Effect of 12-month intervention with lipid-based nutrient supplements on physical activity of 18-month-old Malawian children: a randomised, controlled trial.

PubMed

Pulakka, A; Ashorn, U; Cheung, Y B; Dewey, K G; Maleta, K; Vosti, S A; Ashorn, P

2015-02-01

This study measured the effects of dietary supplementation with lipid-based nutrient supplements (LNSs) on 18-month-old children's physical activity. In a randomised, controlled, outcome-assessor blinded trial 1932 six-month-old children from Malawi received one of five interventions daily from 6-18 months of age: 10-g milk-LNS, 20-g milk-LNS, 20-g non-milk-LNS, 40-g milk-LNS or 40-g non-milk-LNS, or received no intervention in the same period (control). The control group received delayed intervention with corn-soy blend from 18-30 months. Physical activity was measured over 1 week by ActiGraph GT3X+ accelerometer at 18 months. Main outcome was mean vector magnitude accelerometer counts/15 s. Analyses were restricted to children with valid accelerometer data on at least 4 days with minimum 6 h of wearing time per day. Of the 1435 children recruited to this substudy, 1053 provided sufficient data for analysis. The mean (s.d.) vector magnitude accelerometer counts in the total sample were 307 (64). The difference (95% CI) in mean accelerometer counts, compared with the control group, was 8 (-6 to 21, P=0.258) in 10-g milk-LNS, 3 (-11 to 17, P=0.715) in 20-g milk-LNS, 5 (-8 to 19, P=0.445) in 20-g non-milk-LNS, 10 (-3 to 23, P=0.148) in 40-g milk-LNS and 2 (-12 to 16, P=0.760) in 40-g non-milk-LNS groups. Provision of 10-40 g doses of LNS daily for 12 months did not increase physical activity of Malawian toddlers.

Classification of Physical Activity Cut-Points and the Estimation of Energy Expenditure during Walking Using the GT3X+ Accelerometer in Overweight and Obese Adults

ERIC Educational Resources Information Center

Howe, Christopher C. F.; Moir, Hannah J.; Easton, Chris

2017-01-01

This study establishes tri-axial activity count (AC) cut-points for the GT3X+ accelerometer to classify physical activity intensity in overweight and obese adults. Further, we examined the accuracy of established and novel energy expenditure (EE) prediction equations based on AC and other metrics. "Part 1": Twenty overweight or obese…

Assessment of physical activity with the Computer Science and Applications, Inc., accelerometer: laboratory versus field validation.

PubMed

Nichols, J F; Morgan, C G; Chabot, L E; Sallis, J F; Calfas, K J

2000-03-01

Our purpose was to compare the validity of the Computer Science and Applications, (CSA) Inc., accelerometer in laboratory and field settings and establish CSA count ranges for light, moderate, and vigorous physical activity. Validity was determined in 60 adults during treadmill exercise, using oxygen consumption (VO2) as the criterion measure, while 30 adults walked and jogged outdoors on a 400-m track. The relationship between CSA counts and VO2 was linear (R2 = .89 SEE = 3.72 ml.kg-1.min-1), as was the relationship between velocity and counts in the field (R2 = .89, SEE = 0.89 mi.hr-1). However, significant differences were found (p < .05) between laboratory and field measures of CSA counts for light and vigorous intensity. We conclude that the CSA can be used to quantify walking and jogging outdoors on level ground; however, laboratory equations may not be appropriate for use in field settings, particularly for light and vigorous activity.

Concurrent validation of the Actigraph gt3x+, Polar Active accelerometer, Omron HJ-720 and Yamax Digiwalker SW-701 pedometer step counts in lab-based and free-living settings.

PubMed

Lee, Joey A; Williams, Skip M; Brown, Dale D; Laurson, Kelly R

2015-01-01

Activity monitors are frequently used to assess activity in many settings. But as technology advances, so do the mechanisms used to estimate activity causing a continuous need to validate newly developed monitors. The purpose of this study was to examine the step count validity of the Yamax Digiwalker SW-701 pedometer (YX), Omron HJ-720 T pedometer (OP), Polar Active accelerometer (PAC) and Actigraph gt3x+ accelerometer (AG) under controlled and free-living conditions. Participants completed five stages of treadmill walking (n = 43) and a subset of these completed a 3-day free-living wear period (n = 37). Manually counted (MC) steps provided a criterion measure for treadmill walking, whereas the comparative measure during free-living was the YX. During treadmill walking, the OP was the most accurate monitor across all speeds (±1.1% of MC steps), while the PAC underestimated steps by 6.7-16.0% per stage. During free-living, the OP and AG counted 97.5% and 98.5% of YX steps, respectively. The PAC overestimated steps by 44.0%, or 5,265 steps per day. The Omron pedometer seems to provide the most reliable and valid estimate of steps taken, as it was the best performer under lab-based conditions and provided comparable results to the YX in free-living. Future studies should consider these monitors in additional populations and settings.

Prediction of Energy Expenditure from Wrist Accelerometry in People with and without Down Syndrome

ERIC Educational Resources Information Center

Agiovlasitis, Stamatis; Motl, Robert W.; Foley, John T.; Fernhall, Bo

2012-01-01

This study examined the relationship between energy expenditure and wrist accelerometer output during walking in persons with and without Down syndrome (DS). Energy expenditure in metabolic equivalent units (METs) and activity-count rate were respectively measured with portable spirometry and a uniaxial wrist accelerometer in 17 persons with DS…

Validity and reliability of the Fitbit Zip as a measure of preschool children’s step count

PubMed Central

Sharp, Catherine A; Mackintosh, Kelly A; Erjavec, Mihela; Pascoe, Duncan M; Horne, Pauline J

2017-01-01

Objectives Validation of physical activity measurement tools is essential to determine the relationship between physical activity and health in preschool children, but research to date has not focused on this priority. The aims of this study were to ascertain inter-rater reliability of observer step count, and interdevice reliability and validity of Fitbit Zip accelerometer step counts in preschool children. Methods Fifty-six children aged 3–4 years (29 girls) recruited from 10 nurseries in North Wales, UK, wore two Fitbit Zip accelerometers while performing a timed walking task in their childcare settings. Accelerometers were worn in secure pockets inside a custom-made tabard. Video recordings enabled two observers to independently code the number of steps performed in 3 min by each child during the walking task. Intraclass correlations (ICCs), concordance correlation coefficients, Bland-Altman plots and absolute per cent error were calculated to assess the reliability and validity of the consumer-grade device. Results An excellent ICC was found between the two observer codings (ICC=1.00) and the two Fitbit Zips (ICC=0.91). Concordance between the Fitbit Zips and observer counts was also high (r=0.77), with an acceptable absolute per cent error (6%–7%). Bland-Altman analyses identified a bias for Fitbit 1 of 22.8±19.1 steps with limits of agreement between −14.7 and 60.2 steps, and a bias for Fitbit 2 of 25.2±23.2 steps with limits of agreement between −20.2 and 70.5 steps. Conclusions Fitbit Zip accelerometers are a reliable and valid method of recording preschool children’s step count in a childcare setting. PMID:29081984

Compulsory School In- and Outdoors—Implications for School Children’s Physical Activity and Health during One Academic Year

PubMed Central

Pagels, Peter; Raustorp, Anders; Guban, Peter; Fröberg, Andreas; Boldemann, Cecilia

2016-01-01

Regulated school days entail less free-living physical activity (PA) and outdoor stay, which may jeopardize the opportunities for cohesive moderate-to-vigorous physical activity (MVPA) and, by extension, children’s health. The role of outdoor stay during school time for pupils’ free-living PA vs. physical education (PE) and indoor stay was studied during one academic year in 196 pupils aged 7–14 years at four schools in mid-southern Sweden during five consecutive days each in September, March, and May. Actigraph GT3X+ Activity monitors were used. Predictors for PA during school stay were expressed as mean daily accelerometer counts and were measured per season, day, grade, gender, weather, and time outdoors. Overall, free-living PA outdoors generated the highest mean accelerometer counts for moderate and vigorous PA. Outdoor PA and PE, representing 23.7% of the total school time contributed to 50.4% of total mean accelerometer counts, and were the greatest contributors to moderate and vigorous PA. Age and weather impacted PA, with less PA in inclement weather and among older pupils. More time outdoors, at all seasons, would favorably increase school children’s chances of reaching recommended levels of PA. PMID:27420079

Reproducibility of Accelerometer-Assessed Physical Activity and Sedentary Time.

PubMed

Keadle, Sarah Kozey; Shiroma, Eric J; Kamada, Masamitsu; Matthews, Charles E; Harris, Tamara B; Lee, I-Min

2017-04-01

Accelerometers are used increasingly in large epidemiologic studies, but, given logistic and cost constraints, most studies are restricted to a single, 7-day accelerometer monitoring period. It is unknown how well a 7-day accelerometer monitoring period estimates longer-term patterns of behavior, which is critical for interpreting, and potentially improving, disease risk estimates in etiologic studies. A subset of participants from the Women's Health Study (N=209; mean age, 70.6 [SD=5.7] years) completed at least two 7-day accelerometer administrations (ActiGraph GT3X+) within a period of 2-3 years. Monitor output was translated into total counts, steps, and time spent in sedentary, light-intensity, and moderate to vigorous-intensity activity (MVPA) and bouted-MVPA (i.e., 10-minute bouts). For each metric, intraclass correlations (ICCs) and 95% CIs were calculated using linear-mixed models and adjusted for wear time, age, BMI, and season. The data were collected in 2011-2015 and analyzed in 2015-2016. The ICCs ranged from 0.67 (95% CI=0.60, 0.73) for bouted-MVPA to 0.82 (95% CI=0.77, 0.85) for total daily counts and were similar across age, BMI, and for less and more active women. For all metrics, classification accuracy within 1 quartile was >90%. These data provide reassurance that a 7-day accelerometer-assessment protocol provides a reproducible (and practical) measure of physical activity and sedentary time. However, ICCs varied by metric; therefore, future prospective studies of chronic diseases might benefit from existing methods to adjust risk estimates for within-person variability in activity to get a better estimate of the true strength of association. Copyright © 2016 American Journal of Preventive Medicine. All rights reserved.

The impact of accelerometer wear location on the relationship between step counts and arterial stiffness in adults treated for hypertension and diabetes.

PubMed

Cooke, Alexandra B; Daskalopoulou, Stella S; Dasgupta, Kaberi

2018-04-01

Accelerometer placement at the wrist is convenient and increasingly adopted despite less accurate physical activity (PA) measurement than with waist placement. Capitalizing on a study that started with wrist placement and shifted to waist placement, we compared associations between PA measures derived from different accelerometer locations with a responsive arterial health indicator, carotid-femoral pulse wave velocity (cfPWV). Cross-sectional study. We previously demonstrated an inverse association between waist-worn pedometer-assessed step counts (Yamax SW-200, 7 days) and cfPWV (-0.20m/s, 95% CI -0.28, -0.12 per 1000 step/day increment) in 366 adults. Participants concurrently wore accelerometers (ActiGraph GT3X+), most at the waist but the first 46 at the wrist. We matched this subgroup with participants from the 'waist accelerometer' group (sex, age, and pedometer-assessed steps/day) and assessed associations with cfPWV (applanation tonometry, Sphygmocor) separately in each subgroup through linear regression models. Compared to the waist group, wrist group participants had higher step counts (mean difference 3980 steps/day; 95% CI 2517, 5443), energy expenditure (967kcal/day, 95% CI 755, 1179), and moderate-to-vigorous-PA (138min; 95% CI 114, 162). Accelerometer-assessed step counts (waist) suggested an association with cfPWV (-0.28m/s, 95% CI -0.58, 0.01); but no relationship was apparent with wrist-assessed steps (0.02m/s, 95% CI -0.24, 0.27). Waist but not wrist ActiGraph PA measures signal associations between PA and cfPWV. We urge researchers to consider the importance of wear location choice on relationships with health indicators. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Physical Activity Patterns and Sedentary Behavior in Older Women With Urinary Incontinence: an Accelerometer-based Study.

PubMed

Chu, Christine M; Khanijow, Kavita D; Schmitz, Kathryn H; Newman, Diane K; Arya, Lily A; Harvie, Heidi S

2018-01-10

Objective physical activity data for women with urinary incontinence are lacking. We investigated the relationship between physical activity, sedentary behavior, and the severity of urinary symptoms in older community-dwelling women with urinary incontinence using accelerometers. This is a secondary analysis of a study that measured physical activity (step count, moderate-to-vigorous physical activity time) and sedentary behavior (percentage of sedentary time, number of sedentary bouts per day) using a triaxial accelerometer in older community-dwelling adult women not actively seeking treatment of their urinary symptoms. The relationship between urinary symptoms and physical activity variables was measured using linear regression. Our cohort of 35 community-dwelling women (median, age, 71 years) demonstrated low physical activity (median daily step count, 2168; range, 687-5205) and high sedentary behavior (median percentage of sedentary time, 74%; range, 54%-89%). Low step count was significantly associated with nocturia (P = 0.02). Shorter duration of moderate-to-vigorous physical activity time was significantly associated with nocturia (P = 0.001), nocturnal enuresis (P = 0.04), and greater use of incontinence products (P = 0.04). Greater percentage of time spent in sedentary behavior was also significantly associated with nocturia (P = 0.016). Low levels of physical activity are associated with greater nocturia and nocturnal enuresis. Sedentary behavior is a new construct that may be associated with lower urinary tract symptoms. Physical activity and sedentary behavior represent potential new targets for treating nocturnal urinary tract symptoms.

Prediction of activity-related energy expenditure using accelerometer-derived physical activity under free-living conditions: a systematic review.

PubMed

Jeran, S; Steinbrecher, A; Pischon, T

2016-08-01

Activity-related energy expenditure (AEE) might be an important factor in the etiology of chronic diseases. However, measurement of free-living AEE is usually not feasible in large-scale epidemiological studies but instead has traditionally been estimated based on self-reported physical activity. Recently, accelerometry has been proposed for objective assessment of physical activity, but it is unclear to what extent this methods explains the variance in AEE. We conducted a systematic review searching MEDLINE database (until 2014) on studies that estimated AEE based on accelerometry-assessed physical activity in adults under free-living conditions (using doubly labeled water method). Extracted study characteristics were sample size, accelerometer (type (uniaxial, triaxial), metrics (for example, activity counts, steps, acceleration), recording period, body position, wear time), explained variance of AEE (R(2)) and number of additional predictors. The relation of univariate and multivariate R(2) with study characteristics was analyzed using nonparametric tests. Nineteen articles were identified. Examination of various accelerometers or subpopulations in one article was treated separately, resulting in 28 studies. Sample sizes ranged from 10 to 149. In most studies the accelerometer was triaxial, worn at the trunk, during waking hours and reported activity counts as output metric. Recording periods ranged from 5 to 15 days. The variance of AEE explained by accelerometer-assessed physical activity ranged from 4 to 80% (median crude R(2)=26%). Sample size was inversely related to the explained variance. Inclusion of 1 to 3 other predictors in addition to accelerometer output significantly increased the explained variance to a range of 12.5-86% (median total R(2)=41%). The increase did not depend on the number of added predictors. We conclude that there is large heterogeneity across studies in the explained variance of AEE when estimated based on accelerometry. Thus, data on predicted AEE based on accelerometry-assessed physical activity need to be interpreted cautiously.

A comprehensive comparison of simple step counting techniques using wrist- and ankle-mounted accelerometer and gyroscope signals.

PubMed

Rhudy, Matthew B; Mahoney, Joseph M

2018-04-01

The goal of this work is to compare the differences between various step counting algorithms using both accelerometer and gyroscope measurements from wrist and ankle-mounted sensors. Participants completed four different conditions on a treadmill while wearing an accelerometer and gyroscope on the wrist and the ankle. Three different step counting techniques were applied to the data from each sensor type and mounting location. It was determined that using gyroscope measurements allowed for better performance than the typically used accelerometers, and that ankle-mounted sensors provided better performance than those mounted on the wrist.

The validity of the ActiPed for physical activity monitoring.

PubMed

Brown, D K; Grimwade, D; Martinez-Bussion, D; Taylor, M J D; Gladwell, V F

2013-05-01

The ActiPed (FitLinxx) is a uniaxial accelerometer, which objectively measures physical activity, uploads the data wirelessly to a website, allowing participants and researchers to view activity levels remotely. The aim was to validate ActiPed's step count, distance travelled and activity time against direct observation. Further, to compare against pedometer (YAMAX), accelerometer (ActiGraph) and manufacturer's guidelines. 22 participants, aged 28±7 years, undertook 4 protocols, including walking on different surfaces and incremental running protocol (from 2 mph to 8 mph). Bland-Altman plots allowed comparison of direct observation against ActiPed estimates. For step count, the ActiPed showed a low % bias in all protocols: walking on a treadmill (-1.30%), incremental treadmill protocol (-1.98%), walking over grass (-1.67%), and walking over concrete (-0.93%). When differentiating between walking and running step count the ActiPed showed a % bias of 4.10% and -6.30%, respectively. The ActiPed showed >95% accuracy for distance and duration estimations overall, although underestimated distance (p<0.01) for walking over grass and concrete. Overall, the ActiPed showed acceptable levels of accuracy comparable to previous validated pedometers and accelerometers. The accuracy combined with the simple and informative remote gathering of data, suggests that the ActiPed could be a useful tool in objective physical activity monitoring. © Georg Thieme Verlag KG Stuttgart · New York.

Walking as a Contributor to Physical Activity in Healthy Older Adults: 2 Week Longitudinal Study Using Accelerometry and the Doubly Labeled Water Method

PubMed Central

Bonomi, Alberto G; Westerterp, Klaas R

2016-01-01

Background Physical activity is recommended to promote healthy aging. Defining the importance of activities such as walking in achieving higher levels of physical activity might provide indications for interventions. Objective To describe the importance of walking in achieving higher levels of physical activity in older adults. Methods The study included 42 healthy subjects aged between 51 and 84 years (mean body mass index 25.6 kg/m2 [SD 2.6]). Physical activity, walking, and nonwalking activity were monitored with an accelerometer for 2 weeks. Physical activity was quantified by accelerometer-derived activity counts. An algorithm based on template matching and signal power was developed to classify activity counts into nonwalking counts, short walk counts, and long walk counts. Additionally, in a subgroup of 31 subjects energy expenditure was measured using doubly labeled water to derive physical activity level (PAL). Results Subjects had a mean PAL of 1.84 (SD 0.19, range 1.43-2.36). About 20% of the activity time (21% [SD 8]) was spent walking, which accounted for about 40% of the total counts (43% [SD 11]). Short bouts composed 83% (SD 9) of walking time, providing 81% (SD 11) of walking counts. A stepwise regression model to predict PAL included nonwalking counts and short walk counts, explaining 58% of the variance of PAL (standard error of the estimate=0.12). Walking activities produced more counts per minute than nonwalking activities (P<.001). Long walks produced more counts per minute than short walks (P=.001). Nonwalking counts were independent of walking counts (r=−.05, P=.38). Conclusions Walking activities are a major contributor to physical activity in older adults. Walking activities occur at higher intensities than nonwalking activities, which might prevent individuals from engaging in more walking activity. Finally, subjects who engage in more walking activities do not tend to compensate by limiting nonwalking activities. Trial Registration ClinicalTrials.gov NCT01609764; https://clinicaltrials.gov/ct2/show/NCT01609764 (Archived by WebCite at http://www.webcitation.org/6grls0wAp) PMID:27268471

Evaluation of a novel canine activity monitor for at-home physical activity analysis.

PubMed

Yashari, Jonathan M; Duncan, Colleen G; Duerr, Felix M

2015-07-04

Accelerometers are motion-sensing devices that have been used to assess physical activity in dogs. However, the lack of a user-friendly, inexpensive accelerometer has hindered the widespread use of this objective outcome measure in veterinary research. Recently, a smartphone-based, affordable activity monitor (Whistle) has become available for measurement of at-home physical activity in dogs. The aim of this research was to evaluate this novel accelerometer. Eleven large breed, privately owned dogs wore a collar fitted with both the Whistle device and a previously validated accelerometer-based activity monitor (Actical) for a 24-h time period. Owners were asked to have their dogs resume normal daily activities. Total activity time obtained from the Whistle device in minutes was compared to the total activity count from the Actical device. Activity intensity from the Whistle device was calculated manually from screenshots of the activity bars displayed in the smartphone-application and compared to the activity count recorded by the Actical in the same 3-min time period. A total of 3740 time points were compared. There was a strong correlation between activity intensity of both devices for individual time points (Pearson's correlation coefficient 0.81, p < 0.0001). An even stronger correlation was observed between the total activity data between the two devices (Pearson's correlation coefficient 0.925, p < 0.0001). Activity data provided by the Whistle activity monitor may be used as an objective outcome measurement in dogs. The total activity time provided by the Whistle application offers an inexpensive method for obtaining at-home, canine, real-time physical activity data. Limitations of the Whistle device include the limited battery life, the need for manual derivation of activity intensity data and data transfer, and the requirement of Wi-Fi and Bluetooth availability for data transmission.

Reliability and validity of two multidimensional self-reported physical activity questionnaires in people with chronic low back pain.

PubMed

Carvalho, Flávia A; Morelhão, Priscila K; Franco, Marcia R; Maher, Chris G; Smeets, Rob J E M; Oliveira, Crystian B; Freitas Júnior, Ismael F; Pinto, Rafael Z

2017-02-01

Although there is some evidence for reliability and validity of self-report physical activity (PA) questionnaires in the general adult population, it is unclear whether we can assume similar measurement properties in people with chronic low back pain (LBP). To determine the test-retest reliability of the International Physical Activity Questionnaire (IPAQ) long-version and the Baecke Physical Activity Questionnaire (BPAQ) and their criterion-related validity against data derived from accelerometers in patients with chronic LBP. Cross-sectional study. Patients with non-specific chronic LBP were recruited. Each participant attended the clinic twice (one week interval) and completed self-report PA. Accelerometer measures >7 days included time spent in moderate-and-vigorous physical activity, steps/day, counts/minute, and vector magnitude counts/minute. Intraclass Correlation Coefficients (ICC) and Bland and Altman method were used to determine reliability and spearman rho correlation were used for criterion-related validity. A total of 73 patients were included in our analyses. The reliability analyses revealed that the BPAQ and its subscales have moderate to excellent reliability (ICC 2,1 : 0.61 to 0.81), whereas IPAQ and most IPAQ domains (except walking) showed poor reliability (ICC 2,1 : 0.20 to 0.40). The Bland and Altman method revealed larger discrepancies for the IPAQ. For the validity analysis, questionnaire and accelerometer measures showed at best fair correlation (rho < 0.37). Although the BPAQ showed better reliability than the IPAQ long-version, both questionnaires did not demonstrate acceptable validity against accelerometer data. These findings suggest that questionnaire and accelerometer PA measures should not be used interchangeably in this population. Copyright © 2016 Elsevier Ltd. All rights reserved.

Parenting styles, parenting practices, and physical activity in 10- to 11-year olds.

PubMed

Jago, Russell; Davison, Kirsten K; Brockman, Rowan; Page, Angie S; Thompson, Janice L; Fox, Kenneth R

2011-01-01

The objective of this study was to determine whether parenting styles and practices are associated with children's physical activity. Cross-sectional survey of seven hundred ninety-two 10- to 11-year-old UK children in Bristol (UK) in 2008-2009 was conducted. Accelerometer-assessed physical activity and mean minutes of moderate-to-vigorous physical activity (mean MVPA) and mean counts per minute (mean CPM) were obtained. Maternal parenting style and physical activity parenting practices were self-reported. In regression analyses, permissive parenting was associated with higher mean MVPA among girls (+6.0 min/day, p<0.001) and greater mean CPM (+98.9 accelerometer counts/min, p=0.014) among boys when compared to children with authoritative parents. Maternal logistic support was associated with mean CPM for girls (+36.2 counts/min, p=0.001), while paternal logistic support was associated with boys' mean MVPA (+4.0 min/day, p=0.049) and mean CPM (+55.7 counts/min, p=0.014). Maternal permissive parenting was associated with higher levels of physical activity than authoritative parenting, but associations differed by child gender and type of physical activity. Maternal logistic support was associated with girls' physical activity, while paternal logistic support was associated with boys' physical activity. Health professionals could encourage parents to increase logistic support for their children's physical activity. Copyright © 2010 Elsevier Inc. All rights reserved.

Reliability and Validity of Objective Measures of Physical Activity in Youth With Cerebral Palsy Who Are Ambulatory.

PubMed

O'Neil, Margaret E; Fragala-Pinkham, Maria; Lennon, Nancy; George, Ameeka; Forman, Jeffrey; Trost, Stewart G

2016-01-01

Physical therapy for youth with cerebral palsy (CP) who are ambulatory includes interventions to increase functional mobility and participation in physical activity (PA). Thus, reliable and valid measures are needed to document PA in youth with CP. The purpose of this study was to evaluate the inter-instrument reliability and concurrent validity of 3 accelerometer-based motion sensors with indirect calorimetry as the criterion for measuring PA intensity in youth with CP. Fifty-seven youth with CP (mean age=12.5 years, SD=3.3; 51% female; 49.1% with spastic hemiplegia) participated. Inclusion criteria were: aged 6 to 20 years, ambulatory, Gross Motor Function Classification System (GMFCS) levels I through III, able to follow directions, and able to complete the full PA protocol. Protocol activities included standardized activity trials with increasing PA intensity (resting, writing, household chores, active video games, and walking at 3 self-selected speeds), as measured by weight-relative oxygen uptake (in mL/kg/min). During each trial, participants wore bilateral accelerometers on the upper arms, waist/hip, and ankle and a portable indirect calorimeter. Intraclass coefficient correlations (ICCs) were calculated to evaluate inter-instrument reliability (left-to-right accelerometer placement). Spearman correlations were used to examine concurrent validity between accelerometer output (activity and step counts) and indirect calorimetry. Friedman analyses of variance with post hoc pair-wise analyses were conducted to examine the validity of accelerometers to discriminate PA intensity across activity trials. All accelerometers exhibited excellent inter-instrument reliability (ICC=.94-.99) and good concurrent validity (rho=.70-.85). All accelerometers discriminated PA intensity across most activity trials. This PA protocol consisted of controlled activity trials. Accelerometers provide valid and reliable measures of PA intensity among youth with CP. © 2016 American Physical Therapy Association.

Perceived office environments and occupational physical activity in office-based workers.

PubMed

Sawyer, A; Smith, L; Ucci, M; Jones, R; Marmot, A; Fisher, A

2017-06-01

Individuals in office-based occupations have low levels of physical activity but there is little research into the socio-ecological correlates of workplace activity. To identify factors contributing to office-based workers' perceptions of the office environment and explore cross-sectional relationships between these factors and occupational physical activity. Participants in the Active Buildings study reported perceptions of their office environment using the Movement at Work Survey. A principal component analysis (PCA) was conducted on survey items. A sub-sample wore the ActivPAL3TM accelerometer for ≥3 workdays to measure occupational step count, standing, sitting and sit-to-stand transitions. Linear regression analyses assessed relationships between environmental perceptions and activity. There were 433 participants, with accelerometer data available for 115 participants across 11 organ izations. The PCA revealed four factors: (i) perceived distance to office destinations, (ii) perceived office aesthetics and comfort, (iii) perceived office social environment and (iv) perceived management discouragement of unscheduled breaks. Younger participants perceived office destinations as being closer to their desk. Younger and female participants perceived more positive office social environments; there were no other socio-demographic differences. Within the sub-sample with accelerometer data, perceived discouragement of breaks by management was related to occupational step count/hour (B = -64.5; 95% CI -109.7 to -19.2). No other environmental perceptions were related to activity or sitting. Perceived managerial discouragement of breaks could be related to meaningful decreases in occupational step count. Future research should aim to elucidate the role of the workplace socio-cultural environment in occupational walking, with a focus on the role of management. © The Author 2017. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Parenting styles, parenting practices, and physical activity in 10- to 11-year olds

PubMed Central

Jago, Russell; Davison, Kirsten K.; Brockman, Rowan; Page, Angie S.; Thompson, Janice L.; Fox, Kenneth R.

2011-01-01

Objective The objective of this study was to determine whether parenting styles and practices are associated with children's physical activity. Methods Cross-sectional survey of seven hundred ninety-two 10- to 11-year-old UK children in Bristol (UK) in 2008–2009 was conducted. Accelerometer-assessed physical activity and mean minutes of moderate-to-vigorous physical activity (mean MVPA) and mean counts per minute (mean CPM) were obtained. Maternal parenting style and physical activity parenting practices were self-reported. Results In regression analyses, permissive parenting was associated with higher mean MVPA among girls (+ 6.0 min/day, p < 0.001) and greater mean CPM (+ 98.9 accelerometer counts/min, p = 0.014) among boys when compared to children with authoritative parents. Maternal logistic support was associated with mean CPM for girls (+ 36.2 counts/min, p = 0.001), while paternal logistic support was associated with boys' mean MVPA (+ 4.0 min/day, p = 0.049) and mean CPM (+ 55.7 counts/min, p = 0.014). Conclusions Maternal permissive parenting was associated with higher levels of physical activity than authoritative parenting, but associations differed by child gender and type of physical activity. Maternal logistic support was associated with girls' physical activity, while paternal logistic support was associated with boys' physical activity. Health professionals could encourage parents to increase logistic support for their children's physical activity. PMID:21070805

Blood pressure circadian pattern and physical exercise assessment by accelerometer and 7-day physical activity recall scale.

PubMed

García-Ortiz, Luis; Recio-Rodríguez, José I; Puig-Ribera, Anna; Lema-Bartolomé, Jorge; Ibáñez-Jalón, Elisa; González-Viejo, Natividad; Guenaga-Saenz, Nahia; Agudo-Conde, Cristina; Patino-Alonso, Maria C; Gomez-Marcos, Manuel A

2014-05-01

The relationship between regular physical activity, measured objectively and by self-report, and the circadian pattern of 24-hour ambulatory arterial blood pressure (BP) has not been clarified. We performed a cross-sectional study in a cohort of healthy patients. We included 1,345 patients from the EVIDENT study (mean age 55 ± 14 years; 59.3% women). Physical activity was assessed using the 7-day physical activity recall (PAR) questionnaire (metabolic equivalents (MET)/hour/week) and the Actigraph GT3X accelerometer (counts/minute) for 7 days; ambulatory arterial BP was measured with a radial tonometer (B-pro device). The dipper-pattern patients showed a higher level of activity than nondipper patients, as assessed by accelerometer and 7-day PAR. Physical activity measures correlated positively with the percent drop in systolic BP (SBP; ρ = 0.19 to 0.11; P < 0.01) and negatively with the systolic and diastolic sleep to wake ratios (ρ = -0.10 to -0.18; P < 0.01) and heart rate (ρ = -0.13; P < 0.01). In logistic regression, considering the circadian pattern (1, dipper; 0, nondipper) as the dependent variable, the odds ratio of the third tertile of counts/minute was 1.79 (95% confidence interval [CI], 1.35-2.38; P < 0.01) and of MET/hour/week was 1.33 (95% CI, 1.01-1.75; P = 0.04) after adjustment for confounding variables. Physical activity, as evaluated by both the accelerometer and the 7-day PAR, was associated with a more marked nocturnal BP dip and, accordingly, a lower SBP and diastolic BP sleep to wake ratio. Clinical Trials.gov Identifier: NCT01083082.

Accelerometer output and its association with energy expenditure during manual wheelchair propulsion.

PubMed

Learmonth, Y C; Kinnett-Hopkins, D; Rice, I M; Dysterheft, J L; Motl, R W

2016-02-01

This is an experimental design. This study examined the association between rates of energy expenditure (that is, oxygen consumption (VO2)) and accelerometer counts (that is, vector magnitude (VM)) across a range of speeds during manual wheelchair propulsion on a motor-driven treadmill. Such an association allows for the generation of cutoff points for quantifying the time spent in moderate-to-vigorous physical activity (MVPA) during manual wheelchair propulsion. The study was conducted in the University Laboratory. Twenty-four manual wheelchair users completed a 6-min period of seated rest and three 6-min periods of manual wheelchair propulsion on a motor-driven wheelchair treadmill. The 6-min periods of wheelchair propulsion corresponded with three treadmill speeds (1.5, 3.0 and 4.5 mph) that elicited a range of physical activity intensities. Participants wore a portable metabolic unit and accelerometers on both wrists. Primary outcome measures included steady-state VO2 and VM, and the strength of association between VO2 and VM was based on the multiple correlation and squared multiple correlation coefficients from linear regression analyses. Strong linear associations were established between VO2 and VM for the left (R=0.93±0.44; R2=0.87±0.19), right (R=0.95±0.37; R2=0.90±0.14) and combined (R=0.94±0.38; R2=0.88±0.15) accelerometers. The linear relationship between VO2 and VM for the left, right and combined wrists yielded cutoff points for MVPA of 3659 ±1302, 3630±1403 and 3644±1339 counts min(-1), respectively. We provide cutoff points based on the linear association between energy expenditure and accelerometer counts for estimating time spent in MVPA during manual wheelchair propulsion using wrist-worn accelerometry. The similarity across wrist location permits flexibility in selecting a location for wrist accelerometry placement.

Seasonal Variation in Objectively Assessed Physical Activity among Young Norwegian Talented Soccer Players: A Description of Daily Physical Activity Level

PubMed Central

Sæther, Stig A.; Aspvik, Nils P.

2014-01-01

‘Practise makes perfect’ is a well-known expression in most sports, including top-level soccer. However, a high training and match load increases the risk for injury, overtraining and burnout. With the use of accelerometers and a self-report questionnaire, the aim of this study was to describe talented players’ physical activity (PA) level. Data were collected three times during the 2011 Norwegian Football season (March, June and October). The accelerometer output, counts·min–1 (counts per unit time registered), reports the daily PA-level for young talented soccer players. Results showed a stable PA-level across the season (March: 901.2 counts·min–1, June: 854.9 counts·min–1, October: 861.5 counts·min–1). Furthermore, comparison of five different training sessions across the season showed that the PA-level ranged from 2435.8 to 3745.4 counts·min–1. A one-way ANOVA showed no significant differences between the three measured weeks during the soccer season (p≤0.814). However, the training sessions in January had a significantly higher PA-level than those in June and October (p≤0.001). Based on these results, we discuss how potential implications of PA-level affect factors such as risk of injury, overtraining and burnout. We argue that player development must be seen as part of an overall picture in which club training and match load should be regarded as one of many variables influencing players’ PA-level. Key points It is well established that to achieve a high performance level in sport, one must implement a high training and match load in childhood and youth. With the use of accelerometers and a self-reported questionnaire, the aim of this study was to describe talented players’ total physical activity (PA) load. These results indicate that young talented soccer players must overcome large doses of PA on a weekly basis, exposing them to a high risk of injury, overtraining and burnout. PMID:25435792

Seasonal Variation in Objectively Assessed Physical Activity among Young Norwegian Talented Soccer Players: A Description of Daily Physical Activity Level.

PubMed

Sæther, Stig A; Aspvik, Nils P

2014-12-01

'Practise makes perfect' is a well-known expression in most sports, including top-level soccer. However, a high training and match load increases the risk for injury, overtraining and burnout. With the use of accelerometers and a self-report questionnaire, the aim of this study was to describe talented players' physical activity (PA) level. Data were collected three times during the 2011 Norwegian Football season (March, June and October). The accelerometer output, counts·min(-1) (counts per unit time registered), reports the daily PA-level for young talented soccer players. Results showed a stable PA-level across the season (March: 901.2 counts·min(-1), June: 854.9 counts·min(-1), October: 861.5 counts·min(-1)). Furthermore, comparison of five different training sessions across the season showed that the PA-level ranged from 2435.8 to 3745.4 counts·min(-1). A one-way ANOVA showed no significant differences between the three measured weeks during the soccer season (p≤0.814). However, the training sessions in January had a significantly higher PA-level than those in June and October (p≤0.001). Based on these results, we discuss how potential implications of PA-level affect factors such as risk of injury, overtraining and burnout. We argue that player development must be seen as part of an overall picture in which club training and match load should be regarded as one of many variables influencing players' PA-level. Key pointsIt is well established that to achieve a high performance level in sport, one must implement a high training and match load in childhood and youth.With the use of accelerometers and a self-reported questionnaire, the aim of this study was to describe talented players' total physical activity (PA) load.These results indicate that young talented soccer players must overcome large doses of PA on a weekly basis, exposing them to a high risk of injury, overtraining and burnout.

No Evidence of Reciprocal Associations between Daily Sleep and Physical Activity.

PubMed

Mitchell, Jonathan A; Godbole, Suneeta; Moran, Kevin; Murray, Kate; James, Peter; Laden, Francine; Hipp, J Aaron; Kerr, Jacqueline; Glanz, Karen

2016-10-01

This study aimed to determine whether physical activity patterns are associated with sleep later at night and if nighttime sleep is associated with physical activity patterns the next day among adult women. Women (N = 353) living throughout the United States wore a wrist and a hip accelerometer for 7 d. Total sleep time (TST, hours per night) and sleep efficiency (SE, %) were estimated from the wrist accelerometer, and moderate to vigorous physical activity (MVPA, >1040 counts per minute, h·d) and sedentary behavior (SB, <100 counts per minute, h·d) were estimated from the hip accelerometer. Mixed-effects models adjusted for age, race, body mass index, education, employment, marital status, health status, and hip accelerometer wear time were used to analyze the data. Follow-up analyses using quantile regression were used to investigate associations among women with below average TST and MVPA and above average SB. The average age of our sample was 55.5 yr (SD = 10.2 yr). The majority of participants were White (79%) and married (72%), and half were employed full time (49%). The participants spent on average 8.9 and 1.1 h·d in SB and MVPA, respectively, and 6.8 h per night asleep. No associations were observed between MVPA and SB with nighttime TST or SE. There were no associations between nighttime TST and SE with MVPA or SB the next day. The findings were the same in the quantile regression analyses. In free-living adult women, accelerometry-estimated nighttime sleep and physical activity patterns were not associated with one another. On the basis of our observational study involving a sample of adult women, higher physical activity will not necessarily improve sleep at night on a day-to-day basis (and vice versa).

New Insights into Activity Patterns in Children, Found Using Functional Data Analyses.

PubMed

Goldsmith, Jeff; Liu, Xinyue; Jacobson, Judith S; Rundle, Andrew

2016-09-01

Continuous monitoring of activity using accelerometers and other wearable devices provides objective, unbiased measurement of physical activity in minute-by-minute or finer resolutions. Accelerometers have already been widely deployed in studies of healthy aging, recovery of function after heart surgery, and other outcomes. Although common analyses of accelerometer data focus on single summary variables, such as the total or average activity count, there is growing interest in the determinants of diurnal profiles of activity. We use tools from functional data analysis (FDA), an area with an established statistical literature, to treat complete 24-h diurnal profiles as outcomes in a regression model. We illustrate the use of such models by analyzing data collected in New York City from 420 children participating in a Head Start program. Covariates of interest include season, sex, body mass index z-score, presence of an asthma diagnosis, and mother's birthplace. The FDA model finds several meaningful associations between several covariates and diurnal profiles of activity. In some cases, including shifted activity patterns for children of foreign-born mothers and time-specific effects of asthma on activity, these associations exist for covariates that are not associated with average activity count. FDA provides a useful statistical framework for settings in which the effect of covariates on the timing of activity is of interest. The use of similar models in other applications should be considered, and we make code public to facilitate this process.

Influence of speed and step frequency during walking and running on motion sensor output.

PubMed

Rowlands, Ann V; Stone, Michelle R; Eston, Roger G

2007-04-01

Studies have reported strong linear relationships between accelerometer output and walking/running speeds up to 10 km x h(-1). However, ActiGraph uniaxial accelerometer counts plateau at higher speeds. The aim of this study was to determine the relationships of triaxial accelerometry, uniaxial accelerometry, and pedometry with speed and step frequency (SF) across a range of walking and running speeds. Nine male runners wore two ActiGraph uniaxial accelerometers, two RT3 triaxial accelerometers (all set at a 1-s epoch), and two Yamax pedometers. Each participant walked for 60 s at 4 and 6 km x h(-1), ran for 60 s at 10, 12, 14, 16, and 18 km x h(-1), and ran for 30 s at 20, 22, 24, and 26 km x h(-1). Step frequency was recorded by a visual count. ActiGraph counts peaked at 10 km x h(-10 (2.5-3.0 Hz SF) and declined thereafter (r=0.02, P>0.05). After correction for frequency-dependent filtering, output plateaued at 10 km x h(-1) but did not decline (r=0.77, P<0.05). Similarly, RT3 vertical counts plateaued at speeds > 10 km x h(-1) (r=0.86, P<0.01). RT3 vector magnitude and anteroposterior and mediolateral counts maintained a linear relationship with speed (r>0.96, P<0.001). Step frequency assessed by pedometry compared well with actual step frequency up to 20 km x h(-1) (approximately 3.5 Hz) but then underestimated actual steps (Yamax r=0.97; ActiGraph pedometer r=0.88, both P<0.001). Increasing underestimation of activity by the ActiGraph as speed increases is related to frequency-dependent filtering and assessment of acceleration in the vertical plane only. RT3 vector magnitude was strongly related to speed, reflecting the predominance of horizontal acceleration at higher speeds. These results indicate that high-intensity activity is underestimated by the ActiGraph, even after correction for frequency-dependent filtering, but not by the RT3. Pedometer output is highly correlated with step frequency.

Physical activity classification using the GENEA wrist-worn accelerometer.

PubMed

Zhang, Shaoyan; Rowlands, Alex V; Murray, Peter; Hurst, Tina L

2012-04-01

Most accelerometer-based activity monitors are worn on the waist or lower back for assessment of habitual physical activity. Output is in arbitrary counts that can be classified by activity intensity according to published thresholds. The purpose of this study was to develop methods to classify physical activities into walking, running, household, or sedentary activities based on raw acceleration data from the GENEA (Gravity Estimator of Normal Everyday Activity) and compare classification accuracy from a wrist-worn GENEA with a waist-worn GENEA. Sixty participants (age = 49.4 ± 6.5 yr, body mass index = 24.6 ± 3.4 kg·m⁻²) completed an ordered series of 10-12 semistructured activities in the laboratory and outdoor environment. Throughout, three GENEA accelerometers were worn: one at the waist, one on the left wrist, and one on the right wrist. Acceleration data were collected at 80 Hz. Features obtained from both fast Fourier transform and wavelet decomposition were extracted, and machine learning algorithms were used to classify four types of daily activities including sedentary, household, walking, and running activities. The computational results demonstrated that the algorithm we developed can accurately classify certain types of daily activities, with high overall classification accuracy for both waist-worn GENEA (0.99) and wrist-worn GENEA (right wrist = 0.97, left wrist = 0.96). We have successfully developed algorithms suitable for use with wrist-worn accelerometers for detecting certain types of physical activities; the performance is comparable to waist-worn accelerometers for assessment of physical activity.

The influence of a consumer-wearable activity tracker on sedentary time and prolonged sedentary bouts: secondary analysis of a randomized controlled trial.

