. However, problems related to the accumulation of these errors over time and their autonomous and dynamic correction remain. This article proposes a solution to the problem of IMU tilt calibration, i.e., the pitch and roll and the accelerometer bias correction in dynamic conditions, and presents the process of calculating these parameters based on combined accelerometer and gyroscope records using a new approach based on measuring increments or differences in tilt measurement. Verification was performed by simulation under typical conditions and for many different inertial units, i.e., IMU devices, which brings the proposed method closer to the real application context. The article also addresses, to some extent, the issue of navigation, especially in the context of dead reckoning. [ABSTRACT FROM AUTHOR]

Some applications, such as aerospace testing and monitoring the operating conditions of equipment on space missions, require mechanical sensors capable of measuring accelerations at frequencies of several hundred hertz. For such measurements, optomechanical sensors can be used, providing the ability to measure accelerations without calibration. To enable such measurements, improved designs of drum-type sensors with the assigned performance have been elaborated. Such designs make it possible to provide the necessary levels of natural frequencies for optomechanical sensors and eliminate crosstalk. Using mathematical modeling, the dependencies of the mechanical characteristics of the proposed types of acceleration sensors versus their parameters were obtained. The use of such sensor designs ensures their compactness, making their manufacturing more technologically sound and suitable for use, in particular, in space missions. [ABSTRACT FROM AUTHOR]

Individuals with cancer are recommended to engage in regular physical activity (PA) even during cancer therapy. The aim of this study was to explore how patient-reported physician PA counseling influences their PA intention and behavior in addition to psycho-cognitive determinants derived from the theory of planned behavior (TPB). A longitudinal study during cancer treatment was conducted among N = 115 patients with breast, prostate, or colorectal cancer (Mage = 58.0, SD = 11.5; 55.7% female). The median time since diagnosis was 2 months, and 19.1% were diagnosed with metastases. Participants provided information on PA counseling by their physicians and on psycho-cognitive variables of the TPB at three measurement points. Additionally, they wore accelerometers for seven days at baseline and three months later. Nearly half of participants (48%) reported basic PA counseling and 30% reported in-depth PA counseling. Patients in poorer health and with lower education reported significantly less in-depth counseling. In addition to patient self-efficacy in performing PA, only in-depth physician PA counseling, but not basic physician counseling, predicted intention for PA four weeks later. Patients' PA three months after baseline was predicted by patients' PA at baseline and their intention for PA. Overall, the PA level at baseline was identified as the most important predictor of PA three months later. Nevertheless, physicians seem to have the ability to increase their cancer patients' intention for PA by in-depth counseling. [ABSTRACT FROM AUTHOR]

A three-axis seismic accelerometer was developed and created, containing three uniaxial mutually perpendicular sensors, the sensitivity axis of each sensor is located at an angle of 54.736° to the local gravitational vertical. For the first time, additional magnetic rigidity has been introduced into each device, allowing the device to be finely tuned to the conditions of a particular planet. However, the accumulated experience in conducting ground-based tests has shown the need to improve the uniaxial seismic accelerometer, which can significantly improve the characteristics of the device. First, we use a single material—beryllium bronze BrB-2—for the manufacture of massive test mass suspension elements with a thickness of 1.5 mm and an elastic element made of a thin strip 10–20 microns thick, which reduces the likelihood of instability. Secondly, we reduce the gap in the capacitors of capacitive converters from 0.25 to 0.1–0.15 mm to significantly increase the conversion slope of the capacitive sensor. Thirdly, we change the technology of setting up the device, for which we combine all the elements of the sensitive part of a uniaxial seismogravimeter using special vertical inserts. This allows us to place the device as a whole in a system for its configuration, eliminating the possibility of failure of individual elements, thereby increasing the reliability of the device. [ABSTRACT FROM AUTHOR]

Objectives Daily electronic media use, including television viewing and computer use, is common in older adulthood. Yet, increased electronic media usage may disrupt nightly sleep, leading to sleeping fewer hours and more sleep disruptions. The current study examined these relationships in older adulthood, as well as the potential buffering effect of having a regular sleep schedule. Methods Older adults (N  = 273) from the Daily Experiences and Well-Being Study (DEWS) completed 5–6 days of data collection where they answered questions at the beginning of the day about the previous night's sleep as well as questions throughout the day about daily electronic media use. They also wore Actical accelerometers to capture sleep regularity. Results Older adults reported sleeping fewer hours and having more sleep disturbances on days when they reported more instances of computer use. Sleep regularity moderated the daily association between TV viewing and sleep disturbances such that daily TV viewing was associated with more sleep complaints only for older adults who had less regular sleep patterns. However, sleep regularity no longer moderated this association when accounting for napping behavior. Discussion These findings provide evidence that older adults sleep worse after days when they engage in more electronic media use. The association with TV viewing with sleep disturbances on any given day is somewhat mitigated by engaging in regular sleep patterns. Researchers discuss the importance of assessing electronic media use and sleep in daily life as the role of sleep regularity may be a modifiable protective factor. [ABSTRACT FROM AUTHOR]