PubMed

Sloan, Robert A; Kim, Youngdeok; Sahasranaman, Aarti; Müller-Riemenschneider, Falk; Biddle, Stuart J H; Finkelstein, Eric A

2018-03-22

A recent meta-analysis surmised pedometers were a useful panacea to independently reduce sedentary time (ST). To further test and expand on this deduction, we analyzed the ability of a consumer-wearable activity tracker to reduce ST and prolonged sedentary bouts (PSB). We originally conducted a 12-month randomized control trial where 800 employees from 13 organizations were assigned to control, activity tracker, or one of two activity tracker plus incentive groups designed to increase step count. The primary outcome was accelerometer measured moderate-to-vigorous physical activity. We conducted a secondary analysis on accelerometer measured daily ST and PSB bouts. A general linear mixed model was used to examine changes in ST and prolonged sedentary bouts, followed by between-group pairwise comparisons. Regression analyses were conducted to examine the association of changes in step counts with ST and PSB. The changes in ST and PSB were not statistically significant and not different between the groups (P < 0.05). Increases in step counts were concomitantly associated with decreases in ST and PSB, regardless of intervention (P < 0.05). Caution should be taken when considering consumer-wearable activity trackers as a means to reduce sedentary behavior. Trial registration NCT01855776 Registered: August 8, 2012.

Validation of the human activity profile questionnaire as a measure of physical activity levels in older community-dwelling women.

PubMed

Bastone, Alessandra de Carvalho; Moreira, Bruno de Souza; Vieira, Renata Alvarenga; Kirkwood, Renata Noce; Dias, João Marcos Domingues; Dias, Rosângela Corrêa

2014-07-01

The purpose of this study was to assess the validity of the Human Activity Profile (HAP) by comparing scores with accelerometer data and by objectively testing its cutoff points. This study included 120 older women (age 60-90 years). Average daily time spent in sedentary, moderate, and hard activity; counts; number of steps; and energy expenditure were measured using an accelerometer. Spearman rank order correlations were used to evaluate the correlation between the HAP scores and accelerometer variables. Significant relationships were detected (rho = .47-.75, p < .001), indicating that the HAP estimates physical activity at a group level well; however, scatterplots showed individual errors. Receiver operating characteristic curves were constructed to determine HAP cutoff points on the basis of physical activity level recommendations, and the cutoff points found were similar to the original HAP cutoff points. The HAP is a useful indicator of physical activity levels in older women.

Classification of occupational activity categories using accelerometry: NHANES 2003-2004.

PubMed

Steeves, Jeremy A; Tudor-Locke, Catrine; Murphy, Rachel A; King, George A; Fitzhugh, Eugene C; Harris, Tamara B

2015-06-30

An individual's occupational activity (OA) may contribute significantly to daily physical activity (PA) and sedentary behavior (SB). However, there is little consensus about which occupational categories involve high OA or low OA, and the majority of categories are unclassifiable with current methods. The purpose of this study was to present population estimates of accelerometer-derived PA and SB variables for adults (n = 1112, 20-60 years) working the 40 occupational categories collected during the 2003-2004 National Health and Nutrition Examination Survey (NHANES). ActiGraph accelerometer-derived total activity counts/day (TAC), activity counts/minute, and proportion of wear time spent in moderate-to-vigorous PA [MVPA], lifestyle, and light PA organized by occupational category were ranked in ascending order and SB was ranked in descending order. Summing the ranks of the six accelerometer-derived variables generated a summary score for each occupational category, which was re-ranked in ascending order. Higher rankings indicated higher levels of OA, lower rankings indicated lower levels of OA. Tertiles of the summary score were used to establish three mutually exclusive accelerometer-determined OA groupings: high OA, intermediate OA, and low OA. According to their summary score, 'farm and nursery workers' were classified as high OA and 'secretaries, stenographers, and typists' were classified as low OA. Consistent with previous research, some low OA occupational categories (e.g., 'engineers, architects, and scientists', 'technicians and related support occupations', 'management related occupations', 'executives, administrators, and managers', 'protective services', and 'writers, artists, entertainers, and athletes') associated with higher education and income had relatively greater amounts of MVPA compared to other low OA occupational categories, likely due to the greater percentage of men in those occupations and/or the influence of higher levels of leisure time PA. Men had more TAC, activity counts/minute and time in MVPA, but similar proportions of SB compared to women in all three OA groupings. Objectively measured PA allowed for a more precise estimate of the amount of PA and SB associated with different occupations and facilitated systematic classification of the 40 different occupational categories into three distinct OA groupings. This information provides new opportunities to explore the relationship between OA and health outcomes.

Associations between accelerometer-derived physical activity and regional adiposity in young men and women.

PubMed

Smith, H A; Storti, K L; Arena, V C; Kriska, A M; Gabriel, K K Pettee; Sutton-Tyrrell, K; Hames, K C; Conroy, M B

2013-06-01

Empirical evidence supports an inverse relationship between physical activity (PA) and adiposity, but studies using detailed measures of both are scarce. The relationship between regional adiposity and accelerometer-derived PA in men and women are described. Cross-sectional analysis included 253 participants from a weight loss study limited to ages 20-45 years and BMI 25-39.9 kg m(-2) . PA data were collected with accelerometers and expressed as total accelerometer counts and average amount of time per day accumulated in different intensity levels [sedentary, light-, and moderate-to-vigorous intensity PA (MVPA)]. Accumulation of time spent above 100 counts was expressed as total active time. Computed tomography (CT) was used to measure abdominal and adipose tissue (AT). Multivariate linear regression analyses were used to assess the relationship between regional adiposity (dependent variable) and the various PA levels (independent variable), and were executed separately for men and women, adjusting for wear time, age, race, education, and BMI. Among males, light activity was inversely associated with total AT (β = -0.19; P = 0.02) as well as visceral AT (VAT) (β = -0.30; P = 0.03). Among females sedentary time was positively associated with VAT (β = 0.11; P = 0.04) and total active time was inversely associated with VAT (β = -0.12; P = 0.04). Findings from this study suggest that PA intensity level may influence regional adiposity differently in men and women. Additional research is needed in larger samples to clarify the difference in these associations by sex, create recommendations for the frequency, duration and intensity of PA needed to target fat deposits, and determine if these recommendations should differ by sex. Copyright © 2013 The Obesity Society.

[Relationship between physical activity and hemodynamic parameters in adults].

PubMed

Gómez-Sánchez, L; García-Ortiz, L; Recio-Rodríguez, J I; Patino-Alonso, M C; Agudo-Conde, C; Gómez-Marcos, M A

2015-01-01

To analyze the relationship between physical activity, as assessed by accelerometer, with central and peripheral augmentation index and carotid intima media thickness (IMT) in adults. This study analyzed 263 subjects who were included in the EVIDENT study. Physical activity was assessed during 7 days using the ActigraphGT3X accelerometer (counts/min). Carotid ultrasound was used to measure carotid IMT. The Sphygmo Cor System was used to measure central and peripheral augmentation index (CAIx and PAIx). Mean age 55.85±12 years; 59.30% female; 26.7 body mass index and blood pressure 120/77mmHg. Mean physician activity counts/min was 244.37 and 2.63±10.26min/day of vigorous or very vigorous activity. Physical activity showed an inverse correlation with PAIx (r=-0.179; P<.01) and vigorous activity day time with IMT(r=-0.174; P<.01), CAIx (r=-0.217; P<.01) and PAIx (r=-0.324; P<.01). After adjusting for confounding factors in the multiple regression analysis, the inverse association of CAIx with counts/min and the time spent in vigorous/very vigorous activity was maintained. The results suggest that both physical activity and time spent in vigorous or vigorous activity are associated with the central augmentation index in adults. Copyright © 2015 SEHLELHA. Published by Elsevier Espana. All rights reserved.

The association between objectively measured physical activity and life-space mobility among older people.

PubMed

Tsai, L-T; Portegijs, E; Rantakokko, M; Viljanen, A; Saajanaho, M; Eronen, J; Rantanen, T

2015-08-01

The purpose of this cross-sectional study was to investigate the association between objectively measured physical activity and life-space mobility in community-dwelling older people. Life-space refers to the spatial area a person purposefully moves through in daily life (bedroom, home, yard, neighborhood, town, and beyond) and life-space mobility to the frequency of travel and the help needed when moving through different life-space areas. The study population comprised community-living 75- to 90-year-old people {n = 174; median age 79.7 [interquartile range (IQR) 7.1]}, participating in the accelerometer substudy of Life-Space Mobility in Old Age (LISPE) project. Step counts and activity time were measured by an accelerometer (Hookie "AM20 Activity Meter") for 7 days. Life-space mobility was assessed with Life-Space Assessment (LSA) questionnaire. Altogether, 16% had a life-space area restricted to the neighborhood when moving independently. Participants with a restricted life space were less physically active and about 70% of them had exceptionally low values in daily step counts (≤ 615 steps) and moderate activity time (≤ 6.8 min). Higher step counts and activity time correlated positively with life-space mobility. Prospective studies are needed to clarify the temporal order of low physical activity level and restriction in life-space mobility. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Repeat physical activity measurement by accelerometry among colorectal cancer patients--feasibility and minimal number of days of monitoring.

PubMed

Skender, Stephanie; Schrotz-King, Petra; Böhm, Jürgen; Abbenhardt, Clare; Gigic, Biljana; Chang-Claude, Jenny; Siegel, Erin M; Steindorf, Karen; Ulrich, Cornelia M

2015-06-06

Physical activity plays an important role in colorectal cancer and accelerometry is more frequently used to measure physical activity. The aim of this study was to evaluate feasibility of physical activity measurement by accelerometry in colorectal cancer patients under free-living conditions at 6, 12 and 24 months after surgery, to evaluate the appropriate wear time and to compare results to pedometry. Colorectal cancer patients (stage 0/I-IV) from the ColoCare study were asked to optionally wear an accelerometer and a pedometer for ten consecutive days 6, 12 and 24 months post-surgery. Participants completed a feedback questionnaire about the accelerometer measurement. The course of moderate-to-vigorous physical activity over the 10 days was investigated. Additionally, daily step counts from accelerometers and pedometers were compared. In total, there were 317 individual time points, at which 198 participants were asked to wear an accelerometer. Fifty-nine% initially agreed to participate and of these, 83% (n = 156) completed the assessment with at least 4 days of data. Twenty-one% more consents were obtained when participants were asked on a face-to-face basis compared to recruitment by telephone (P = 0.0002). There were no significant differences in time spent in moderate-to-vigorous physical activity between different wear-time lengths of accelerometry. Both Spearman and intraclass correlation coefficients showed strong correlations (0.92-0.99 and 0.84-0.99, respectively) of moderate-to-vigorous physical activity across 3, 4, 7 and 10 days measurement. Step counts measured by accelerometry and pedometry were strongly correlated (ρ = 0.91, P < 0.0001). This study suggest that accelerometry is a feasible method to assess physical activity in free-living colorectal cancer patients and that three valid days of physical activity measurement are sufficient for an accurate assessment.

Validity of Using Tri-Axial Accelerometers to Measure Human Movement – Part II: Step Counts at a Wide Range of Gait Velocities

PubMed Central

Fortune, Emma; Lugade, Vipul; Morrow, Melissa; Kaufman, Kenton

2014-01-01

A subject-specific step counting method with a high accuracy level at all walking speeds is needed to assess the functional level of impaired patients. The study aim was to validate step counts and cadence calculations from acceleration data by comparison to video data during dynamic activity. Custom-built activity monitors, each containing one tri-axial accelerometer, were placed on the ankles, thigh, and waist of 11 healthy adults. ICC values were greater than 0.98 for video inter-rater reliability of all step counts. The activity monitoring system (AMS) algorithm demonstrated a median (interquartile range; IQR) agreement of 92% (8%) with visual observations during walking/jogging trials at gait velocities ranging from 0.1 m/s to 4.8 m/s, while FitBits (ankle and waist), and a Nike Fuelband (wrist) demonstrated agreements of 92% (36%), 93% (22%), and 33% (35%), respectively. The algorithm results demonstrated high median (IQR) step detection sensitivity (95% (2%)), positive predictive value (PPV) (99% (1%)), and agreement (97% (3%)) during a laboratory-based simulated free-living protocol. The algorithm also showed high median (IQR) sensitivity, PPV, and agreement identifying walking steps (91% (5%), 98% (4%), and 96% (5%)), jogging steps (97% (6%), 100% (1%), and 95% (6%)), and less than 3% mean error in cadence calculations. PMID:24656871

Validity of using tri-axial accelerometers to measure human movement - Part II: Step counts at a wide range of gait velocities.

PubMed

Fortune, Emma; Lugade, Vipul; Morrow, Melissa; Kaufman, Kenton

2014-06-01

A subject-specific step counting method with a high accuracy level at all walking speeds is needed to assess the functional level of impaired patients. The study aim was to validate step counts and cadence calculations from acceleration data by comparison to video data during dynamic activity. Custom-built activity monitors, each containing one tri-axial accelerometer, were placed on the ankles, thigh, and waist of 11 healthy adults. ICC values were greater than 0.98 for video inter-rater reliability of all step counts. The activity monitoring system (AMS) algorithm demonstrated a median (interquartile range; IQR) agreement of 92% (8%) with visual observations during walking/jogging trials at gait velocities ranging from 0.1 to 4.8m/s, while FitBits (ankle and waist), and a Nike Fuelband (wrist) demonstrated agreements of 92% (36%), 93% (22%), and 33% (35%), respectively. The algorithm results demonstrated high median (IQR) step detection sensitivity (95% (2%)), positive predictive value (PPV) (99% (1%)), and agreement (97% (3%)) during a laboratory-based simulated free-living protocol. The algorithm also showed high median (IQR) sensitivity, PPV, and agreement identifying walking steps (91% (5%), 98% (4%), and 96% (5%)), jogging steps (97% (6%), 100% (1%), and 95% (6%)), and less than 3% mean error in cadence calculations. Copyright © 2014 IPEM. Published by Elsevier Ltd. All rights reserved.

Walking for Health in Pregnancy: Assessment by Indirect Calorimetry and Accelerometry

ERIC Educational Resources Information Center

DiNallo, Jennifer M.; Le Masurier, Guy C.; Williams, Nancy I.; Downs, Danielle Symons

2008-01-01

The purpose of this study was to examine RT3 accelerometer activity counts and activity energy expenditure of 36 pregnant women at 20 and 32 weeks' gestation during treadmill walking and free-living conditions. During treadmill walking, oxygen consumption was collected, and activity energy expenditure was estimated for a 30-min walk at a…

Associations of Physical Activity, Sports Participation and Active Commuting on Mathematic Performance and Inhibitory Control in Adolescents.

PubMed

Domazet, Sidsel L; Tarp, Jakob; Huang, Tao; Gejl, Anne Kær; Andersen, Lars Bo; Froberg, Karsten; Bugge, Anna

2016-01-01

To examine objectively measured physical activity level, organized sports participation and active commuting to school in relation to mathematic performance and inhibitory control in adolescents. The design was cross-sectional. A convenient sample of 869 sixth and seventh grade students (12-14 years) was invited to participate in the study. A total of 568 students fulfilled the inclusion criteria and comprised the final sample for this study. Mathematic performance was assessed by a customized test and inhibitory control was assessed by a modified Eriksen flanker task. Physical activity was assessed with GT3X and GT3X+ accelerometers presented in sex-specific quartiles of mean counts per minute and mean minutes per day in moderate-to-vigorous physical activity. Active commuting and sports participation was self-reported. Mixed model regression was applied. Total physical activity level was stratified by bicycling status in order to bypass measurement error subject to the accelerometer. Non-cyclists in the 2nd quartile of counts per minute displayed a higher mathematic score, so did cyclists in the 2nd and 3rd quartile of moderate-to-vigorous physical activity relative to the least active quartile. Non-cyclists in the 3rd quartile of counts per minute had an improved reaction time and cyclists in the 2nd quartile of counts per minute and moderate-to-vigorous physical activity displayed an improved accuracy, whereas non-cyclists in the 2nd quartile of counts per minute showed an inferior accuracy relative to the least active quartile. Bicycling to school and organized sports participation were positively associated with mathematic performance. Sports participation and bicycling were positively associated with mathematic performance. Results regarding objectively measured physical activity were mixed. Although, no linear nor dose-response relationship was observed there was no indication of a higher activity level impairing the scholastic or cognitive performance.

Associations of Physical Activity, Sports Participation and Active Commuting on Mathematic Performance and Inhibitory Control in Adolescents

PubMed Central

Huang, Tao; Gejl, Anne Kær; Froberg, Karsten

2016-01-01

Objectives To examine objectively measured physical activity level, organized sports participation and active commuting to school in relation to mathematic performance and inhibitory control in adolescents. Methods The design was cross-sectional. A convenient sample of 869 sixth and seventh grade students (12–14 years) was invited to participate in the study. A total of 568 students fulfilled the inclusion criteria and comprised the final sample for this study. Mathematic performance was assessed by a customized test and inhibitory control was assessed by a modified Eriksen flanker task. Physical activity was assessed with GT3X and GT3X+ accelerometers presented in sex-specific quartiles of mean counts per minute and mean minutes per day in moderate-to-vigorous physical activity. Active commuting and sports participation was self-reported. Mixed model regression was applied. Total physical activity level was stratified by bicycling status in order to bypass measurement error subject to the accelerometer. Results Non-cyclists in the 2nd quartile of counts per minute displayed a higher mathematic score, so did cyclists in the 2nd and 3rd quartile of moderate-to-vigorous physical activity relative to the least active quartile. Non-cyclists in the 3rd quartile of counts per minute had an improved reaction time and cyclists in the 2nd quartile of counts per minute and moderate-to-vigorous physical activity displayed an improved accuracy, whereas non-cyclists in the 2nd quartile of counts per minute showed an inferior accuracy relative to the least active quartile. Bicycling to school and organized sports participation were positively associated with mathematic performance. Conclusions Sports participation and bicycling were positively associated with mathematic performance. Results regarding objectively measured physical activity were mixed. Although, no linear nor dose-response relationship was observed there was no indication of a higher activity level impairing the scholastic or cognitive performance. PMID:26727211

Activity Monitors Step Count Accuracy in Community-Dwelling Older Adults.

PubMed

Johnson, Marquell

2015-01-01

Objective: To examine the step count accuracy of activity monitors in community-dwelling older adults. Method : Twenty-nine participants aged 67.70 ± 6.07 participated. Three pedometers and the Actical accelerometer step count functions were compared with actual steps taken during a 200-m walk around an indoor track and during treadmill walking at three different speeds. Results : There was no statistical difference between activity monitors step counts and actual steps during self-selected pace walking. During treadmill walking at 0.67 m∙s -1 , all activity monitors step counts were significantly different from actual steps. During treadmill walking at 0.894m∙s -1 , the Omron HJ-112 pedometer step counts were not significantly different from actual steps. During treadmill walking at 1.12 m∙s -1 , the Yamax SW-200 pedometer steps were significantly different from actual steps. Discussion : Activity monitor selection should be deliberate when examining the walking behaviors of community-dwelling older adults, especially for those who walk at a slower pace.

Activity Monitors Step Count Accuracy in Community-Dwelling Older Adults

PubMed Central

2015-01-01

Objective: To examine the step count accuracy of activity monitors in community-dwelling older adults. Method: Twenty-nine participants aged 67.70 ± 6.07 participated. Three pedometers and the Actical accelerometer step count functions were compared with actual steps taken during a 200-m walk around an indoor track and during treadmill walking at three different speeds. Results: There was no statistical difference between activity monitors step counts and actual steps during self-selected pace walking. During treadmill walking at 0.67 m∙s−1, all activity monitors step counts were significantly different from actual steps. During treadmill walking at 0.894m∙s−1, the Omron HJ-112 pedometer step counts were not significantly different from actual steps. During treadmill walking at 1.12 m∙s−1, the Yamax SW-200 pedometer steps were significantly different from actual steps. Discussion: Activity monitor selection should be deliberate when examining the walking behaviors of community-dwelling older adults, especially for those who walk at a slower pace. PMID:28138464

Self-Reported Versus Accelerometer-Measured Physical Activity and Biomarkers Among NHANES Youth.

PubMed

Belcher, Britni R; Moser, Richard P; Dodd, Kevin W; Atienza, Audie A; Ballard-Barbash, Rachel; Berrigan, David

2015-05-01

Discrepancies in self-report and accelerometer-measured moderate-to-vigorous physical activity (MVPA) may influence relationships with obesity-related biomarkers in youth. Data came from 2003-2006 National Health and Nutrition Examination Surveys (NHANES) for 2174 youth ages 12 to 19. Biomarkers were: body mass index (BMI, kg/m2), BMI percentile, height and waist circumference (WC, cm), triceps and subscapular skinfolds (mm), systolic & diastolic blood pressure (BP, mmHg), high-density lipoprotein (HDL, mg/dL), total cholesterol (mg/dL), triglycerides (mg/dL), insulin (μU/ml), C-reactive protein (mg/dL), and glycohemoglobin (%). In separate sex-stratified models, each biomarker was regressed on accelerometer variables [mean MVPA (min/day), nonsedentary counts, and MVPA bouts (mean min/day)] and self-reported MVPA. Covariates were age, race/ethnicity, SES, physical limitations, and asthma. In boys, correlations between self-report and accelerometer MVPA were stronger (boys: r = 0.14-0.21; girls: r = 0.07-0.11; P < .010) and there were significant associations with BMI, WC, triceps skinfold, and SBP and accelerometer MVPA (P < .01). In girls, there were no significant associations between biomarkers and any measures of physical activity. Physical activity measures should be selected based on the outcome of interest and study population; however, associations between PA and these biomarkers appear to be weak regardless of the measure used.

Detecting free-living steps and walking bouts: validating an algorithm for macro gait analysis.

PubMed

Hickey, Aodhán; Del Din, Silvia; Rochester, Lynn; Godfrey, Alan

2017-01-01

Research suggests wearables and not instrumented walkways are better suited to quantify gait outcomes in clinic and free-living environments, providing a more comprehensive overview of walking due to continuous monitoring. Numerous validation studies in controlled settings exist, but few have examined the validity of wearables and associated algorithms for identifying and quantifying step counts and walking bouts in uncontrolled (free-living) environments. Studies which have examined free-living step and bout count validity found limited agreement due to variations in walking speed, changing terrain or task. Here we present a gait segmentation algorithm to define free-living step count and walking bouts from an open-source, high-resolution, accelerometer-based wearable (AX3, Axivity). Ten healthy participants (20-33 years) wore two portable gait measurement systems; a wearable accelerometer on the lower-back and a wearable body-mounted camera (GoPro HERO) on the chest, for 1 h on two separate occasions (24 h apart) during free-living activities. Step count and walking bouts were derived for both measurement systems and compared. For all participants during a total of almost 20 h of uncontrolled and unscripted free-living activity data, excellent relative (rho  ⩾  0.941) and absolute (ICC (2,1)   ⩾  0.975) agreement with no presence of bias were identified for step count compared to the camera (gold standard reference). Walking bout identification showed excellent relative (rho  ⩾  0.909) and absolute agreement (ICC (2,1)   ⩾  0.941) but demonstrated significant bias. The algorithm employed for identifying and quantifying steps and bouts from a single wearable accelerometer worn on the lower-back has been demonstrated to be valid and could be used for pragmatic gait analysis in prolonged uncontrolled free-living environments.

Measuring moderate-intensity walking in older adults using the ActiGraph accelerometer.

PubMed

Barnett, Anthony; van den Hoek, Daniel; Barnett, David; Cerin, Ester

2016-12-08

Accelerometry is the method of choice for objectively assessing physical activity in older adults. Many studies have used an accelerometer count cut point corresponding to 3 metabolic equivalents (METs) derived in young adults during treadmill walking and running with a resting metabolic rate (RMR) assumed at 3.5 mL · kg -1  · min -1 (corresponding to 1 MET). RMR is lower in older adults; therefore, their 3 MET level occurs at a lower absolute energy expenditure making the cut point derived from young adults inappropriate for this population. The few studies determining older adult specific moderate-to-vigorous intensity physical activity (MVPA) cut points had methodological limitations, such as not measuring RMR and using treadmill walking. This study determined a MVPA hip-worn accelerometer cut point for older adults using measured RMR and overground walking. Following determination of RMR, 45 older adults (mean age 70.2 ± 7 years, range 60-87.6 years) undertook an outdoor, overground walking protocol with accelerometer count and energy expenditure determined at five walking speeds. Mean RMR was 2.8 ± 0.6 mL · kg -1  · min -1 . The MVPA cut points (95% CI) determined using linear mixed models were: vertical axis 1013 (734, 1292) counts · min -1 ; vector magnitude 1924 (1657, 2192) counts · min -1 ; and walking speed 2.5 (2.2, 2.8) km · hr -1 . High levels of inter-individual variability in cut points were found. These MVPA accelerometer and speed cut points for walking, the most popular physical activity in older adults, were lower than those for younger adults. Using cut points determined in younger adults for older adult population studies is likely to underestimate time spent engaged in MVPA. In addition, prescription of walking speed based on the adult cut point is likely to result in older adults working at a higher intensity than intended.

Factors associated with change in objectively measured physical activity in older people - data from the physical activity cohort Scotland study.

PubMed

Clarke, Clare L; Sniehotta, Falko F; Vadiveloo, Thenmalar; Argo, Ishbel S; Donnan, Peter T; McMurdo, Marion E T; Witham, Miles D

2017-08-14

Cross-sectional relationships between physical activity and health have been explored extensively, but less is known about how physical activity changes with time in older people. The aim of this study was to assess baseline predictors of how objectively measured physical activity changes with time in older people. Longitudinal cohort study using data from the Physical Activity Cohort Scotland. A sample of community-dwelling older people aged 65 and over were recruited in 2009-2011, then followed up 2-3 years later. Physical activity was measured using Stayhealthy RT3 accelerometers over 7 days. Other data collected included baseline comorbidity, health-related quality of life (SF-36), extended Theory of Planned Behaviour Questionnaire and Social Capital Module of the General Household Survey. Associations between follow-up accelerometer counts and baseline predictors were analysed using a series of linear regression models, adjusting for baseline activity levels and follow-up time. Follow up data were available for 339 of the original 584 participants. The mean age was 77 years, 185 (55%) were female and mean follow up time was 26 months. Mean activity counts fell by between 2% per year (age < =80, deprivation decile 5-10) and 12% per year (age > 80, deprivation decile 5-10) from baseline values. In univariate analysis age, sex, deprivation decile, most SF-36 domains, most measures of social connectedness, most measures from the extended Theory of Planned Behaviour, hypertension, diabetes mellitus, chronic pain and depression score were significantly associated with adjusted activity counts at follow-up. In multivariate regression age, satisfactory friend network, SF-36 physical function score, and the presence of diabetes mellitus were independent predictors of activity counts at follow up after adjustment for baseline count and duration of follow up. Health status and social connectedness, but not extended Theory of Planned Behaviour measures, independently predicted changes in physical activity in community dwelling older people.

Prospective associations between physical activity and obesity among adolescent girls: racial differences and implications for prevention.

PubMed

White, James; Jago, Russell

2012-06-01

To test for differences in prospective associations between physical activity and obesity among black and white adolescent girls. Prospective cohort study using data from the National Heart, Lung, and Blood Institute Growth and Health Study. SETTING Multicenter study at the University of California (Berkeley), Children's Medical Center at the University of Cincinnati (Cincinnati, Ohio), and Westat, Inc, and Group Health Association (Rockville, Maryland). A total of 1148 adolescent girls (538 black and 610 white) who provided valid data on levels of physical activity and obesity at ages 12 and 14 years. Physical activity, assessed as accelerometer counts per day. Three measurements of obesity were obtained using the Centers for Disease Control and Prevention definition of obesity (at or above the age-specific 95th percentile of body mass index), the International Obesity Task Force reference body mass index cut points for obesity in children, and the sums of skinfold thickness (with the cohort ≥90th percentile as indicative of obesity). We found a strong negative dose-response association between quartiles of accelerometer counts per day at age 12 years and obesity at age 14 years (using all 3 measurements of obesity) in white but not black girls (P < .001 for body mass index interaction and P = .06 for sums of skinfold thickness interaction). The odds ratios for obesity (using the cohort ≥90th percentile for sums of skinfold thickness) in adjusted models between the top and the bottom quartiles of accelerometer counts per day were 0.15 (95% CI, 0.04-0.63; P = .03 for trend) in white girls and 0.85 (95% CI, 0.32-2.26; P = .93 for trend) in black girls. Higher levels of physical activity are prospectively associated with lower levels of obesity in white adolescent girls but not in black adolescent girls. Obesity prevention interventions may need to be adapted to account for the finding that black girls are less sensitive to the effects of physical activity.

Validity of the global physical activity questionnaire (GPAQ) in Bangladesh.

PubMed

Mumu, Shirin Jahan; Ali, Liaquat; Barnett, Anthony; Merom, Dafna

2017-08-10

Feasible and cost-effective as well as population specific instruments for monitoring physical activity (PA) levels are needed for the management and prevention of non-communicable diseases. The WHO-endorsed Global Physical Activity Questionnaire (GPAQ) has been widely used in developing countries, but the evidence base for its validity, particularly for rural populations, is still limited. The aim of the study was to validate GPAQ among rural and urban residents in Bangladesh. A total of 162 healthy participants of both genders aged 18-60 years were recruited from Satia village (n = 97) and Dhaka City (n = 65). Participants were invited to take part in the study and were asked to wear an accelerometer (GT3X) for 7 days, after which they were invited to answer the GPAQ in a face to face interview. Valid accelerometer data (i.e., ≥10 h of wear times over ≥3 days) were received from 155 participants (rural = 94, urban = 61). The mean age was 35 (SD = ±9) years, 55% were females and 19% of the participants had no schooling, which was higher in the rural area (21% vs 17%). The mean ± SD steps/day was 9998 ± 3936 (8658 ± 2788 and 12,063 ± 4534 for rural and urban respectively, p = 0.0001) and the mean ± SD daily moderate-to-vigorous physical activity (MVPA) was 58 ± 30 min (51 ± 26 for rural and 69 ± 34 for the urban, p = 0.001) for accelerometer. In case of GPAQ, rural residents reported significantly higher moderate work related PA (MET-minutes/week: 600 vs. 360 p = 0.02). Spearman correlation coefficients between GPAQ total MVPA MET-min/day and accelerometer MVPA min/day, counts per minute (CPM) or steps counts/day were acceptable for urban residents (rho: 0.46, 0.55 and 0.63, respectively; p < 0.01) but poor for rural residents. The overall correlation between the GPAQ and accelerometer for sitting was low (rho: 0.23; p < 0.001). GPAQ-Accelerometer correlation for MVPA was higher for females (rho: 0.42), ≤35 age group (rho: 0.31) and those with higher education attainment (rho: 0.48). The Bland-Altman plots illustrated bias towards over estimation of GPAQ MVPA with increased activity levels for urban and rural residents. GPAQ is an acceptable measure for physical activity surveillance in Bangladesh particularly for urban residents, women and people with high education. Given waist worn accelerometers do not capture the typical PA in rural context, further study using a physical activity diary and a combination of multiple sensors (e.g., wrist, ankle and waist worn accelerometers) to capture all movement is warranted among rural population with purposive sampling of all education levels.

Establishing school day pedometer step count cut-points using ROC curves in low-income children.

PubMed

Burns, Ryan D; Brusseau, Timothy A; Fu, You; Hannon, James C

2016-05-01

Previous research has not established pedometer step count cut-points that discriminate children that meet school day physical activity recommendations using a tri-axial ActiGraph accelerometer criterion. The purpose of this study was to determine step count cut-points that associate with 30min of school day moderate-to-vigorous physical activity (MVPA) in school-aged children. Participants included 1053 school-aged children (mean age=8.4±1.8years) recruited from three low-income schools from the state of Utah in the U.S. Physical activity was assessed using Yamax DigiWalker CW600 pedometers and ActiGraph wGT3X-BT triaxial accelerometers that were concurrently worn during school hours. Data were collected at each school during the 2014-2015 school year. Receiver operating characteristic (ROC) curves were used to determine pedometer step count cut-points that associated with at least 30min of MVPA during school hours. Cut-points were determined using the maximum Youden's J statistic (J max). For the total sample, the area-under-the-curve (AUC) was 0.77 (p<0.001) with a pedometer cut-point of 5505 steps (J max=0.46, Sensitivity=63%, Specificity=84%; Accuracy=76%). Step counts showed greater diagnostic ability in girls (AUC=0.81, p<0.001; Cut-point=5306 steps; Accuracy=78.8%) compared to boys (AUC=0.72, p<0.01; Cut-point=5786 steps; Accuracy=71.4%). Pedometer step counts showed good diagnostic ability in girls and fair diagnostic ability in boys for discriminating children that met at least 30min of MVPA during school hours. Copyright © 2016 Elsevier Inc. All rights reserved.

Evaluation of low-cost, objective instruments for assessing physical activity in 10-11-year-old children.

PubMed

Hart, Teresa L; Brusseau, Timothy; Kulinna, Pamela Hodges; McClain, James J; Tudor-Locke, Catrine

2011-12-01

This study compared step counts detected by four, low-cost, objective, physical-activity-assessment instruments and evaluated their ability to detect moderate-to-vigorous physical activity (MVPA) compared to the ActiGraph accelerometer (AG). Thirty-six 10-11-year-old children wore the NL-1000, Yamax Digiwalker SW 200, Omron HJ-151, and Walk4Life MVP concurrently with the AG during school hours on a single day. AG MVPA was derived from activity count data using previously validated cut points. Two of the evaluated instruments provided similar group mean MVPA and step counts compared to AG (dependent on cut point). Low-cost instruments may be useful for measurement of both MVPA and steps in children's physical activity interventions and program evaluation.

Accuracy of piezoelectric pedometer and accelerometer step counts.

PubMed

Cruz, Joana; Brooks, Dina; Marques, Alda

2017-04-01

This study aimed to assess step-count accuracy of a piezoeletric pedometer (Yamax PW/EX-510), when worn at different body parts, and a triaxial accelerometer (GT3X+), and to compare device accuracy; and identify the preferred location(s) to wear a pedometer. Sixty-three healthy adults (45.8±20.6 years old) wore 7 pedometers (neck, lateral right and left of the waist, front right and left of the waist, front pockets of the trousers) and 1 accelerometer (over the right hip), while walking 120 m at slow, self-preferred/normal and fast paces. Steps were recorded. Participants identified their preferred location(s) to wear the pedometer. Absolute percent error (APE) and Bland and Altman (BA) method were used to assess device accuracy (criterion measure: manual counts) and BA method for device comparisons. Pedometer APE was below 3% at normal and fast paces despite wearing location, but higher at slow pace (4.5-9.1%). Pedometers were more accurate at the front waist and inside the pockets. Accelerometer APE was higher than pedometer APE (P<0.05); nevertheless, limits of agreement between devices were relatively small. Preferred wearing locations were inside the front right (N.=25) and left (N.=20) pockets of the trousers. Yamax PW/EX-510 pedometers may be preferable than GT3X+ accelerometers to count steps, as they provide more accurate results. These pedometers should be worn at the front right or left positions of the waist or inside the front pockets of the trousers.

A calibration protocol for population-specific accelerometer cut-points in children.

PubMed

Mackintosh, Kelly A; Fairclough, Stuart J; Stratton, Gareth; Ridgers, Nicola D

2012-01-01

To test a field-based protocol using intermittent activities representative of children's physical activity behaviours, to generate behaviourally valid, population-specific accelerometer cut-points for sedentary behaviour, moderate, and vigorous physical activity. Twenty-eight children (46% boys) aged 10-11 years wore a hip-mounted uniaxial GT1M ActiGraph and engaged in 6 activities representative of children's play. A validated direct observation protocol was used as the criterion measure of physical activity. Receiver Operating Characteristics (ROC) curve analyses were conducted with four semi-structured activities to determine the accelerometer cut-points. To examine classification differences, cut-points were cross-validated with free-play and DVD viewing activities. Cut-points of ≤ 372, >2160 and >4806 counts • min(-1) representing sedentary, moderate and vigorous intensity thresholds, respectively, provided the optimal balance between the related needs for sensitivity (accurately detecting activity) and specificity (limiting misclassification of the activity). Cross-validation data demonstrated that these values yielded the best overall kappa scores (0.97; 0.71; 0.62), and a high classification agreement (98.6%; 89.0%; 87.2%), respectively. Specificity values of 96-97% showed that the developed cut-points accurately detected physical activity, and sensitivity values (89-99%) indicated that minutes of activity were seldom incorrectly classified as inactivity. The development of an inexpensive and replicable field-based protocol to generate behaviourally valid and population-specific accelerometer cut-points may improve the classification of physical activity levels in children, which could enhance subsequent intervention and observational studies.

The validity of consumer-level, activity monitors in healthy adults worn in free-living conditions: a cross-sectional study.

PubMed

Ferguson, Ty; Rowlands, Alex V; Olds, Tim; Maher, Carol

2015-03-27

Technological advances have seen a burgeoning industry for accelerometer-based wearable activity monitors targeted at the consumer market. The purpose of this study was to determine the convergent validity of a selection of consumer-level accelerometer-based activity monitors. 21 healthy adults wore seven consumer-level activity monitors (Fitbit One, Fitbit Zip, Jawbone UP, Misfit Shine, Nike Fuelband, Striiv Smart Pedometer and Withings Pulse) and two research-grade accelerometers/multi-sensor devices (BodyMedia SenseWear, and ActiGraph GT3X+) for 48-hours. Participants went about their daily life in free-living conditions during data collection. The validity of the consumer-level activity monitors relative to the research devices for step count, moderate to vigorous physical activity (MVPA), sleep and total daily energy expenditure (TDEE) was quantified using Bland-Altman analysis, median absolute difference and Pearson's correlation. All consumer-level activity monitors correlated strongly (r > 0.8) with research-grade devices for step count and sleep time, but only moderately-to-strongly for TDEE (r = 0.74-0.81) and MVPA (r = 0.52-0.91). Median absolute differences were generally modest for sleep and steps (<10% of research device mean values for the majority of devices) moderate for TDEE (<30% of research device mean values), and large for MVPA (26-298%). Across the constructs examined, the Fitbit One, Fitbit Zip and Withings Pulse performed most strongly. In free-living conditions, the consumer-level activity monitors showed strong validity for the measurement of steps and sleep duration, and moderate valid for measurement of TDEE and MVPA. Validity for each construct ranged widely between devices, with the Fitbit One, Fitbit Zip and Withings Pulse being the strongest performers.

The impact of playworks on boys' and girls' physical activity during recess.

PubMed

Bleeker, Martha; Beyler, Nicholas; James-Burdumy, Susanne; Fortson, Jane

2015-03-01

School-based programs, such as Playworks, that guide students in organized activities during recess and make improvements to the recess play yard may lead to significant increases in physical activity-especially for girls. This study builds on past research by investigating the impact of Playworks separately for girls and boys. Twenty-nine schools were randomly assigned to receive Playworks for 1 school year or serve as a control group. Postintervention physical activity data were collected via accelerometers and recess observations. Impacts were estimated separately for girls and boys using regression models. Girls in Playworks schools had significantly higher accelerometer intensity counts and spent more time in vigorous physical activity than girls in control schools. No significant differences based on accelerometer data were found for boys. A significant impact was also found on the types of activities in which girls engaged during recess; girls in the treatment group were less likely than those in the control group to be sedentary and more likely to engage in jumping, tag, and playground games. The current findings suggest that Playworks had a significant impact on some measures of girls' physical activity, but no significant impact on measures of boys' physical activity. © 2015, American School Health Association.

Evaluation of Low-Cost, Objective Instruments for Assessing Physical Activity in 10-11-Year-Old Children

ERIC Educational Resources Information Center

Hart, Teresa L.; Brusseau, Timothy; Kulinna, Pamela Hodges; McClain, James J.; Tudor-Locke, Catrine

2011-01-01

This study compared step counts detected by four, low-cost, objective, physical-activity-assessment instruments and evaluated their ability to detect moderate-to-vigorous physical activity (MVPA) compared to the ActiGraph accelerometer (AG). Thirty-six 10-11-year-old children wore the NL-1000, Yamax Digiwalker SW 200, Omron HJ-151, and Walk4Life…

Using pedometers for measuring and increasing physical activity in children and adolescents: The next step

USDA-ARS?s Scientific Manuscript database

The science and practice of step counting in children (typically aged 6-11 years) and adolescents (typically aged 12-19 years) has evolved rapidly over a relatively brief period with the commercial availability of research-grade pedometers and accelerometers. Recent reviews have summarized considera...

Study protocol of physical activity and sedentary behaviour measurement among schoolchildren by accelerometry--cross-sectional survey as part of the ENERGY-project.

PubMed

Yıldırım, Mine; Verloigne, Maïté; de Bourdeaudhuij, Ilse; Androutsos, Odysseas; Manios, Yannis; Felso, Regina; Kovács, Éva; Doessegger, Alain; Bringolf-Isler, Bettina; te Velde, Saskia J; Brug, Johannes; Chinapaw, Mai J M

2011-03-25

Physical activity and sedentary behaviour among children should be measured accurately in order to investigate their relationship with health. Accelerometry provides objective and accurate measurement of body movement, which can be converted to meaningful behavioural outcomes. The aim of this study was to evaluate the best evidence for the decisions on data collection and data processing with accelerometers among children resulting in a standardized protocol for use in the participating countries. This cross-sectional accelerometer study was conducted as part of the European ENERGY-project that aimed to produce an obesity prevention intervention among schoolchildren. Five countries, namely Belgium, Greece, Hungary, Switzerland and the Netherlands participated in the accelerometer study. We used three different Actigraph models--Actitrainers (triaxial), GT3Xs and GT1Ms. Children wore the device for six consecutive days including two weekend days. We selected an epoch length of 15 seconds. Accelerometers were placed at children's waist at the right side of the body in an elastic belt. In total, 1082 children participated in the study (mean age = 11.7 ± 0.75 y, 51% girls). Non-wearing time was calculated as periods of more than 20 minutes of consecutive zero counts. The minimum daily wearing time was set to 10 hours for weekdays and 8 hours for weekend days. The inclusion criterion for further analysis was having at least three valid weekdays and one valid weekend day. We selected a cut-point (count per minute (cpm)) of <100 cpm for sedentary behaviour, <3000 cpm for light, <5200 cpm for moderate, and >5200 cpm for vigorous physical activity. We also created time filters for school-time during data cleaning in order to explore school-time physical activity and sedentary behaviour patterns in particular. This paper describes the decisions for data collection and processing. Use of standardized protocols would ease future use of accelerometry and the comparability of results between studies.

The method of attachment influences accelerometer-based activity data in dogs.

PubMed

Martin, Kyle W; Olsen, Anastasia M; Duncan, Colleen G; Duerr, Felix M

2017-02-10

Accelerometer-based activity monitoring is a promising new tool in veterinary medicine used to objectively assess activity levels in dogs. To date, it is unknown how device orientation, attachment method, and attachment of a leash to the collar holding an accelerometer affect canine activity data. It was our goal to evaluate whether attachment methods of accelerometers affect activity counts. Eight healthy, client-owned dogs were fitted with two identical neck collars to which two identical activity monitors were attached using six different methods of attachment. These methods of attachment evaluated the use of a protective case, positioning of the activity monitor and the tightness of attachment of the accelerometer. Lastly, the effect of leash attachment to the collar was evaluated. For trials where the effect of leash attachment to the collar was not being studied, the leash was attached to a harness. Activity data obtained from separate monitors within a given experiment were compared using Pearson correlation coefficients and across all experiments using the Kruskal-Wallis Test. There was excellent correlation and low variability between activity monitors on separate collars when the leash was attached to a harness, regardless of their relative positions. There was good correlation when activity monitors were placed on the same collar regardless of orientation. There were poor correlations between activity monitors in three experiments: when the leash was fastened to the collar that held an activity monitor, when one activity monitor was housed in the protective casing, and when one activity monitor was loosely zip-tied to the collar rather than threaded on using the provided metal loop. Follow-up, pair-wise comparisons identified the correlation associated with these three methods of attachment to be statistically different from the level of correlation when monitors were placed on separate collars. While accelerometer-based activity monitors are useful tools to objectively assess physical activity in dogs, care must be taken when choosing a method to attach the device. The attachment of the activity monitor to the collar should utilize a second, dedicated collar that is not used for leash attachment and the attachment method should remain consistent throughout a study period.

Relationship between objectively measured physical activity and vascular structure and function in adults.

PubMed

Gomez-Marcos, Manuel A; Recio-Rodríguez, José I; Patino-Alonso, Maria C; Agudo-Conde, Cristina; Lasaosa-Medina, Lourdes; Rodriguez-Sanchez, Emiliano; Maderuelo-Fernandez, José A; García-Ortiz, Luis

2014-06-01

To analyze the relationship between regular physical activity, as assessed by accelerometer and 7-day physical activity recall (PAR) with vascular structure and function based on carotid intima-media thickness, pulse wave velocity, central and peripheral augmentation index and the ambulatory arterial stiffness index in adults. This study analyzed 263 subjects who were included in the EVIDENT study (mean age 55.85 ± 12.21 years; 59.30% female). Physical activity was assessed during 7 days using the Actigraph GT3X accelerometer (counts/minute) and 7-day PAR (metabolic equivalents (METs)/hour/week). Carotid ultrasound was used to measure carotid intima media thickness (IMT). The SphygmoCor System was used to measure pulse wave velocity (PWV), and central and peripheral augmentation index (CAIx and PAIx). The B-pro device was used to measure ambulatory arterial stiffness index (AASI). Median counts/minute was 244.37 and mean METs/hour/week was 11.49. Physical activity showed an inverse correlation with PAIx (r = -0.179; p < 0.01) and vigorous activity day time with IMT (r = -0.174), CAIx (r = -0.217) and PAIx (r = -0.324) (p < 0.01, all). Sedentary activity day time was correlated positively with CAIx (r = 0.103; p < 0.05). In multiple regression analysis, after adjusting for confounding factors, the inverse association of CAIx with counts/minute and the time spent in moderate and vigorous activity were maintained as well as the positive association with sedentary activity day time (p < 0.05). Physical activity, assessed by counts/minute, and the amount of time spent in moderate, vigorous/very vigorous physical activity, showed an inverse association with CAIx. Likewise, the time spent in sedentary activity was positively associated with the CAIx. Clinical Trials.gov Identifier: NCT01083082. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

National youth sedentary behavior and physical activity daily patterns using latent class analysis applied to accelerometry.

PubMed

Evenson, Kelly R; Wen, Fang; Hales, Derek; Herring, Amy H

2016-05-03

Applying latent class analysis (LCA) to accelerometry can help elucidated underlying patterns. This study described the patterns of accelerometer-determined sedentary behavior and physical activity among youth by applying LCA to a nationally representative United States (US) sample. Using 2003-2006 National Health and Nutrition Examination Survey data, 3998 youths 6-17 years wore an ActiGraph 7164 accelerometer for one week, providing > =3 days of wear for > =8 h/day from 6:00 am-midnight. Cutpoints defined sedentary behavior (<100 counts/minute), light activity (100-2295 counts/minute), moderate to vigorous physical activity (MVPA; > = 2296 counts/minute), and vigorous activity (> = 4012 counts/minute). To account for wear time differences, outcomes were expressed as percent of day in a given intensity. LCA was used to classify daily (Monday through Sunday) patterns of average counts/minute, sedentary behavior, light activity, MVPA, and vigorous activity separately. The latent classes were explored overall and by age (6-11, 12-14, 15-17 years), gender, and whether or not youth attended school during measurement. Estimates were weighted to account for the sampling frame. For average counts/minute/day, four classes emerged from least to most active: 40.9% of population (mean 323.5 counts/minute/day), 40.3% (559.6 counts/minute/day), 16.5% (810.0 counts/minute/day), and 2.3% (1132.9 counts/minute/day). For percent of sedentary behavior, four classes emerged: 13.5% of population (mean 544.6 min/day), 30.1% (455.1 min/day), 38.5% (357.7 min/day), and 18.0% (259.2 min/day). For percent of light activity, four classes emerged: 12.3% of population (mean 222.6 min/day), 29.3% (301.7 min/day), 41.8% (384.0 min/day), and 16.6% (455.5 min/day). For percent of MVPA, four classes emerged: 59.9% of population (mean 25.0 min/day), 33.3% (60.9 min/day), 3.1% (89.0 min/day), and 3.6% (109.3 min/day). For percent of vigorous activity, three classes emerged: 76.8% of population (mean 7.1 min/day), 18.5% (23.9 min/day), and 4.7% (47.4 min/day). Classes were developed by age, gender, and school attendance since some patterns differed when stratifying by these factors. The models supported patterns for average intensity, sedentary behavior, light activity, MVPA, and vigorous activity. These latent class derived patterns can be used in other youth studies to explore correlates or outcomes and to target sedentary behavior or physical activity interventions.

A joint modeling and estimation method for multivariate longitudinal data with mixed types of responses to analyze physical activity data generated by accelerometers.

PubMed

Li, Haocheng; Zhang, Yukun; Carroll, Raymond J; Keadle, Sarah Kozey; Sampson, Joshua N; Matthews, Charles E

2017-11-10

A mixed effect model is proposed to jointly analyze multivariate longitudinal data with continuous, proportion, count, and binary responses. The association of the variables is modeled through the correlation of random effects. We use a quasi-likelihood type approximation for nonlinear variables and transform the proposed model into a multivariate linear mixed model framework for estimation and inference. Via an extension to the EM approach, an efficient algorithm is developed to fit the model. The method is applied to physical activity data, which uses a wearable accelerometer device to measure daily movement and energy expenditure information. Our approach is also evaluated by a simulation study. Copyright © 2017 John Wiley & Sons, Ltd.

Use of population-referenced total activity counts percentiles to assess and classify physical activity of population groups.

PubMed

Wolff-Hughes, Dana L; Troiano, Richard P; Boyer, William R; Fitzhugh, Eugene C; McClain, James J

2016-06-01

Population-referenced total activity counts per day (TAC/d) percentiles provide public health practitioners a standardized measure of physical activity (PA) volume obtained from an accelerometer that can be compared across populations. The purpose of this study was to describe the application of TAC/d population-referenced percentiles to characterize the PA levels of population groups relative to US estimates. A total of 679 adults participating in the 2011 NYC Physical Activity Transit survey wore an ActiGraph accelerometer on their hip for seven consecutive days. Accelerometer-derived TAC/d was classified into age- and gender-specific quartiles of US population-referenced TAC/d to compare differences in the distributions by borough (N=5). Males in Brooklyn, Manhattan, and Staten Island had significantly greater TAC/d than US males. Females in Brooklyn and Queens had significantly greater levels of TAC/d compared to US females. The proportion of males in each population-referenced TAC/d quartile varied significantly by borough (χ(2)(12)=2.63, p=0.002), with disproportionately more men in Manhattan and the Bronx found to be in the highest and lowest US population-referenced TAC/d quartiles, respectively. For females, there was no significant difference in US population-reference TAC/d quartile by borough (χ(2)(12)=1.09, p=0.36). These results demonstrate the utility of population-referenced TAC/d percentiles in public health monitoring and surveillance. These findings also provide insights into the PA levels of NYC residents relative to the broader US population, which can be used to guide health promotion efforts. Published by Elsevier Inc.

Use of population-referenced total activity counts percentiles to assess and classify physical activity of population groups

PubMed Central

Wolff-Hughes, Dana L.; Troiano, Richard P.; Boyer, William R.; Fitzhugh, Eugene C.; McClain, James J.

2016-01-01

Objectives Population-referenced total activity counts per day (TAC/d) percentiles provide public health practitioners a standardized measure of physical activity (PA) volume obtained from an accelerometer that can be compared across populations. The purpose of this study was to describe the application of TAC/d population-referenced percentiles to characterize the PA levels of population groups relative to US estimates. Methods A total of 679 adults participating in the 2011 NYC Physical Activity Transit survey wore an ActiGraph accelerometer on their hip for seven consecutive days. Accelerometer-derived TAC/d was classified into age- and gender-specific quartiles of US population-referenced TAC/d to compare differences in the distributions by borough (N=5). Results Males in Brooklyn, Manhattan, and Staten Island had significantly greater TAC/d than US males. Females in Brooklyn and Queens had significantly greater levels of TAC/d compared to US females. The proportion of males in each population-referenced TAC/d quartile varied significantly by borough (χ2(12)=2.63, p=0.002), with disproportionately more men in Manhattan and the Bronx found to be in the highest and lowest US population-referenced TAC/d quartiles, respectively. For females, there was no significant difference in US population-reference TAC/d quartile by borough (χ2(12)=1.09, p=0.36). Conclusions These results demonstrate the utility of population-referenced TAC/d percentiles in public health monitoring and surveillance. These findings also provide insights into the PA levels of NYC residents relative to the broader US population, which can be used to guide health promotion efforts. PMID:26876630

Objectively measured physical activity and sedentary time of breast cancer survivors, and associations with adiposity: findings from NHANES (2003-2006).

PubMed

Lynch, Brigid M; Dunstan, David W; Healy, Genevieve N; Winkler, Elisabeth; Eakin, Elizabeth; Owen, Neville

2010-02-01

Obesity and physical inactivity are poor prognostic indicators for breast cancer. Studies to date have relied on self-report measures of physical activity, which tend mainly to assess moderate-to-vigorous intensity leisure-time physical activity. We report the cross-sectional associations of objectively assessed physical activity and sedentary time with adiposity in a sample of breast cancer survivors from the United States. One hundred and eleven women from the National Health and Nutrition Examination Survey (NHANES) 2003-2004 and 2005-2006 reported a history of breast cancer. Participants wore an accelerometer for 7 days, and activity levels were summarized as moderate-to-vigorous intensity (accelerometer counts/min > or =1,952), light intensity (counts/min 100-1,951), and sedentary time (counts/min <100). Anthropometric measures were taken by study staff at examination centers. Participants spent the majority of their day in sedentary time (66%) or in light intensity activities (33%). Log moderate-to-vigorous intensity physical activity was negatively associated with adiposity (waist circumference beta = -9.805 [95% CI: -15.836, -3.775]; BMI beta = -3.576 [95% CI: -6.687, -0.464]). Light intensity physical activity was negatively associated with adiposity; however, the fully adjusted models did not retain statistical significance. Similarly, sedentary time was positively associated with adiposity, but the fully adjusted models were not statistically significant. This is the first study to describe the objectively assessed physical activity and sedentary time of breast cancer survivors. Increasing moderate-to-vigorous and light intensity physical activity, and decreasing sedentary time, may assist with weight management and improve other metabolic health outcomes for breast cancer survivors.

Step-Count Accuracy of 3 Motion Sensors for Older and Frail Medical Inpatients.

PubMed

McCullagh, Ruth; Dillon, Christina; O'Connell, Ann Marie; Horgan, N Frances; Timmons, Suzanne

2017-02-01

To measure the step-count accuracy of an ankle-worn accelerometer, a thigh-worn accelerometer, and a pedometer in older and frail inpatients. Cross-sectional design study. Research room within a hospital. Convenience sample of inpatients (N=32; age, ≥65 years) who were able to walk 20m independently with or without a walking aid. Patients completed a 40-minute program of predetermined tasks while wearing the 3 motion sensors simultaneously. Video recording of the procedure provided the criterion measurement of step count. Mean percentage errors were calculated for all tasks, for slow versus fast walkers, for independent walkers versus walking-aid users, and over shorter versus longer distances. The intraclass correlation was calculated, and accuracy was graphically displayed by Bland-Altman plots. Thirty-two patients (mean age, 78.1±7.8y) completed the study. Fifteen (47%) were women, and 17 (51%) used walking aids. Their median speed was .46m/s (interquartile range [IQR], .36-.66m/s). The ankle-worn accelerometer overestimated steps (median error, 1% [IQR, -3% to 13%]). The other motion sensors underestimated steps (median error, 40% [IQR, -51% to -35%] and 38% [IQR -93% to -27%], respectively). The ankle-worn accelerometer proved to be more accurate over longer distances (median error, 3% [IQR, 0%-9%]) than over shorter distances (median error, 10% [IQR, -23% to 9%]). The ankle-worn accelerometer gave the most accurate step-count measurement and was most accurate over longer distances. Neither of the other motion sensors had acceptable margins of error. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Significant changes in physical activity among pregnant women in the UK as assessed by accelerometry and self-reported activity.

PubMed

Rousham, E K; Clarke, P E; Gross, H

2006-03-01

Research on the impact of maternal physical activity on pregnancy outcomes has often employed subjective measures of physical activity obtained by diary or questionnaire. This study investigates the feasibility of using accelerometry as an objective measure of physical activity of pregnant women compared with subjective data obtained via activity recall among pregnant women. Activity data were collected prospectively on 57 women at 12, 16, 25, 34 and 38 weeks of gestation. Total daily physical activity was assessed by ambulatory accelerometer and activity interview (self-report). Maternal personality variables (health value, extroversion) were assessed by established scales. Leicestershire, UK. Pregnant women were recruited by voluntary participation via antenatal booking clinics. In all, 64 pregnant women with low-risk pregnancy were enrolled onto the study, of whom 57 completed the study. Mean 24 h physical activity levels (PAL) decreased significantly from second to third trimester as assessed by self-report interview (1.51-1.29 Metabolic Equivalent TEE-h/day, P<0.01) and accelerometry (200.05-147.42 counts/min, P<0.01). The correlation between the two measures declined as pregnancy progressed (r value ranging from 0.55 to 0.08). Compliance with the accelerometers declined from 90% at 12 weeks to 47% at 34 weeks (P<0.01). Compliance with the self-report interviews was 100%. Those who fully complied with the accelerometry demonstrated a significantly higher health value (P<0.05) and a significantly greater level of extroversion (P<0.05) than those who did not. Accelerometers and self-reported activity interviews both indicated a significant decline in PAL during pregnancy. Although subjects showed a willingness to use both methods, accelerometers resulted in variable compliance with 72 h monitoring. Both techniques may be limited by the need to measure low levels of physical activity during the third trimester. Cambridge Neurotechnology Ltd, UK, assisted with the provision of Actiwatch accelerometers.

The contribution of walking to work to adult physical activity levels: a cross sectional study.

PubMed

Audrey, Suzanne; Procter, Sunita; Cooper, Ashley R

2014-03-11

To objectively examine the contribution to adult physical activity levels of walking to work. Employees (n = 103; 36.3 ± 11.7 years) at 17 workplaces in south-west England, who lived within 2 miles (3.2 km) of their workplace, wore Actigraph accelerometers for seven days during waking hours and carried GPS receivers during the commute to and from work. Physical activity volume (accelerometer counts per minute (cpm)) and intensity (minutes of moderate to vigorous physical activity (MVPA)) were computed overall and during the walk to work. Total weekday physical activity was 45% higher in participants who walked to work compared to those travelling by car (524.6. ± 170.4 vs 364.6 ± 138.4 cpm) and MVPA almost 60% higher (78.1 ± 24.9 vs 49.8 ± 25.2 minutes per day). No differences were seen in weekend physical activity, and sedentary time did not differ between the groups. Combined accelerometer and GPS data showed that walking to work contributed 47.3% of total weekday MVPA. Walking to work was associated with overall higher levels of physical activity in young and middle-aged adults. These data provide preliminary evidence to underpin the need for interventions to increase active commuting, specifically walking, in adults.

Objective vs. self-reported physical activity and sedentary time: effects of measurement method on relationships with risk biomarkers.

PubMed

Celis-Morales, Carlos A; Perez-Bravo, Francisco; Ibañez, Luis; Salas, Carlos; Bailey, Mark E S; Gill, Jason M R

2012-01-01

Imprecise measurement of physical activity variables might attenuate estimates of the beneficial effects of activity on health-related outcomes. We aimed to compare the cardiometabolic risk factor dose-response relationships for physical activity and sedentary behaviour between accelerometer- and questionnaire-based activity measures. Physical activity and sedentary behaviour were assessed in 317 adults by 7-day accelerometry and International Physical Activity Questionnaire (IPAQ). Fasting blood was taken to determine insulin, glucose, triglyceride and total, LDL and HDL cholesterol concentrations and homeostasis model-estimated insulin resistance (HOMA(IR)). Waist circumference, BMI, body fat percentage and blood pressure were also measured. For both accelerometer-derived sedentary time (<100 counts.min(-1)) and IPAQ-reported sitting time significant positive (negative for HDL cholesterol) relationships were observed with all measured risk factors--i.e. increased sedentary behaviour was associated with increased risk (all p ≤ 0.01). However, for HOMA(IR) and insulin the regression coefficients were >50% lower for the IPAQ-reported compared to the accelerometer-derived measure (p<0.0001 for both interactions). The relationships for moderate-to-vigorous physical activity (MVPA) and risk factors were less strong than those observed for sedentary behaviours, but significant negative relationships were observed for both accelerometer and IPAQ MVPA measures with glucose, and insulin and HOMA(IR) values (all p<0.05). For accelerometer-derived MVPA only, additional negative relationships were seen with triglyceride, total cholesterol and LDL cholesterol concentrations, BMI, waist circumference and percentage body fat, and a positive relationship was evident with HDL cholesterol (p = 0.0002). Regression coefficients for HOMA(IR), insulin and triglyceride were 43-50% lower for the IPAQ-reported compared to the accelerometer-derived MVPA measure (all p≤0.01). Using the IPAQ to determine sitting time and MVPA reveals some, but not all, relationships between these activity measures and metabolic and vascular disease risk factors. Using this self-report method to quantify activity can therefore underestimate the strength of some relationships with risk factors.

Using Commercial Activity Monitors to Measure Gait in Patients with Suspected iNPH: Implications for Ambulatory Monitoring

PubMed Central

Gaglani, Shiv; Haynes, M Ryan; Hoffberger, Jamie B; Rigamonti, Daniele

2015-01-01

Objectives: This study seeks to validate the use of activity monitors to detect and record gait abnormalities, potentially identifying patients with idiopathic normal pressure hydrocephalus (iNPH) prior to the onset of cognitive or urinary symptoms. Methods: This study compared the step counts of four common activity monitors (Omron Step Counter HJ-113, New Lifestyles 2000, Nike Fuelband, and Fitbit Ultra) to an observed step count in 17 patients with confirmed iNPH. Results: Of the four devices, the Fitbit Ultra (Fitbit, Inc., San Francisco, CA) provided the most accurate step count. The correlation with the observed step count was significantly higher (p<0.009) for the Fitbit Ultra than for any of the other three devices. Conclusions: These preliminary findings suggest that existing activity monitors have variable efficacy in the iNPH patient population and that the MEMS tri-axial accelerometer and algorithm of the Fitbit Ultra provides the most accurate gait measurements of the four devices tested. PMID:26719825

Using Commercial Activity Monitors to Measure Gait in Patients with Suspected iNPH: Implications for Ambulatory Monitoring.

PubMed

Gaglani, Shiv; Moore, Jessica; Haynes, M Ryan; Hoffberger, Jamie B; Rigamonti, Daniele

2015-11-17

This study seeks to validate the use of activity monitors to detect and record gait abnormalities, potentially identifying patients with idiopathic normal pressure hydrocephalus (iNPH) prior to the onset of cognitive or urinary symptoms. This study compared the step counts of four common activity monitors (Omron Step Counter HJ-113, New Lifestyles 2000, Nike Fuelband, and Fitbit Ultra) to an observed step count in 17 patients with confirmed iNPH. Of the four devices, the Fitbit Ultra (Fitbit, Inc., San Francisco, CA) provided the most accurate step count. The correlation with the observed step count was significantly higher (p<0.009) for the Fitbit Ultra than for any of the other three devices. These preliminary findings suggest that existing activity monitors have variable efficacy in the iNPH patient population and that the MEMS tri-axial accelerometer and algorithm of the Fitbit Ultra provides the most accurate gait measurements of the four devices tested.

Habitual Physical Activity in Children With Cerebral Palsy Aged 4 to 5 Years Across All Functional Abilities.

PubMed

Keawutan, Piyapa; Bell, Kristie L; Oftedal, Stina; Davies, Peter S W; Ware, Robert S; Boyd, Roslyn N

2017-01-01

To compare ambulatory status in children with cerebral palsy aged 4 to 5 years with their habitual physical activity and time spent sedentary, and to compare their activity with physical activity guidelines. Sixty-seven participants-independently ambulant, marginally ambulant, and nonambulant-wore accelerometers for 3 days. Time spent sedentary as a percentage of wear time and activity counts were compared between groups. There were significant differences in time spent sedentary and activity counts between groups. Children who were independently ambulant were more likely to meet physical activity guidelines. Children with cerebral palsy spent more than half of their waking hours in sedentary time. Interventions to reduce sedentary behavior and increase habitual physical activity are needed in children with cerebral palsy at age 4 to 5 years.

Age- and sex-specific criterion validity of the health survey for England Physical Activity and Sedentary Behavior Assessment Questionnaire as compared with accelerometry.

PubMed

Scholes, Shaun; Coombs, Ngaire; Pedisic, Zeljko; Mindell, Jennifer S; Bauman, Adrian; Rowlands, Alex V; Stamatakis, Emmanuel

2014-06-15

The criterion validity of the 2008 Physical Activity and Sedentary Behavior Assessment Questionnaire (PASBAQ) was examined in a nationally representative sample of 2,175 persons aged ≥16 years in England using accelerometry. Using accelerometer minutes/day greater than or equal to 200 counts as a criterion, Spearman's correlation coefficient (ρ) for PASBAQ-assessed total activity was 0.30 (95% confidence interval (CI): 0.25, 0.35) in women and 0.20 (95% CI: 0.15, 0.26) in men. Correlations between accelerometer counts/minute of wear time and questionnaire-assessed relative energy expenditure (metabolic equivalent-minutes/day) were higher in women (ρ = 0.41, 95% CI: 0.36, 0.46) than in men (ρ = 0.32, 95% CI: 0.26, 0.38). Similar correlations were observed for minutes/day spent in vigorous activity (women: ρ = 0.39, 95% CI: 0.33, 0.46; men: ρ = 0.31, 95% CI: 0.26, 0.36) and moderate-to-vigorous activity (women: ρ = 0.42, 95% CI: 0.36, 0.48; men: ρ = 0.38, 95% CI: 0.32, 0.45). Correlations for time spent being sedentary (<100 counts/minute) were 0.30 (95% CI: 0.24, 0.35) and 0.25 (95% CI: 0.19, 0.30) in women and men, respectively. Sedentary behavior correlations showed no sex difference. The validity of sedentary behavior and total physical activity was higher in older age groups, but validity was higher in younger persons for vigorous-intensity activity. The PASBAQ is a useful and valid instrument for ranking individuals according to levels of physical activity and sedentary behavior. © The Author 2014. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health.

Age- and Sex-Specific Criterion Validity of the Health Survey for England Physical Activity and Sedentary Behavior Assessment Questionnaire as Compared With Accelerometry

PubMed Central

Scholes, Shaun; Coombs, Ngaire; Pedisic, Zeljko; Mindell, Jennifer S.; Bauman, Adrian; Rowlands, Alex V.; Stamatakis, Emmanuel

2014-01-01

The criterion validity of the 2008 Physical Activity and Sedentary Behavior Assessment Questionnaire (PASBAQ) was examined in a nationally representative sample of 2,175 persons aged ≥16 years in England using accelerometry. Using accelerometer minutes/day greater than or equal to 200 counts as a criterion, Spearman's correlation coefficient (ρ) for PASBAQ-assessed total activity was 0.30 (95% confidence interval (CI): 0.25, 0.35) in women and 0.20 (95% CI: 0.15, 0.26) in men. Correlations between accelerometer counts/minute of wear time and questionnaire-assessed relative energy expenditure (metabolic equivalent-minutes/day) were higher in women (ρ = 0.41, 95% CI: 0.36, 0.46) than in men (ρ = 0.32, 95% CI: 0.26, 0.38). Similar correlations were observed for minutes/day spent in vigorous activity (women: ρ = 0.39, 95% CI: 0.33, 0.46; men: ρ = 0.31, 95% CI: 0.26, 0.36) and moderate-to-vigorous activity (women: ρ = 0.42, 95% CI: 0.36, 0.48; men: ρ = 0.38, 95% CI: 0.32, 0.45). Correlations for time spent being sedentary (<100 counts/minute) were 0.30 (95% CI: 0.24, 0.35) and 0.25 (95% CI: 0.19, 0.30) in women and men, respectively. Sedentary behavior correlations showed no sex difference. The validity of sedentary behavior and total physical activity was higher in older age groups, but validity was higher in younger persons for vigorous-intensity activity. The PASBAQ is a useful and valid instrument for ranking individuals according to levels of physical activity and sedentary behavior. PMID:24863551

Evaluation of artificial neural network algorithms for predicting METs and activity type from accelerometer data: validation on an independent sample.

PubMed

Freedson, Patty S; Lyden, Kate; Kozey-Keadle, Sarah; Staudenmayer, John

2011-12-01

Previous work from our laboratory provided a "proof of concept" for use of artificial neural networks (nnets) to estimate metabolic equivalents (METs) and identify activity type from accelerometer data (Staudenmayer J, Pober D, Crouter S, Bassett D, Freedson P, J Appl Physiol 107: 1330-1307, 2009). The purpose of this study was to develop new nnets based on a larger, more diverse, training data set and apply these nnet prediction models to an independent sample to evaluate the robustness and flexibility of this machine-learning modeling technique. The nnet training data set (University of Massachusetts) included 277 participants who each completed 11 activities. The independent validation sample (n = 65) (University of Tennessee) completed one of three activity routines. Criterion measures were 1) measured METs assessed using open-circuit indirect calorimetry; and 2) observed activity to identify activity type. The nnet input variables included five accelerometer count distribution features and the lag-1 autocorrelation. The bias and root mean square errors for the nnet MET trained on University of Massachusetts and applied to University of Tennessee were +0.32 and 1.90 METs, respectively. Seventy-seven percent of the activities were correctly classified as sedentary/light, moderate, or vigorous intensity. For activity type, household and locomotion activities were correctly classified by the nnet activity type 98.1 and 89.5% of the time, respectively, and sport was correctly classified 23.7% of the time. Use of this machine-learning technique operates reasonably well when applied to an independent sample. We propose the creation of an open-access activity dictionary, including accelerometer data from a broad array of activities, leading to further improvements in prediction accuracy for METs, activity intensity, and activity type.

The Effect of Increasing Autonomy Through Choice on Young Children's Physical Activity Behavior.

PubMed

Sanders, Gabriel J; Juvancic-Heltzel, Judith; Williamson, Megan L; Roemmich, James N; Feda, Denise M; Barkley, Jacob E

2016-04-01

Increasing autonomy by manipulating the choice of available physical activity options in a laboratory setting can increase physical activity in older children and adults. However, the effect of manipulating the number of physically active choices has yet to be examined in young children in a gymnasium environment. Twenty children (n = 10 girls, 6.1 ± 1.4 years old) individually participated in 2 [low choice (LC), high choice (HC)] free-choice activity conditions for 30 minutes in a 4360 square foot gymnasium. Children had access to 2 or 8 physical activity options in the LC and HC conditions, respectively. Physical activity behavior was measured via accelerometry. Children's 30-minute accelerometer counts increased (P < .03) from the LC (2675 ± 294 counts·min-1) to the HC (3224 ± 280 counts·min-1) condition. Providing greater autonomy through choice of a greater number of physically active options increased young children's physical activity participation by 20.5%.

Multiple Imputation of Completely Missing Repeated Measures Data within Person from a Complex Sample: Application to Accelerometer Data in the National Health and Nutrition Examination Survey

PubMed Central

Liu, Benmei; Yu, Mandi; Graubard, Barry I; Troiano, Richard P; Schenker, Nathaniel

2016-01-01

The Physical Activity Monitor (PAM) component was introduced into the 2003-2004 National Health and Nutrition Examination Survey (NHANES) to collect objective information on physical activity including both movement intensity counts and ambulatory steps. Due to an error in the accelerometer device initialization process, the steps data were missing for all participants in several primary sampling units (PSUs), typically a single county or group of contiguous counties, who had intensity count data from their accelerometers. To avoid potential bias and loss in efficiency in estimation and inference involving the steps data, we considered methods to accurately impute the missing values for steps collected in the 2003-2004 NHANES. The objective was to come up with an efficient imputation method which minimized model-based assumptions. We adopted a multiple imputation approach based on Additive Regression, Bootstrapping and Predictive mean matching (ARBP) methods. This method fits alternative conditional expectation (ace) models, which use an automated procedure to estimate optimal transformations for both the predictor and response variables. This paper describes the approaches used in this imputation and evaluates the methods by comparing the distributions of the original and the imputed data. A simulation study using the observed data is also conducted as part of the model diagnostics. Finally some real data analyses are performed to compare the before and after imputation results. PMID:27488606

Assessing the validity of a physical activity questionnaire developed for parents of preschool children in Mexico.

PubMed

Bacardi-Gascón, Montserrat; Reveles-Rojas, Claudia; Woodward-Lopez, Gail; Crawford, Patricia; Jiménez-Cruz, Arturo

2012-12-01

To assess the validity of a questionnaire developed for parents of preschool children to know their physical activity (PA) status, we compared the questionnaire results with the measures of accelerometer for children's activities. Thirty-five preschoolers who wore the accelerometer for at least 10 hours daily on 3 weekdays and one weekend day were included in the analyses. Time spent in activities of varied intensity was calculated by applying 15-second ActiGraph count cutoffs (ACC). Parents' perceptions of their children's PA were associated with the percentage of vigorous and moderate physical activity recorded with ACC at r = 0.62 (p = 0.0001). An association was shown between the percentage of a child's time spent in vigorous physical activity, as reported by parents, with that measured by ACC at r = 0.53 (p = 0.001). Results of this study suggest that the designed questionnaire might be a useful tool for assessing children's activity while, additionally, it warrants further investigation on larger samples of children.

Assessing the Validity of a Physical Activity Questionnaire Developed for Parents of Preschool Children in Mexico

PubMed Central

Bacardi-Gascón, Montserrat; Reveles-Rojas, Claudia; Woodward-Lopez, Gail; Crawford, Patricia

2012-01-01

To assess the validity of a questionnaire developed for parents of preschool children to know their physical activity (PA) status, we compared the questionnaire results with the measures of accelerometer for children's activities. Thirty-five preschoolers who wore the accelerometer for at least 10 hours daily on 3 weekdays and one weekend day were included in the analyses. Time spent in activities of varied intensity was calculated by applying 15-second ActiGraph count cutoffs (ACC). Parents’ perceptions of their children's PA were associated with the percentage of vigorous and moderate physical activity recorded with ACC at r=0.62 (p=0.0001). An association was shown between the percentage of a child's time spent in vigorous physical activity, as reported by parents, with that measured by ACC at r=0.53 (p=0.001). Results of this study suggest that the designed questionnaire might be a useful tool for assessing children's activity while, additionally, it warrants further investigation on larger samples of children. PMID:23304910

Physical activity of Canadian children and youth: accelerometer results from the 2007 to 2009 Canadian Health Measures Survey.

PubMed

Colley, Rachel C; Garriguet, Didier; Janssen, Ian; Craig, Cora L; Clarke, Janine; Tremblay, Mark S

2011-03-01

Physical activity is an important determinant of health and fitness. This study provides contemporary estimates of the physical activity levels of Canadians aged 6 to 19 years. Data are from the 2007 to 2009 Canadian Health Measures Survey. The physical activity of a nationally representative sample was measured using accelerometers. Data are presented as time spent in sedentary, light, moderate and vigorous intensity movement, and in steps accumulated per day. An estimated 9% of boys and 4% of girls accumulate 60 minutes of moderate-to-vigorous physical activity on at least 6 days a week. Regardless of age group, boys are more active than girls. Canadian children and youth spend 8.6 hours per day-62% of their waking hours-in sedentary pursuits. Daily step counts average 12,100 for boys and 10,300 for girls. Based on objective and robust measures, physical activity levels of Canadian children and youth are low.

Eliciting upper extremity purposeful movements using video games: a comparison with traditional therapy for stroke rehabilitation.

PubMed

Rand, Debbie; Givon, Noa; Weingarden, Harold; Nota, Ayala; Zeilig, Gabi

2014-10-01

Video games have become popular in stroke rehabilitation; however, the nature of this intervention is not fully understood. To compare the number of (a) purposeful and nonpurposeful repetitions of the weaker upper extremity (UE) and (b) movement accelerations as assessed by accelerometer activity counts of the weaker and stronger UEs of individuals with chronic stroke while playing video games or participating in traditional therapy. Twenty-nine individuals (mean age 59 years, 1-7 years poststroke) took part in a group intervention of video -games (n = 15) or traditional therapy (n = 14) as part of a randomized controlled trial. During 1-2 sessions, participants were video-taped while wearing wrist accelerometers. Assessors counted the number of repetitions and classified movements as purposeful or nonpurposeful using videotapes. The weaker UE motor impairments were correlated to movement accelerations, to determine if participants were using their potential during the sessions. Participants in the video game group performed a median of 271 purposeful movements and 37 970 activity counts compared to 48 purposeful movements and 14,872 activity counts in the traditional group (z = -3.0, P = .001 and z = -1.9, P = .05, respectively). Participants in the traditional group performed a median of 26 nonpurposeful (exercises) compared with 0 in the video game group (z = -4.2, P = .000). Strong significant correlations were found between the motor ability of the weak UE to repetitions of participants in both groups (r = .86, P < .01). Participants with higher motor ability performed more repetitions. Video games elicited more UE purposeful repetitions and higher acceleration of movement compared with traditional therapy in individuals with chronic stroke. © The Author(s) 2014.

Sedentary Time and Physical Activity Surveillance Through Accelerometer Pooling in Four European Countries.

PubMed

Loyen, Anne; Clarke-Cornwell, Alexandra M; Anderssen, Sigmund A; Hagströmer, Maria; Sardinha, Luís B; Sundquist, Kristina; Ekelund, Ulf; Steene-Johannessen, Jostein; Baptista, Fátima; Hansen, Bjørge H; Wijndaele, Katrien; Brage, Søren; Lakerveld, Jeroen; Brug, Johannes; van der Ploeg, Hidde P

2017-07-01

The objective of this study was to pool, harmonise and re-analyse national accelerometer data from adults in four European countries in order to describe population levels of sedentary time and physical inactivity. Five cross-sectional studies were included from England, Portugal, Norway and Sweden. ActiGraph accelerometer count data were centrally processed using the same algorithms. Multivariable logistic regression analyses were conducted to study the associations of sedentary time and physical inactivity with sex, age, weight status and educational level, in both the pooled sample and the separate study samples. Data from 9509 participants were used. On average, participants were sedentary for 530 min/day, and accumulated 36 min/day of moderate to vigorous intensity physical activity. Twenty-three percent accumulated more than 10 h of sedentary time/day, and 72% did not meet the physical activity recommendations. Nine percent of all participants were classified as high sedentary and low active. Participants from Norway showed the highest levels of sedentary time, while participants from England were the least physically active. Age and weight status were positively associated with sedentary time and not meeting the physical activity recommendations. Men and higher-educated people were more likely to be highly sedentary, while women and lower-educated people were more likely to be inactive. We found high levels of sedentary time and physical inactivity in four European countries. Older people and obese people were most likely to display these behaviours and thus deserve special attention in interventions and policy planning. In order to monitor these behaviours, accelerometer-based cross-European surveillance is recommended.

An Experimental Study in Determining Energy Expenditure from Treadmill Walking using Hip-Worn Inertial Sensors

PubMed Central

Vathsangam, Harshvardhan; Emken, Adar; Schroeder, E. Todd; Spruijt-Metz, Donna; Sukhatme, Gaurav S.

2011-01-01

This paper describes an experimental study in estimating energy expenditure from treadmill walking using a single hip-mounted triaxial inertial sensor comprised of a triaxial accelerometer and a triaxial gyroscope. Typical physical activity characterization using accelerometer generated counts suffers from two drawbacks - imprecison (due to proprietary counts) and incompleteness (due to incomplete movement description). We address these problems in the context of steady state walking by directly estimating energy expenditure with data from a hip-mounted inertial sensor. We represent the cyclic nature of walking with a Fourier transform of sensor streams and show how one can map this representation to energy expenditure (as measured by V O2 consumption, mL/min) using three regression techniques - Least Squares Regression (LSR), Bayesian Linear Regression (BLR) and Gaussian Process Regression (GPR). We perform a comparative analysis of the accuracy of sensor streams in predicting energy expenditure (measured by RMS prediction accuracy). Triaxial information is more accurate than uniaxial information. LSR based approaches are prone to outlier sensitivity and overfitting. Gyroscopic information showed equivalent if not better prediction accuracy as compared to accelerometers. Combining accelerometer and gyroscopic information provided better accuracy than using either sensor alone. We also analyze the best algorithmic approach among linear and nonlinear methods as measured by RMS prediction accuracy and run time. Nonlinear regression methods showed better prediction accuracy but required an order of magnitude of run time. This paper emphasizes the role of probabilistic techniques in conjunction with joint modeling of triaxial accelerations and rotational rates to improve energy expenditure prediction for steady-state treadmill walking. PMID:21690001

Changes in physical activity during the transition from primary to secondary school in Belgian children: what is the role of the school environment?

PubMed

De Meester, Femke; Van Dyck, Delfien; De Bourdeaudhuij, Ilse; Deforche, Benedicte; Cardon, Greet

2014-03-19

Key life periods have been associated with changes in physical activity (PA). This study investigated (1) how PA changes when primary school children transfer to secondary school, (2) if school environmental characteristics differ between primary and secondary schools and (3) if changes in school environmental characteristics can predict changes in PA in Belgian schoolchildren. Moderating effects of gender and the baseline level of PA were investigated for the first and third research question. In total, 736 children (10-13 years) of the last year of primary school participated in the first phase of this longitudinal study. Two years later, 502 of these children (68.2%) agreed to participate in the second phase. Accelerometers, pedometers and the Flemish Physical Activity Questionnaire were used to measure PA. School environmental characteristics were reported by the school principals. Cross-classified regression models were conducted to analyze the data. Self-reported active transport to school and accelerometer weekday moderate to vigorous PA (MVPA) increased after the transition to secondary school while self-reported extracurricular PA and total PA decreased. Pedometer weekday step counts decreased, but this decrease was only apparent among those who achieved the PA guidelines in primary school.Secondary schools scored higher on the school environmental characteristics: provision of sports and PA during lunch break, active schoolyards and playgrounds and health education policy but lower on sports and PA after-school than primary schools. Changes in the school environmental characteristics: active commuting to school, active schoolyards and playgrounds and health education policy resulted in changes in self-reported extracurricular PA, total PA , pedometer/accelerometer determined step counts and accelerometer determined MVPA. Moderating effects were found for baseline PA and gender. PA changed after the transition to secondary school. In general, secondary schools seem more likely to foster strategies to promote PA during school hours than primary schools who seem more likely to foster strategies to promote PA after school. Changes in school environmental characteristics may contribute to changes in PA. Thus, if confirmed in future studies, efforts are needed to implement these components in schools as early as possible to positively affect the change in PA.

Evolution of accelerometer methods for physical activity research.

PubMed

Troiano, Richard P; McClain, James J; Brychta, Robert J; Chen, Kong Y

2014-07-01

The technology and application of current accelerometer-based devices in physical activity (PA) research allow the capture and storage or transmission of large volumes of raw acceleration signal data. These rich data not only provide opportunities to improve PA characterisation, but also bring logistical and analytic challenges. We discuss how researchers and developers from multiple disciplines are responding to the analytic challenges and how advances in data storage, transmission and big data computing will minimise logistical challenges. These new approaches also bring the need for several paradigm shifts for PA researchers, including a shift from count-based approaches and regression calibrations for PA energy expenditure (PAEE) estimation to activity characterisation and EE estimation based on features extracted from raw acceleration signals. Furthermore, a collaborative approach towards analytic methods is proposed to facilitate PA research, which requires a shift away from multiple independent calibration studies. Finally, we make the case for a distinction between PA represented by accelerometer-based devices and PA assessed by self-report. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Office workers' objectively measured sedentary behavior and physical activity during and outside working hours.

PubMed

Clemes, Stacy A; O'Connell, Sophie E; Edwardson, Charlotte L

2014-03-01

To examine objectively determined sedentary behavior and physical activity (PA) during and outside working hours in full-time office workers. A total of 170 participants wore an ActiGraph GT1M accelerometer for 7 days. Time spent sedentary (<100 counts/min), in light-intensity PA (100 to 1951 counts/min), and moderate-to-vigorous PA (≥1952 counts/min) was calculated for workdays (including working hours and nonworking hours) and nonworkdays. Participants accumulated significantly higher levels of sedentary behavior (68% vs 60%) and lower levels of light-intensity activity (28% vs 36%) on workdays in comparison with nonworkdays. Up to 71% of working hours were spent sedentary. Individuals who were most sedentary at work were also more sedentary outside work. Those who are most sedentary at work do not compensate by increasing their PA or reducing their sedentary time outside work. Occupational interventions should address workplace and leisure-time sedentary behavior.

Accelerometer profiles of physical activity and inactivity in normal weight, overweight, and obese U.S. men and women.

PubMed

Tudor-Locke, Catrine; Brashear, Meghan M; Johnson, William D; Katzmarzyk, Peter T

2010-08-03

The 2005-2006 National Health and Nutrition Examination Survey (NHANES) is used to describe an accelerometer-derived physical activity/inactivity profile in normal weight (BMI < 25 kg/m2), overweight (25 /= 30 kg/m2) U.S. adults. We computed physical activity volume indicators (activity counts/day, uncensored and censored steps/day), rate indicators (e.g., steps/minute), time indicators (employing NHANES activity counts/minute cut points to infer time in non-wear, sedentary, low, light, moderate, and vigorous intensities), the number of breaks in sedentary time (occasions when activity counts rose from < 100 activity/counts in one minute to >/= 100 activity counts in the subsequent minute), achievement of public health guidelines, and classification by step-defined physical activity levels. Data were examined for evidence of consistent and significant gradients across BMI-defined categories. In 2005-2006, U.S adults averaged 6,564 +/- SE 107 censored steps/day, and after considering non-wear time, they spent approximately 56.8% of the rest of the waking day in sedentary time, 23.7% in low intensity, 16.7% in light intensity, 2.6% in moderate intensity, and 0.2% in vigorous intensity. Overall, approximately 3.2% of U.S. adults achieved public health guidelines. The normal weight category took 7,190 +/- SE 157 steps/day, and spent 25.7 +/- 0.9 minutes/day in moderate intensity and 7.3 +/- 0.4 minutes/day in vigorous intensity physical activity. The corresponding numbers for the overweight category were 6,879 +/- 140 steps/day, 25.3 +/- 0.9 minutes/day, and 5.3 +/- 0.5 minutes/day and for the obese category 5,784 +/- 124 steps/day, 17.3 +/- 0.7 minutes/day and 3.2 +/- 0.4 minutes/day. Across BMI categories, increasing gradients and significant trends were apparent in males for sedentary time and decreasing gradients and significant trends were evident in time spent in light intensity, moderate intensity, and vigorous intensity. For females, there were only consistent gradients and significant trends apparent for decreasing amounts of time spent in moderate and vigorous intensity. Simple indicators of physical activity volume (i.e., steps/day) and time in light, moderate or vigorous intensity physical activity differ across BMI categories for both sexes, suggesting that these should continue to be targets for surveillance.