Well maintained cycleways will encourage more people to cycle, as the condition of cycleways is important for the safety, accessibility and riding comfort of cyclists. Despite that, only a few models used to describe the quality of service for cyclists take the surface condition into account. Objective measuring methods are needed to enable reliable and effective assessment of surface conditions, and measurable performance criteria related to the needs of cyclists should be developed. The purpose of this study has been to test the reliability and validity of using accelerometers in smartphones to assess the riding comfort on cycleways. A smartphone application converting three-dimensional accelerometer measurements into a single indicator for cycleways has been used to assess road surfaces in two field studies, in Sweden and Norway, respectively. Both studies assessed test sections of varying quality. To relate the measurements to subjective riding comfort assessments by cyclists, recruited cyclists collected quantitative data using the app, whilst also rating their perceived riding comfort by completing a survey. Measurements were also related to standard road surface condition indicators, generated from a road surface tester equipped with 19 laser sensors: international roughness index (IRI), mega- and macro-texture. The results show that it is possible to describe the unevenness of a cycleway using the technology present in smartphones. A software application can be used to collect and analyse data from the acceleration sensors in the phone, which can then be used to describe the riding comfort of cyclists. It is mainly the unevenness in the 50-1000 mm size-range that create the greatest discomfort for cyclists, and intermittent vibrations are perceived as more uncomfortable than more evenly distributed vibrations. Therefore, IRI is not a relevant measurement for describing the riding comfort of cyclists. [ABSTRACT FROM AUTHOR]

The aim of this study was twofold: to explore the concordance between two measures of physical activity (accelerometer and IPAQ) among female fibromyalgia (FM) patients, as well as to examine the impact of psychosocial variables (catastrophism, activity avoidance) on walking among these patients. Helplessness, activity avoidance, and commitment to physical activity were evaluated in 132 FM women. After the first assessment, an accelerometer was placed by a psychologist on each participant for seven consecutive days. Eight days later, accelerometers were collected, and participants were evaluated again using the IPAQ. Two models were tested to analyze mediation and a moderated mediation effect. The mediating role of activity avoidance between helplessness and minutes walked was corroborated regarding the objective measure of walking. The effect of helplessness on minutes walked during a week was mediated by activity avoidance and assessed by accelerometers. Cognitive variables played a contextual role when trying to promote exercise. Activity avoidance must be understood as a key variable in physical activity promotion, specifically in the promotion of walking with the aim to do exercise in individuals with FM. [ABSTRACT FROM AUTHOR]

In this paper, serial elastic actuators (SEAs) in conjunction with an accelerometer are proposed as force sensors to detect the intention of movement, and the SEA is proposed as a gentle actuator of a patient's upper-limb exoskeleton. A smooth trajectory is proposed to provide comfortable performance. There is an offset trajectory between the link and the motor, which increases safety by preventing sudden movements, and the offset is equivalent to the torsional elastic spring constant. The proposed control law is based on a backstepping approach tested in real-time experiments with robust results in a 2-DoF upper-limb rehabilitation exoskeleton. The experimental results showed a sensitivity of 100% and a positive predictive value of 97.5% for movement intention detection. [ABSTRACT FROM AUTHOR]

Introduction: Physical activity is known to positively influence cognitive performance. For adults with mild cognitive impairment (MCI), the relationship between physical activity levels and cognitive performance is unknown. This cross‐sectional study aimed to determine if cognitive performance [as measured by the Montreal Cognitive Assessment (MoCA)] of people living in the community with MCI is associated with their physical activity levels or sedentary behaviour. Methods: ActivPAL™ accelerometers were used to objectively measure physical activity and sedentary behaviour for seven full days. Cognitive performance was measured using the MoCA. Consumer and Community Involvement: No involvement other than as research participants Results: Eighty‐two participants from the Balance on the Brain randomised controlled trial were included. Most participants were retired (88%), with 33 (40%) reporting a fall in the last year. The median MoCA score was 24 (IQR 22–26). Participants achieved a mean of 6296 (±2420) steps per day and were sedentary for 10.6 (±2) hours per day. The only physical activity outcomes that had a fair, positive correlation were moderate‐ to vigorous‐intensity physical activity measures of total stepping time and total number of steps (with a cadence of ≥100 steps/min) with the orientation MoCA domain score (r(82) = 0.36, p ≤ 0.001 and r(82) = 0.37, p ≤ 0.001, respectively). Higher total sedentary time had a weak, positive correlation with better visuospatial/executive performance (r(82) = 0.23, p = 0.041). The orientation outcomes remained significant when analysed in an adjusted logistic regression model. Conclusion: This study found that performance in the MoCA orientation domain had a fair‐positive correlation with moderate‐intensity physical activity (i.e., stepping time and step count with a cadence of ≥100 steps/min) as measured by a thigh‐worn accelerometer for community‐dwelling older adults with MCI. When considering the relationship between cognitive domains and sedentary behaviour, consideration may be needed regarding whether cognitive enhancing activities (such as crosswords and other brain games) are being performed, which may confound this relationship. Further investigation is required to confirm these results. PLAIN LANGUAGE SUMMARY: Physical activity is good for people of all ages. Regular moderate to vigorous physical activity is known to help memory and thinking skills. Moderate physical activity includes brisk walking, lawn mowing and water aerobics. Vigorous physical activity includes running, fast‐paced swimming, cycling and brisk walking up hills and steps. For adults with mild cognitive impairment (i.e., a person who is starting to have trouble with their memory, but the difficulty is not yet advanced enough to be diagnosed as dementia), we did not know how their level of engagement with physical activity may be related to their memory and thinking skills. A strength of this study is that we had a large population of 82 people living in the community with mild cognitive impairment to review. We found that people who completed more moderate to vigorous physical activity had better skills in remembering the current day, date and place (orientation). [ABSTRACT FROM AUTHOR]