Assessment of Objectively Measured Physical Activity Levels in Individuals with Intellectual Disabilities with and without Down's Syndrome

PubMed Central

Phillips, Alexander C.; Holland, Anthony J.

2011-01-01

Objective To investigate, using accelerometers, the levels of physical activity being undertaken by individuals with intellectual disabilities with and without Down's syndrome. Methods One hundred and fifty two individuals with intellectual disabilities aged 12–70 years from East and South-East England. Physical activity levels in counts per minute (counts/min), steps per day (steps/day), and minutes of sedentary, light, moderate, vigorous, and moderate to vigorous physical activity (MVPA) measured with a uni-axial accelerometer (Actigraph GT1M) for seven days. Results No individuals with intellectual disabilities met current physical activity recommendations. Males were more active than females. There was a trend for physical activity to decline and sedentary behaviour to increase with age, and for those with more severe levels of intellectual disability to be more sedentary and less physically active, however any relationship was not significant when adjusted for confounding variables. Participants with Down's syndrome engaged in significantly less physical activity than those with intellectual disabilities without Down's syndrome and levels of activity declined significantly with age. Conclusions Individuals with intellectual disabilities, especially those with Down's syndrome may be at risk of developing diseases associated with physical inactivity. There is a need for well-designed, accessible, preventive health promotion strategies and interventions designed to raise the levels of physical activity for individuals with intellectual disabilities. We propose that there are physiological reasons why individuals with Down's syndrome have particularly low levels of physical activity that also decline markedly with age. PMID:22205957

Screening Physical Activity in Family Practice: Validity of the Spanish Version of a Brief Physical Activity Questionnaire

PubMed Central

Puig-Ribera, Anna; Martín-Cantera, Carlos; Puigdomenech, Elisa; Real, Jordi; Romaguera, Montserrat; Magdalena-Belio, José Félix; Recio-Rodríguez, Jose Ignacio; Rodriguez-Martin, Beatriz; Arietaleanizbeaskoa, Maria Soledad; Repiso–Gento, Irene; Garcia-Ortiz, Luis

2015-01-01

Objectives The use of brief screening tools to identify inactive patients is essential to improve the efficiency of primary care-based physical activity (PA) programs. However, the current employment of short PA questionnaires within the Spanish primary care pathway is unclear. This study evaluated the validity of the Spanish version of a Brief Physical Activity Assessment Tool (SBPAAT). Methods A validation study was carried out within the EVIDENT project. A convenience sample of patients (n = 1,184; age 58.9±13.7 years; 60.5% female) completed the SBPAAT and the 7-day Physical Activity Recall (7DPAR) and, in addition, wore an accelerometer (ActiGraph GT3X) for seven consecutive days. Validity was evaluated by measuring agreement, Kappa correlation coefficients, sensitivity and specificity in achieving current PA recommendations with the 7DPAR. Pearson correlation coefficients with the number of daily minutes engaged in moderate and vigorous intensity PA according to the accelerometer were also assessed. Comparison with accelerometer counts, daily minutes engaged in sedentary, light, moderate, and vigorous intensity PA, total daily kilocalories, and total PA and leisure time expenditure (METs-hour-week) between the sufficiently and insufficiently active groups identified by SBPAAT were reported. Results The SBPAAT identified 41.3% sufficiently active (n = 489) and 58.7% insufficiently active (n = 695) patients; it showed moderate validity (k = 0.454, 95% CI: 0.402–0.505) and a specificity and sensitivity of 74.3% and 74.6%, respectively. Validity was fair for identifying daily minutes engaged in moderate (r = 0.215, 95% CI:0.156 to 0.272) and vigorous PA (r = 0.282, 95% CI:0.165 to 0.391). Insufficiently active patients according to the SBPAAT significantly reported fewer counts/minute (-22%), fewer minutes/day of moderate (-11.38) and vigorous PA (-2.69), spent fewer total kilocalories/day (-753), and reported a lower energy cost (METs-hour-week) of physical activities globally (-26.82) and during leisure time (-19.62). Conclusions The SBPAAT is a valid tool to identify Spanish-speaking patients who are insufficiently active to achieve health benefits. PMID:26379036

Screening Physical Activity in Family Practice: Validity of the Spanish Version of a Brief Physical Activity Questionnaire.

PubMed

Puig-Ribera, Anna; Martín-Cantera, Carlos; Puigdomenech, Elisa; Real, Jordi; Romaguera, Montserrat; Magdalena-Belio, José Félix; Recio-Rodríguez, Jose Ignacio; Rodriguez-Martin, Beatriz; Arietaleanizbeaskoa, Maria Soledad; Repiso-Gento, Irene; Garcia-Ortiz, Luis

2015-01-01

The use of brief screening tools to identify inactive patients is essential to improve the efficiency of primary care-based physical activity (PA) programs. However, the current employment of short PA questionnaires within the Spanish primary care pathway is unclear. This study evaluated the validity of the Spanish version of a Brief Physical Activity Assessment Tool (SBPAAT). A validation study was carried out within the EVIDENT project. A convenience sample of patients (n = 1,184; age 58.9±13.7 years; 60.5% female) completed the SBPAAT and the 7-day Physical Activity Recall (7DPAR) and, in addition, wore an accelerometer (ActiGraph GT3X) for seven consecutive days. Validity was evaluated by measuring agreement, Kappa correlation coefficients, sensitivity and specificity in achieving current PA recommendations with the 7DPAR. Pearson correlation coefficients with the number of daily minutes engaged in moderate and vigorous intensity PA according to the accelerometer were also assessed. Comparison with accelerometer counts, daily minutes engaged in sedentary, light, moderate, and vigorous intensity PA, total daily kilocalories, and total PA and leisure time expenditure (METs-hour-week) between the sufficiently and insufficiently active groups identified by SBPAAT were reported. The SBPAAT identified 41.3% sufficiently active (n = 489) and 58.7% insufficiently active (n = 695) patients; it showed moderate validity (k = 0.454, 95% CI: 0.402-0.505) and a specificity and sensitivity of 74.3% and 74.6%, respectively. Validity was fair for identifying daily minutes engaged in moderate (r = 0.215, 95% CI:0.156 to 0.272) and vigorous PA (r = 0.282, 95% CI:0.165 to 0.391). Insufficiently active patients according to the SBPAAT significantly reported fewer counts/minute (-22%), fewer minutes/day of moderate (-11.38) and vigorous PA (-2.69), spent fewer total kilocalories/day (-753), and reported a lower energy cost (METs-hour-week) of physical activities globally (-26.82) and during leisure time (-19.62). The SBPAAT is a valid tool to identify Spanish-speaking patients who are insufficiently active to achieve health benefits.

Cross-sectional time series and multivariate adaptive regression splines models using accelerometry and heart rate predict energy expenditure of preschoolers

USDA-ARS?s Scientific Manuscript database

Prediction equations of energy expenditure (EE) using accelerometers and miniaturized heart rate (HR) monitors have been developed in older children and adults but not in preschool-aged children. Because the relationships between accelerometer counts (ACs), HR, and EE are confounded by growth and ma...

Design and Evaluation of a Computer-Based 24-Hour Physical Activity Recall (cpar24) Instrument.

PubMed

Kohler, Simone; Behrens, Gundula; Olden, Matthias; Baumeister, Sebastian E; Horsch, Alexander; Fischer, Beate; Leitzmann, Michael F

2017-05-30

Widespread access to the Internet and an increasing number of Internet users offers the opportunity of using Web-based recalls to collect detailed physical activity data in epidemiologic studies. The aim of this investigation was to evaluate the validity and reliability of a computer-based 24-hour physical activity recall (cpar24) instrument with respect to the recalled 24-h period. A random sample of 67 German residents aged 22 to 70 years was instructed to wear an ActiGraph GT3X+ accelerometer for 3 days. Accelerometer counts per min were used to classify activities as sedentary (<100 counts per min), light (100-1951 counts per min), and moderate to vigorous (≥1952 counts per min). On day 3, participants were also requested to specify the type, intensity, timing, and context of all activities performed during day 2 using the cpar24. Using metabolic equivalent of task (MET), the cpar24 activities were classified as sedentary (<1.5 MET), light (1.5-2.9 MET), and moderate to vigorous (≥3.0 MET). The cpar24 was administered twice at a 3-h interval. The Spearman correlation coefficient (r) was used as primary measure of concurrent validity and test-retest reliability. As compared with accelerometry, the cpar24 underestimated light activity by -123 min (median difference, P difference <.001) and overestimated moderate to vigorous activity by 89 min (P difference <.001). By comparison, time spent sedentary assessed by the 2 methods was similar (median difference=+7 min, P difference=.39). There was modest agreement between the cpar24 and accelerometry regarding sedentary (r=.54), light (r=.46), and moderate to vigorous (r=.50) activities. Reliability analyses revealed modest to high intraclass correlation coefficients for sedentary (r=.75), light (r=.65), and moderate to vigorous (r=.92) activities and no statistically significant differences between replicate cpar24 measurements (median difference for sedentary activities=+10 min, for light activities=-5 min, for moderate to vigorous activities=0 min, all P difference ≥.60). These data show that the cpar24 is a valid and reproducible Web-based measure of physical activity in adults. ©Simone Kohler, Gundula Behrens, Matthias Olden, Sebastian E Baumeister, Alexander Horsch, Beate Fischer, Michael F Leitzmann. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 30.05.2017.

Active living neighborhoods: is neighborhood walkability a key element for Belgian adolescents?

PubMed

De Meester, Femke; Van Dyck, Delfien; De Bourdeaudhuij, Ilse; Deforche, Benedicte; Sallis, James F; Cardon, Greet

2012-01-04

In adult research, neighborhood walkability has been acknowledged as an important construct among the built environmental correlates of physical activity. Research into this association has only recently been extended to adolescents and the current empirical evidence is not consistent. This study investigated whether neighborhood walkability and neighborhood socioeconomic status (SES) are associated with physical activity among Belgian adolescents and whether the association between neighborhood walkability and physical activity is moderated by neighborhood SES and gender. In Ghent (Belgium), 32 neighborhoods were selected based on GIS-based walkability and SES derived from census data. In total, 637 adolescents (aged 13-15 year, 49.6% male) participated in the study. Physical activity was assessed using accelerometers and the Flemish Physical Activity Questionnaire. To analyze the associations between neighborhood walkability, neighborhood SES and individual physical activity, multivariate multi-level regression analyses were conducted. Only in low-SES neighborhoods, neighborhood walkability was positively associated with accelerometer-based moderate to vigorous physical activity and the average activity level expressed in counts/minute. For active transport to and from school, cycling for transport during leisure time and sport during leisure time no association with neighborhood walkability nor, with neighborhood SES was found. For walking for transport during leisure time a negative association with neighborhood SES was found. Gender did not moderate the associations of neighborhood walkability and SES with adolescent physical activity. Neighborhood walkability was related to accelerometer-based physical activity only among adolescent boys and girls living in low-SES neighborhoods. The relation of built environment to adolescent physical activity may depend on the context.

Active living neighborhoods: is neighborhood walkability a key element for Belgian adolescents?

PubMed Central

2012-01-01

Background In adult research, neighborhood walkability has been acknowledged as an important construct among the built environmental correlates of physical activity. Research into this association has only recently been extended to adolescents and the current empirical evidence is not consistent. This study investigated whether neighborhood walkability and neighborhood socioeconomic status (SES) are associated with physical activity among Belgian adolescents and whether the association between neighborhood walkability and physical activity is moderated by neighborhood SES and gender. Methods In Ghent (Belgium), 32 neighborhoods were selected based on GIS-based walkability and SES derived from census data. In total, 637 adolescents (aged 13-15 year, 49.6% male) participated in the study. Physical activity was assessed using accelerometers and the Flemish Physical Activity Questionnaire. To analyze the associations between neighborhood walkability, neighborhood SES and individual physical activity, multivariate multi-level regression analyses were conducted. Results Only in low-SES neighborhoods, neighborhood walkability was positively associated with accelerometer-based moderate to vigorous physical activity and the average activity level expressed in counts/minute. For active transport to and from school, cycling for transport during leisure time and sport during leisure time no association with neighborhood walkability nor, with neighborhood SES was found. For walking for transport during leisure time a negative association with neighborhood SES was found. Gender did not moderate the associations of neighborhood walkability and SES with adolescent physical activity. Conclusions Neighborhood walkability was related to accelerometer-based physical activity only among adolescent boys and girls living in low-SES neighborhoods. The relation of built environment to adolescent physical activity may depend on the context. PMID:22216923

Accelerometry-based monitoring of daily physical activity in children with juvenile idiopathic arthritis.

PubMed

Nørgaard, M; Twilt, M; Andersen, L B; Herlin, T

2016-01-01

Juvenile idiopathic arthritis (JIA) may cause functional impairment, reduced participation in physical activity (PA) and, over time, physical deconditioning. The aim of this study was to objectively monitor daily free-living PA in 10-16-year-old children with JIA using accelerometry with regard to disease activity and physical variables and to compare the data with those from healthy age- and gender-matched controls. Patients underwent an evaluation of disease activity, functional ability, physical capacity, and pain. Accelerometer monitoring was assessed using the GT1M ActiGraph. Normative data from two major studies on PA in Danish schoolchildren were used for comparison. Data of accelerometry were available for 61 JIA patients and 2055 healthy controls. Of the JIA patients, 57% showed below-average values of maximal physical capacity (fitness level). JIA patients showed low disease activity and pain and were physically well functioning. Accelerometer counts were lower in JIA patients than in controls. Accelerometer measurements were negatively correlated with disease activity, erythrocyte sedimentation rate (ESR), and number of joints with swelling and/or limited range of motion (ROM). No correlation was found between PA and pain scores, functional ability, and hypermobility. Patients with involvement of ankles or hips demonstrated significantly lower levels of PA. Children with JIA are less physically active and have lower physical capacity and fitness than their age- and gender-matched healthy peers despite good disease control. The involvement of hips or ankles is associated with lower PA.

Differences in daily in-hospital physical activity and geriatric nutritional risk index in older cardiac inpatients: preliminary results.

PubMed

Izawa, Kazuhiro P; Watanabe, Satoshi; Oka, Koichiro; Osada, Naohiko; Omiya, Kazuto; Brubaker, Peter H; Shimizu, Hiroyuki

2014-12-01

Little is known about the differences in the geriatric nutritional risk index (GNRI) status in older patients and their relationship to accelerometer-derived measures of physical activity (PA) levels. We determined both differences in daily measured PA based on the GNRI and related cut-off values for PA in elderly cardiac inpatients. We divided 235 consecutive elderly cardiac inpatients (mean age 73.6 years, men 70.6%) into four groups by age and GNRI: older-high group, 65-74 years with high GNRI (≥92 points) (n = 111); older-low group, low GNRI (<92 points) (n = 30); very old-high group, ≥75 years with high GNRI (n = 55); and very old-low group with low GNRI (n = 39). Average step count and physical activity energy expenditure (PAEE in kcal) per day for 2 days of these inpatients were assessed by accelerometer and compared between the four groups to determine cut-off values of PA. Step counts and PAEE were significantly lower in the low-GNRI versus high-GNRI groups in the older (2,742.1 vs. 4,198.1 steps, 55.4 vs. 101.3 kcal, P < 0.001), and very old (2,469.6 vs. 3,423.7 steps, 54.5 vs. 79.1 kcal, P < 0.001) cardiac inpatients. Respective cut-off values for step counts and PAEE were 3,017.6 steps/day and 69.4 kcal (P < 0.01) in the older and 2,579.4 steps/day and 58.8 kcal in the very old cardiac inpatients (P < 0.01). Poor nutritional status, as indicated by a low GNRI, may be a useful predictor of step counts and PAEE. The cut-off values determined in this study might be target values to be attained by older cardiac inpatients.

Obesity History and Daily Patterns of Physical Activity at Age 60-64 Years: Findings From the MRC National Survey of Health and Development.

PubMed

Cooper, Rachel; Huang, Lei; Hardy, Rebecca; Crainiceanu, Adina; Harris, Tamara; Schrack, Jennifer A; Crainiceanu, Ciprian; Kuh, Diana

2017-10-01

The aim of this study was to investigate associations of current body mass index (BMI) and obesity history with daily patterns of physical activity. At age 60-64, participants from a British birth cohort study wore accelerometers for 5 days. Accelerometry counts were log-transformed and mean log-counts were used to derive a summary variable indicating total daily log-activity counts. Among those with complete data (n = 1,388) the associations of current BMI and age of first obesity were examined with: (a) total daily log-activity counts and (b) total log-activity counts in four segments of the day. Higher current BMI and younger age at obesity were strongly associated with lower levels of total daily activity at age 60-64 even after adjustment for sex, socioeconomic factors, and health status. The fully-adjusted mean difference in total daily log-activity counts was -581.7 (95% confidence interval: -757.2, -406.3) when comparing BMI ≥35 kg/m2 with <25 kg/m2, representing an 18.4% difference. Participants who had been obese since early adulthood had the lowest levels of activity (mean difference in total daily log-activity counts was -413.1 (-638.1, -188.2) when comparing those who were obese by age 26 or 36 with those who were never obese, representing a 13.1% difference). Obese older adults may require targeted interventions and additional support to improve their daily activity levels. As younger generations with greater lifetime exposure to obesity reach old age the proportion of adults achieving sufficient levels of activity to realize its associated health benefits is likely to decline. © The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America.

Obesity History and Daily Patterns of Physical Activity at Age 60–64 Years: Findings From the MRC National Survey of Health and Development

PubMed Central

Cooper, Rachel; Huang, Lei; Hardy, Rebecca; Crainiceanu, Adina; Harris, Tamara; Schrack, Jennifer A; Crainiceanu, Ciprian; Kuh, Diana

2017-01-01

Abstract Background The aim of this study was to investigate associations of current body mass index (BMI) and obesity history with daily patterns of physical activity. Methods At age 60–64, participants from a British birth cohort study wore accelerometers for 5 days. Accelerometry counts were log-transformed and mean log-counts were used to derive a summary variable indicating total daily log-activity counts. Among those with complete data (n = 1,388) the associations of current BMI and age of first obesity were examined with: (a) total daily log-activity counts and (b) total log-activity counts in four segments of the day. Results Higher current BMI and younger age at obesity were strongly associated with lower levels of total daily activity at age 60–64 even after adjustment for sex, socioeconomic factors, and health status. The fully-adjusted mean difference in total daily log-activity counts was −581.7 (95% confidence interval: −757.2, −406.3) when comparing BMI ≥35 kg/m2 with <25 kg/m2, representing an 18.4% difference. Participants who had been obese since early adulthood had the lowest levels of activity (mean difference in total daily log-activity counts was −413.1 (−638.1, −188.2) when comparing those who were obese by age 26 or 36 with those who were never obese, representing a 13.1% difference). Conclusions Obese older adults may require targeted interventions and additional support to improve their daily activity levels. As younger generations with greater lifetime exposure to obesity reach old age the proportion of adults achieving sufficient levels of activity to realize its associated health benefits is likely to decline. PMID:28329086

Walking Objectively Measured: Classifying Accelerometer Data with GPS and Travel Diaries

PubMed Central

Kang, Bumjoon; Moudon, Anne V.; Hurvitz, Philip M.; Reichley, Lucas; Saelens, Brian E.

2013-01-01

Purpose This study developed and tested an algorithm to classify accelerometer data as walking or non-walking using either GPS or travel diary data within a large sample of adults under free-living conditions. Methods Participants wore an accelerometer and a GPS unit, and concurrently completed a travel diary for 7 consecutive days. Physical activity (PA) bouts were identified using accelerometry count sequences. PA bouts were then classified as walking or non-walking based on a decision-tree algorithm consisting of 7 classification scenarios. Algorithm reliability was examined relative to two independent analysts’ classification of a 100-bout verification sample. The algorithm was then applied to the entire set of PA bouts. Results The 706 participants’ (mean age 51 years, 62% female, 80% non-Hispanic white, 70% college graduate or higher) yielded 4,702 person-days of data and had a total of 13,971 PA bouts. The algorithm showed a mean agreement of 95% with the independent analysts. It classified physical activity into 8,170 (58.5 %) walking bouts and 5,337 (38.2%) non-walking bouts; 464 (3.3%) bouts were not classified for lack of GPS and diary data. Nearly 70% of the walking bouts and 68% of the non-walking bouts were classified using only the objective accelerometer and GPS data. Travel diary data helped classify 30% of all bouts with no GPS data. The mean duration of PA bouts classified as walking was 15.2 min (SD=12.9). On average, participants had 1.7 walking bouts and 25.4 total walking minutes per day. Conclusions GPS and travel diary information can be helpful in classifying most accelerometer-derived PA bouts into walking or non-walking behavior. PMID:23439414

Home-based system for physical activity monitoring in patients with multiple sclerosis (Pilot study).

PubMed

Shammas, Layal; Zentek, Tom; von Haaren, Birte; Schlesinger, Stefan; Hey, Stefan; Rashid, Asarnusch

2014-02-06

Limitations in physical activity are considered as a key problem in patients with multiple sclerosis (PwMS). Contemporary methods to assess the level of physical activity in PwMS are regular clinical observation. However, these methods either rely on high recall and accurate reporting from the patients (e.g. self-report questionnaires), or they are conducted during a particular clinical assessment with predefined activities. Therefore, the main aim of this pilot study was to develop an objective method to gather information about the real type and intensity of daily activities performed by PwMS in every-day living situations using an accelerometer. Furthermore, the accelerometer-derived measures are investigated regarding their potential for discriminating between different MS groups. Eleven PwMS that were able to walk independently (EDSS ≤ 5) were divided into two groups: mild disability (EDSS 1-2.5; n = 6) and moderate disability (EDSS 3 -5; n = 5). Participants made use of an activity monitor device attached to their waist during their normal daily activities over 4 measurements. Activity parameters were assessed and compared for the time of each participant's first measurement and follow-up measurement. Furthermore, differences between both subgroups, and the correlation of activity parameters with the clinical neurological variable (EDSS) were investigated. Participants showed significant decline in step count (p = 0.008), maximum walking speed (p = 0.02) and physical activity intensity (p = 0.03) throughout the study period. Compared to the mild subgroup, moderate affected participant accumulated less number of steps (G1: 9214.33 ± 2439.11, G2: 5018.13 ± 2416.96; p < 0.005) and were slower (G1: 1.48 ± 0.19, G2: 1.12 ± 0.44; p = 0.03). Additionally, the EDSS correlated negatively with mean walking speed (r = - 0.71, p = 0.01) and steps count (r = - 0.54, p = 0.08). In this study, we used a portable activity monitoring sensor to gather information about everyday physical activity in PwMS at home. We showed that objective measurements using simple 3D accelerometers can track daily physical activity fluctuation. Furthermore, they track disability changes better than clinical measures. Thus, they can help to develop activity based treatments for PwMS.

Preliminary efficacy of prize-based contingency management to increase activity levels in healthy adults.

PubMed

Washington, Wendy Donlin; Banna, Kelly M; Gibson, Amanda L

2014-01-01

An estimated 30% of Americans meet the criteria for obesity. Effective, low-cost interventions to increase physical activity are needed to prevent and treat obesity. In this study, 11 healthy adults wore Fitbit accelerometers for 3 weeks. During the initial baseline, subjects earned prize draws for wearing the Fitbit. During intervention, percentile schedules were used to calculate individual prize-draw criteria. The final week was a return to baseline. Four subjects increased step counts as a result of the intervention. A bout analysis of interresponse times revealed that subjects increased overall step counts by increasing daily minutes active and within-bout response rates and decreasing pauses between bouts of activity. Strategies to improve effectiveness are suggested, such as modification of reinforcement probability and amount and identification of the function of periods of inactivity. © Society for the Experimental Analysis of Behavior.

Comparison of Different Physical Activity Measurement Methods in Adults Aged 45 to 64 Years Under Free-Living Conditions.

PubMed

Lipert, Anna; Jegier, Anna

2017-07-01

To compare physical activity (PA) measured by 4 methods in adults under free-living conditions in relation to selected demographic and anthropometric variables. Cohort study. Department of Sports Medicine. Clinically healthy men (81) and women (69) aged 45 to 64 years. Physical activity monitoring for 7 consecutive days under free-living conditions by pedometer (P) and accelerometer (A) simultaneously and PA questionnaires: International Physical Activity Questionnaire (IPAQ) and Seven-Day Physical Activity Questionnaire Recall (SDPAR) completed after the 7-day PA. Comparison of PA measured by pedometer, IPAQ, and SDPAR with accelerometer with regard to age, body mass, gender, and obesity type. Total energy expenditure (EE) by IPAQ was higher than A (P < 0.001) in both groups regardless of age, body mass, or obesity type. Mean EE value by P was greater than A (P < 0.001) in central-obesity males and lower than A (P < 0.001) in central-obesity females. There were differences in step counts in women, unnoticed in men. SDPAR overestimated total EE in gynoid-obesity males and in central-obesity females compared with A. Ninety-five percent CI was the largest around IPAQ compared with P and SDPAR, with SDPAR showing the best agreement with A. Body mass and obesity type influenced PA measurements. To monitor PA, it is recommended to use pedometer in normal bodyweight and overweight groups while accelerometer is advisable in obese subjects. A combined approach of objective and subjective PA monitoring tools is preferable.

Factors Associated With Ambulatory Activity in De Novo Parkinson Disease.

PubMed

Christiansen, Cory; Moore, Charity; Schenkman, Margaret; Kluger, Benzi; Kohrt, Wendy; Delitto, Anthony; Berman, Brian; Hall, Deborah; Josbeno, Deborah; Poon, Cynthia; Robichaud, Julie; Wellington, Toby; Jain, Samay; Comella, Cynthia; Corcos, Daniel; Melanson, Ed

2017-04-01

Objective ambulatory activity during daily living has not been characterized for people with Parkinson disease prior to initiation of dopaminergic medication. Our goal was to characterize ambulatory activity based on average daily step count and examine determinants of step count in nonexercising people with de novo Parkinson disease. We analyzed baseline data from a randomized controlled trial, which excluded people performing regular endurance exercise. Of 128 eligible participants (mean ± SD = 64.3 ± 8.6 years), 113 had complete accelerometer data, which were used to determine daily step count. Multiple linear regression was used to identify factors associated with average daily step count over 10 days. Candidate explanatory variable categories were (1) demographics/anthropometrics, (2) Parkinson disease characteristics, (3) motor symptom severity, (4) nonmotor and behavioral characteristics, (5) comorbidities, and (6) cardiorespiratory fitness. Average daily step count was 5362 ± 2890 steps per day. Five factors explained 24% of daily step count variability, with higher step count associated with higher cardiorespiratory fitness (10%), no fear/worry of falling (5%), lower motor severity examination score (4%), more recent time since Parkinson disease diagnosis (3%), and the presence of a cardiovascular condition (2%). Daily step count in nonexercising people recruited for this intervention trial with de novo Parkinson disease approached sedentary lifestyle levels. Further study is warranted for elucidating factors explaining ambulatory activity, particularly cardiorespiratory fitness, and fear/worry of falling. Clinicians should consider the costs and benefits of exercise and activity behavior interventions immediately after diagnosis of Parkinson disease to attenuate the health consequences of low daily step count.Video Abstract available for more insights from the authors (see Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A170).

Comparability of children's sedentary time estimates derived from wrist worn GENEActiv and hip worn ActiGraph accelerometer thresholds.

PubMed

Boddy, Lynne M; Noonan, Robert J; Kim, Youngwon; Rowlands, Alex V; Welk, Greg J; Knowles, Zoe R; Fairclough, Stuart J

2018-03-28

To examine the comparability of children's free-living sedentary time (ST) derived from raw acceleration thresholds for wrist mounted GENEActiv accelerometer data, with ST estimated using the waist mounted ActiGraph 100count·min -1 threshold. Secondary data analysis. 108 10-11-year-old children (n=43 boys) from Liverpool, UK wore one ActiGraph GT3X+ and one GENEActiv accelerometer on their right hip and left wrist, respectively for seven days. Signal vector magnitude (SVM; mg) was calculated using the ENMO approach for GENEActiv data. ST was estimated from hip-worn ActiGraph data, applying the widely used 100count·min -1 threshold. ROC analysis using 10-fold hold-out cross-validation was conducted to establish a wrist-worn GENEActiv threshold comparable to the hip ActiGraph 100count·min -1 threshold. GENEActiv data were also classified using three empirical wrist thresholds and equivalence testing was completed. Analysis indicated that a GENEActiv SVM value of 51mg demonstrated fair to moderate agreement (Kappa: 0.32-0.41) with the 100count·min -1 threshold. However, the generated and empirical thresholds for GENEActiv devices were not significantly equivalent to ActiGraph 100count·min -1 . GENEActiv data classified using the 35.6mg threshold intended for ActiGraph devices generated significantly equivalent ST estimates as the ActiGraph 100count·min -1 . The newly generated and empirical GENEActiv wrist thresholds do not provide equivalent estimates of ST to the ActiGraph 100count·min -1 approach. More investigation is required to assess the validity of applying ActiGraph cutpoints to GENEActiv data. Future studies are needed to examine the backward compatibility of ST data and to produce a robust method of classifying SVM-derived ST. Copyright © 2018 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Sex differences in relationships between habitual physical activity and health in the elderly: practical implications for epidemiologists based on pedometer/accelerometer data from the Nakanojo Study.

PubMed

Aoyagi, Yukitoshi; Shephard, Roy J

2013-01-01

We review sex differences in the relationship between habitual physical activity and health in the elderly, with particular reference to pedometer/accelerometer data from the Nakanojo Study. Maximal aerobic power, walking speed and habitual physical activity are 10-30% greater in men than in women. This reflects not only biological but also socio-cultural and environmental factors, with the latter becoming dominant as age advances. It implies a need for sex-specific thresholds of moderate activity. Overall health is associated with both the year-averaged daily step count (the best indicator in women) and the year-averaged daily duration of physical activity >3 metabolic equivalents (METs) (the best indicator in men). In both sexes, the threshold ranges of step count and/or duration of activity >3 METs associated with a reduced prevalence of health problems are: 4000-5000 steps/day and/or 5-7.5 min/day for impaired mental and psychosocial health, such as a depressed mood state and a poor health-related quality of life; 7000-8000 steps/day and/or 15-20 min/day for markers of aortic arteriosclerosis, osteoporosis, sarcopenia and poor physical fitness; and 8000-10,000 steps/day and/or 20-30 min/day for components of the metabolic syndrome, especially hypertension and hyperglycemia. Irrespective of sex, both the intensity and the total volume of physical activity are influenced by stressful life events, such as a partner's death, and immediate meteorological factors, particularly precipitation and mean ambient temperature, underlining the need for long-term measurement of activity patterns. These findings have practical implications for those who engage in epidemiological studies and/or design health promotional programs for the elderly. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Are parents’ motivations to exercise and intention to engage in regular family-based activity associated with both adult and child physical activity?

PubMed Central

Solomon-Moore, Emma; Sebire, Simon J; Thompson, Janice L; Zahra, Jesmond; Lawlor, Debbie A; Jago, Russ

2016-01-01

Background/aim To examine the associations between parents’ motivation to exercise and intention to engage in family-based activity with their own and their child’s physical activity. Methods Cross-sectional data from 1067 parent–child pairs (76.1% mother–child); children were aged 5–6 years. Parents reported their exercise motivation (ie, intrinsic motivation, identified regulation, introjected regulation, external regulation and amotivation) as described in self-determination theory and their intention to engage in family-based activity. Parents’ and children’s mean minutes of moderate-to-vigorous-intensity physical activity (MVPA) and mean counts per minute were derived from ActiGraph accelerometers worn for 3 to 5 days (including a mixture of weekdays and weekend days). Multivariable linear regression models, adjusted for parent sex, number of children, indices of multiple deprivation and clustering of children in schools were used to examine associations (total of 24 associations tested). Results In fully adjusted models, each unit increase in identified regulation was associated with a 6.08 (95% CI 3.27 to 8.89, p<0.001) min-per-day increase in parents’ MVPA. Parents’ external regulation was associated with children performing 2.93 (95% CI −5.83 to −0.03, p=0.05) fewer minutes of MVPA per day and a 29.3 (95% CI −53.8 to −4.7, p=0.02) accelerometer count-per-minute reduction. There was no evidence of association for the other 21 associations tested. Conclusions Future family-based physical activity interventions may benefit from helping parents identify personal value in exercise while avoiding the use of external control or coercion to motivate behaviour. PMID:28879025

Energy Expenditure in Playground Games in Primary School Children Measured by Accelerometer and Heart Rate Monitors.

PubMed

García-Prieto, Jorge Cañete; Martinez-Vizcaino, Vicente; García-Hermoso, Antonio; Sánchez-López, Mairena; Arias-Palencia, Natalia; Fonseca, Juan Fernando Ortega; Mora-Rodriguez, Ricardo

2017-10-01

The aim of this study was to examine the energy expenditure (EE) measured using indirect calorimetry (IC) during playground games and to assess the validity of heart rate (HR) and accelerometry counts as indirect indicators of EE in children´s physical activity games. 32 primary school children (9.9 ± 0.6 years old, 19.8 ± 4.9 kg · m -2 BMI and 37.6 ± 7.2 ml · kg -1 · min -1 VO 2max ). Indirect calorimetry (IC), accelerometry and HR data were simultaneously collected for each child during a 90 min session of 30 playground games. Thirty-eight sessions were recorded in 32 different children. Each game was recorded at least in three occasions in other three children. The intersubject coefficient of variation within a game was 27% for IC, 37% for accelerometry and 13% for HR. The overall mean EE in the games was 4.2 ± 1.4 kcals · min -1 per game, totaling to 375 ± 122 kcals/per 90 min/session. The correlation coefficient between indirect calorimetry and accelerometer counts was 0.48 (p = .026) for endurance games and 0.21 (p = .574) for strength games. The correlation coefficient between indirect calorimetry and HR was 0.71 (p = .032) for endurance games and 0.48 (p = .026) for strength games. Our data indicate that both accelerometer and HR monitors are useful devices for estimating EE during endurance games, but only HR monitors estimates are accurate for endurance games.

A Descriptive Study of Objectively Measured Pokémon GO Playtime in College Students.

PubMed

Fountaine, Charles J; Springer, Emily J; Sward, Jasmine R

2018-01-01

Since its debut in July 2016, Pokémon GO has been a wildly popular mobile gaming app. In contrast to many previous apps, Pokémon GO requires the user to be physically active. However, the extent to which Pokémon GO contributes to physical activity is unknown. Therefore, the purpose of this study was to investigate the physical activity profile of playing Pokémon GO for 60 minutes in recreationally active college students. College students (n=27, n=19 female) were fitted with an accelerometer, pedometer, and heart rate monitor to assess the activity demands during a 60-min bout of Pokémon GO. Troiano accelerometer cut points were utilized to estimate time spent in sedentary, light, moderate, and vigorous-intensity physical activity. Of the 60-min allotted playtime, accelerometry indicated 82% was achieved via moderate-to vigorous-intensity physical activity. Pedometer counts indicated approximately 6000-steps/100-steps/min, indicative of moderate-intensity physical activity. Heart rates were approximately 50% of age-predicted maximum, also indicative of moderate-intensity physical activity. The results of this study provide evidence that playing one hour of Pokémon GO can be an effective means of accumulating recommended levels of daily/weekly physical activity.

A Descriptive Study of Objectively Measured Pokémon GO Playtime in College Students

PubMed Central

FOUNTAINE, CHARLES J.; SPRINGER, EMILY J.; SWARD, JASMINE R.

2018-01-01

Since its debut in July 2016, Pokémon GO has been a wildly popular mobile gaming app. In contrast to many previous apps, Pokémon GO requires the user to be physically active. However, the extent to which Pokémon GO contributes to physical activity is unknown. Therefore, the purpose of this study was to investigate the physical activity profile of playing Pokémon GO for 60 minutes in recreationally active college students. College students (n=27, n=19 female) were fitted with an accelerometer, pedometer, and heart rate monitor to assess the activity demands during a 60-min bout of Pokémon GO. Troiano accelerometer cut points were utilized to estimate time spent in sedentary, light, moderate, and vigorous-intensity physical activity. Of the 60-min allotted playtime, accelerometry indicated 82% was achieved via moderate-to vigorous-intensity physical activity. Pedometer counts indicated approximately 6000-steps/100-steps/min, indicative of moderate-intensity physical activity. Heart rates were approximately 50% of age-predicted maximum, also indicative of moderate-intensity physical activity. The results of this study provide evidence that playing one hour of Pokémon GO can be an effective means of accumulating recommended levels of daily/weekly physical activity. PMID:29541340

The Effect of Parental Involvement on Children's Physical Activity.

PubMed

Rebold, Michael J; Lepp, Andrew; Kobak, Mallory S; McDaniel, John; Barkley, Jacob E

2016-03-01

To assess the amount, intensity, enjoyment, and preference of children's physical activity in a controlled gymnasium setting under 3 experimental, social conditions: alone, with a parent watching, and with a parent participating. Children (n = 10 girls, 10 boys), 3-6 years old, along with 1 parent (n = 17 mothers, 3 fathers) per child participated in each social condition on separate days for 30 minutes in which they could choose from a variety of physical and/or sedentary activities. A greater number of accelerometer counts (P ≤ .02) were accumulated during the parent participating (109,523 ± 32,155 counts) condition than the alone (67,938 ± 37,857 counts) and parent watching (85,624 ± 44,985 counts) conditions. Counts during parent watching were also greater (P = .01) than alone. More time (P ≤ .008) was allocated to sedentary activities during the alone (16.2 ± 9.6 minutes) condition than parent watching (9.6 ± 9.3 minutes) and parent participating (3.8 ± 5.1 minutes). Children liked (P ≤ .02) the parent participating (9.9 ± 0.45 cm) condition more than alone (8.0 ± 2.72 cm) and parent watching (8.7 ± 1.52 cm). A greater (P < .001) proportion of children identified the parent participating (80%) as their preferred condition over either the parent watching (10%) or alone (10%) conditions. Parental participation during physical activity (or at minimum direct supervision) may be an important component in the development of physical activity environments intended to maximize physical activity behavior in children. Copyright © 2016 Elsevier Inc. All rights reserved.

Energy expended playing video console games: an opportunity to increase children's physical activity?

PubMed

Maddison, Ralph; Mhurchu, Cliona Ni; Jull, Andrew; Jiang, Yannan; Prapavessis, Harry; Rodgers, Anthony

2007-08-01

This study sought to quantify the energy expenditure and physical activity associated with playing the "new generation" active and nonactive console-based video games in 21 children ages 10-14 years. Energy expenditure (kcal) derived from oxygen consumption (VO2) was continuously assessed while children played nonactive and active console video games. Physical activity was assessed continuously using the Actigraph accelerometer. Significant (p < .001) increases from baseline were found for energy expenditure (129-400%), heart rate (43-84%), and activity counts (122-1288 versus 0-23) when playing the active console video games. Playing active console video games over short periods of time is similar in intensity to light to moderate traditional physical activities such as walking, skipping, and jogging.

Daily physical activity and its contribution to the health-related quality of life of ambulatory individuals with chronic stroke

PubMed Central

2010-01-01

Background Participation in daily physical activity (PA) post-stroke has not previously been investigated as a possible explanatory variable of health-related quality of life (HRQL). The aims were 1) to determine the contribution of daily PA to the HRQL of individuals with chronic stroke and 2) to assess the relationship between the functional ability of these individuals to the amount of daily PA. Methods The amount of daily PA of forty adults with chronic stroke (mean age 66.5 ± 9.6 years) was monitored using two measures. Accelerometers (Actical) were worn on the hip for three consecutive days in conjunction with a self-report questionnaire [the PA Scale for Individuals with Physical Disabilities (PASIPD)]. The daily physical activity was measured as the mean total accelerometer activity counts/day and the PASIPD scores as the metabolic equivalent (MET) hr/day. HRQL was assessed by the Physical and Mental composite scores of the Medical Outcomes Study Short-Form 36 (SF-36) in addition to the functional ability of the participants. Correlation and regression analyses were performed. Results After controlling for the severity of the motor impairment, the amount of daily PA, as assessed by the PASIPD and accelerometers, was found to independently contribute to 10-12% of the variance of the Physical Composite Score of the SF-36. No significant relationship was found between PA and the Mental Composite Score of the SF-36.The functional ability of the participants was found to be correlated to the amount of daily PA (r = 0.33 - 0.67, p < 0.01). Conclusion The results suggest that daily PA is associated with better HRQL (as assessed by the Physical composite score of the SF-36) for people living with stroke. Daily PA should be encouraged to potentially increase HRQL. Accelerometers in conjunction with a self-report questionnaire may provide important measures of PA which can be monitored and modified, and potentially influence HRQL. PMID:20682071

Daily physical activity and its contribution to the health-related quality of life of ambulatory individuals with chronic stroke.

PubMed

Rand, Debbie; Eng, Janice J; Tang, Pei-Fang; Hung, Chihya; Jeng, Jiann-Shing

2010-08-03

Participation in daily physical activity (PA) post-stroke has not previously been investigated as a possible explanatory variable of health-related quality of life (HRQL). The aims were 1) to determine the contribution of daily PA to the HRQL of individuals with chronic stroke and 2) to assess the relationship between the functional ability of these individuals to the amount of daily PA. The amount of daily PA of forty adults with chronic stroke (mean age 66.5 +/- 9.6 years) was monitored using two measures. Accelerometers (Actical) were worn on the hip for three consecutive days in conjunction with a self-report questionnaire [the PA Scale for Individuals with Physical Disabilities (PASIPD)]. The daily physical activity was measured as the mean total accelerometer activity counts/day and the PASIPD scores as the metabolic equivalent (MET) hr/day. HRQL was assessed by the Physical and Mental composite scores of the Medical Outcomes Study Short-Form 36 (SF-36) in addition to the functional ability of the participants. Correlation and regression analyses were performed. After controlling for the severity of the motor impairment, the amount of daily PA, as assessed by the PASIPD and accelerometers, was found to independently contribute to 10-12% of the variance of the Physical Composite Score of the SF-36. No significant relationship was found between PA and the Mental Composite Score of the SF-36.The functional ability of the participants was found to be correlated to the amount of daily PA (r = 0.33 - 0.67, p < 0.01). The results suggest that daily PA is associated with better HRQL (as assessed by the Physical composite score of the SF-36) for people living with stroke. Daily PA should be encouraged to potentially increase HRQL. Accelerometers in conjunction with a self-report questionnaire may provide important measures of PA which can be monitored and modified, and potentially influence HRQL.

Objectively measured physical activity level during a physical education class: a pilot study with Swedish youth.

PubMed

Raustorp, Anders; Boldemann, Cecilia; Johansson, Maria; Mårtensson, Fredrika

2010-01-01

The aim of this study is to advance our knowledge of the contribution of a typical physical education (PE) class to children's daily physical activity. The pilot project is a part of a survey study comprising 11 fourth grader classes (250 pupils). One class of 19 pupils (9 girls) participated in the pilot study. Daily step counts were measured by Yamax pedometers during four consecutive weekdays. During PE class, the participants wore a second pedometer and an Actigraph GT1M accelerometer. The total average step count during PE class was 2512, average 74 steps/min. The counts for the whole day were 16668, and 19 steps/min respectively. The total share of moderate-vigorous physical activity (MVPA) of the PE class was 50.4% (52.5% and 48.3% for boys and girls respectively). There was an inverse correlation between daily mean step count and contribution of PE class step to daily mean step (r = -0.64, p = .003). The contribution of PE class to MVPA was in high in both boys and girls. Considering the suggested independent role of physical fitness for cardiovascular health in children, the PE class must be seen as an important health factor, especially for otherwise inactive children.

Comparison of GT3X accelerometer and YAMAX pedometer steps/day in a free-living sample of overweight and obese adults.

PubMed

Barriera, Tiago V; Tudor-Locke, Catrine; Champagne, Catherine M; Broyles, Stephanie T; Johnson, William D; Katzmarzyk, Peter T

2013-02-01

The purpose of this study was to compare steps/day detected by the YAMAX SW-200 pedometer versus the Actigraph GT3X accelerometer in free-living adults. Daily YAMAX and GT3X steps were collected from a sample of 23 overweight and obese participants (78% female; age = 52.6 ± 8.4 yr.; BMI = 31.0 ± 3.7 m·kg-2). Because a pedometer is more likely to be used in a community-based intervention program, it was used as the standard for comparison. Percent difference (PD) and absolute percent difference (APD) were calculated to examine between-instrument agreement. In addition, days were categorized based on PD: a) under-counting (> -10 PD), b) acceptable counting (-10 to 10 PD), and c) over-counting (> 10 PD). The YAMAX and GT3X detected 8,025 ± 3,967 and 7131 ± 3066 steps/day, respectively, and the outputs were highly correlated (r = .87). Average PD was -3.1% ± 30.7% and average APD was 23.9% ± 19.4%. Relative to the YAMAX, 53% of the days detected by the GT3X were classified as under-counting, 25% acceptable counting, and 23% over-counting. Although the output of these 2 instruments is highly correlated, caution is advised when directly comparing or using their output interchangeably.

Part-Time Work and Physical Activity in American High School Students.

PubMed

Van Domelen, Dane R

2015-08-01

To compare physical activity (PA) in American high school students who work part-time with those who do not work. Data were obtained from the National Health and Nutrition Examination Survey 2003 to 2006 (n = 791). Work status was self-reported and PA was measured using accelerometers. In males, adjusted for age, race, and poverty-income ratio, workers averaged greater counts per minute, less sedentary time, and greater moderate-to-vigorous PA compared with nonworkers. In females, workers and nonworkers had similar counts per minute, whereas nonworkers had somewhat greater moderate-to-vigorous PA. There was a work-by-school status interaction on sedentary time (P = 0.021), whereby work was associated with less sedentary time among students not on break from school. In American high school students, work is associated with greater PA in males and a different composition of PA in females.

Movement Discordance between Healthy and Non-Healthy US Adults

PubMed Central

Swartz, Ann M.; Cho, Young; Welch, Whitney A.; Strath, Scott J.

2016-01-01

Introduction Physical activity is known to significantly impact cardiometabolic health. Accelerometer data, as a measure of physical activity, can be used to objectively identify a disparity in movement (movement discordance) between healthy and unhealthy adults. The purpose of this study was to examine the Movement Discordance between healthy and unhealthy adults in a large US population sample. Methods Demographic, health and accelerometer data from the National Health and Nutrition Examination Study (NHANES) 2003–2004 and 2005–2006 cohorts were used for this study. Participants were classified as either having a “normal” or “abnormal” value for each cardiometabolic health parameter examined, based on published criteria. Linear regression analyses were performed to determine significance of each abnormal health parameter (risk factor) in its unique effect on the accelerometer counts, controlling for age and gender. Average accelerometer counts per minute (cpm) by gender and age categories were estimated separately for the groups of normal and abnormal cardiometabolic risk. Results Average cpm for those with healthy levels of each individual cardiometabolic health parameter range from 296 cpm (for C reactive protein) to 337 cpm (for waist circumference), while average cpm for those with abnormal levels of each individual cardiometabolic health parameter range from 216 cpm (for insulin) to 291 cpm (for LDL-cholesterol). After controlling for age and gender, waist circumference, HbA1c, Insulin, Homocysteine, and HDL-Cholesterol were the cardiometabolic health parameters that showed significant, unique and independent effects on cpm. Overall, individuals who have abnormal values for all significant cardiometabolic health parameters (“unhealthy”) averaged 267 cpm (SE = 15 cpm), while the healthy sample of this study averaged 428 cpm (SE = 10 cpm). The difference in cpm between the unhealthy and healthy groups is similar between males and females. Further, for both males and females, the cpm gap between unhealthy and healthy is largest in the 30s (males: 183 cpm; females 144 cpm) and lessens as age increases, with the lowest gap seen in those 80+ years (males, 81 cpm; females, 85 cpm). Conclusion This Movement Discordance between healthy and unhealthy adults represents a gap in movement that needs to be closed to improve the health of individuals with, or at risk for cardiometabolic disease. PMID:26918868

Self-Reported Sitting Time in New York City Adults, The Physical Activity and Transit Survey, 2010–2011

PubMed Central

Bartley, Katherine F.; Firestone, Melanie J.; Lee, Karen K.; Eisenhower, Donna L.

2015-01-01

Introduction Recent studies have demonstrated the negative health consequences associated with extended sitting time, including metabolic disturbances and decreased life expectancy. The objectives of this study were to characterize sitting time in an urban adult population and assess the validity of a 2-question method of self-reported sitting time. Methods The New York City Health Department conducted the 2010–2011 Physical Activity and Transit Survey (N = 3,597); a subset of participants wore accelerometers for 1 week (n = 667). Self-reported sitting time was assessed from 2 questions on time spent sitting (daytime and evening hours). Sedentary time was defined as accelerometer minutes with less than 100 counts on valid days. Descriptive statistics were used to estimate the prevalence of sitting time by demographic characteristics. Validity of sitting time with accelerometer-measured sedentary time was assessed using Spearman’s correlation and Bland-Altman techniques. All data were weighted to be representative of the New York City adult population based on the 2006–2008 American Community Survey. Results Mean daily self-reported sitting time was 423 minutes; mean accelerometer-measured sedentary time was 490 minutes per day (r = 0.32, P < .001). The mean difference was 49 minutes per day (limits of agreement: −441 to 343). Sitting time was higher in respondents at lower poverty and higher education levels and lower in Hispanics and people who were foreign-born. Conclusion Participants of higher socioeconomic status, who are not typically the focus of health disparities–related research, had the highest sitting times; Hispanics had the lowest levels. Sitting time may be accurately assessed by self-report with the 2-question method for population surveillance but may be limited in accurately characterizing individual-level behavior. PMID:26020549

Self-reported sitting time in New York City adults, the Physical Activity and Transit Survey, 2010-2011.

PubMed

Yi, Stella S; Bartley, Katherine F; Firestone, Melanie J; Lee, Karen K; Eisenhower, Donna L

2015-05-28

Recent studies have demonstrated the negative health consequences associated with extended sitting time, including metabolic disturbances and decreased life expectancy. The objectives of this study were to characterize sitting time in an urban adult population and assess the validity of a 2-question method of self-reported sitting time. The New York City Health Department conducted the 2010-2011 Physical Activity and Transit Survey (N = 3,597); a subset of participants wore accelerometers for 1 week (n = 667). Self-reported sitting time was assessed from 2 questions on time spent sitting (daytime and evening hours). Sedentary time was defined as accelerometer minutes with less than 100 counts on valid days. Descriptive statistics were used to estimate the prevalence of sitting time by demographic characteristics. Validity of sitting time with accelerometer-measured sedentary time was assessed using Spearman's correlation and Bland-Altman techniques. All data were weighted to be representative of the New York City adult population based on the 2006-2008 American Community Survey. Mean daily self-reported sitting time was 423 minutes; mean accelerometer-measured sedentary time was 490 minutes per day (r = 0.32, P < .001). The mean difference was 49 minutes per day (limits of agreement: -441 to 343). Sitting time was higher in respondents at lower poverty and higher education levels and lower in Hispanics and people who were foreign-born. Participants of higher socioeconomic status, who are not typically the focus of health disparities-related research, had the highest sitting times; Hispanics had the lowest levels. Sitting time may be accurately assessed by self-report with the 2-question method for population surveillance but may be limited in accurately characterizing individual-level behavior.

Disparities in moderate-to-vigorous physical activity among girls and overweight and obese schoolchildren during school- and out-of-school time.

PubMed

Hubbard, Kristie; Economos, Christina D; Bakun, Peter; Boulos, Rebecca; Chui, Kenneth; Mueller, Megan P; Smith, Katie; Sacheck, Jennifer

2016-03-22

Increasing physical activity (PA) during the school day and out-of-school time are critical strategies for preventing childhood obesity and improving overall health. The purpose of the present investigation was to examine schoolchildren's volume and type of PA during school-time and out-of-school, compared to national recommendations and differences by sex and weight status. This cross-sectional analysis included 517 3(rd)-5(th) grade schoolchildren from 13 New England elementary schools (October 2013-January 2014). Demographics were collected by parent questionnaire. Measured height and weight were used to categorize child weight status. Accelerometer data were collected over 7 days. PA was coded as total activity counts and minutes of sedentary, light, and moderate-to-vigorous physical activity (SED, LPA, MVPA) during 1) school, 2) weekday out-of-school, 3) weekend, and 4) total daily time. Multivariable mixed models were used to examine associations between sex and weight status and total counts, SED, LPA, and MVPA, controlling for demographics, wear-time, and clustering within schools. 453 participants (60.5% girls; mean age 9.1 years; 30.5% overweight/obese) had valid accelerometer wear time (≥3 days, ≥ 10 h/day). Few children achieved 60 min total daily (15.0%) or school-time (8.0 %) MVPA recommendations. For all time-of-day categories, girls achieved fewer MVPA minutes than boys (p < .0001), and overweight/obese participants achieved fewer MVPA minutes than normal/underweight participants (p = 0.05). Minutes of LPA declined by grade-level (p < .05) and were lower in girls than boys during school-time only (p < .05). Disparities in MVPA by sex and weight status across school and out-of-school time highlight the need for programs with equitable reach.

International study of objectively measured physical activity and sedentary time with body mass index and obesity: IPEN adult study.

PubMed

Van Dyck, D; Cerin, E; De Bourdeaudhuij, I; Hinckson, E; Reis, R S; Davey, R; Sarmiento, O L; Mitas, J; Troelsen, J; MacFarlane, D; Salvo, D; Aguinaga-Ontoso, I; Owen, N; Cain, K L; Sallis, J F

2015-02-01

Physical activity (PA) has been consistently implicated in the etiology of obesity, whereas recent evidence on the importance of sedentary time remains inconsistent. Understanding of dose-response associations of PA and sedentary time with overweight and obesity in adults can be improved with large-scale studies using objective measures of PA and sedentary time. The purpose of this study was to examine the strength, direction and shape of dose-response associations of accelerometer-based PA and sedentary time with body mass index (BMI) and weight status in 10 countries, and the moderating effects of study site and gender. Data from the International Physical activity and the Environment Network (IPEN) Adult study were used. IPEN Adult is an observational multi-country cross-sectional study, and 12 sites in 10 countries are included. Participants wore an accelerometer for seven consecutive days, completed a socio-demographic questionnaire and reported height and weight. In total, 5712 adults (18-65 years) were included in the analyses. Generalized additive mixed models, conducted in R, were used to estimate the strength and shape of the associations. A curvilinear relationship of accelerometer-based moderate-to-vigorous PA and total counts per minute with BMI and the probability of being overweight/obese was identified. The associations were negative, but weakened at higher levels of moderate-to-vigorous PA (>50 min per day) and higher counts per minute. No associations between sedentary time and weight outcomes were found. Complex site- and gender-specific findings were revealed for BMI, but not for weight status. On the basis of these results, the current Institute of Medicine recommendation of 60 min per day of moderate-to-vigorous PA to prevent weight gain in normal-weight adults was supported. No relationship between sedentary time and the weight outcomes was present, calling for further examination. If moderator findings are confirmed, the relationship between PA and BMI may be country- and gender-dependent, which could have important implications for country-specific health guidelines.

International Study of Objectively-measured Physical Activity and Sedentary Time with Body Mass Index and Obesity: IPEN Adult Study

PubMed Central

Van Dyck, Delfien; Cerin, Ester; De Bourdeaudhuij, Ilse; Hinckson, Erica; Reis, Rodrigo S; Davey, Rachel; Sarmiento, Olga Lucia; Mitas, Josef; Troelsen, Jens; MacFarlane, Duncan; Salvo, Deborah; Aguinaga-Ontoso, Ines; Owen, Neville; Cain, Kelli L; Sallis, James F

2014-01-01

Background Physical activity (PA) has been consistently implicated in the etiology of obesity, while recent evidence on the importance of sedentary time remains inconsistent. Understanding of dose-response associations of PA and sedentary time with overweight and obesity in adults can be improved with large-scale studies using objective measures of PA and sedentary time. The purpose of this study was to examine the strength, direction and shape of dose-response associations of accelerometer-based PA and sedentary time with BMI and weight status in 10 countries, and the moderating effects of study site and gender. Methods Data from the International Physical activity and the Environment Network (IPEN) Adult study were used. IPEN Adult is an observational multi-country cross-sectional study, and 12 sites in 10 countries are included. Participants wore an accelerometer for seven consecutive days, completed a socio-demographic questionnaire and reported height and weight. In total, 5712 adults (18–65 years) were included in the analyses. Generalized additive mixed models, conducted in R, were used to estimate the strength and shape of the associations. Results A curvilinear relationship of accelerometer-based moderate-to-vigorous PA and total counts/minute with BMI and the probability of being overweight/obese was identified. The associations were negative, but weakened at higher levels of moderate-to-vigorous PA (>50 min/day) and higher counts/minute. No associations between sedentary time and weight outcomes were found. Complex site- and gender-specific findings were revealed for BMI, but not for weight status. Conclusions Based on these results, the current Institute of Medicine recommendation of 60 minutes/day of moderate-to-vigorous PA to prevent weight gain in normal-weight adults was supported. No relationship between sedentary time and the weight outcomes was present, calling for further examination. If moderator findings are confirmed, the relationship between PA and BMI may be country- and gender-dependent, which could have important implications for country-specific health guidelines. PMID:24984753

Assessment of Physical Activity in Chronic Kidney Disease

PubMed Central

Robinson-Cohen, Cassianne; Littman, Alyson J; Duncan, Glen E; Roshanravan, Baback; Ikizler, T. Alp; Himmelfarb, Jonathan; Kestenbaum, Bryan R

2012-01-01

Background Physical activity (PA) plays important roles in the development of kidney disease and its complications; however, the validity of standard tools for measuring PA is not well understood. Study Design We investigated the performance of several readily-available and widely-used PA and physical function questionnaires, individually and in combination, against accelerometry among a cohort of CKD participants. Setting and Participants Forty-six participants from the Seattle Kidney Study, an observational cohort study of persons with CKD, completed the PA Scale for the Elderly, Human Activity Profile (HAP), Medical Outcomes Study SF-36 questionnaire, and the Four Week PA History Questionnaire (FWH). We simultaneously measured PA using an Actigraph GT3X accelerometer over a 14-day period. We estimated the validity of each instrument by testing its associations with log-transformed accelerometry counts. We used the Akaike information criterion to investigate the performance of combinations of questionnaires. Results All questionnaire scores were significantly associated with log-transformed accelerometry counts. The HAP correlated best with accelerometry counts (r2=0.32) followed by the SF-36 (r2=0.23). Forty-three percent of the variability in accelerometry counts data was explained by a model that combined the HAP, SF-36 and FWH. Conclusion A combination of measurement tools can account for a modest component of PA in patients with CKD; however, a substantial proportion of physical activity is not captured by standard assessments. PMID:22739659

Comparison of pedometer and accelerometer measures of free-living physical activity.

PubMed

Tudor-Locke, Catrine; Ainsworth, Barbara E; Thompson, Raymond W; Matthews, Charles E

2002-12-01

The purpose of this investigation was 1) to evaluate agreement between dual-mode CSA accelerometer outputs and Yamax pedometer outputs assessed concurrently under free-living conditions; 2) to determine the relationship between pedometer-steps per day and CSA-time spent in inactivity and in light-, moderate-, and vigorous-intensity activities; and 3) to identify a value of pedometer-steps per day that corresponds with a minimum of 30 CSA-min x d(-1) of moderate ambulatory activity. Data were analyzed from 52 participants (27 men, 25 women; mean age = 38.2 +/- 12.0 yr; mean BMI = 26.4 +/- 4.5 kg x m(-2)) who were enrolled in the International Physical Activity Questionnaire study and wore both motion sensors during waking hours for 7 consecutive days. Participants averaged 415.0+/-159.5 CSA-counts x min(-1) x d(-1), 357,601 +/- 138,425 CSA-counts x d(-1), 11,483 +/- 3,856 CSA-steps x d(-1), and 9,638 +/- 4,030 pedometer-steps x d(-1). There was a strong relationship between all CSA outputs and pedometer outputs (r = 0.74-0.86). The mean difference in steps detected between instruments was 1845+/-2116 steps x d(-1) (CSA > pedometer; t = 6.29, P < 0.0001). There were distinct differences (effect sizes >0.80) in mean CSA-time (min x d(-1)) in moderate and vigorous activity with increasing pedometer-determined activity quartiles; no differences were noted for inactivity or light activity. Approximately 33 CSA-min x d(-1) of moderate activity corresponded with 8000 pedometer-steps x d(-1). Differences in mean steps per day detected may be due to differences in set instrument sensitivity thresholds and/or attachment. Additional studies with different populations are needed to confirm a recommended number of steps per day associated with the duration and intensity of public health recommendations for ambulatory activity.

Assessment of physical activity in chronic kidney disease.

PubMed

Robinson-Cohen, Cassianne; Littman, Alyson J; Duncan, Glen E; Roshanravan, Baback; Ikizler, T Alp; Himmelfarb, Jonathan; Kestenbaum, Bryan R

2013-03-01

Physical inactivity plays an important role in the development of kidney disease and its complications; however, the validity of standard tools for measuring physical activity (PA) is not well understood. We investigated the performance of several readily available and widely used PA and physical function questionnaires, individually and in combination, against accelerometry among a cohort of chronic kidney disease (CKD) participants. Forty-six participants from the Seattle Kidney Study, an observational cohort study of persons with CKD, completed the Physical Activity Scale for the Elderly, Human Activity Profile (HAP), Medical Outcomes Study SF-36 questionnaire, and the Four-week Physical Activity History questionnaires. We simultaneously measured PA using an Actigraph GT3X accelerometer during a 14-day period. We estimated the validity of each instrument by testing its associations with log-transformed accelerometry counts. We used the Akaike information criterion to investigate the performance of combinations of questionnaires. All questionnaire scores were significantly associated with log-transformed accelerometry counts. The HAP correlated best with accelerometry counts (r(2) = 0.32) followed by SF-36 (r(2) = 0.23). Forty-three percent of the variability in accelerometry counts data was explained by a model that combined the HAP, SF-36, and Four-week Physical Activity History questionnaires. A combination of measurement tools can account for a modest component of PA in patients with CKD; however, a substantial proportion of PA is not captured by standard assessments. Copyright © 2013 National Kidney Foundation, Inc. All rights reserved.

Open-loop feedback to increase physical activity in obese children.

PubMed

Goldfield, G S; Kalakanis, L E; Ernst, M M; Epstein, L H

2000-07-01

The present study investigated whether making access to sedentary activities contingent on physical activity would increase physical activity. Experimental. Thirty-four obese children aged 8-12 y were randomized to one of three groups in which children had to accumulate 750 or 1500 pedometer counts to earn 10 min of access to video games or movies, or to a control group in which access to sedentary behaviors was provided noncontingently. Physical activity in the 20 min experimental session was measured by electronic pedometer and triaxial accelerometer (ie TriTrac(R)). Activity liking was measured by visual analog scales. Anthropometric and demographic characteristics were also assessed. Children in the 750 and 1500 count contingency groups engaged in significantly more physical activity and spent more time in moderate intensity activity or higher compared with controls. Children in the Contingent 1500 group engaged in more activity and spent more time in moderate or greater intensity activity compared to children in the Contingent 750 group. Findings suggest that contingent access to sedentary activities can reinforce physical activity in obese children, and changes in physical activity level depend in part on the targeted physical activity goal.

The improved physical activity index for measuring physical activity in EPIC Germany.

PubMed

Wientzek, Angelika; Vigl, Matthäus; Steindorf, Karen; Brühmann, Boris; Bergmann, Manuela M; Harttig, Ulrich; Katzke, Verena; Kaaks, Rudolf; Boeing, Heiner

2014-01-01

In the European Investigation into Cancer and Nutrition study (EPIC), physical activity (PA) has been indexed as a cross-tabulation between PA at work and recreational activity. As the proportion of non-working participants increases, other categorization strategies are needed. Therefore, our aim was to develop a valid PA index for this population, which will also be able to express PA continuously. In the German EPIC centers Potsdam and Heidelberg, a clustered sample of 3,766 participants was re-invited to the study center. 1,615 participants agreed to participate and 1,344 participants were finally included in this study. PA was measured by questionnaires on defined activities and a 7-day combined heart rate and acceleration sensor. In a training sample of 433 participants, the Improved Physical Activity Index (IPAI) was developed. Its performance was evaluated in a validation sample of 911 participants and compared with the Cambridge Index and the Total PA Index. The IPAI consists of items covering five areas including PA at work, sport, cycling, television viewing, and computer use. The correlations of the IPAI with accelerometer counts in the training and validation sample ranged r = 0.40-0.43 and with physical activity energy expenditure (PAEE) r = 0.33-0.40 and were higher than for the Cambridge Index and the Total PA Index previously applied in EPIC. In non-working participants the IPAI showed higher correlations than the Cambridge Index and the Total PA Index, with r = 0.34 for accelerometer counts and r = 0.29 for PAEE. In conclusion, we developed a valid physical activity index which is able to express PA continuously as well as to categorize participants according to their PA level. In populations with increasing rates of non-working people the performance of the IPAI is better than the established indices used in EPIC.

The Improved Physical Activity Index for Measuring Physical Activity in EPIC Germany

PubMed Central

Wientzek, Angelika; Vigl, Matthäus; Steindorf, Karen; Brühmann, Boris; Bergmann, Manuela M.; Harttig, Ulrich; Katzke, Verena; Kaaks, Rudolf; Boeing, Heiner

2014-01-01

In the European Investigation into Cancer and Nutrition study (EPIC), physical activity (PA) has been indexed as a cross-tabulation between PA at work and recreational activity. As the proportion of non-working participants increases, other categorization strategies are needed. Therefore, our aim was to develop a valid PA index for this population, which will also be able to express PA continuously. In the German EPIC centers Potsdam and Heidelberg, a clustered sample of 3,766 participants was re-invited to the study center. 1,615 participants agreed to participate and 1,344 participants were finally included in this study. PA was measured by questionnaires on defined activities and a 7-day combined heart rate and acceleration sensor. In a training sample of 433 participants, the Improved Physical Activity Index (IPAI) was developed. Its performance was evaluated in a validation sample of 911 participants and compared with the Cambridge Index and the Total PA Index. The IPAI consists of items covering five areas including PA at work, sport, cycling, television viewing, and computer use. The correlations of the IPAI with accelerometer counts in the training and validation sample ranged r = 0.40–0.43 and with physical activity energy expenditure (PAEE) r = 0.33–0.40 and were higher than for the Cambridge Index and the Total PA Index previously applied in EPIC. In non-working participants the IPAI showed higher correlations than the Cambridge Index and the Total PA Index, with r = 0.34 for accelerometer counts and r = 0.29 for PAEE. In conclusion, we developed a valid physical activity index which is able to express PA continuously as well as to categorize participants according to their PA level. In populations with increasing rates of non-working people the performance of the IPAI is better than the established indices used in EPIC. PMID:24642812

Physical Limitations, Walkability, Perceived Environmental Facilitators and Physical Activity of Older Adults in Finland

PubMed Central

Portegijs, Erja; Keskinen, Kirsi E.; Tsai, Li-Tang; Rantanen, Taina; Rantakokko, Merja

2017-01-01

The aim was to study objectively assessed walkability of the environment and participant perceived environmental facilitators for outdoor mobility as predictors of physical activity in older adults with and without physical limitations. 75–90-year-old adults living independently in Central Finland were interviewed (n = 839) and reassessed for self-reported physical activity one or two years later (n = 787). Lower-extremity physical limitations were defined as Short Physical Performance Battery score ≤9. Number of perceived environmental facilitators was calculated from a 16-item checklist. Walkability index (land use mix, street connectivity, population density) of the home environment was calculated from geographic information and categorized into tertiles. Accelerometer-based step counts were registered for one week (n = 174). Better walkability was associated with higher numbers of perceived environmental facilitators (p < 0.001) and higher physical activity (self-reported p = 0.021, step count p = 0.010). Especially among those with physical limitations, reporting more environmental facilitators was associated with higher odds for reporting at least moderate physical activity (p < 0.001), but not step counts. Perceived environmental facilitators only predicted self-reported physical activity at follow-up. To conclude, high walkability of the living environment provides opportunities for physical activity in old age, but among those with physical limitations especially, awareness of environmental facilitators may be needed to promote physical activity. PMID:28327543

Physical Limitations, Walkability, Perceived Environmental Facilitators and Physical Activity of Older Adults in Finland.

PubMed

Portegijs, Erja; Keskinen, Kirsi E; Tsai, Li-Tang; Rantanen, Taina; Rantakokko, Merja

2017-03-22

The aim was to study objectively assessed walkability of the environment and participant perceived environmental facilitators for outdoor mobility as predictors of physical activity in older adults with and without physical limitations. 75-90-year-old adults living independently in Central Finland were interviewed ( n = 839) and reassessed for self-reported physical activity one or two years later ( n = 787). Lower-extremity physical limitations were defined as Short Physical Performance Battery score ≤9. Number of perceived environmental facilitators was calculated from a 16-item checklist. Walkability index (land use mix, street connectivity, population density) of the home environment was calculated from geographic information and categorized into tertiles. Accelerometer-based step counts were registered for one week ( n = 174). Better walkability was associated with higher numbers of perceived environmental facilitators ( p < 0.001) and higher physical activity (self-reported p = 0.021, step count p = 0.010). Especially among those with physical limitations, reporting more environmental facilitators was associated with higher odds for reporting at least moderate physical activity ( p < 0.001), but not step counts. Perceived environmental facilitators only predicted self-reported physical activity at follow-up. To conclude, high walkability of the living environment provides opportunities for physical activity in old age, but among those with physical limitations especially, awareness of environmental facilitators may be needed to promote physical activity.

Comparison of Physical Activity Adult Questionnaire results with accelerometer data.

PubMed

Garriguet, Didier; Tremblay, Sylvain; Colley, Rachel C

2015-07-01

Discrepancies between self-reported and objectively measured physical activity are well-known. For the purpose of validation, this study compares a new self-reported physical activity questionnaire with an existing one and with accelerometer data. Data collected at one site of the Canadian Health Measures Survey in 2013 were used for this validation study. The International Physical Activity Questionnaire (IPAQ) was administered to respondents during the household interview, and the new Physical Activity for Adults Questionnaire (PAAQ) was administered during a subsequent visit to a mobile examination centre (MEC). At the MEC, respondents were given an accelerometer to wear for seven days. The analysis pertains to 112 respondents aged 18 to 79 who wore the accelerometer for 10 or more hours on at least four days. Moderate-to-vigorous physical activity (MVPA) measured by accelerometer had higher correlation with data from the PAAQ (r = 0.44) than with data from the IPAQ (r = 0.20). The differences between accelerometer and PAAQ data were greater based on accelerometer-measured physical activity accumulated in 10-minute bouts (30-minute difference in MVPA) than on all minutes (9-minute difference). The percentages of respondents meeting the Canadian Physical Activity Guidelines were 90% based on self-reported IPAQ minutes, 70% based on all accelerometer MVPA minutes, 29% based on accelerometer MVPA minutes accumulated in 10-minute bouts, and 61% based on self-reported PAAQ minutes. The PAAQ demonstrated reasonable validity against the accelerometer criterion. Based on correlations and absolute differences between daily minutes of MVPA and the percentages of respondents meeting the Canadian Physical Activity Guidelines, PAAQ results were closer to accelerometer data than were the IPAQ results for the study sample and previous Statistics Canada self-reported questionnaire findings.

Toddler physical activity study: laboratory and community studies to evaluate accelerometer validity and correlates.

PubMed

Hager, Erin R; Gormley, Candice E; Latta, Laura W; Treuth, Margarita S; Caulfield, Laura E; Black, Maureen M

2016-09-06

Toddlerhood is an important age for physical activity (PA) promotion to prevent obesity and support a physically active lifestyle throughout childhood. Accurate assessment of PA is needed to determine trends/correlates of PA, time spent in sedentary, light, or moderate-vigorous PA (MVPA), and the effectiveness of PA promotion programs. Due to the limited availability of objective measures that have been validated and evaluated for feasibility in community studies, it is unclear which subgroups of toddlers are at the highest risk for inactivity. Using Actical ankle accelerometry, the objectives of this study are to develop valid thresholds, examine feasibility, and examine demographic/ anthropometric PA correlates of MVPA among toddlers from low-income families. Two studies were conducted with toddlers (12-36 months). Laboratory Study (n = 24)- Two Actical accelerometers were placed on the ankle. PA was observed using the Child Activity Rating Scale (CARS, prescribed activities). Analyses included device equivalence reliability (correlation: activity counts of two Acticals), criterion-related validity (correlation: activity counts and CARS ratings), and sensitivity/specificity for thresholds. Community Study (n = 277, low-income mother-toddler dyads recruited)- An Actical was worn on the ankle for > 7 days (goal >5, 24-h days). Height/weight was measured. Mothers reported demographics. Analyses included frequencies (feasibility) and stepwise multiple linear regression (sMLR). Laboratory Study- Acticals demonstrated reliability (r = 0.980) and validity (r = 0.75). Thresholds demonstrated sensitivity (86 %) and specificity (88 %). Community Study- 86 % wore accelerometer, 69 % had valid data (mean = 5.2 days). Primary reasons for missing/invalid data: refusal (14 %) and wear-time ≤2 days (11 %). The MVPA threshold (>2200 cpm) yielded 54 min/day. In sMLR, MVPA was associated with age (older > younger, β = 32.8, p < 0.001), gender (boys > girls, β = -11.21, p = 0.032), maternal MVPA (β = 0.44, p = 0.002) and recruitment location (suburban > urban, β = 19.6, p < 0.001), or race (non-Black > Black, β = 18.5, p = 0.001). No association with toddler weight status. Ankle accelerometry is a valid, reliable, and feasible method of assessing PA in community studies of toddlers from low-income families. Sub-populations of toddlers may be at increased risk for inactivity, including toddlers that are younger, female, Black, those with less active mothers, and those living in an urban location.

Sleep Estimates Using Microelectromechanical Systems (MEMS)

PubMed Central

te Lindert, Bart H. W.; Van Someren, Eus J. W.

2013-01-01

Study Objectives: Although currently more affordable than polysomnography, actigraphic sleep estimates have disadvantages. Brand-specific differences in data reduction impede pooling of data in large-scale cohorts and may not fully exploit movement information. Sleep estimate reliability might improve by advanced analyses of three-axial, linear accelerometry data sampled at a high rate, which is now feasible using microelectromechanical systems (MEMS). However, it might take some time before these analyses become available. To provide ongoing studies with backward compatibility while already switching from actigraphy to MEMS accelerometry, we designed and validated a method to transform accelerometry data into the traditional actigraphic movement counts, thus allowing for the use of validated algorithms to estimate sleep parameters. Design: Simultaneous actigraphy and MEMS-accelerometry recording. Setting: Home, unrestrained. Participants: Fifteen healthy adults (23-36 y, 10 males, 5 females). Interventions: None. Measurements: Actigraphic movement counts/15-sec and 50-Hz digitized MEMS-accelerometry. Analyses: Passing-Bablok regression optimized transformation of MEMS-accelerometry signals to movement counts. Kappa statistics calculated agreement between individual epochs scored as wake or sleep. Bland-Altman plots evaluated reliability of common sleep variables both between and within actigraphs and MEMS-accelerometers. Results: Agreement between epochs was almost perfect at the low, medium, and high threshold (kappa = 0.87 ± 0.05, 0.85 ± 0.06, and 0.83 ± 0.07). Sleep parameter agreement was better between two MEMS-accelerometers or a MEMS-accelerometer and an actigraph than between two actigraphs. Conclusions: The algorithm allows for continuity of outcome parameters in ongoing actigraphy studies that consider switching to MEMS-accelerometers. Its implementation makes backward compatibility feasible, while collecting raw data that, in time, could provide better sleep estimates and promote cross-study data pooling. Citation: te Lindert BHW; Van Someren EJW. Sleep estimates using microelectromechanical systems (MEMS). SLEEP 2013;36(5):781-789. PMID:23633761

Development of an accelerometer-based multivariate model to predict free-living energy expenditure in a large military cohort.

PubMed

Horner, Fleur; Bilzon, James L; Rayson, Mark; Blacker, Sam; Richmond, Victoria; Carter, James; Wright, Anthony; Nevill, Alan

2013-01-01

This study developed a multivariate model to predict free-living energy expenditure (EE) in independent military cohorts. Two hundred and eighty-eight individuals (20.6 ± 3.9 years, 67.9 ± 12.0 kg, 1.71 ± 0.10 m) from 10 cohorts wore accelerometers during observation periods of 7 or 10 days. Accelerometer counts (PAC) were recorded at 1-minute epochs. Total energy expenditure (TEE) and physical activity energy expenditure (PAEE) were derived using the doubly labelled water technique. Data were reduced to n = 155 based on wear-time. Associations between PAC and EE were assessed using allometric modelling. Models were derived using multiple log-linear regression analysis and gender differences assessed using analysis of covariance. In all models PAC, height and body mass were related to TEE (P < 0.01). For models predicting TEE (r (2) = 0.65, SE = 462 kcal · d(-1) (13.0%)), PAC explained 4% of the variance. For models predicting PAEE (r (2) = 0.41, SE = 490 kcal · d(-1) (32.0%)), PAC accounted for 6% of the variance. Accelerometry increases the accuracy of EE estimation in military populations. However, the unique nature of military life means accurate prediction of individual free-living EE is highly dependent on anthropometric measurements.

A universal, accurate intensity-based classification of different physical activities using raw data of accelerometer.

PubMed

Vähä-Ypyä, Henri; Vasankari, Tommi; Husu, Pauliina; Suni, Jaana; Sievänen, Harri

2015-01-01

Accelerometers are increasingly used for objective assessment of physical activity. However, because of lack of the proprietary analysis algorithms, direct comparisons between accelerometer brands are difficult. In this study, we propose and evaluate open source methods for commensurate assessment of raw accelerometer data irrespective of the brand. Twenty-one participants carried simultaneously three different tri-axial accelerometers on their waist during five different sedentary activities and five different intensity levels of bipedal movement from slow walking to running. Several time and frequency domain traits were calculated from the measured raw data, and their performance in classifying the activities was compared. Of the several traits, the mean amplitude deviation (MAD) provided consistently the best performance in separating the sedentary activities and different speeds of bipedal movement from each other. Most importantly, the universal cut-off limits based on MAD classified sedentary activities and different intensity levels of walking and running equally well for all three accelerometer brands and reached at least 97% sensitivity and specificity in each case. Irrespective of the accelerometer brand, a simply calculable MAD with universal cut-off limits provides a universal method to evaluate physical activity and sedentary behaviour using raw accelerometer data. A broader application of the present approach is expected to render different accelerometer studies directly comparable with each other. © 2014 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Associations of Low- and High-Intensity Light Activity with Cardiometabolic Biomarkers.

PubMed

Howard, Bethany; Winkler, Elisabeth A H; Sethi, Parneet; Carson, Valerie; Ridgers, Nicola D; Salmon, J O; Healy, Genevieve N; Owen, Neville; Dunstan, David W

2015-10-01

Light-intensity physical activity (LIPA) accounts for much of adults' waking hours (≈40%) and substantially contributes to overall daily energy expenditure. Encompassing activity behaviors of low intensity (standing with little movement) to those of higher intensity (slow walking), LIPA is ubiquitous, yet little is known about how associations with health may vary depending on its intensity. We examined the associations of objectively assessed LIPA (categorized as either low LIPA [LLPA] or high LIPA [HLPA]) and moderate- to vigorous-intensity activity with cardiometabolic risk biomarkers. Cardiometabolic biomarkers were measured in 4614 US adults (47 ± 17 yr) who participated in the 2003-2004 and 2005-2006 National Health and Nutrition Examination Survey cycles. Multiple linear regression analyses examined the associations of three accelerometer-derived physical activity (SD increment per day) intensity categories (LLPA, 100-761 counts per minute; HLPA, 762-1951 counts per minute; moderate-intensity physical activity [MPA], 1952-5724 counts per minute; vigorous-intensity physical activity [VPA], ≥5725 counts per minute) with cardiometabolic biomarkers, adjusting for potential sociodemographic, behavioral, and medical confounders. All intensities of physical activity were beneficially associated with waist circumference, C-reactive protein, triglycerides, fasting insulin, β-cell function, and insulin sensitivity (P < 0.05); only some activity intensities showed significant associations with systolic blood pressure (LLPA), body mass index, HDL cholesterol, fasting glucose, and 2-h plasma glucose (HLPA, MPA, and VPA). Generally, effect size increased with intensity of physical activity. Overall, further adjustment for waist circumference attenuated associations with MPA and VPA to a greater extent than associations with LLPA and HLPA. The cross-sectional findings provide novel evidence for the potential benefits of increasing both LLPA and HLPA. They further reinforce the established importance of moderate- to vigorous-intensity activity, the mainstay of public health recommendations.

The effect of simulated ostracism on physical activity behavior in children.

PubMed

Barkley, Jacob E; Salvy, Sarah-Jeanne; Roemmich, James N

2012-03-01

To assess the effects of simulated ostracism on children's physical activity behavior, time allocated to sedentary behavior, and liking of physical activity. Nineteen children (11 boys, 8 girls; age 11.7 ± 1.3 years) completed 2 experimental sessions. During each session, children played a virtual ball-toss computer game (Cyberball). In one session, children played Cyberball and experienced ostracism; in the other session, they were exposed to the inclusion/control condition. The order of conditions was randomized. After playing Cyberball, children were taken to a gymnasium where they had free-choice access to physical and sedentary activities for 30 minutes. Children could participate in the activities, in any pattern they chose, for the entire period. Physical activity during the free-choice period was assessed via accelerometery and sedentary time via observation. Finally, children reported their liking for the activity session via a visual analog scale. Children accumulated 22% fewer (P < .01) accelerometer counts and 41% more (P < .04) minutes of sedentary activity in the ostracized condition (8.9(e+4) ± 4.5(e+4) counts, 11.1 ± 9.3 minutes) relative to the included condition (10.8(e+4) ± 4.7(e+4) counts, 7.9 ± 7.9 minutes). Liking (8.8 ± 1.5 cm included, 8.1 ± 1.9 cm ostracized) of the activity sessions was not significantly different (P > .10) between conditions. Simulated ostracism elicits decreased subsequent physical activity participation in children. Ostracism may contribute to children's lack of physical activity.

Comparison of four Fitbit and Jawbone activity monitors with a research-grade ActiGraph accelerometer for estimating physical activity and energy expenditure.

PubMed

Imboden, Mary T; Nelson, Michael B; Kaminsky, Leonard A; Montoye, Alexander Hk

2017-05-08

Consumer-based physical activity (PA) monitors have become popular tools to track PA behaviours. Currently, little is known about the validity of the measurements provided by consumer monitors. We aimed to compare measures of steps, energy expenditure (EE) and active minutes of four consumer monitors with one research-grade accelerometer within a semistructured protocol. Thirty men and women (18-80 years old) wore Fitbit One (worn at the waist), Fitbit Zip (waist), Fitbit Flex (wrist), Jawbone UP24 (wrist) and one waist-worn research-grade accelerometer (ActiGraph) while participating in an 80 min protocol. A validated EE prediction equation and active minute cut-points were applied to ActiGraph data. Criterion measures were assessed using direct observation (step count) and portable metabolic analyser (EE, active minutes). A repeated measures analysis of variance (ANOVA) was used to compare differences between consumer monitors, ActiGraph, and criterion measures. Similarly, a repeated measures ANOVA was applied to a subgroup of subjects who didn't cycle. Participants took 3321±571 steps, had 28±6 active min and expended 294±56 kcal based on criterion measures. Comparatively, all monitors underestimated steps and EE by 13%-32% (p<0.01); additionally the Fitbit Flex, UP24, and ActiGraph underestimated active minutes by 35%-65% (p<0.05). Underestimations of PA and EE variables were found to be similar in the subgroup analysis. Consumer monitors had similar accuracy for PA assessment as the ActiGraph, which suggests that consumer monitors may serve to track personal PA behaviours and EE. However, due to discrepancies among monitors, individuals should be cautious when comparing relative and absolute differences in PA values obtained using different monitors. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Validation of Accelerometer Cut-Points in Children With Cerebral Palsy Aged 4 to 5 Years.

PubMed

Keawutan, Piyapa; Bell, Kristie L; Oftedal, Stina; Davies, Peter S W; Boyd, Roslyn N

2016-01-01

To derive and validate triaxial accelerometer cut-points in children with cerebral palsy (CP) and compare these with previously established cut-points in children with typical development. Eighty-four children with CP aged 4 to 5 years wore the ActiGraph during a play-based gross motor function measure assessment that was video-taped for direct observation. Receiver operating characteristic and Bland-Altman plots were used for analyses. The ActiGraph had good classification accuracy in Gross Motor Function Classification System (GMFCS) levels III and V and fair classification accuracy in GMFCS levels I, II, and IV. These results support the use of the previously established cut-points for sedentary time of 820 counts per minute in children with CP aged 4 to 5 years across all functional abilities. The cut-point provides an objective measure of sedentary and active time in children with CP. The cut-point is applicable to group data but not for individual children.

Daytime Physical Activity and Sleep in Hospitalized Older Adults: Association with Demographic Characteristics and Disease Severity.

PubMed

Beveridge, Claire; Knutson, Kristen; Spampinato, Lisa; Flores, Andrea; Meltzer, David O; Van Cauter, Eve; Arora, Vineet M

2015-07-01

To assess objectively measured daytime physical activity and sleep duration and efficiency in hospitalized older adults and explore associations with demographic characteristics and disease severity. Prospective cohort study. University of Chicago Medical Center general medicine wards. Community-dwelling inpatients aged 50 and older (N = 120) MEASUREMENTS: Physical activity and sleep were measured using wrist accelerometers. Information on Charlson Comorbidity Index and length of stay was collected from charts. Random-effects linear regression analysis was used to examine the association between in-hospital sleep and physical activity. From March 2010 to May 2013, 120 participants wore wrist actigraphy monitors for at least 2 nights and 1 intervening day. Median activity level over the waking period was 77 counts/min (interquartile range 51-121 counts/min), an activity level that approximately corresponds to sitting while watching television (65 counts/min). Mean sleep duration the night before the activity interval was 289 ± 157 minutes, and mean sleep efficiency the night before the activity interval was 65.2 ± 26.9%. Mean activity counts/min were lowest for the oldest participants (oldest quartile 62, 95% confidence interval (CI) = 50-75; youngest quartile 121, 95% CI = 98-145, trend test P < .001) and those with highest Charlson Comorbidity Index (highest tertile 71, 95% CI = 60-83; lowest tertile 125, 95% CI = 104-147, trend test P = .01). Controlling for severity of illness and demographic characteristics, activity declined by 3 counts/min (95% CI = -5.65 to -0.43, P = .02) for each additional hour of inpatient sleep. Older, sicker adults are less physically active during hospitalization. In contrast to studies in the community, inpatients who slept more were not more active. This may highlight that need for sleep is greater in the hospital than in the community. © 2015, Copyright the Authors Journal compilation © 2015, The American Geriatrics Society.

Preschool physical activity and functional constipation: the Generation R study.

PubMed

Driessen, Lisa M; Kiefte-de Jong, Jessica C; Wijtzes, Anne; de Vries, Sanne I; Jaddoe, Vincent W V; Hofman, Albert; Raat, Hein; Moll, Henriette A

2013-12-01

Decreased physical activity levels in children may partly explain the rising prevalence of functional constipation in childhood. The aim of the present study, therefore, was to examine the association between physical activity and functional constipation during the preschool period. This study was embedded in the Generation R study, a large prospective birth-cohort study in Rotterdam, The Netherlands. Physical activity was measured by an Actigraph accelerometer in 347 children (182 boys, 165 girls; mean age 25.1 months) and data were expressed as counts per minute. Data were categorized into light activity (302-614 counts/15 seconds), moderate activity (615-1230 counts/15 seconds), and vigorous activity (≥1231 counts/15 seconds). Functional constipation in the third and fourth year of life was defined according to the Rome II criteria. Children spending time in the highest tertile of light (adjusted odds ratio [OR] 0.34; 95% confidence interval [CI] 0.13-0.87), moderate (adjusted OR 0.37; 95% CI 0.14-0.97), and total activity (adjusted OR 0.37; 95% CI 0.15-0.92) at the age of 2 years had significantly less functional constipation in the fourth year of life. For functional constipation in the third year of life, the results were in similar direction but not statistically significant. Additionally, children with physical activity of more than the WHO recommendation of 60 min/day had significantly less functional constipation in the fourth year of life (adjusted OR 0.48; 95% CI 0.24-0.97). Physical activity is associated with a decreased risk of functional constipation in the preschool period, but this may be time dependent.

Promoting Physical Activity With the Out of School Nutrition and Physical Activity (OSNAP) Initiative: A Cluster-Randomized Controlled Trial.

PubMed

Cradock, Angie L; Barrett, Jessica L; Giles, Catherine M; Lee, Rebekka M; Kenney, Erica L; deBlois, Madeleine E; Thayer, Julie C; Gortmaker, Steven L

2016-02-01

Millions of children attend after-school programs in the United States. Increasing physical activity levels of program participants could have a broad effect on children's health. To test the effectiveness of the Out of School Nutrition and Physical Activity (OSNAP) Initiative in increasing children's physical activity levels in existing after-school programs. Cluster-randomized controlled trial with matched program pairs. Baseline data were collected September 27 through November 12, 2010, with follow-up data collected April 25 through May 27, 2011. The dates of our analysis were March 11, 2014, through August 18, 2015. The setting was 20 after-school programs in Boston, Massachusetts. All children 5 to 12 years old in participating programs were eligible for study inclusion. Ten programs participated in a series of three 3-hour learning collaborative workshops, with additional optional opportunities for training and technical assistance. Change in number of minutes and bouts of moderate to vigorous physical activity, vigorous physical activity, and sedentary activity and change in total accelerometer counts between baseline and follow-up. Participants with complete data were 402 racially/ethnically diverse children, with a mean age of 7.7 years. Change in the duration of physical activity opportunities offered to children during program time did not differ between conditions (-1.2 minutes; 95% CI, -14.2 to 12.4 minutes; P = .87). Change in moderate to vigorous physical activity minutes accumulated by children during program time did not differ significantly by intervention status (-1.0; 95% CI, -3.3 to 1.3; P = .40). Total minutes per day of vigorous physical activity (3.2; 95% CI, 1.8-4.7; P < .001), vigorous physical activity minutes in bouts (4.1; 95% CI, 2.7-5.6; P < .001), and total accelerometer counts per day (16,894; 95% CI, 5101-28,686; P = .01) increased significantly during program time among intervention participants compared with control participants. Although programs participating in the OSNAP Initiative did not allot significantly more time for physical activity, they successfully made existing time more vigorously active for children receiving the intervention. clinicaltrials.gov Identifier: NCT01396473.

Accelerometry Shows Inpatients With Acute Medical or Surgical Conditions Spend Little Time Upright and Are Highly Sedentary: Systematic Review.

PubMed

Baldwin, Claire; van Kessel, Gisela; Phillips, Anna; Johnston, Kylie

2017-11-01

Physical inactivity and sedentary behaviors have significant and independent effects on health. The use of wearable monitors to measure these constructs in people who are hospitalized with an acute illness is rapidly expanding, but has not been systematically described. The purpose of this study was to review the use of accelerometer monitoring with inpatients who are acutely ill, including what activity and sedentary behaviors have been measured and how active or sedentary inpatients are. Databases used were MEDLINE, EMBASE, CINAHL, and Scopus. Quantitative studies of adults with an acute medical or surgical hospital admission, on whom an accelerometer was used to measure a physical activity or sedentary behavior, were selected. Procedures were completed independently by 2 reviewers, with differences resolved and cross-checked by a third reviewer. Forty-two studies were identified that recruited people who had medical diagnoses (n = 10), stroke (n = 5), critical illness (n = 3), acute exacerbations of lung disease (n = 7), cardiac conditions (n = 7), or who were postsurgery (n = 10). Physical activities or sedentary behaviors were reported in terms of time spent in a particular posture (lying/sitting, standing/stepping), active/inactive, or at a particular activity intensity. Physical activity was also reported as step count, number of episodes or postural transitions, and bouts. Inpatients spent 93% to 98.8% (range) of their hospital stay sedentary, and in most studies completed <1,000 steps/day despite up to 50 postural transitions/day. No study reported sedentary bouts. Many studies controlled for preadmission function as part of the recruitment strategy or analysis or both. Heterogeneity in monitoring devices (17 models), protocols, and variable definitions limited comparability between studies and clinical groups to descriptive synthesis without meta-analysis. Hospitalized patients were highly inactive, especially those with medical admissions, based on time and step parameters. Accelerometer monitoring of sedentary behavior patterns was less reported and warrants further research. © 2017 American Physical Therapy Association

Examining differences in physical activity levels by employment status and/or job activity level: Gender-specific comparisons between the United States and Sweden.

PubMed

Kwak, Lydia; Berrigan, David; Van Domelen, Dane; Sjöström, Michael; Hagströmer, Maria

2016-06-01

The aim of the study was to examine the relationship between employment status and job activity level with physical activity (PA) and sedentary time, stratified by gender and country. Cross-sectional study design. Data from working age adults (18-65 years) from two cross-sectional studies, the Swedish 2001-2002 and 2007-2008 Attitude Behavior and Change Study (ABC; n=1165) and the 2003-2006 US National Health and Nutrition Examination Survey (NHANES; n=4201), were stratified by employment status (employed and not employed) and job activity level (active, sedentary and mixed). PA in counts×min(-1) and time spent in sedentary, low and moderate or higher intensity were measured with accelerometers. Analyses were conducted in 2012-2013. In NHANES, the employed had significantly higher counts×min(-1) and spent more time in moderate or higher intensity PA than those not employed. In ABC, no significant differences were observed between employed and unemployed. Adults with active versus sedentary occupations had higher counts×min(-1) and less sedentary time in both the USA and Sweden and in both men and women. For example, counts×min(-1) were 20-40% greater in active versus sedentary jobs. Employment status is related to PA and sedentary time among men and women in the USA but not in Sweden. Among the employed, occupational PA is associated with total PA and sedentary time for both genders and in both countries. Comparisons of PA levels based on objective measurements can refine understanding of country differences in activity. Copyright © 2015 Sports Medicine Australia. All rights reserved.

Comparison of self-reported versus accelerometer-measured physical activity.

PubMed

Dyrstad, Sindre M; Hansen, Bjørge H; Holme, Ingar M; Anderssen, Sigmund A

2014-01-01

The International Physical Activity Questionnaire (IPAQ) is one of the most widely used questionnaires to assess physical activity (PA). Validation studies for the IPAQ have been executed, but still there is a need for studies comparing absolute values between IPAQ and accelerometer in large population studies. To compare PA and sedentary time from the self-administered, short version of the IPAQ with data from ActiGraph accelerometer in a large national sample. A total of 1751 adults (19-84 yr) wore an accelerometer (ActiGraph GT1M) for seven consecutive days and completed the IPAQ-Short Form. Sedentary time, total PA, and time spent in moderate to vigorous activity were compared in relation to sex, age, and education. Men and women reported, on average, 131 min·d (SE = 4 min·d) less sedentary time compared with the accelerometer measurements. The difference between self-reported and measured sedentary time and vigorous-intensity PA was greatest among men with a lower education level and for men 65 yr and older. Although men reported 47% more moderate to vigorous physical activity (MVPA) compared with women, there were no differences between sexes in accelerometer-determined MVPA. Accelerometer-determined moderate PA was reduced from 110 to 42 min·d (62%) when analyzed in blocks of 10 min (P < 0.0001) compared with 1-min blocks. The main correlation coefficients between self-reported variables and accelerometer measures of physical activity were between 0.20 and 0.46. The participants report through IPAQ-Short Form more vigorous PA and less sedentary time compared with the accelerometer. The difference between self-reported and accelerometer-measured MVPA increased with higher activity and intensity levels. Associations between the methods were affected by sex, age, and education, but not body mass index.

A pilot study of physical activity and sedentary behavior distribution patterns in older women.

PubMed

Fortune, Emma; Mundell, Benjamin; Amin, Shreyasee; Kaufman, Kenton

2017-09-01

The study aims were to investigate free-living physical activity and sedentary behavior distribution patterns in a group of older women, and assess the cross-sectional associations with body mass index (BMI). Eleven older women (mean (SD) age: 77 (9) yrs) wore custom-built activity monitors, each containing a tri-axial accelerometer (±16g, 100Hz), on the waist and ankle for lab-based walking trials and 4 days in free-living. Daily active time, step counts, cadence, and sedentary break number were estimated from acceleration data. The sedentary bout length distribution and sedentary time accumulation pattern, using the Gini index, were investigated. Associations of the parameters' total daily values and coefficients of variation (CVs) of their hourly values with BMI were assessed using linear regression. The algorithm demonstrated median sensitivity, positive predictive value, and agreement values >98% and <1% mean error in cadence calculations with video identification during lab trials. Participants' sedentary bouts were found to be power law distributed with 56% of their sedentary time occurring in 20min bouts or longer. Meaningful associations were detectable in the relationships of total active time, step count, sedentary break number and their CVs with BMI. Active time and step counts had moderate negative associations with BMI while sedentary break number had a strong negative association. Active time, step count and sedentary break number CVs also had strong positive associations with BMI. The results highlight the importance of measuring sedentary behavior and suggest a more even distribution of physical activity throughout the day is associated with lower BMI. Copyright © 2017 Elsevier B.V. All rights reserved.

Validation and Comparison of Accelerometers Worn on the Hip, Thigh, and Wrists for Measuring Physical Activity and Sedentary Behavior.

PubMed

Montoye, Alexander H K; Pivarnik, James M; Mudd, Lanay M; Biswas, Subir; Pfeiffer, Karin A

2016-01-01

Recent evidence suggests that physical activity (PA) and sedentary behavior (SB) exert independent effects on health. Therefore, measurement methods that can accurately assess both constructs are needed. To compare the accuracy of accelerometers placed on the hip, thigh, and wrists, coupled with machine learning models, for measurement of PA intensity category (SB, light-intensity PA [LPA], and moderate- to vigorous-intensity PA [MVPA]) and breaks in SB. Forty young adults (21 female; age 22.0 ± 4.2 years) participated in a 90-minute semi-structured protocol, performing 13 activities (three sedentary, 10 non-sedentary) for 3-10 minutes each. Participants chose activity order, duration, and intensity. Direct observation (DO) was used as a criterion measure of PA intensity category, and transitions from SB to a non-sedentary activity were breaks in SB. Participants wore four accelerometers (right hip, right thigh, and both wrists), and a machine learning model was created for each accelerometer to predict PA intensity category. Sensitivity and specificity for PA intensity category classification were calculated and compared across accelerometers using repeated measures analysis of variance, and the number of breaks in SB was compared using repeated measures analysis of variance. Sensitivity and specificity values for the thigh-worn accelerometer were higher than for wrist- or hip-worn accelerometers, > 99% for all PA intensity categories. Sensitivity and specificity for the hip-worn accelerometer were 87-95% and 93-97%. The left wrist-worn accelerometer had sensitivities and specificities of > 97% for SB and LPA and 91-95% for MVPA, whereas the right wrist-worn accelerometer had sensitivities and specificities of 93-99% for SB and LPA but 67-84% for MVPA. The thigh-worn accelerometer had high accuracy for breaks in SB; all other accelerometers overestimated breaks in SB. Coupled with machine learning modeling, the thigh-worn accelerometer should be considered when objectively assessing PA and SB.

Objective measurements of daily physical activity patterns and sedentary behaviour in older adults: Age, Gene/Environment Susceptibility-Reykjavik Study.

PubMed

Arnardottir, Nanna Yr; Koster, Annemarie; Van Domelen, Dane R; Brychta, Robert J; Caserotti, Paolo; Eiriksdottir, Gudny; Sverrisdottir, Johanna Eyrun; Launer, Lenore J; Gudnason, Vilmundur; Johannsson, Erlingur; Harris, Tamara B; Chen, Kong Y; Sveinsson, Thorarinn

2013-03-01

objectively measured population physical activity (PA) data from older persons is lacking. The aim of this study was to describe free-living PA patterns and sedentary behaviours in Icelandic older men and women using accelerometer. from April 2009 to June 2010, 579 AGESII-study participants aged 73-98 years wore an accelerometer (Actigraph GT3X) at the right hip for one complete week in the free-living settings. in all subjects, sedentary time was the largest component of the total wear time, 75%, followed by low-light PA, 21%. Moderate-vigorous PA (MVPA) was <1%. Men had slightly higher average total PA (counts × day(-1)) than women. The women spent more time in low-light PA but less time in sedentary PA and MVPA compared with men (P < 0.001). In persons <75 years of age, 60% of men and 34% of women had at least one bout ≥10 min of MVPA, which decreased with age, with only 25% of men and 9% of women 85 years and older reaching this. sedentary time is high in this Icelandic cohort, which has high life-expectancy and is living north of 60° northern latitude.

Application of Accelerometer Data to Mars Odyssey Aerobraking and Atmospheric Modeling

NASA Technical Reports Server (NTRS)

Tolson, R. H.; Keating, G. M.; George, B. E.; Escalera, P. E.; Werner, M. R.; Dwyer, A. M.; Hanna, J. L.

2002-01-01

Aerobraking was an enabling technology for the Mars Odyssey mission even though it involved risk due primarily to the variability of the Mars upper atmosphere. Consequently, numerous analyses based on various data types were performed during operations to reduce these risk and among these data were measurements from spacecraft accelerometers. This paper reports on the use of accelerometer data for determining atmospheric density during Odyssey aerobraking operations. Acceleration was measured along three orthogonal axes, although only data from the component along the axis nominally into the flow was used during operations. For a one second count time, the RMS noise level varied from 0.07 to 0.5 mm/s2 permitting density recovery to between 0.15 and 1.1 kg per cu km or about 2% of the mean density at periapsis during aerobraking. Accelerometer data were analyzed in near real time to provide estimates of density at periapsis, maximum density, density scale height, latitudinal gradient, longitudinal wave variations and location of the polar vortex. Summaries are given of the aerobraking phase of the mission, the accelerometer data analysis methods and operational procedures, some applications to determining thermospheric properties, and some remaining issues on interpretation of the data. Pre-flight estimates of natural variability based on Mars Global Surveyor accelerometer measurements proved reliable in the mid-latitudes, but overestimated the variability inside the polar vortex.

Validity of activity trackers, smartphones, and phone applications to measure steps in various walking conditions.

PubMed

Höchsmann, C; Knaier, R; Eymann, J; Hintermann, J; Infanger, D; Schmidt-Trucksäss, A

2018-02-20

To examine the validity of popular smartphone accelerometer applications and a consumer activity wristband compared to a widely used research accelerometer while assessing the impact of the phone's position on the accuracy of step detection. Twenty volunteers from 2 different age groups (Group A: 18-25 years, n = 10; Group B 45-70 years, n = 10) were equipped with 3 iPhone SE smartphones (placed in pants pocket, shoulder bag, and backpack), 1 Samsung Galaxy S6 Edge (pants pocket), 1 Garmin Vivofit 2 wristband, and 2 ActiGraph wGTX+ devices (worn at wrist and hip) while walking on a treadmill (1.6, 3.2, 4.8, and 6.0 km/h) and completing a walking course. All smartphones included 6 accelerometer applications. Video observation was used as gold standard. Validity was evaluated by comparing each device with the gold standard using mean absolute percentage errors (MAPE). The MAPE of the iPhone SE (all positions) and the Garmin Vivofit was small (<3) for treadmill walking ≥3.2 km/h and for free walking. The Samsung Galaxy and hip-worn ActiGraph showed small MAPE only for treadmill walking at 4.8 and 6.0 km/h and for free walking. The wrist-worn ActiGraph showed high MAPE (17-47) for all walking conditions. The iPhone SE and the Garmin Vivofit 2 are accurate tools for step counting in different age groups and during various walking conditions, even during slow walking. The phone's position does not impact the accuracy of step detection, which substantially improves the versatility for physical activity assessment in clinical and research settings. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Improved Signal Processing Technique Leads to More Robust Self Diagnostic Accelerometer System

NASA Technical Reports Server (NTRS)

Tokars, Roger; Lekki, John; Jaros, Dave; Riggs, Terrence; Evans, Kenneth P.

2010-01-01

The self diagnostic accelerometer (SDA) is a sensor system designed to actively monitor the health of an accelerometer. In this case an accelerometer is considered healthy if it can be determined that it is operating correctly and its measurements may be relied upon. The SDA system accomplishes this by actively monitoring the accelerometer for a variety of failure conditions including accelerometer structural damage, an electrical open circuit, and most importantly accelerometer detachment. In recent testing of the SDA system in emulated engine operating conditions it has been found that a more robust signal processing technique was necessary. An improved accelerometer diagnostic technique and test results of the SDA system utilizing this technique are presented here. Furthermore, the real time, autonomous capability of the SDA system to concurrently compensate for effects from real operating conditions such as temperature changes and mechanical noise, while monitoring the condition of the accelerometer health and attachment, will be demonstrated.

White blood cell counts mediate the effects of physical activity on prostate-specific antigen levels.

PubMed

Loprinzi, Paul D; Richart, Sarah M

2014-09-01

The purpose of this study was to examine whether white blood cell (WBC) level mediated the relationship between physical activity and prostate-specific antigen (PSA) levels. Data from the 2003-2006 National Health and Nutrition Examination Survey were used; 1,726 U.S. adult men (aged 40 years or older) provided complete data on the study variables. Participants wore an ActiGraph 7164 accelerometer for a 7-day period to measure their physical activity behavior, and PSA and WBC levels were obtained from a blood sample. After adjustments, results showed that moderate-to-vigorous physical activity (MVPA) was inversely associated with WBC count (b = - .03; 95% CI [ - 0.04, - 0.006; p = .01), and WBC count (b = .10; 95% CI [0.009, 0.18; p = .04) was positively associated with PSA. Both the Sobel (coef. = - .004, SE = .002; z = - 2.0; p = .03) and the Aroian (coef. = - .004, SE = .002; z = - 1.9; p = .03) tests demonstrated that WBC mediated the relationship between physical activity and PSA. Additionally, among 107 participants with prostate cancer, survivors engaging in more MVPA had lower levels of WBC (b = - .04; 95% CI [ - 0.09, - 0.0009; p = .04). Conclusion Physical activity may influence PSA levels through WBC modulation; however, future research is needed to determine the direction of causality. Additionally, prostate cancer survivors engaging in higher levels of MVPA had lower levels of WBC, underscoring the importance of promoting physical activity among prostate cancer survivors.

GT3X+ accelerometer, Yamax pedometer and SC-StepMX pedometer step count accuracy in community-dwelling older adults.

PubMed

Webber, Sandra C; Magill, Sheila M; Schafer, Jenessa L; Wilson, Kaylie C S

2014-07-01

The purpose was to compare step count accuracy of an accelerometer (ActiGraph GT3X+), a mechanical pedometer (Yamax SW200), and a piezoelectric pedometer (SC-StepMX). Older adults (n = 13 with walking aids, n = 22 without; M = 81.5 years old, SD = 5.0) walked 100 m wearing the devices. Device-detected steps were compared with manually counted steps. We found no significant differences among monitors for those who walked without aids (p = .063). However, individuals who used walking aids exhibited slower gait speeds (M = 0.83 m/s, SD = 0.2) than non-walking aid users (M = 1.21 m/s, SD = 0.2, p < .001), and for them the SC-StepMX demonstrated a significantly lower percentage of error (Mdn = 1.0, interquartile range [IQR] = 0.5-2.0) than the other devices (Yamax SW200, Mdn = 68.9, IQR = 35.9-89.3; left GT3X+, Mdn = 52.0, IQR = 37.1-58.9; right GT3X+, Mdn = 51.0, IQR = 32.3-66.5; p < .05). These results support using a piezoelectric pedometer for measuring steps in older adults who use walking aids and who walk slowly.

Implementation of accelerometer sensor module and fall detection monitoring system based on wireless sensor network.

PubMed

Lee, Youngbum; Kim, Jinkwon; Son, Muntak; Lee, Myoungho

2007-01-01

This research implements wireless accelerometer sensor module and algorithm to determine wearer's posture, activity and fall. Wireless accelerometer sensor module uses ADXL202, 2-axis accelerometer sensor (Analog Device). And using wireless RF module, this module measures accelerometer signal and shows the signal at ;Acceloger' viewer program in PC. ADL algorithm determines posture, activity and fall that activity is determined by AC component of accelerometer signal and posture is determined by DC component of accelerometer signal. Those activity and posture include standing, sitting, lying, walking, running, etc. By the experiment for 30 subjects, the performance of implemented algorithm was assessed, and detection rate for postures, motions and subjects was calculated. Lastly, using wireless sensor network in experimental space, subject's postures, motions and fall monitoring system was implemented. By the simulation experiment for 30 subjects, 4 kinds of activity, 3 times, fall detection rate was calculated. In conclusion, this system can be application to patients and elders for activity monitoring and fall detection and also sports athletes' exercise measurement and pattern analysis. And it can be expected to common person's exercise training and just plaything for entertainment.

Physical Activity Levels in Early Knee Osteoarthritis Patients Measured by Accelerometry

PubMed Central

Farr, Joshua N.; Going, Scott B.; Lohman, Timothy G.; Rankin, Lucinda; Kasle, Shelley; Cornett, Michelle; Cussler, Ellen

2008-01-01

Objective: Physical activity (PA) is recommended for osteoarthritis (OA) management to reduce pain and improve function. The purpose of this study was to objectively assess the level and pattern of PA in male and female knee OA patients to determine adherence to CDC/ACSM and EPAC recommendations for PA. Methods: Early OA patients (n = 255, 76% women, 54.6 ± 7.1 years, body mass index (BMI) 27.8 ± 4.3 kg/m2) having radiographic status of Kellgren and Lawrence-defined grade II OA (and no higher) in at least one knee wore an accelerometer (Actigraph MTI) for 6-7 contiguous days. Light (LPA), moderate (MPA) and vigorous (VPA) PA intensities were defined as accelerometer recordings of 100 to 2,224, 2,225 to 5,950, and > 5,950 counts per minute, respectively. Results: Subjects wore accelerometers for 6.8 ± 0.3 days and 13.8 ± 2.2 hours per day (hr/day) and spent much more (P < 0.001) time in MPA (23.6 ± 17.2 min/day) compared to VPA (0.95 ± 3.5 min/day). Males spent significantly (P < 0.05) more time in all PA intensities than females. Only 30% of subjects achieved recommended PA levels. The proportion of males (47%) achieving the recommendation was significantly (P = 0.04) higher than females (24%). Conclusion: Knee OA patients accumulate little vigorous PA and most (70%) do not achieve recommended levels for moderate or greater intensity PA. New strategies to increase levels of PA in this population are needed. PMID:18759320

Criterion and Concurrent Validity of the activPAL™ Professional Physical Activity Monitor in Adolescent Females

PubMed Central

Dowd, Kieran P.; Harrington, Deirdre M.; Donnelly, Alan E.

2012-01-01

Background The activPAL has been identified as an accurate and reliable measure of sedentary behaviour. However, only limited information is available on the accuracy of the activPAL activity count function as a measure of physical activity, while no unit calibration of the activPAL has been completed to date. This study aimed to investigate the criterion validity of the activPAL, examine the concurrent validity of the activPAL, and perform and validate a value calibration of the activPAL in an adolescent female population. The performance of the activPAL in estimating posture was also compared with sedentary thresholds used with the ActiGraph accelerometer. Methodologies Thirty adolescent females (15 developmental; 15 cross-validation) aged 15–18 years performed 5 activities while wearing the activPAL, ActiGraph GT3X, and the Cosmed K4B2. A random coefficient statistics model examined the relationship between metabolic equivalent (MET) values and activPAL counts. Receiver operating characteristic analysis was used to determine activity thresholds and for cross-validation. The random coefficient statistics model showed a concordance correlation coefficient of 0.93 (standard error of the estimate = 1.13). An optimal moderate threshold of 2997 was determined using mixed regression, while an optimal vigorous threshold of 8229 was determined using receiver operating statistics. The activPAL count function demonstrated very high concurrent validity (r = 0.96, p<0.01) with the ActiGraph count function. Levels of agreement for sitting, standing, and stepping between direct observation and the activPAL and ActiGraph were 100%, 98.1%, 99.2% and 100%, 0%, 100%, respectively. Conclusions These findings suggest that the activPAL is a valid, objective measurement tool that can be used for both the measurement of physical activity and sedentary behaviours in an adolescent female population. PMID:23094069

Artificial neural networks to predict activity type and energy expenditure in youth.

PubMed

Trost, Stewart G; Wong, Weng-Keen; Pfeiffer, Karen A; Zheng, Yonglei

2012-09-01

Previous studies have demonstrated that pattern recognition approaches to accelerometer data reduction are feasible and moderately accurate in classifying activity type in children. Whether pattern recognition techniques can be used to provide valid estimates of physical activity (PA) energy expenditure in youth remains unexplored in the research literature. The objective of this study is to develop and test artificial neural networks (ANNs) to predict PA type and energy expenditure (PAEE) from processed accelerometer data collected in children and adolescents. One hundred participants between the ages of 5 and 15 yr completed 12 activity trials that were categorized into five PA types: sedentary, walking, running, light-intensity household activities or games, and moderate-to-vigorous-intensity games or sports. During each trial, participants wore an ActiGraph GT1M on the right hip, and VO2 was measured using the Oxycon Mobile (Viasys Healthcare, Yorba Linda, CA) portable metabolic system. ANNs to predict PA type and PAEE (METs) were developed using the following features: 10th, 25th, 50th, 75th, and 90th percentiles and the lag one autocorrelation. To determine the highest time resolution achievable, we extracted features from 10-, 15-, 20-, 30-, and 60-s windows. Accuracy was assessed by calculating the percentage of windows correctly classified and root mean square error (RMSE). As window size increased from 10 to 60 s, accuracy for the PA-type ANN increased from 81.3% to 88.4%. RMSE for the MET prediction ANN decreased from 1.1 METs to 0.9 METs. At any given window size, RMSE values for the MET prediction ANN were 30-40% lower than the conventional regression-based approaches. ANNs can be used to predict both PA type and PAEE in children and adolescents using count data from a single waist mounted accelerometer.

Validity of the SC-StepMX pedometer during treadmill walking and running.

PubMed

Colley, Rachel C; Barnes, Joel D; Leblanc, Allana G; Borghese, Michael; Boyer, Charles; Tremblay, Mark S

2013-05-01

The purpose of this study was to examine the validity of the SC-StepMX pedometer for measuring step counts. A convenience sample of 40 participants wore 4 SC-StepMX pedometers, 2 Yamax DigiWalker pedometers, and 2 Actical accelerometers around their waist on a treadmill at 4 speeds based on each participant's self-paced walking speed (50%, 100%, 180%, and 250%; range: 1.4-14.1 km·h(-1)). The SC-StepMX demonstrated lower mean absolute percent error (-0.2%) compared with the Yamax DigiWalker (-20.5%) and the Actical (-26.1%). Mean measurement bias was lower for the SC-StepMX (0.1 ± 9.1; 95% confidence interval = -17.8 to 18.0 steps·min(-1)) when compared with both the Yamax DigiWalker (-15.9 ± 23.3; 95% confidence interval = -61.6 to 29.7 steps·min(-1)) and the Actical (-22.0 ± 36.3; 95% CI = -93.1 to 49.1 steps·min(-1)). This study demonstrates that the SC-StepMX pedometer is a valid tool for the measurement of step counts. The SC-StepMX accurately measures step counts at slower walking speeds when compared with 2 other commercially available activity monitors. This makes the SC-StepMX useful in measuring step counts in populations that are active at lower intensities (e.g., sedentary individuals, the elderly).

Identifying walking trips from GPS and accelerometer data in adolescent females

PubMed Central

Rodriguez, Daniel; Cho, GH; Elder, John; Conway, Terry; Evenson, Kelly R; Ghosh-Dastidar, Bonnie; Shay, Elizabeth; Cohen, Deborah A; Veblen-Mortenson, Sarah; Pickrell, Julie; Lytle, Leslie

2013-01-01

Background Studies that have combined accelerometers and global positioning systems (GPS) to identify walking have done so in carefully controlled conditions. This study tested algorithms for identifying walking trips from accelerometer and GPS data in free-living conditions. The study also assessed the accuracy of the locations where walking occurred compared to what participants reported in a diary. Methods A convenience sample of high school females was recruited (N=42) in 2007. Participants wore a GPS unit and an accelerometer, and recorded their out-of-school travel for six days. Split-sample validation was used to examine agreement in the daily and total number of walking trips with Kappa statistics and count regression models, while agreement in locations visited by walking was examined with geographic information systems. Results Agreement varied based on the parameters of the algorithm, with algorithms exhibiting moderate to substantial agreement with self-reported daily (Kappa = 0.33–0.48) and weekly (Kappa = 0.41–0.64) walking trips. Comparison of reported locations reached by walking and GPS data suggest that reported locations are accurate. Conclusions The use of GPS and accelerometers is promising for assessing the number of walking trips and the walking locations of adolescent females. PMID:21934163

Physical activity monitoring by use of accelerometer-based body-worn sensors in older adults: a systematic literature review of current knowledge and applications.

PubMed

Taraldsen, Kristin; Chastin, Sebastien F M; Riphagen, Ingrid I; Vereijken, Beatrix; Helbostad, Jorunn L

2012-01-01

To systematically review the literature on physical activity variables derived from body-worn sensors during long term monitoring in healthy and in-care older adults. Using pre-designed inclusion and exclusion criteria, a PubMed search strategy was designed to trace relevant reports of studies. Last search date was March 8, 2011. Studies that included persons with mean or median age of >65 years, used accelerometer-based body-worn sensors with a monitoring length of >24h, and reported values on physical activity in the samples assessed. 1403 abstracts were revealed and 134 full-text papers included in the final review. A variety of variables derived from activity counts or recognition of performed activities were reported in healthy older adults as well as in in-care older adults. Three variables were possible to compare across studies, level of Energy Expenditure in kcal per day and activity recognition in terms of total time in walking and total activity. However, physical activity measured by these variables demonstrated large variation between studies and did not distinguish activity between healthy and in-care samples. There is a rich variety in methods used for data collection and analysis as well as in reported variables. Different aspects of physical activity can be described, but the variety makes it challenging to compare across studies. There is an urgent need for developing consensus on activity monitoring protocols and which variables to report. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Employment and physical activity in the U.S.

PubMed

Van Domelen, Dane R; Koster, Annemarie; Caserotti, Paolo; Brychta, Robert J; Chen, Kong Y; McClain, James J; Troiano, Richard P; Berrigan, David; Harris, Tamara B

2011-08-01

Physical inactivity is a risk factor for obesity, cardiovascular disease, hypertension, and other chronic diseases that are increasingly prevalent in the U.S. and worldwide. Time at work represents a major portion of the day for employed people. To determine how employment status (full-time, part-time, or not employed) and job type (active or sedentary) are related to daily physical activity levels in American adults. Cross-sectional data from the National Health and Nutrition Examination Survey (NHANES) were collected in 2003-2004 and analyzed in 2010. Physical activity was measured using Actigraph uniaxial accelerometers, and participants aged 20-60 years with ≥4 days of monitoring were included (N=1826). Accelerometer variables included mean counts/minute during wear time and proportion of wear time spent in various intensity levels. In men, full-time workers were more active than healthy nonworkers (p=0.004), and in weekday-only analyses, even workers with sedentary jobs were more active (p=0.03) and spent less time sedentary (p<0.001) than nonworkers. In contrast with men, women with full-time sedentary jobs spent more time sedentary (p=0.008) and had less light and lifestyle intensity activity than healthy nonworkers on weekdays. Within full-time workers, those with active jobs had greater weekday activity than those with sedentary jobs (22% greater in men, 30% greater in women). In men, full-time employment, even in sedentary occupations, is positively associated with physical activity compared to not working, and in both genders job type has a major bearing on daily activity levels. Copyright © 2011. Published by Elsevier Inc.

Validity of the International Physical Activity Questionnaire and the Singapore Prospective Study Program physical activity questionnaire in a multiethnic urban Asian population.

PubMed

Nang, Ei Ei Khaing; Gitau Ngunjiri, Susan Ayuko; Wu, Yi; Salim, Agus; Tai, E Shyong; Lee, Jeannette; Van Dam, Rob M

2011-10-13

Physical activity patterns of a population remain mostly assessed by the questionnaires. However, few physical activity questionnaires have been validated in Asian populations. We previously utilized a combination of different questionnaires to assess leisure time, transportation, occupational and household physical activity in the Singapore Prospective Study Program (SP2). The International Physical Activity Questionnaire (IPAQ) has been developed for a similar purpose. In this study, we compared estimates from these two questionnaires with an objective measure of physical activity in a multi-ethnic Asian population. Physical activity was measured in 152 Chinese, Malay and Asian Indian adults using an accelerometer over five consecutive days, including a weekend. Participants completed both the physical activity questionnaire in SP2 (SP2PAQ) and IPAQ long form. 43 subjects underwent a second set of measurements on average 6 months later to assess reproducibility of the questionnaires and the accelerometer measurements. Spearman correlations were used to evaluate validity and reproducibility and correlations for validity were corrected for within-person variation of accelerometer measurements. Agreement between the questionnaires and the accelerometer measurements was also evaluated using Bland Altman plots. The corrected correlation with accelerometer estimates of energy expenditure from physical activity was better for the SP2PAQ (vigorous activity: r = 0.73; moderate activity: r = 0.27) than for the IPAQ (vigorous activity: r = 0.31; moderate activity: r = 0.15). For moderate activity, the corrected correlation between SP2PAQ and the accelerometer was higher for Chinese (r = 0.38) and Malays (r = 0.57) than for Indians (r = -0.09). Both questionnaires overestimated energy expenditure from physical activity to a greater extent at higher levels of physical activity than at lower levels of physical activity. The reproducibility for moderate activity (accelerometer: r = 0.68; IPAQ: r = 0.58; SP2PAQ: r = 0.55) and vigorous activity (accelerometer: 0.52; IPAQ: r = 0.38; SP2PAQ: r = 0.75) was moderate to high for all instruments. The agreement between IPAQ and accelerometer measurements of energy expenditure from physical activity was poor in our Asian study population. The SP2PAQ showed good validity and reproducibility for vigorous activity, but performed less well for moderate activity particularly in Indians. Further effort is needed to develop questionnaires that better capture moderate activity in Asian populations.

Activity Levels in Healthy Older Adults: Implications for Joint Arthroplasty

PubMed Central

Thorp, Laura E.; Orozco, Diego; Block, Joel A.; Sumner, Dale R.; Wimmer, Markus A.

2012-01-01

This work evaluated activity levels in a group of healthy older adults to establish a target activity level for adults of similar age after total joint arthroplasty (TJA). With the decreasing age of TJA patients, it is essential to have a reference for activity level in younger patients as activity level affects quality of life and implant design. 54 asymptomatic, healthy older adults with no clinical evidence of lower extremity OA participated. The main outcome measure, average daily step count, was measured using an accelerometer-based activity monitor. On average the group took 8813 ± 3611 steps per day, approximately 4000 more steps per day than has been previously reported in patients following total joint arthroplasty. The present work provides a reference for activity after joint arthroplasty which is relevant given the projected number of people under the age of 65 who will undergo joint arthroplasty in the coming years. PMID:23577274

Comparison of the performance of the activPAL Professional physical activity logger to a discrete accelerometer-based activity monitor.

PubMed

Godfrey, A; Culhane, K M; Lyons, G M

2007-10-01

The aim of this study was to assess the accuracy of the 'activPAL Professional' physical activity logger by comparing its output to that of a proven discrete accelerometer-based activity monitor during extended measurements on healthy subjects while performing activities of daily living (ADL). Ten healthy adults, with unrestricted mobility, wore both the activPAL and the discrete dual accelerometer (Analog Devices ADXL202)-based activity monitor that recorded in synchronization with each other. The accelerometer derived data were then compared to that generated by the activPAL and a complete statistical and error analysis was performed using a Matlab program. This program determined trunk and thigh inclination angles to distinguish between sitting/lying, standing and stepping for the discrete accelerometer device and amount of time spent on each activity. Analysis was performed on a second-by-second basis and then categorized at 15s intervals in direct comparison with the activPAL generated data. Of the total time monitored (approximately 60 h) the detection accuracies for static and dynamic activities were approximately 98%. In a population of healthy adults, the data obtained from the activPAL Professional physical activity logger for both static and dynamic activities showed a close match to a proven discrete accelerometer data with an offset of approximately 2% between the two systems.

Using open source accelerometer analysis to assess physical activity and sedentary behaviour in overweight and obese adults.

PubMed

Innerd, Paul; Harrison, Rory; Coulson, Morc

2018-04-23

Physical activity and sedentary behaviour are difficult to assess in overweight and obese adults. However, the use of open-source, raw accelerometer data analysis could overcome this. This study compared raw accelerometer and questionnaire-assessed moderate-to-vigorous physical activity (MVPA), walking and sedentary behaviour in normal, overweight and obese adults, and determined the effect of using different methods to categorise overweight and obesity, namely body mass index (BMI), bioelectrical impedance analysis (BIA) and waist-to-hip ratio (WHR). One hundred twenty adults, aged 24-60 years, wore a raw, tri-axial accelerometer (Actigraph GT3X+), for 3 days and completed a physical activity questionnaire (IPAQ-S). We used open-source accelerometer analyses to estimate MVPA, walking and sedentary behaviour from a single raw accelerometer signal. Accelerometer and questionnaire-assessed measures were compared in normal, overweight and obese adults categorised using BMI, BIA and WHR. Relationships between accelerometer and questionnaire-assessed MVPA (Rs = 0.30 to 0.48) and walking (Rs = 0.43 to 0.58) were stronger in normal and overweight groups whilst sedentary behaviour were modest (Rs = 0.22 to 0.38) in normal, overweight and obese groups. The use of WHR resulted in stronger agreement between the questionnaire and accelerometer than BMI and BIA. Finally, accelerometer data showed stronger associations with BMI, BIA and WHR (Rs = 0.40 to 0.77) than questionnaire data (Rs = 0.24 to 0.37). Open-source, raw accelerometer data analysis can be used to estimate MVPA, walking and sedentary behaviour from a single acceleration signal in normal, overweight and obese adults. Our data supports the use of WHR to categorise overweight and obese adults. This evidence helps researchers obtain more accurate measures of physical activity and sedentary behaviour in overweight and obese populations.

Do Young People Ever Sit Still? Variations in Accelerometer Counts, Muscle Activity and Heart Rate across Various Sedentary Activities in Youth.

PubMed

van Ekris, Evi; Chinapaw, Mai J M; Rotteveel, Joost; Altenburg, Teatske M

2018-05-17

Evidence of adverse health effects of TV viewing is stronger than for overall sedentary behaviour in youth. One explanation may be that TV viewing involves less body movement than other sedentary activities. Variations in body movement across sedentary activities are currently unknown, as are age differences in such variations. This study examined body movement differences across various sedentary activities in children and adolescents, assessed by hip-, thigh- and wrist-worn accelerometers, muscle activity and heart rate. Body movement differences between sedentary activities and standing were also examined. Fifty-three children (aged 10⁻12 years) and 37 adolescents (aged 16⁻18 years) performed seven different sedentary activities, a standing activity, and a dancing activity (as a control activity) in a controlled setting. Each activity lasted 10 minutes. Participants wore an Actigraph on their hip and both wrists, an activPAL on their thigh and a heart rate monitor. The muscle activity of weight-bearing leg muscles was measured in a subgroup ( n = 38) by surface electromyography. Variations in body movement across activities were examined using general estimation equations analysis. Children showed significantly more body movement during sedentary activities and standing than adolescents. In both age groups, screen-based sedentary activities involved less body movement than non-screen-based sedentary activities. This may explain the stronger evidence for detrimental health effects of TV viewing while evidence for child sedentary behaviour in general is inconsistent. Differences in body movement during standing and sedentary activities were relatively small. Future research should examine the potential health effects of differences in body movement between screen-based versus non-screen based and standing versus sedentary activities.

Assessing Physical Activity in Children with Asthma: Convergent Validity between Accelerometer and Electronic Diary Data

ERIC Educational Resources Information Center

Floro, Josh N.; Dunton, Genevieve F.; Delfino, Ralph J.

2009-01-01

Convergent validity of accelerometer and electronic diary physical activity data was assessed in children with asthma. Sixty-two participants, ages 9-18 years, wore an accelerometer and reported their physical activity level in quarter-hour segments every 2 hr using the Ambulatory Diary Assessment (ADA). Moderate validity was found between…

Detecting Human Activity Using Acoustic, Seismic, Accelerometer, Video, and E-field Sensors

DTIC Science & Technology

2011-09-01

Detecting Human Activity using Acoustic, Seismic, Accelerometer, Video, and E-field Sensors by Sarah H. Walker and Geoffrey H. Goldman...Adelphi, MD 20783-1197 ARL-TR-5729 September 2011 Detecting Human Activity using Acoustic, Seismic, Accelerometer, Video, and E-field Sensors...DD-MM-YYYY) September 2011 2. REPORT TYPE 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE Detecting Human Activity using Acoustic

Physical Activity and Adiposity Markers at Older Ages: Accelerometer Vs Questionnaire Data

PubMed Central

Sabia, Séverine; Cogranne, Pol; van Hees, Vincent T.; Bell, Joshua A.; Elbaz, Alexis; Kivimaki, Mika; Singh-Manoux, Archana

2015-01-01

Objective Physical activity is critically important for successful aging, but its effect on adiposity markers at older ages is unclear as much of the evidence comes from self-reported data on physical activity. We assessed the associations of questionnaire-assessed and accelerometer-assessed physical activity with adiposity markers in older adults. Design/Setting/Participants This was a cross-sectional study on 3940 participants (age range 60-83 years) of the Whitehall II study who completed a 20-item physical activity questionnaire and wore a wrist-mounted accelerometer for 9 days in 2012 and 2013. Measurements Total physical activity was estimated using metabolic equivalent hours/week for the questionnaire and mean acceleration for the accelerometer. Time spent in moderate-and-vigorous physical activity (MVPA) was also assessed by questionnaire and accelerometer. Adiposity assessment included body mass index, waist circumference, and fat mass index. Fat mass index was calculated as fat mass/height² (kg/m²), with fat mass estimated using bioimpedance. Results Greater total physical activity was associated with lower adiposity for all adiposity markers in a dose-response manner. In men, the strength of this association was 2.4 to 2.8 times stronger with the accelerometer than with questionnaire data. In women, it was 1.9 to 2.3 times stronger. For MVPA, questionnaire data in men suggested no further benefit for adiposity markers past 1 hour/week of activity. This was not the case for accelerometer-assessed MVPA where, for example, compared with men undertaking <1 hour/week of accelerometer-assessed MVPA, waist circumference was 3.06 (95% confidence interval 2.06–4.06) cm lower in those performing MVPA 1–2.5 hours/week, 4.69 (3.47–5.91) cm lower in those undertaking 2.5–4 hours/week, and 7.11 (5.93–8.29) cm lower in those performing ≥4 hours/week. Conclusions The association of physical activity with adiposity markers in older adults was stronger when physical activity was assessed by accelerometer compared with questionnaire, suggesting that physical activity might be more important for adiposity than previously estimated. PMID:25752539

GPS-based exposure to greenness and walkability and accelerometry-based physical activity

PubMed Central

James, Peter; Hart, Jaime E.; Hipp, J. Aaron; Mitchell, Jonathan A.; Kerr, Jacqueline; Hurvitz, Philip M.; Glanz, Karen; Laden, Francine

2017-01-01

Background Physical inactivity is a risk factor for cancer that may be influenced by environmental factors. Indeed, dense and well-connected built environments and environments with natural vegetation may create opportunities for higher routine physical activity. However, studies have focused primarily on residential environments to define exposure and self-reported methods to estimate physical activity. The current study explores the momentary association between minute-level global positioning systems (GPS)-based greenness exposure and time-matched objectively measured physical activity. Methods Adult women were recruited from sites across the US. Participants wore a GPS device and accelerometer on the hip for 7 days to assess location and physical activity at minute-level epochs. GPS records were linked to 250m resolution satellite-based vegetation data and Census Block Group-level EPA Smart Location Database walkability data. Minute-level generalized additive mixed models were conducted to test for associations between GPS measures and accelerometer count data, accounting for repeated measures within participant and allowing for deviations from linearity using splines. Results Among 360 adult women (mean age of 55.3 ± 10.2 years), we observed positive nonlinear relationships between physical activity and both greenness and walkability. In exploratory analyses, the relationship between environmental factors and physical activity were strongest among those who were White, had higher incomes, and who were middle-aged. Conclusions Our results indicate that higher levels of physical activity occurred in areas with higher greenness and higher walkability. Impact Findings suggest that planning and design policies should focus on these environments to optimize opportunities for physical activity. PMID:28196848

Better with a buddy: influence of best friends on children's physical activity.

PubMed

Jago, Russell; Macdonald-Wallis, Kyle; Thompson, Janice L; Page, Angie S; Brockman, Rowan; Fox, Kenneth R

2011-02-01

the purpose of this study was to examine the extent to which the physical activity modeling and physical activity actions of best friends are associated with the physical activity of 10- to 11-yr-old children. data were collected from 986 children of whom 472 provided complete physical activity and best friend data. Participants identified their "best friend" within the school and answered how often they took part in physical activity with the friend and if the friend had encouraged them to be active. Physical activity was assessed via accelerometer for all children and friends. Mean minutes of moderate-to-vigorous physical activity per day (MVPA) and mean accelerometer counts per minute (CPM) were obtained for all children and best friends. Regression models were run separately for boys and girls and used to examine associations between child and best friend physical activity. for girls, mean MVPA was associated with frequency of activity of the best friend (P ≤ 0.02 for all categories) and engaging in physical activity at home or in the neighborhood (t = 2.27, P = 0.030), with similar patterns for mean CPM. Boys' mean MVPA was associated with their best friend's mean MVPA (t = 3.68, P = 0.001) and being active at home or in the local neighborhood (t = 2.52, P = 0.017). boys who have active friends spend more minutes in MVPA. Girls who frequently take part in physical activity with their best friend obtain higher levels of physical activity. Boys and girls who take part in physical activity with their best friend at home or in the neighborhood where they live engage in higher levels of physical activity.

Accelerometry is associated with walking mobility, not physical activity, in persons with multiple sclerosis.

PubMed

Weikert, Madeline; Suh, Yoojin; Lane, Abbi; Sandroff, Brian; Dlugonski, Deirdre; Fernhall, Bo; Motl, Robert W

2012-06-01

Accelerometers are seemingly a criterion standard of real-life walking mobility and this is supported by assumptions and empirical data. This application would be strengthened by including objective measures of walking mobility along with a matched control sample for verifying specificity versus generality in accelerometer output. We compared associations among accelerometer output, walking mobility, and physical activity between persons with multiple sclerosis (MS) and controls without a neurological disorder. Sixty-six persons (33 MS, 33 matched controls) completed a battery of questionnaires, performed the six-minute walk (6MW) and timed-up-and-go (TUG), and wore an accelerometer for a 7-day period. After this period, participants completed the Godin Leisure-Time Exercise Questionnaire (GLTEQ) and International Physical Activity Questionnaire (IPAQ). Accelerometer output was significantly correlated with only mobility measures (6MW, ρ=.78; TUG, ρ=-.68) in MS, whereas it correlated with both mobility (6MW, ρ=.58; TUG, ρ=-.49) and physical activity (GLTEQ, ρ=.56; IPAQ, ρ=.53) measures in controls. Regression analysis indicated that only 6MW explained variance in accelerometer output in MS (β=.65, R(2)=.43). These findings support the possibility that accelerometers primarily and specifically measure real-life walking mobility, not physical activity, in persons with MS. Copyright © 2011 IPEM. Published by Elsevier Ltd. All rights reserved.

Contribution of free play towards physical activity guidelines for New Zealand primary school children aged 7-9 years.

PubMed

McGall, S E; McGuigan, M R; Nottle, C

2011-02-01

the objectives of this study were to investigate children's physical activity patterns to gain comparisons between home and school and to determine whether the current physical activity guidelines of 60 min of moderate to vigorous physical activity (MVPA) daily were being met. participants were recruited from two New Zealand primary schools (60 children, mean age (SD) 8.3 (0.7) years). Physical activity was measured for seven consecutive days using Actigraph accelerometers. Total activity and average counts were determined for school playtime, after school and weekends. Differences between average counts for these intervals were compared using the t statistic. Time and percentage of time spent were categorised into the activity thresholds: sedentary (<100), light (101-299), moderate (3000-5200) and vigorous (>5200). Total activity for each day was also determined. no child met the recommended 60 min of MVPA daily during the investigation. Compared to school playtime, activity counts were lower by 36% (CI 25% to 45.5%, p<0.001, effect size (ES)=-1.29) after school, 50.1% (CI 37% to 60.5%, p<0.001, ES=-2.01) on Saturday and 57.4% (CI 46.3% to 66.3%, p<0.001, ES=-2.47) on Sunday. Mean results showed children spent 91-96% of their time engaged in light or sedentary activities. Even during school playtime, where the children were most active, only 8 of 80 min were spent engaged in MVPA. this study found activity levels were considerably lower than the recommended guidelines, and children were more active during school playtime compared to after school and weekends.

Understanding Environmental and Contextual Influences of Physical Activity During First-Year University: The Feasibility of Using Ecological Momentary Assessment in the MovingU Study

PubMed Central

Bedard, Chloe; King-Dowling, Sara; McDonald, Madeline; Dunton, Genevieve; Cairney, John

2017-01-01

Background It is well established that drastic declines in physical activity (PA) occur during young adults’ transition into university; however, our understanding of contextual and environmental factors as it relates to young adults’ PA is limited. Objective The purpose of our study was to examine the feasibility of using wrist-worn accelerometers and the use of ecological momentary assessment (EMA) to assess the context and momentary correlates of PA on multiple occasions each day during first-year university. Methods First-year university students were asked to participate in the study. The participants completed a brief questionnaire and were subsequently asked to wear an ActiGraph GT9X-Link accelerometer and respond to a series of EMA prompts (7/day) via their phones for 5 consecutive days. Results A total of 96 first-year university students with smartphones agreed to participate in the study (mean age 18.3 [SD 0.51]; n=45 females). Overall, there was good compliance for wearing the accelerometers, with 91% (78/86) of the participants having ≥2 days of ≥10 hours of wear time (mean=3.53 valid days). Students were generally active, averaging 10,895 steps/day (SD 3413) or 1123.23 activity counts/min (SD 356.10). Compliance to EMA prompts was less desirable, with 64% (55/86) of the participants having usable EMA data (responding to a minimum of ≥3 days of 3 prompts/day or ≥4 days of 2 prompts/day), and only 47% (26/55) of these participants were considered to have excellent EMA compliance (responding to ≥5 days of 4 prompts/day or ≥ 4 days of 5 prompts/day). Conclusions This study represents one of the first studies to use an intensive real-time data capture strategy to examine time-varying correlates of PA among first-year university students. These data will aim to describe the physical and social contexts in which PA occurs and examine the relationships between momentary correlates of PA among the first-year university students. Overall, current results suggest that wrist-worn accelerometers and EMA are feasible methods for data collection among the young adult population; however, more work is needed to understand how to improve upon compliance to a real-time data capture method such as EMA. PMID:28566264

Combining global positioning system and accelerometer data to determine the locations of physical activity in children.

PubMed

Oreskovic, Nicolas M; Blossom, Jeff; Field, Alison E; Chiang, Sylvia R; Winickoff, Jonathan P; Kleinman, Ronald E

2012-05-01

National trends indicate that children and adolescents are not achieving sufficient levels of physical activity. Combining global positioning system (GPS) technology with accelerometers has the potential to provide an objective determination in locations where youth engage in physical activity. The aim of this study was to identify the optimal methods for collecting combined accelerometer and GPS data in youth, to best locate where children spend time and are physically active. A convenience sample of 24 mid-school children in Massachusetts was included. Accelerometers and GPS units were used to quantify and locate childhood physical activity over 5 weekdays and 2 weekend days. Accelerometer and GPS data were joined by time and mapped with a geographical information system (GIS) using ArcGIS software. Data were collected in winter, spring, summer in 2009-2010, collecting a total of 26,406 matched datapoints overall. Matched data yield was low (19.1% total), regardless of season (winter, 12.8%; spring, 30.1%; summer, 14.3%). Teacher-provided, pre-charged equipment yielded the most matched (30.1%; range: 10.1-52.3%) and greatest average days (6.1 days) of data. Across all seasons, children spent most of their time at home. Outdoor use patterns appeared to vary by season, with street use increasing in spring, and park and playground use increasing in summer. Children spent equal amounts of physical activity time at home and walking in the streets. Overall, the various methods for combining GPS and accelerometer data provided similarly low amounts of combined data. No combined GPS and accelerometer data collection method proved superior in every data return category, but use of GIS to map joined accelerometer and GPS data can demarcate childhood physical activity locations.

Measurement of peak impact loads differ between accelerometers - Effects of system operating range and sampling rate.

PubMed

Ziebart, Christina; Giangregorio, Lora M; Gibbs, Jenna C; Levine, Iris C; Tung, James; Laing, Andrew C

2017-06-14

A wide variety of accelerometer systems, with differing sensor characteristics, are used to detect impact loading during physical activities. The study examined the effects of system characteristics on measured peak impact loading during a variety of activities by comparing outputs from three separate accelerometer systems, and by assessing the influence of simulated reductions in operating range and sampling rate. Twelve healthy young adults performed seven tasks (vertical jump, box drop, heel drop, and bilateral single leg and lateral jumps) while simultaneously wearing three tri-axial accelerometers including a criterion standard laboratory-grade unit (Endevco 7267A) and two systems primarily used for activity-monitoring (ActiGraph GT3X+, GCDC X6-2mini). Peak acceleration (gmax) was compared across accelerometers, and errors resulting from down-sampling (from 640 to 100Hz) and range-limiting (to ±6g) the criterion standard output were characterized. The Actigraph activity-monitoring accelerometer underestimated gmax by an average of 30.2%; underestimation by the X6-2mini was not significant. Underestimation error was greater for tasks with greater impact magnitudes. gmax was underestimated when the criterion standard signal was down-sampled (by an average of 11%), range limited (by 11%), and by combined down-sampling and range-limiting (by 18%). These effects explained 89% of the variance in gmax error for the Actigraph system. This study illustrates that both the type and intensity of activity should be considered when selecting an accelerometer for characterizing impact events. In addition, caution may be warranted when comparing impact magnitudes from studies that use different accelerometers, and when comparing accelerometer outputs to osteogenic impact thresholds proposed in literature. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Objectively Measured School Day Physical Activity Among Elementary Students in the United States and Finland.

PubMed

Yli-Piipari, Sami; Kulmala, Janne Santeri; Jaakkola, Timo; Hakonen, Harto; Fish, Joseph Cole; Tammelin, Tuija

2016-04-01

Schools are in a unique position to ensure that all students meet the current physical activity (PA) recommendations. This study aimed to examine 1st to 3rd grade elementary students' accelerometer measured school day PA in the United States (U.S.) and Finland. The sample consisted of 200 students (107 girls, 93 boys; ages 6 to 8) and their school day PA was monitored with hip-worn ActiGraph GT3X+ accelerometers across a 5-day school week and the thresholds 100 and 2296 count per minute were used to separate sedentary time, light PA, and moderate-to-vigorous PA (MVPA). On an average school day, students were engaged in MVPA for 20.0 min in the U.S. and 24.1 min in Finland. Students' school-day MVPA was 9 to 16 minutes higher during physical education (PE) days compared with non-PE days (U.S: 25.8 vs. 16.6 min/day; Finland: 36.3 vs. 20.1 min/day). Girls had less MVPA and more sedentary time compared with boys in both samples. This study highlights both the role of PE and other school day physical activities in meeting PA guidelines. Policy measures are needed to change the structure of the school day and enhance PA to ensure that students meet the PA recommendations.

Associations of lifetime walking and weight bearing exercise with accelerometer-measured high impact physical activity in later life.

PubMed

Elhakeem, Ahmed; Hannam, Kimberly; Deere, Kevin C; Hartley, April; Clark, Emma M; Moss, Charlotte; Edwards, Mark H; Dennison, Elaine; Gaysin, Tim; Kuh, Diana; Wong, Andrew; Fox, Kenneth R; Cooper, Cyrus; Cooper, Rachel; Tobias, Jon H

2017-12-01

High impact physical activity (PA) is thought to benefit bone. We examined associations of lifetime walking and weight bearing exercise with accelerometer-measured high impact and overall PA in later life. Data were from 848 participants (66.2% female, mean age = 72.4 years) from the Cohort for Skeletal Health in Bristol and Avon, Hertfordshire Cohort Study and MRC National Survey of Health and Development. Acceleration peaks from seven-day hip-worn accelerometer recordings were used to derive counts of high impact and overall PA. Walking and weight bearing exercise up to age 18, between 18-29, 30-49 and since age 50 were recalled using questionnaires. Responses in each age category were dichotomised and cumulative scores derived. Linear regression was used for analysis. Greater lifetime walking was related to higher overall, but not high impact PA, whereas greater lifetime weight bearing exercise was related to higher overall and high impact PA. For example, fully-adjusted differences in log-overall and log-high impact PA respectively for highest versus lowest lifetime scores were: walking [0.224 (0.087, 0.362) and 0.239 (- 0.058, 0.536)], and weight bearing exercise [0.754 (0.432, 1.076) and 0.587 (0.270, 0.904)]. For both walking and weight bearing exercise, associations were strongest in the 'since age 50' category. Those reporting the most walking and weight bearing exercise since age 50 had highest overall and high impact PA, e.g. fully-adjusted difference in log-high impact PA versus least walking and weight bearing exercise = 0.588 (0.226, 0.951). Promoting walking and weight bearing exercise from midlife may help increase potentially osteogenic PA levels in later life.

The use of MP3 recorders to log data from equine hoof mounted accelerometers.

PubMed

Parsons, K J; Wilson, A M

2006-11-01

MP3 recorders are readily available, small, lightweight and low cost, providing the potential for logging analogue hoof mounted accelerometer signals for the characterisation of equine locomotion. These, however, require testing in practice. To test whether 1) multiple MP3 recorders can maintain synchronisation, giving the ability to synchronise independent recorders for the logging of multiple limbs simultaneously; and 2) features of a foot mounted accelerometer signal attributable to foot-on and foot-off can be accurately identified from horse foot mounted accelerometers logged directly into an MP3 recorder. Three experiments were performed: 1) Maintenance of synchronisation was assessed by counting the number of samples recorded by each of 4 MP3 recorders while mounted on a trotting horse and over 2 consecutive 30 min periods in 8 recorders on a bench. 2) Foot-on and foot-off times obtained from manual transcription of MP3 logged data and directly logged accelerometer signal were compared. 3) MP3/accelerometer acquisition units were used to log accelerometer signals from racehorses during extended training sessions. Mean absolute error of synchronisation between MP3 recorders was 10 samples per million (compared to mean number of samples, range 1-32 samples per million). Error accumulation showed a linear correlation with time. Features attributable to foot on and foot off were equally identifiable from the MP3 recorded signal over a range of equine gaits. Multiple MP3 recorders can be synchronised and used as a relatively cheap, robust, reliable and accurate logging system when combined with an accelerometer and external battery for the specific application of the measurement of stride timing variables across the range of equine gaits during field locomotion. Footfall timings can be used to identify intervals between the fore and hind contacts, the identification of diagonal advanced placement and to calculate stride timing variables (stance time, protraction time and stride time). These parameters are invaluable for the characterisation and assessment of equine locomotion.

Physical Activity and Symptoms in Pulmonary Arterial Hypertension.

PubMed

Matura, Lea Ann; Shou, Haochang; Fritz, Jason S; Smith, K Akaya; Vaidya, Anjali; Pinder, Diane; Archer-Chicko, Christine; Dubow, Danielle; Palevsky, Harold I; Sommers, Marilyn S; Kawut, Steven M

2016-07-01

Fatigue is a common symptom in patients with pulmonary arterial hypertension (PAH); however, the impact of fatigue on daily physical activity in PAH is unknown. Accelerometry is a validated measure for assessing physical activity. We hypothesized that patients with PAH reporting higher levels of fatigue would have lower daily physical activity measured by accelerometry. We performed a prospective cohort study of 15 women with PAH. On day 1, subjects completed the Multidimensional Fatigue Inventory (MFI), the United States Cambridge Pulmonary Hypertension Outcome Review (US CAMPHOR), and a 6-min walk test. Subjects wore the accelerometer on their dominant hip and completed an activity diary for 7 days. On day 15, subjects repeated the MFI and the US CAMPHOR, and then wore the accelerometer and completed an activity diary for an additional 7 days. All multivariate analyses were adjusted for age, BMI, and PAH type. The mean age was 50.5 years, and 53% had idiopathic or heritable PAH. During the 2 weeks, subjects were mostly sedentary (85% of the time), although 10% of their time was spent performing low-level activity. Lower average daily counts were associated with worse self-reported energy levels, whereas less day-to-day physical activity variability was associated with more self-reported mental fatigue, physical fatigue, and total activity. Higher percentage of activity bouts was also associated with worse energy. Women with PAH may spend most of their time being sedentary, and lower self-reported energy levels are associated with less daily activity. Interventions to improve symptoms such as fatigue may also increase physical activity levels in PAH. Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

Effectiveness of physical activity intervention among government employees with metabolic syndrome.

PubMed

Huei Phing, Chee; Abu Saad, Hazizi; Barakatun Nisak, M Y; Mohd Nasir, M T

2017-12-01

Our study aimed to assess the effects of physical activity interventions via standing banners (point-of-decision prompt) and aerobics classes to promote physical activity among individuals with metabolic syndrome. We conducted a cluster randomized controlled intervention trial (16-week intervention and 8-week follow-up). Malaysian government employees in Putrajaya, Malaysia, with metabolic syndrome were randomly assigned by cluster to a point-of-decision prompt group (n = 44), an aerobics group (n = 42) or a control group (n = 103) based on sample size calculation formula. Step counts were evaluated by Lifecorder e-STEP accelerometers for all participants. Metabolic syndrome was defined according to the 'harmonizing' definition, in which individuals who have at least three of the five metabolic risk factors (waist circumference, high-density lipoprotein cholesterol, triglycerides, fasting glucose levels, systolic and diastolic blood pressure) will be classified as having metabolic syndrome. A total of 80% of the enrolled government employees with metabolic syndrome completed the programme. Data were analyzed using SPSS for Windows (version 20, SPSS, Chicago, IL). There were significantly higher step counts on average in the aerobics group compared to the control group over assessments. Assessments at baseline, post-intervention and follow-up showed a significant difference in step counts between the intervention and control groups. The greatest reductions in the proportions of individuals with metabolic syndrome were observed in the aerobics group with a reduction of 79.4% in the post-intervention assessment compared to the assessment at baseline. The findings of this study suggest that physical activity intervention via aerobics classes is an effective strategy for improving step counts and reducing the prevalence of metabolic syndrome.

Gender-related differences in maximum gait speed and daily physical activity in elderly hospitalized cardiac inpatients: a preliminary study.

PubMed

Izawa, Kazuhiro P; Watanabe, Satoshi; Hirano, Yasuyuki; Matsushima, Shinya; Suzuki, Tomohiro; Oka, Koichiro; Kida, Keisuke; Suzuki, Kengo; Osada, Naohiko; Omiya, Kazuto; Brubaker, Peter H; Shimizu, Hiroyuki; Akashi, Yoshihiro J

2015-03-01

Maximum gait speed and physical activity (PA) relate to mortality and morbidity, but little is known about gender-related differences in these factors in elderly hospitalized cardiac inpatients. This study aimed to determine differences in maximum gait speed and daily measured PA based on sex and the relationship between these measures in elderly cardiac inpatients.A consecutive 268 elderly Japanese cardiac inpatients (mean age, 73.3 years) were enrolled and divided by sex into female (n = 75, 28%) and male (n = 193, 72%) groups. Patient characteristics and maximum gait speed, average step count, and PA energy expenditure (PAEE) in kilocalorie per day for 2 days assessed by accelerometer were compared between groups.Gait speed correlated positively with in-hospital PA measured by average daily step count (r = 0.46, P < 0.001) and average daily PAEE (r = 0.47, P < 0.001) in all patients. After adjustment for left ventricular ejection fraction, step counts and PAEE were significantly lower in females than males (2651.35 ± 1889.92 vs 4037.33 ± 1866.81 steps, P < 0.001; 52.74 ± 51.98 vs 99.33 ± 51.40 kcal, P < 0.001), respectively.Maximum gait speed was slower and PA lower in elderly female versus male inpatients. Minimum gait speed and step count values in this study might be minimum target values for elderly male and female Japanese cardiac inpatients.

Automatic machine-learning based identification of jogging periods from accelerometer measurements of adolescents under field conditions.

PubMed

Zdravevski, Eftim; Risteska Stojkoska, Biljana; Standl, Marie; Schulz, Holger

2017-01-01

Assessment of health benefits associated with physical activity depend on the activity duration, intensity and frequency, therefore their correct identification is very valuable and important in epidemiological and clinical studies. The aims of this study are: to develop an algorithm for automatic identification of intended jogging periods; and to assess whether the identification performance is improved when using two accelerometers at the hip and ankle, compared to when using only one at either position. The study used diarized jogging periods and the corresponding accelerometer data from thirty-nine, 15-year-old adolescents, collected under field conditions, as part of the GINIplus study. The data was obtained from two accelerometers placed at the hip and ankle. Automated feature engineering technique was performed to extract features from the raw accelerometer readings and to select a subset of the most significant features. Four machine learning algorithms were used for classification: Logistic regression, Support Vector Machines, Random Forest and Extremely Randomized Trees. Classification was performed using only data from the hip accelerometer, using only data from ankle accelerometer and using data from both accelerometers. The reported jogging periods were verified by visual inspection and used as golden standard. After the feature selection and tuning of the classification algorithms, all options provided a classification accuracy of at least 0.99, independent of the applied segmentation strategy with sliding windows of either 60s or 180s. The best matching ratio, i.e. the length of correctly identified jogging periods related to the total time including the missed ones, was up to 0.875. It could be additionally improved up to 0.967 by application of post-classification rules, which considered the duration of breaks and jogging periods. There was no obvious benefit of using two accelerometers, rather almost the same performance could be achieved from either accelerometer position. Machine learning techniques can be used for automatic activity recognition, as they provide very accurate activity recognition, significantly more accurate than when keeping a diary. Identification of jogging periods in adolescents can be performed using only one accelerometer. Performance-wise there is no significant benefit from using accelerometers on both locations.

Physical activity classification with dynamic discriminative methods.

PubMed

Ray, Evan L; Sasaki, Jeffer E; Freedson, Patty S; Staudenmayer, John

2018-06-19

A person's physical activity has important health implications, so it is important to be able to measure aspects of physical activity objectively. One approach to doing that is to use data from an accelerometer to classify physical activity according to activity type (e.g., lying down, sitting, standing, or walking) or intensity (e.g., sedentary, light, moderate, or vigorous). This can be formulated as a labeled classification problem, where the model relates a feature vector summarizing the accelerometer signal in a window of time to the activity type or intensity in that window. These data exhibit two key characteristics: (1) the activity classes in different time windows are not independent, and (2) the accelerometer features have moderately high dimension and follow complex distributions. Through a simulation study and applications to three datasets, we demonstrate that a model's classification performance is related to how it addresses these aspects of the data. Dynamic methods that account for temporal dependence achieve better performance than static methods that do not. Generative methods that explicitly model the distribution of the accelerometer signal features do not perform as well as methods that take a discriminative approach to establishing the relationship between the accelerometer signal and the activity class. Specifically, Conditional Random Fields consistently have better performance than commonly employed methods that ignore temporal dependence or attempt to model the accelerometer features. © 2018, The International Biometric Society.

Validation of Physical Activity Tracking via Android Smartphones Compared to ActiGraph Accelerometer: Laboratory-Based and Free-Living Validation Studies.

PubMed

Hekler, Eric B; Buman, Matthew P; Grieco, Lauren; Rosenberger, Mary; Winter, Sandra J; Haskell, William; King, Abby C

2015-04-15

There is increasing interest in using smartphones as stand-alone physical activity monitors via their built-in accelerometers, but there is presently limited data on the validity of this approach. The purpose of this work was to determine the validity and reliability of 3 Android smartphones for measuring physical activity among midlife and older adults. A laboratory (study 1) and a free-living (study 2) protocol were conducted. In study 1, individuals engaged in prescribed activities including sedentary (eg, sitting), light (sweeping), moderate (eg, walking 3 mph on a treadmill), and vigorous (eg, jogging 5 mph on a treadmill) activity over a 2-hour period wearing both an ActiGraph and 3 Android smartphones (ie, HTC MyTouch, Google Nexus One, and Motorola Cliq). In the free-living study, individuals engaged in usual daily activities over 7 days while wearing an Android smartphone (Google Nexus One) and an ActiGraph. Study 1 included 15 participants (age: mean 55.5, SD 6.6 years; women: 56%, 8/15). Correlations between the ActiGraph and the 3 phones were strong to very strong (ρ=.77-.82). Further, after excluding bicycling and standing, cut-point derived classifications of activities yielded a high percentage of activities classified correctly according to intensity level (eg, 78%-91% by phone) that were similar to the ActiGraph's percent correctly classified (ie, 91%). Study 2 included 23 participants (age: mean 57.0, SD 6.4 years; women: 74%, 17/23). Within the free-living context, results suggested a moderate correlation (ie, ρ=.59, P<.001) between the raw ActiGraph counts/minute and the phone's raw counts/minute and a strong correlation on minutes of moderate-to-vigorous physical activity (MVPA; ie, ρ=.67, P<.001). Results from Bland-Altman plots suggested close mean absolute estimates of sedentary (mean difference=-26 min/day of sedentary behavior) and MVPA (mean difference=-1.3 min/day of MVPA) although there was large variation. Overall, results suggest that an Android smartphone can provide comparable estimates of physical activity to an ActiGraph in both a laboratory-based and free-living context for estimating sedentary and MVPA and that different Android smartphones may reliably confer similar estimates.

Criterion validity of the Physical Activity Questionnaire for Schoolchildren (PAQ-S) in assessing physical activity levels: the Healthy Growth Study.

PubMed

Manios, Y; Androutsos, O; Moschonis, G; Birbilis, M; Maragkopoulou, K; Giannopoulou, A; Argyri, E; Kourlaba, G

2013-10-01

The aim of this paper was to evaluate the criterion validity of the Physical Activity Questionnaire for Schoolchildren (PAQ-S). The current study is a subcohort of the Healthy Growth Study, a large-scale cross-sectional study. 202 schoolchildren aged 9-13 years from Greece completed the PAQ-S and wore an accelerometer for 4 consecutive days. Time spent moderate (MPA), moderate to vigorous (MVPA) and vigorous (VPA) physical activity was calculated based on PAQ-S and accelerometer data. The average time spent on MPA and MVPA as derived from PAQ-S and from accelerometers were significantly moderately correlated (r=0.462, P<0.001 and r=0.483, P<0.001, respectively). No significant correlation was detected between PAQ-S and accelerometer-measured time spent performing VPA (rho=0.150, P=0.057). Intraclass Correlation Coefficient (ICC) indicated a moderate agreement between PAQ-S and accelerometer in estimating MPA (ICC=0.592, P<0.001) and MVPA (ICC=0.581, P<0.001). Bland-Altman analysis revealed a small mean difference (the "bias"), between the two methods, in estimating MPA, although this difference was found to be significantly higher than zero ("bias"=27.4% of the accelerometer-measured mean score, P=0.006). On the other hand, Bland-Altman analysis revealed a large mean difference in estimating MVPA and VPA ("bias"=84.2% and 357% of the accelerometer-measured mean score for MVPA and VPA, respectively and P<0.001). The high correlation coefficient between the average and difference values between all physical activity scores derived from accelerometers and PAQ-S, indicate a systematic overestimation of physical activity time with increasing physical activity for PAQ-S. The validity of PAQ-S for the estimation of MPA and MVPA was found to be slightly similar self-reported measures for schoolchildren. Therefore, this questionnaire could be used as a tool for physical activity assessment in large population studies.

Identifying physical activity type in manual wheelchair users with spinal cord injury by means of accelerometers.

PubMed

García-Massó, X; Serra-Añó, P; Gonzalez, L M; Ye-Lin, Y; Prats-Boluda, G; Garcia-Casado, J

2015-10-01

This was a cross-sectional study. The main objective of this study was to develop and test classification algorithms based on machine learning using accelerometers to identify the activity type performed by manual wheelchair users with spinal cord injury (SCI). The study was conducted in the Physical Therapy department and the Physical Education and Sports department of the University of Valencia. A total of 20 volunteers were asked to perform 10 physical activities, lying down, body transfers, moving items, mopping, working on a computer, watching TV, arm-ergometer exercises, passive propulsion, slow propulsion and fast propulsion, while fitted with four accelerometers placed on both wrists, chest and waist. The activities were grouped into five categories: sedentary, locomotion, housework, body transfers and moderate physical activity. Different machine learning algorithms were used to develop individual and group activity classifiers from the acceleration data for different combinations of number and position of the accelerometers. We found that although the accuracy of the classifiers for individual activities was moderate (55-72%), with higher values for a greater number of accelerometers, grouped activities were correctly classified in a high percentage of cases (83.2-93.6%). With only two accelerometers and the quadratic discriminant analysis algorithm we achieved a reasonably accurate group activity recognition system (>90%). Such a system with the minimum of intervention would be a valuable tool for studying physical activity in individuals with SCI.

Hip and Wrist Accelerometer Algorithms for Free-Living Behavior Classification.

PubMed

Ellis, Katherine; Kerr, Jacqueline; Godbole, Suneeta; Staudenmayer, John; Lanckriet, Gert

2016-05-01

Accelerometers are a valuable tool for objective measurement of physical activity (PA). Wrist-worn devices may improve compliance over standard hip placement, but more research is needed to evaluate their validity for measuring PA in free-living settings. Traditional cut-point methods for accelerometers can be inaccurate and need testing in free living with wrist-worn devices. In this study, we developed and tested the performance of machine learning (ML) algorithms for classifying PA types from both hip and wrist accelerometer data. Forty overweight or obese women (mean age = 55.2 ± 15.3 yr; BMI = 32.0 ± 3.7) wore two ActiGraph GT3X+ accelerometers (right hip, nondominant wrist; ActiGraph, Pensacola, FL) for seven free-living days. Wearable cameras captured ground truth activity labels. A classifier consisting of a random forest and hidden Markov model classified the accelerometer data into four activities (sitting, standing, walking/running, and riding in a vehicle). Free-living wrist and hip ML classifiers were compared with each other, with traditional accelerometer cut points, and with an algorithm developed in a laboratory setting. The ML classifier obtained average values of 89.4% and 84.6% balanced accuracy over the four activities using the hip and wrist accelerometer, respectively. In our data set with average values of 28.4 min of walking or running per day, the ML classifier predicted average values of 28.5 and 24.5 min of walking or running using the hip and wrist accelerometer, respectively. Intensity-based cut points and the laboratory algorithm significantly underestimated walking minutes. Our results demonstrate the superior performance of our PA-type classification algorithm, particularly in comparison with traditional cut points. Although the hip algorithm performed better, additional compliance achieved with wrist devices might justify using a slightly lower performing algorithm.

Accelerometer-determined physical activity and walking capacity in persons with Down syndrome, Williams syndrome and Prader-Willi syndrome.

PubMed

Nordstrøm, Marianne; Hansen, Bjørge Herman; Paus, Benedicte; Kolset, Svein Olav

2013-12-01

In this study we describe by use of accelerometers the total physical activity (PA), intensity pattern and walking capacity in 87 persons age 16-45 years with Down syndrome (DS), Williams syndrome (WS) and Prader-Willi syndrome (PWS). Participants were recruited from all over Norway, and lived either with their parents or in community residences with support. On average the participants generated 294 counts per minute (cpm) or 6712 steps per day, with most of the day spent in sedentary activity, 522 min/day, followed by 212 min/day in light PA, 71 min/day in lifestyle activity and 27 min/day in moderate-to-vigorous physical activity (MVPA). Inactivity was prevalent, as only 12% meet the current Nordic recommendations for PA. When compared, no differences for total physical activity or time in MVPA were observed between the three groups. However, participant with DS spent a mean of 73 min/day less and 43 min/day less in sedentary activities compared to participants with PWS and WS, respectively, (p=0.011, 95% CI: -10.9; -80.1). In addition the DS-group spent a mean of 66 min/day more in light PA than the PWS-group and 41 min/day more than the WS-group, (p<0.001, 95% CI: 29.3; 79.7). Participants with PWS spent on average 30 min/day less in lifestyle activities compared to both participants with DS and WS, (p<0.001, 95% CI: -14.2; -45.4). No association between total PA and BMI were observed. Males were more active than females across all diagnoses. Males accumulated on average 85 counts per minutes more than females, (p=0.002, 95% CI: 33.3; 136.7), 2137 more steps per day, (p=0.002, 95% CI: 778; 3496). The mean walking capacity during six-minutes was 507 m (SD 112 m) for males and 466 m (SD 88 m) for females. Distance walked during testing decreased with 33.6 m when comparing normal or underweight participants to overweight participants, and 78.1 m when comparing overweight to obese participants (p<0.001 95% CI: -40.4; -85.8). When adjusted for BMI no differences in walking capacity between the three genetic conditions were observed. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

GPS-Based Exposure to Greenness and Walkability and Accelerometry-Based Physical Activity.

PubMed

James, Peter; Hart, Jaime E; Hipp, J Aaron; Mitchell, Jonathan A; Kerr, Jacqueline; Hurvitz, Philip M; Glanz, Karen; Laden, Francine

2017-04-01

Background: Physical inactivity is a risk factor for cancer that may be influenced by environmental factors. Indeed, dense and well-connected built environments and environments with natural vegetation may create opportunities for higher routine physical activity. However, studies have focused primarily on residential environments to define exposure and self-reported methods to estimate physical activity. This study explores the momentary association between minute-level global positioning systems (GPS)-based greenness exposure and time-matched objectively measured physical activity. Methods: Adult women were recruited from sites across the United States. Participants wore a GPS device and accelerometer on the hip for 7 days to assess location and physical activity at minute-level epochs. GPS records were linked to 250 m resolution satellite-based vegetation data and Census Block Group-level U.S. Environmental Protection Agency (EPA) Smart Location Database walkability data. Minute-level generalized additive mixed models were conducted to test for associations between GPS measures and accelerometer count data, accounting for repeated measures within participant and allowing for deviations from linearity using splines. Results: Among 360 adult women (mean age of 55.3 ± 10.2 years), we observed positive nonlinear relationships between physical activity and both greenness and walkability. In exploratory analyses, the relationships between environmental factors and physical activity were strongest among those who were white, had higher incomes, and who were middle-aged. Conclusions: Our results indicate that higher levels of physical activity occurred in areas with higher greenness and higher walkability. Impact: Findings suggest that planning and design policies should focus on these environments to optimize opportunities for physical activity. Cancer Epidemiol Biomarkers Prev; 26(4); 525-32. ©2017 AACR See all the articles in this CEBP Focus section, "Geospatial Approaches to Cancer Control and Population Sciences." ©2017 American Association for Cancer Research.

Light and sporadic physical activity overlooked by current guidelines makes older women more active than older men.

PubMed

Amagasa, Shiho; Fukushima, Noritoshi; Kikuchi, Hiroyuki; Takamiya, Tomoko; Oka, Koichiro; Inoue, Shigeru

2017-05-02

Men are generally believed to be more physically active than women when evaluated using current physical activity (PA) guidelines, which count only moderate-to-vigorous physical activity (MVPA) in bouts lasting at least 10 min. However, it remains unclear men are truly more physically active provided that all-intensity PA are evaluated. This population based cross-sectional study aimed to examine gender differences in patterns of objectively-assessed PA in older adults. One thousand two hundred ten community-dwelling Japanese older adults who were originally randomly selected from residential registry of three municipalities were asked to respond a questionnaire and wear an accelerometer (HJA-350IT, Omron Healthcare). The prevalence of achieving current PA guidelines, ≥150 min/week MVPA in bouts lasting at least 10 min, was calculated. Gender differences in volume of each-intensity activity (METs-hour) were assessed by analysis of covariance after adjustment for age and wear time. Data from 450 (255 men, mean 74 years) participants who had valid accelerometer data were analyzed. Women were less likely to meet the guidelines (men: 31.0, women: 21.5%; p < 0.05). However, women accumulated more light-intensity PA (LPA) and short-bout (1-9 min) MVPA, and thus established higher total volume of PA (men: 22.0 METs-hour/day, women: 23.9 METs-hour/day) (p < 0.05). Older women were less active when evaluated against current PA guidelines, but more active by total PA. Considering accumulated evidence on health benefits of LPA and short-bout MVPA, our findings highlight the potential for the limitation of assessing PA using current PA guidelines.

Calibration of GENEActiv accelerometer wrist cut-points for the assessment of physical activity intensity of preschool aged children.

PubMed

Roscoe, Clare M P; James, Rob S; Duncan, Michael J

2017-08-01

This study sought to validate cut-points for use of wrist-worn GENEActiv accelerometer data, to analyse preschool children's (4 to 5 year olds) physical activity (PA) levels via calibration with oxygen consumption values (VO 2 ). This was a laboratory-based calibration study. Twenty-one preschool children, aged 4.7 ± 0.5 years old, completed six activities (ranging from lying supine to running) whilst wearing the GENEActiv accelerometers at two locations (left and right wrist), these being the participants' non-dominant and dominant wrist, and a Cortex face mask for gas analysis. VO 2 data was used for the assessment of criterion validity. Location specific activity intensity cut-points were established via receiver operator characteristic curve (ROC) analysis. The GENEActiv accelerometers, irrespective of their location, accurately discriminated between all PA intensities (sedentary, light, and moderate and above), with the dominant wrist monitor providing a slightly more precise discrimination at light PA and the non-dominant at the sedentary behaviour and moderate and above intensity levels (area under the curve (AUC) for non-dominant = 0.749-0.993, compared to AUC dominant = 0.760-0.988). This study establishes wrist-worn physical activity cut-points for the GENEActiv accelerometer in preschoolers. What is Known: • GENEActiv accelerometers have been validated as a PA measurement tool in adolescents and adults. • No study to date has validated the GENEActiv accelerometers in preschoolers. What is New: • Cut-points were determined for the wrist-worn GENEActiv accelerometer in preschoolers. • These cut-points can be used in future research to help classify and increase preschoolers' compliance rates with PA.

Daylight saving time as a potential public health intervention: an observational study of evening daylight and objectively-measured physical activity among 23,000 children from 9 countries.

PubMed

Goodman, Anna; Page, Angie S; Cooper, Ashley R

2014-10-23

It has been proposed that introducing daylight saving measures could increase children's physical activity, but there exists little research on this issue. This study therefore examined associations between time of sunset and activity levels, including using the bi-annual 'changing of the clocks' as a natural experiment. 23,188 children aged 5-16 years from 15 studies in nine countries were brought together in the International Children's Accelerometry Database. 439 of these children were of particular interest for our analyses as they contributed data both immediately before and after the clocks changed. All children provided objectively-measured physical activity data from Actigraph accelerometers, and we used their average physical activity level (accelerometer counts per minute) as our primary outcome. Date of accelerometer data collection was matched to time of sunset, and to weather characteristics including daily precipitation, humidity, wind speed and temperature. Adjusting for child and weather covariates, we found that longer evening daylight was independently associated with a small increase in daily physical activity. Consistent with a causal interpretation, the magnitude of these associations was largest in the late afternoon and early evening and these associations were also evident when comparing the same child just before and just after the clocks changed. These associations were, however, only consistently observed in the five mainland European, four English and two Australian samples (adjusted, pooled effect sizes 0.03-0.07 standard deviations per hour of additional evening daylight). In some settings there was some evidence of larger associations between daylength and physical activity in boys. There was no evidence of interactions with weight status or maternal education, and inconsistent findings for interactions with age. In Europe and Australia, evening daylight seems to play a causal role in increasing children's activity in a relatively equitable manner. Although the average increase in activity is small in absolute terms, these increases apply across all children in a population. Moreover, these small effect sizes actually compare relatively favourably with the typical effect of intensive, individual-level interventions. We therefore conclude that, by shifting the physical activity mean of the entire population, the introduction of additional daylight saving measures could yield worthwhile public health benefits.

Comparison of IPAQ-SF and Two Other Physical Activity Questionnaires with Accelerometer in Adolescent Boys.

PubMed

Rääsk, Triin; Mäestu, Jarek; Lätt, Evelin; Jürimäe, Jaak; Jürimäe, Toivo; Vainik, Uku; Konstabel, Kenn

2017-01-01

Self-report measures of physical activity (PA) are easy to use and popular but their reliability is often questioned. Therefore, the general aim of the present study was to investigate the association of PA questionnaires with accelerometer derived PA, in a sample of adolescent boys. In total, 191 pubertal boys (mean age 14.0 years) completed three self-report questionnaires and wore an accelerometer (ActiGraph GT1M) for 7 consecutive days. The PA questionnaires were: International Physical Activity Questionnaire-Short Form (IPAQ-SF), Tartu Physical Activity Questionnaire (TPAQ), and the Inactivity subscale from Domain-Specific Impulsivity (DSI) scale. All three questionnaires were significantly correlated with accelerometer derived MVPA: the correlations were 0.31 for the IPAQ-SF MVPA, 0.34 for the TPAQ MVPA and -0.29 for the DSI Inactivity scale. Nevertheless, none of the questionnaires can be used as a reliable individual-level estimate of MVPA in male adolescents. The boys underreported their MVPA in IPAQ-SF as compared to accelerometer-derived MVPA (respective averages 43 and 56 minutes); underreporting was more marked in active boys with average daily MVPA at least 60 minutes, and was not significant in less active boys. Conversely, MVPA index from TPAQ overestimated the MVPA in less active boys but underestimated it in more active boys. The sedentary time reported in IPAQ-SF was an underestimate as compared to accelerometer-derived sedentary time (averages 519 and 545 minutes, respectively).

Prior automatic posture and activity identification improves physical activity energy expenditure prediction from hip-worn triaxial accelerometry.

PubMed

Garnotel, M; Bastian, T; Romero-Ugalde, H M; Maire, A; Dugas, J; Zahariev, A; Doron, M; Jallon, P; Charpentier, G; Franc, S; Blanc, S; Bonnet, S; Simon, C

2018-03-01

Accelerometry is increasingly used to quantify physical activity (PA) and related energy expenditure (EE). Linear regression models designed to derive PAEE from accelerometry-counts have shown their limits, mostly due to the lack of consideration of the nature of activities performed. Here we tested whether a model coupling an automatic activity/posture recognition (AAR) algorithm with an activity-specific count-based model, developed in 61 subjects in laboratory conditions, improved PAEE and total EE (TEE) predictions from a hip-worn triaxial-accelerometer (ActigraphGT3X+) in free-living conditions. Data from two independent subject groups of varying body mass index and age were considered: 20 subjects engaged in a 3-h urban-circuit, with activity-by-activity reference PAEE from combined heart-rate and accelerometry monitoring (Actiheart); and 56 subjects involved in a 14-day trial, with PAEE and TEE measured using the doubly-labeled water method. PAEE was estimated from accelerometry using the activity-specific model coupled to the AAR algorithm (AAR model), a simple linear model (SLM), and equations provided by the companion-software of used activity-devices (Freedson and Actiheart models). AAR-model predictions were in closer agreement with selected references than those from other count-based models, both for PAEE during the urban-circuit (RMSE = 6.19 vs 7.90 for SLM and 9.62 kJ/min for Freedson) and for EE over the 14-day trial, reaching Actiheart performances in the latter (PAEE: RMSE = 0.93 vs. 1.53 for SLM, 1.43 for Freedson, 0.91 MJ/day for Actiheart; TEE: RMSE = 1.05 vs. 1.57 for SLM, 1.70 for Freedson, 0.95 MJ/day for Actiheart). Overall, the AAR model resulted in a 43% increase of daily PAEE variance explained by accelerometry predictions. NEW & NOTEWORTHY Although triaxial accelerometry is widely used in free-living conditions to assess the impact of physical activity energy expenditure (PAEE) on health, its precision and accuracy are often debated. Here we developed and validated an activity-specific model which, coupled with an automatic activity-recognition algorithm, improved the variance explained by the predictions from accelerometry counts by 43% of daily PAEE compared with models relying on a simple relationship between accelerometry counts and EE.

Introducing a modular activity monitoring system.

PubMed

Reiss, Attila; Stricker, Didier

2011-01-01

In this paper, the idea of a modular activity monitoring system is introduced. By using different combinations of the system's three modules, different functionality becomes available: 1) a coarse intensity estimation of physical activities 2) different features based on HR-data and 3) the recognition of basic activities and postures. 3D-accelerometers--placed on lower arm, chest and foot--and a heart rate monitor were used as sensors. A dataset with 8 subjects and 14 different activities was recorded to evaluate the performance of the system. The overall performance on the intensity estimation task, relying on the chest-worn accelerometer and the HR-monitor, was 94.37%. The overall performance on the activity recognition task, using all three accelerometer placements and the HR-monitor, was 90.65%. This paper also gives an analysis of the importance of different accelerometer placements and the importance of a HR-monitor for both tasks.

24 h Accelerometry: impact of sleep-screening methods on estimates of sedentary behaviour and physical activity while awake.

PubMed

Meredith-Jones, Kim; Williams, Sheila; Galland, Barbara; Kennedy, Gavin; Taylor, Rachael

2016-01-01

Although accelerometers can assess sleep and activity over 24 h, sleep data must be removed before physical activity and sedentary time can be examined appropriately. We compared the effect of 6 different sleep-scoring rules on physical activity and sedentary time. Activity and sleep were obtained by accelerometry (ActiGraph GT3X) over 7 days in 291 children (51.3% overweight or obese) aged 4-8.9 years. Three methods removed sleep using individualised time filters and two methods applied standard time filters to remove sleep each day (9 pm-6 am, 12 am-6 am). The final method did not remove sleep but simply defined non-wear as at least 60 min of consecutive zeros over the 24-h period. Different methods of removing sleep from 24-h data markedly affect estimates of sedentary time, yielding values ranging from 556 to 1145 min/day. Estimates of non-wear time (33-193 min), wear time (736-1337 min) and counts per minute (384-658) also showed considerable variation. By contrast, estimates of moderate-to-vigorous activity (MVPA) were similar, varying by less than 1 min/day. Different scoring methods to remove sleep from 24-h accelerometry data do not affect measures of MVPA, whereas estimates of counts per minute and sedentary time depend considerably on which technique is used.

The Impact of Accelerometers on Physical Activity and Weight Loss: A Systematic Review

PubMed Central

Goode, Adam P.; Hall, Katherine S.; Batch, Bryan C.; Huffman, Kim M.; Hastings, S. Nicole; Allen, Kelli D.; Shaw, Ryan J.; Kanach, Frances A.; McDuffie, Jennifer R.; Kosinski, Andrzej S.; Williams, John W.; Gierisch, Jennifer M.

2016-01-01

Background Regular physical activity is important for improving and maintaining health, but sedentary behavior is difficult to change. Providing objective, real-time feedback on physical activity with wearable motion-sensing technologies (activity monitors) may be a promising, scalable strategy to increase physical activity or decrease weight. Purpose We synthesized the literature on the use of wearable activity monitors for improving physical activity and weight-related outcomes and evaluated moderating factors that may have an impact on effectiveness. Methods We searched five databases from January 2000 to January 2015 for peer-reviewed, English-language randomized controlled trials among adults. Random-effects models were used to produce standardized mean differences (SMDs) for physical activity outcomes and mean differences (MDs) for weight outcomes. Heterogeneity was measured with I2. Results Fourteen trials (2,972 total participants) met eligibility criteria; accelerometers were used in all trials. Twelve trials examined accelerometer interventions for increasing physical activity. A small significant effect was found for increasing physical activity (SMD 0.26; 95% CI 0.04 to 0.49; I2=64.7%). Intervention duration was the only moderator found to significantly explain high heterogeneity for physical activity. Eleven trials examined effects of accelerometer interventions on weight. Pooled estimates showed a small significant effect for weight loss (MD −1.65 kg; 95% CI −3.03 to −0.28; I2=81%), and no moderators were significant. Conclusions Accelerometers demonstrated small positive effects on physical activity and weight loss. The small sample sizes with moderate to high heterogeneity in the current studies limit the conclusions that may be drawn. Future studies should focus on how best to integrate accelerometers with other strategies to increase physical activity and weight loss. PMID:27565168

Automatic machine-learning based identification of jogging periods from accelerometer measurements of adolescents under field conditions

PubMed Central

Risteska Stojkoska, Biljana; Standl, Marie; Schulz, Holger

2017-01-01

Background Assessment of health benefits associated with physical activity depend on the activity duration, intensity and frequency, therefore their correct identification is very valuable and important in epidemiological and clinical studies. The aims of this study are: to develop an algorithm for automatic identification of intended jogging periods; and to assess whether the identification performance is improved when using two accelerometers at the hip and ankle, compared to when using only one at either position. Methods The study used diarized jogging periods and the corresponding accelerometer data from thirty-nine, 15-year-old adolescents, collected under field conditions, as part of the GINIplus study. The data was obtained from two accelerometers placed at the hip and ankle. Automated feature engineering technique was performed to extract features from the raw accelerometer readings and to select a subset of the most significant features. Four machine learning algorithms were used for classification: Logistic regression, Support Vector Machines, Random Forest and Extremely Randomized Trees. Classification was performed using only data from the hip accelerometer, using only data from ankle accelerometer and using data from both accelerometers. Results The reported jogging periods were verified by visual inspection and used as golden standard. After the feature selection and tuning of the classification algorithms, all options provided a classification accuracy of at least 0.99, independent of the applied segmentation strategy with sliding windows of either 60s or 180s. The best matching ratio, i.e. the length of correctly identified jogging periods related to the total time including the missed ones, was up to 0.875. It could be additionally improved up to 0.967 by application of post-classification rules, which considered the duration of breaks and jogging periods. There was no obvious benefit of using two accelerometers, rather almost the same performance could be achieved from either accelerometer position. Conclusions Machine learning techniques can be used for automatic activity recognition, as they provide very accurate activity recognition, significantly more accurate than when keeping a diary. Identification of jogging periods in adolescents can be performed using only one accelerometer. Performance-wise there is no significant benefit from using accelerometers on both locations. PMID:28880923

Women Workers and Women at Home Are Equally Inactive: NHANES 2003-2006.

PubMed

Steeves, Jeremy A; Murphy, Rachel A; Zipunnikov, Vadim; Strath, Scott J; Harris, Tamara B

2015-08-01

The prevalence of female homemakers (those who stay at home to care for the home or family) has increased to 29%. Homemakers may be more active than employed women (EW). Limited data are available for domestic-related activity; therefore, the assessment of the activity levels of homemakers has been sparse. This study compared objectively measured activity (total activity counts, counts per minute, and percent time in various activity intensity levels) of homemakers and EW. Women's (18-60 yr) accelerometer data from the 2003-2006 National Health and Nutrition Examination Survey were analyzed in 2014 (n = 1763). Daily (hour-by-hour) profiles of activity were compared between homemakers and EW. Women spent most of their day in sedentary (∼55%) and light (∼32%) activity, with limited lifestyle (∼11%) and moderate vigorous physical activity (MVPA; ∼2%); and there were no differences between the homemakers and EW. Hour-by-hour analysis showed that the homemakers had more light and less sedentary activity than EW during the afternoon (P < 0.002), whereas EW had more MVPA at times corresponding to commuting to and from work and midday (P < 0.002). On weekdays, EW initiated activity earlier than homemakers but not on weekends. On weekends, both groups had less MVPA than weekdays. Employed women with child(ren) younger than 18 yr had greater counts per minute and lifestyle activity and less sedentary activity than EW without child(ren) younger than 18 yr. Our hourly analysis delineated important differences in activity between the groups. Homemakers accumulate enough light activity throughout the day to be as active as EW who are highly sedentary during the workday, but seem to acquire activity through commuting. Interventions to reduce sedentary behavior and increase activity are highly desirable and should take into consideration the temporality of homemakers and EW activity patterns.

Physical activity patterns in adults who are blind as assessed by accelerometry.

PubMed

Marmeleira, José; Laranjo, Luis; Marques, Olga; Pereira, Catarina

2014-07-01

The main purpose of our study was to quantify, by using accelerometry, daily physical activity (PA) in adults with visual impairments. Sixty-three adults (34.9% women) who are blind (18-65 years) wore an accelerometer for at least 3 days (minimum of 10 hr per day), including 1 weekend day. Nineteen participants (~30%) reached the recommendation of 30 min per day of PA, when counting every minute of moderate or greater intensity. No one achieved that goal when considering bouts of at least 10 min. No differences were found between genders in PA measures. Chronological age, age of blindness onset, and body mass index were not associated with PA. We conclude that adults who are blind have low levels of PA and are considerably less active compared with the general population. Health promotion strategies should be implemented to increase daily PA for people with visual impairments.

Adolescent pedometer protocols: examining reactivity, tampering and participants' perceptions.

PubMed

Scott, Joseph John; Morgan, Philip James; Plotnikoff, Ronald Cyril; Trost, Stewart Graeme; Lubans, David Revalds

2014-01-01

The aim of this study was to investigate adolescents' potential reactivity and tampering while wearing pedometers by comparing different monitoring protocols to accelerometer output. The sample included adolescents (N = 123, age range = 14-15 years) from three secondary schools in New South Wales, Australia. Schools were randomised to one of the three pedometer monitoring protocols: (i) daily sealed (DS) pedometer group, (ii) unsealed (US) pedometer group or (iii) weekly sealed (WS) pedometer group. Participants wore pedometers (Yamax Digi-Walker CW700, Yamax Corporation, Kumamoto City, Japan) and accelerometers (Actigraph GT3X+, Pensacola, USA) simultaneously for seven days. Repeated measures analysis of variance was used to examine potential reactivity. Bivariate correlations between step counts and accelerometer output were calculated to explore potential tampering. The correlation between accelerometer output and pedometer steps/day was strongest among participants in the WS group (r = 0.82, P ≤ 0.001), compared to the US (r = 0.63, P ≤ 0.001) and DS (r = 0.16, P = 0.324) groups. The DS (P ≤ 0.001) and US (P = 0.003), but not the WS (P = 0.891), groups showed evidence of reactivity. The results suggest that reactivity and tampering does occur in adolescents and contrary to existing research, pedometer monitoring protocols may influence participant behaviour.

Comparison of home and away-from-home physical activity using accelerometers and cellular network-based tracking devices.

PubMed

Ramulu, Pradeep Y; Chan, Emilie S; Loyd, Tara L; Ferrucci, Luigi; Friedman, David S

2012-08-01

Measuring physical at home and away from home is essential for assessing health and well-being, and could help design interventions to increase physical activity. Here, we describe how physical activity at home and away from home can be quantified by combining information from cellular network-based tracking devices and accelerometers. Thirty-five working adults wore a cellular network-based tracking device and an accelerometer for 6 consecutive days and logged their travel away from home. Performance of the tracking device was determined using the travel log for reference. Tracking device and accelerometer data were merged to compare physical activity at home and away from home. The tracking device detected 98.6% of all away-from-home excursions, accurately measured time away from home and demonstrated few prolonged signal drop-out periods. Most physical activity took place away from home on weekdays, but not on weekends. Subjects were more physically active per unit of time while away from home, particularly on weekends. Cellular network-based tracking devices represent an alternative to global positioning systems for tracking location, and provide information easily integrated with accelerometers to determine where physical activity takes place. Promoting greater time spent away from home may increase physical activity.

Miniaturized accelerometer made with ZnO nanowires

NASA Astrophysics Data System (ADS)

Song, Sangho; Kim, Jeong Woong; Kim, Hyun Chan; Yun, Youngmin; Kim, Jaehwan

2017-04-01

Miniaturized accelerometer is required in many applications, such as, robotics, haptic devices, gyroscopes, simulators and mobile devices. ZnO is an essential semiconductor material with wide direct band gap, thermal stability and piezoelectricity. Especially, well aligned ZnO nanowire is appropriate for piezoelectric applications since it can produce high electrical signal under mechanical load. To miniaturize accelerometer, an aligned ZnO nanowire is adopted to implement active piezoelectric layer of the accelerometer and copper is chosen for the head mass. To grow ZnO nanowire on the copper head mass, hydrothermal synthesis is conducted and the effect of ZnO nanowire length on the accelerometer performance is investigated. Refresh hydrothermal synthesis can increase the length of ZnO nanowire. The performance of the fabricated ZnO accelerometers is compared with a commercial accelerometer. Sensitivity and linearity of the fabricated accelerometers are investigated.

Are context-specific measures of parental-reported physical activity and sedentary behaviour associated with accelerometer data in 2-9-year-old European children?

PubMed

Verbestel, Vera; De Henauw, Stefaan; Bammann, Karin; Barba, Gianvincenzo; Hadjigeorgiou, Charalambos; Eiben, Gabriele; Konstabel, Kenn; Kovács, Eva; Pitsiladis, Yannis; Reisch, Lucia; Santaliestra-Pasías, Alba M; Maes, Lea; De Bourdeaudhuij, Ilse

2015-04-01

The aim of the present study was to investigate if context-specific measures of parental-reported physical activity and sedentary behaviour are associated with objectively measured physical activity and sedentary time in children. Cross-sectional study. Seven European countries taking part in the IDEFICS (Identification and Prevention of Dietary- and Lifestyle-induced Health Effects in Children and Infants) study. Data were analysed from 2-9-year-old children (n 5982) who provided both parental-reported and accelerometer-derived physical activity/sedentary behaviour measures. Parents reported their children's daily screen-time, weekly sports participation and daily outdoor playtime by means of the Outdoor Playtime Checklist (OPC) and Outdoor Playtime Recall Questions (OPRQ). Sports participation, OPC- and OPRQ-derived outdoor play were positively associated with accelerometer-derived physical activity. Television viewing and computer use were positively associated with accelerometer-derived sedentary time. All parental-reported measures that were significantly associated with accelerometer outcomes explained only a minor part of the variance in accelerometer-derived physical activity or sedentary time. Parental-reported measures of physical activity and sedentary behaviour are not useful as a proxy for 2-9-year-old children's physical activity and sedentary time. Findings do not preclude the use of context-specific measures but imply that conclusions should be limited to the context-specific behaviours that are actually measured. Depending on the aim of the study, future research should carefully consider the choice of measurements, including the use of subjective or objective measures of the behaviour of interest or a combination of both.

Environmental influences on children's physical activity

PubMed Central

Pouliou, Theodora; Sera, Francesco; Griffiths, Lucy; Joshi, Heather; Geraci, Marco; Cortina-Borja, Mario; Law, Catherine

2015-01-01

Background This paper aims to assess whether 7-year-olds’ physical activity is associated with family and area-level measures of the physical and socioeconomic environments. Methods We analysed the association of environments with physical activity in 6497 singleton children from the UK Millennium Cohort Study with reliable accelerometer data (≥2 days and ≥10 h/day). Activity levels were assessed as counts per minute; minutes of moderate to vigorous activity (MVPA); and whether meeting recommended guidelines (≥60 min/day MVPA). Results Higher levels of children's physical activity were associated with households without use of a car and with having a television in a child's bedroom (for counts per minute only). Aspects of the home socioeconomic environment that were associated with more children's physical activity were lone motherhood, lower maternal socioeconomic position and education, family income below 60% national median, and not owning the home. Children's activity levels were higher when parents perceived their neighbourhood as poor for bringing up children and also when families were living in the most deprived areas. Relationships were independent of characteristics such as child's body mass index and ethnic group. When adjusted for physical and socioeconomic correlates, the factors remaining significant in all outcomes were: household car usage and maternal education. Conclusions Although physical and socioeconomic environments are associated with children’s physical activity, much of the variation appears to be determined by the child's home socioeconomic circumstances rather than the wider environment where they live. PMID:25359920

Gender-related Differences in Maximum Gait Speed and Daily Physical Activity in Elderly Hospitalized Cardiac Inpatients

PubMed Central

Izawa, Kazuhiro P.; Watanabe, Satoshi; Hirano, Yasuyuki; Matsushima, Shinya; Suzuki, Tomohiro; Oka, Koichiro; Kida, Keisuke; Suzuki, Kengo; Osada, Naohiko; Omiya, Kazuto; Brubaker, Peter H.; Shimizu, Hiroyuki; Akashi, Yoshihiro J.

2015-01-01

Abstract Maximum gait speed and physical activity (PA) relate to mortality and morbidity, but little is known about gender-related differences in these factors in elderly hospitalized cardiac inpatients. This study aimed to determine differences in maximum gait speed and daily measured PA based on sex and the relationship between these measures in elderly cardiac inpatients. A consecutive 268 elderly Japanese cardiac inpatients (mean age, 73.3 years) were enrolled and divided by sex into female (n = 75, 28%) and male (n = 193, 72%) groups. Patient characteristics and maximum gait speed, average step count, and PA energy expenditure (PAEE) in kilocalorie per day for 2 days assessed by accelerometer were compared between groups. Gait speed correlated positively with in-hospital PA measured by average daily step count (r = 0.46, P < 0.001) and average daily PAEE (r = 0.47, P < 0.001) in all patients. After adjustment for left ventricular ejection fraction, step counts and PAEE were significantly lower in females than males (2651.35 ± 1889.92 vs 4037.33 ± 1866.81 steps, P < 0.001; 52.74 ± 51.98 vs 99.33 ± 51.40 kcal, P < 0.001), respectively. Maximum gait speed was slower and PA lower in elderly female versus male inpatients. Minimum gait speed and step count values in this study might be minimum target values for elderly male and female Japanese cardiac inpatients. PMID:25789953

Understanding Environmental and Contextual Influences of Physical Activity During First-Year University: The Feasibility of Using Ecological Momentary Assessment in the MovingU Study.

PubMed

Bedard, Chloe; King-Dowling, Sara; McDonald, Madeline; Dunton, Genevieve; Cairney, John; Kwan, Matthew

2017-05-31

It is well established that drastic declines in physical activity (PA) occur during young adults' transition into university; however, our understanding of contextual and environmental factors as it relates to young adults' PA is limited. The purpose of our study was to examine the feasibility of using wrist-worn accelerometers and the use of ecological momentary assessment (EMA) to assess the context and momentary correlates of PA on multiple occasions each day during first-year university. First-year university students were asked to participate in the study. The participants completed a brief questionnaire and were subsequently asked to wear an ActiGraph GT9X-Link accelerometer and respond to a series of EMA prompts (7/day) via their phones for 5 consecutive days. A total of 96 first-year university students with smartphones agreed to participate in the study (mean age 18.3 [SD 0.51]; n=45 females). Overall, there was good compliance for wearing the accelerometers, with 91% (78/86) of the participants having ≥2 days of ≥10 hours of wear time (mean=3.53 valid days). Students were generally active, averaging 10,895 steps/day (SD 3413) or 1123.23 activity counts/min (SD 356.10). Compliance to EMA prompts was less desirable, with 64% (55/86) of the participants having usable EMA data (responding to a minimum of ≥3 days of 3 prompts/day or ≥4 days of 2 prompts/day), and only 47% (26/55) of these participants were considered to have excellent EMA compliance (responding to ≥5 days of 4 prompts/day or ≥ 4 days of 5 prompts/day). This study represents one of the first studies to use an intensive real-time data capture strategy to examine time-varying correlates of PA among first-year university students. These data will aim to describe the physical and social contexts in which PA occurs and examine the relationships between momentary correlates of PA among the first-year university students. Overall, current results suggest that wrist-worn accelerometers and EMA are feasible methods for data collection among the young adult population; however, more work is needed to understand how to improve upon compliance to a real-time data capture method such as EMA. ©Chloe Bedard, Sara King-Dowling, Madeline McDonald, Genevieve Dunton, John Cairney, Matthew Kwan. Originally published in JMIR Public Health and Surveillance (http://publichealth.jmir.org), 31.05.2017.

Physical activity correlates with neurological impairment and disability in multiple sclerosis.

PubMed

Motl, Robert W; Snook, Erin M; Wynn, Daniel R; Vollmer, Timothy

2008-06-01

This study examined the correlation of physical activity with neurological impairment and disability in persons with multiple sclerosis (MS). Eighty individuals with MS wore an accelerometer for 7 days and completed the Symptom Inventory (SI), Performance Scales (PS), and Expanded Disability Status Scale. There were large negative correlations between the accelerometer and SI (r = -0.56; rho = -0.58) and Expanded Disability Status Scale (r = -0.60; rho = -0.69) and a moderate negative correlation between the accelerometer and PS (r = -0.39; rho = -0.48) indicating that physical activity was associated with reduced neurological impairment and disability. Such findings provide a preliminary basis for using an accelerometer and the SI and PS as outcome measures in large-scale prospective and experimental examinations of the effect of physical activity behavior on disability and dependence in MS.

Effect of physical activity and sedentary behavior on serum prostate-specific antigen concentrations: results from the National Health and Nutrition Examination Survey (NHANES), 2003-2006.

PubMed

Loprinzi, Paul D; Kohli, Manish

2013-01-01

To examine the association between accelerometer-derived sedentary and physical activity and prostate-specific antigen (PSA) in a nationally representative sample of men in the United States. Data from the 2003-2004 and 2005-2006 National Health and Nutrition Examination Survey cycles were used in the present study, with data from 1672 adult male participants used in the analyses. The manuscript was prepared between July 7, 2012, and September 26, 2012. Sedentary and physical activity was objectively measured using an accelerometer. Covariates included various demographic, dietary, biological, and immunologic variables including age, height, weight, body mass index, race/ethnicity, marital status, education, and poverty-income ratio; dietary fiber, fat, protein, and carbohydrate intake and total energy intake; vitamin C and vitamin E; alcohol intake; medication use; concentrations of cotinine, total cholesterol, and high-density lipoprotein cholesterol; blood pressure (elevated or not elevated); diabetes; C-reactive protein; and white blood cell count and number of basophils and eosinophils. Only after controlling for all covariates, for every 1-hour increase in sedentary behavior, participants were 16% more likely to have an elevated PSA concentration (odds ratio, 1.16 [95% CI, 1.06-1.27]; P=.001). For every 1-hour increase in light physical activity, participants were 18% less likely to have an elevated PSA concentration (odds ratio, 0.82 [95% CI, 0.68-1.00]; P=.05). Individuals who engage in more sedentary behavior and lower levels of light physical activity have higher PSA concentrations. Future studies are needed to better identify the potential underlying mechanisms delineating the association between sedentary and physical activity and PSA concentration. Copyright © 2013 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

Review of physical activity measurement using accelerometers in older adults: considerations for research design and conduct.

PubMed

Murphy, Susan L

2009-02-01

Accelerometers are being increasingly used in studies of physical activity (PA) among older adults, however the use of these monitors requires some specialized knowledge and up-to-date information on technological innovations. The purpose of this review article is to provide researchers with a guide to some commonly-used accelerometers in order to better design and conduct PA research with older adults. A literature search was conducted to obtain all available literature on commonly-used accelerometers in older adult samples with specific attention to articles discussing research design. The use of accelerometers in older adults requires a basic understanding of the type being used, rationale for their placement, and attention to calibration when needed. The updated technology in some monitors should make study conduct less difficult, however comparison studies of the newer versus the older generation models will be needed. Careful considerations for design and conduct of accelerometer research as outlined in this review should help to enhance the quality and comparability of future research studies.

Walk this way: validity evidence of iphone health application step count in laboratory and free-living conditions.

PubMed

Duncan, Markus J; Wunderlich, Kelly; Zhao, Yingying; Faulkner, Guy

2018-08-01

Several attempts have been made to demonstrate the accuracy of the iPhone pedometer function in laboratory test conditions. However, no studies have attempted to evaluate evidence of convergent validity of the iPhone step counts as a surveillance tool in the field. This study takes a pragmatic approach to evaluating Health application derived iPhone step counts by measuring accuracy of a standardized criterion iPhone SE and a heterogeneous sample of participant owned iPhones (6 or newer) in a laboratory condition, as well as comparing personal iPhones to accelerometer derived steps in a free-living test. During lab tests, criterion and personal iPhones differed from manually counted steps by a mean bias of less than ±5% when walking at 5km/h, 7.5km/h and 10km/h on a treadmill, which is generally considered acceptable for pedometers. In the free-living condition steps differed by a mean bias of 21.5% or 1340 steps/day when averaged across observation days. Researchers should be cautioned in considering the use of iPhone models as a research grade pedometer for physical activity surveillance or evaluation, likely due to the iPhone not being continually carried by participants; if compliance can be maximized then the iPhone might be suitable.

Accelerometer-based measures in physical activity surveillance: current practices and issues.

PubMed

Pedišić, Željko; Bauman, Adrian

2015-02-01

Self-reports of physical activity (PA) have been the mainstay of measurement in most non-communicable disease (NCD) surveillance systems. To these, other measures are added to summate to a comprehensive PA surveillance system. Recently, some national NCD surveillance systems have started using accelerometers as a measure of PA. The purpose of this paper was specifically to appraise the suitability and role of accelerometers for population-level PA surveillance. A thorough literature search was conducted to examine aspects of the generalisability, reliability, validity, comprehensiveness and between-study comparability of accelerometer estimates, and to gauge the simplicity, cost-effectiveness, adaptability and sustainability of their use in NCD surveillance. Accelerometer data collected in PA surveillance systems may not provide estimates that are generalisable to the target population. Accelerometer-based estimates have adequate reliability for PA surveillance, but there are still several issues associated with their validity. Accelerometer-based prevalence estimates are largely dependent on the investigators' choice of intensity cut-off points. Maintaining standardised accelerometer data collections in long-term PA surveillance systems is difficult, which may cause discontinuity in time-trend data. The use of accelerometers does not necessarily produce useful between-study and international comparisons due to lack of standardisation of data collection and processing methods. To conclude, it appears that accelerometers still have limitations regarding generalisability, validity, comprehensiveness, simplicity, affordability, adaptability, between-study comparability and sustainability. Therefore, given the current evidence, it seems that the widespread adoption of accelerometers specifically for large-scale PA surveillance systems may be premature. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Performance improvement of miniaturized ZnO nanowire accelerometer fabricated by refresh hydrothermal synthesis

PubMed Central

Song, Sangho; Kim, Hyun Chan; Kim, Jung Woong; Kim, Debora

2017-01-01

Miniaturized accelerometers are necessary for evaluating the performance of small devices, such as haptics, robotics and simulators. In this study, we fabricated miniaturized accelerometers using well-aligned ZnO nanowires. The layer of ZnO nanowires is used for active piezoelectric layer of the accelerometer, and copper was chosen as a head mass. Seedless and refresh hydrothermal synthesis methods were conducted to grow ZnO nanowires on the copper substrate and the effect of ZnO nanowire length on the accelerometer performance was investigated. The refresh hydrothermal synthesis exhibits longer ZnO nanowires, 12 µm, than the seedless hydrothermal synthesis, 6 µm. Performance of the fabricated accelerometers was verified by comparing with a commercial accelerometer. The sensitivity of the fabricated accelerometer by the refresh hydrothermal synthesis is shown to be 37.7 pA g−1, which is about 30 times larger than the previous result. PMID:28989760

Activity recognition in planetary navigation field tests using classification algorithms applied to accelerometer data.

PubMed

Song, Wen; Ade, Carl; Broxterman, Ryan; Barstow, Thomas; Nelson, Thomas; Warren, Steve

2012-01-01

Accelerometer data provide useful information about subject activity in many different application scenarios. For this study, single-accelerometer data were acquired from subjects participating in field tests that mimic tasks that astronauts might encounter in reduced gravity environments. The primary goal of this effort was to apply classification algorithms that could identify these tasks based on features present in their corresponding accelerometer data, where the end goal is to establish methods to unobtrusively gauge subject well-being based on sensors that reside in their local environment. In this initial analysis, six different activities that involve leg movement are classified. The k-Nearest Neighbors (kNN) algorithm was found to be the most effective, with an overall classification success rate of 90.8%.

Validation of Accelerometer Prediction Equations in Children with Chronic Disease.

PubMed

Stephens, Samantha; Takken, Tim; Esliger, Dale W; Pullenayegum, Eleanor; Beyene, Joseph; Tremblay, Mark; Schneiderman, Jane; Biggar, Doug; Longmuir, Pat; McCrindle, Brian; Abad, Audrey; Ignas, Dan; Van Der Net, Janjaap; Feldman, Brian

2016-02-01

The purpose of this study was to assess the criterion validity of existing accelerometer-based energy expenditure (EE) prediction equations among children with chronic conditions, and to develop new prediction equations. Children with congenital heart disease (CHD), cystic fibrosis (CF), dermatomyositis (JDM), juvenile arthritis (JA), inherited muscle disease (IMD), and hemophilia (HE) completed 7 tasks while EE was measured using indirect calorimetry with counts determined by accelerometer. Agreement between predicted EE and measured EE was assessed. Disease-specific equations and cut points were developed and cross-validated. In total, 196 subjects participated. One participant dropped out before testing due to time constraints, while 15 CHD, 32 CF, 31 JDM, 31 JA, 30 IMD, 28 HE, and 29 healthy controls completed the study. Agreement between predicted and measured EE varied across disease group and ranged from (ICC) .13-.46. Disease-specific prediction equations exhibited a range of results (ICC .62-.88) (SE 0.45-0.78). In conclusion, poor agreement was demonstrated using current prediction equations in children with chronic conditions. Disease-specific equations and cut points were developed.

Ngram time series model to predict activity type and energy cost from wrist, hip and ankle accelerometers: implications of age

PubMed Central

Strath, Scott J; Kate, Rohit J; Keenan, Kevin G; Welch, Whitney A; Swartz, Ann M

2016-01-01

To develop and test time series single site and multi-site placement models, we used wrist, hip and ankle processed accelerometer data to estimate energy cost and type of physical activity in adults. Ninety-nine subjects in three age groups (18–39, 40–64, 65 + years) performed 11 activities while wearing three triaxial accelereometers: one each on the non-dominant wrist, hip, and ankle. During each activity net oxygen cost (METs) was assessed. The time series of accelerometer signals were represented in terms of uniformly discretized values called bins. Support Vector Machine was used for activity classification with bins and every pair of bins used as features. Bagged decision tree regression was used for net metabolic cost prediction. To evaluate model performance we employed the jackknife leave-one-out cross validation method. Single accelerometer and multi-accelerometer site model estimates across and within age group revealed similar accuracy, with a bias range of −0.03 to 0.01 METs, bias percent of −0.8 to 0.3%, and a rMSE range of 0.81–1.04 METs. Multi-site accelerometer location models improved activity type classification over single site location models from a low of 69.3% to a maximum of 92.8% accuracy. For each accelerometer site location model, or combined site location model, percent accuracy classification decreased as a function of age group, or when young age groups models were generalized to older age groups. Specific age group models on average performed better than when all age groups were combined. A time series computation show promising results for predicting energy cost and activity type. Differences in prediction across age group, a lack of generalizability across age groups, and that age group specific models perform better than when all ages are combined needs to be considered as analytic calibration procedures to detect energy cost and type are further developed. PMID:26449155

Improving Hip-Worn Accelerometer Estimates of Sitting Using Machine Learning Methods.

PubMed

Kerr, Jacqueline; Carlson, Jordan; Godbole, Suneeta; Cadmus-Bertram, Lisa; Bellettiere, John; Hartman, Sheri

2018-02-13

To improve estimates of sitting time from hip worn accelerometers used in large cohort studies by employing machine learning methods developed on free living activPAL data. Thirty breast cancer survivors concurrently wore a hip worn accelerometer and a thigh worn activPAL for 7 days. A random forest classifier, trained on the activPAL data, was employed to detect sitting, standing and sit-stand transitions in 5 second windows in the hip worn accelerometer. The classifier estimates were compared to the standard accelerometer cut point and significant differences across different bout lengths were investigated using mixed effect models. Overall, the algorithm predicted the postures with moderate accuracy (stepping 77%, standing 63%, sitting 67%, sit to stand 52% and stand to sit 51%). Daily level analyses indicated that errors in transition estimates were only occurring during sitting bouts of 2 minutes or less. The standard cut point was significantly different from the activPAL across all bout lengths, overestimating short bouts and underestimating long bouts. This is among the first algorithms for sitting and standing for hip worn accelerometer data to be trained from entirely free living activPAL data. The new algorithm detected prolonged sitting which has been shown to be most detrimental to health. Further validation and training in larger cohorts is warranted.This is an open access article distributed under the Creative Commons Attribution License 4.0 (CCBY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Validation of uniaxial and triaxial accelerometers for the assessment of physical activity in preschool children

USDA-ARS?s Scientific Manuscript database

Given the unique physical activity patterns of preschoolers, wearable electronic devices for quantitative assessment of physical activity require validation in this population. Study objective was to validate uniaxial and triaxial accelerometers in preschoolers. Room calorimetry was performed over 3...

Self-Reported Versus Accelerometer-Assessed Daily Physical Activity in Childhood Obesity Treatment.

PubMed

Schnurr, Theresia M; Bech, Bianca; Nielsen, Tenna R H; Andersen, Ida G; Hjorth, Mads F; Aadahl, Mette; Fonvig, Cilius E; Hansen, Torben; Holm, Jens-Christian

2017-08-01

We investigated the relationship between interview-based subjective ratings of physical activity (PA) engagement and accelerometer-assessed objectively measured PA in children and adolescents with overweight or obesity. A total of 92 children and adolescents (40 males, 52 females) with BMI ≥ 90th percentile for sex and age, aged 5-17 years had valid GT3X + accelerometer-assessed PA and interview-assessed self-reported information on PA engagement at the time of enrollment in a multidisciplinary outpatient tertiary treatment for childhood obesity. Accelerometer-derived mean overall PA and time spent in moderate to vigorous physical intensity were generated, applying cut-offs based on Vector Magnitude settings as defined by Romanzini et al. (2014), and a physical activity score (PAS) based on self-reported data. Overall, a higher self-reported PAS was correlated with higher accelerometer-assessed daily total PA levels ( r = 0.34, p < .01) and children who reported a high PAS were more physically active compared with children who reported a low PAS. There was a fair level of agreement between self-reported PAS and accelerometer-assessed PA (Kappa agreement = 0.23; 95% CI = [0.03, 0.43]; p = .01). PAS, derived from self-report, may be a useful instrument for evaluating PA at a group level among children and adolescents enrolled in multidisciplinary obesity treatment.

Leptin and energy restriction induced adaptation in energy expenditure.

PubMed

Camps, Stefan G J A; Verhoef, Sanne P M; Westerterp, Klaas R

2015-10-01

Diet-induced weight loss is accompanied by adaptive thermogenesis, i.e. a disproportional reduction of resting energy expenditure (REE) a decrease in physical activity and increased movement economy. To determine if energy restriction induced adaptive thermogenesis and adaptations in physical activity are related to changes in leptin concentrations. Eighty-two healthy subjects (23 men, 59 women), mean ± SD age 41 ± 8 years and BMI 31.9 ± 3.0 kg/m(2), followed a very low energy diet for 8 weeks with measurements before and after the diet. Leptin concentrations were determined from fasting blood plasma. Body composition was assessed with a three-compartment model based on body weight, total body water (deuterium dilution) and body volume (BodPod). REE was measured (REEm) with a ventilated hood and predicted (REEp) from measured body composition. Adaptive thermogenesis was calculated as REEm/REEp. Parameters for the amount of physical activity were total energy expenditure expressed as a multiple of REEm (PAL), activity-induced energy expenditure divided by body weight (AEE/kg) and activity counts measured by a tri-axial accelerometer. Movement economy was calculated as AEE/kg (MJ/kg/d) divided by activity counts (Mcounts/d). Subjects lost on average 10.7 ± 4.1% body weight (P<0.001). Leptin decreased from 26.9 ± 14.3 before to 13.9 ± 11.3 μg/l after the diet (P<0.001). REEm/REEp after the diet (0.963 ± 0.08) was related to changes in leptin levels (R(2)=0.06; P<0.05). There was no significant correlation between changes in leptin concentrations and changes in amount of physical activity. Movement economy changed from 0.036 ± 0.011 J/kg/count to 0.028 ± 0.010 J/kg/count and was correlated to the changes in leptin concentrations (R(2)=0.07; P<0.05). During energy restriction, the decrease in leptin explains part of the variation in adaptive thermogenesis. Changes in leptin are not related to the amount of physical activity but could partly explain the increased movement economy. Copyright © 2015 Elsevier Inc. All rights reserved.

Effect of surgical approach on physical activity and pain control after sacral colpopexy.

PubMed

Collins, Sarah A; Tulikangas, Paul K; O'Sullivan, David M

2012-05-01

We sought to compare recovery of activity and pain control after robotic (ROB) vs abdominal (ABD) sacral colpopexy. Women undergoing ROB and ABD sacral colpopexy wore accelerometers for 7 days preoperatively and the first 10 days postoperatively. They completed postoperative pain diaries and Short Form-36 questionnaires before and after surgery. At 5 days postoperatively, none of the 14 subjects in the ABD group and 4 of 28 (14.3%) in the ROB group achieved 50% total baseline activity counts (P = .283). At 10 days, 5 of 14 (35.7%) in the ABD group and 8 of 26 (30.8%) in the ROB group (P = .972) achieved 50%. Postoperative pain was similar in both groups. Short Form-36 vitality scores were lower (P = .017) after surgery in the ABD group, but not in the ROB group. Women undergoing ROB vs ABD sacral colpopexy do not recover physical activity faster, and pain control is not improved. Copyright © 2012 Mosby, Inc. All rights reserved.

Application of Acceleration Sensors in Physiological Experiments

NASA Astrophysics Data System (ADS)

Vavrinský, Erik; Moskal'vá, Daniela; Darříček, Martin; Donoval, Martin; Horínek, František; Popovič, Marían; Miklovič, Peter

2014-09-01

This paper illustrates a promising application of an accelerometer sensor in physiological research, we demonstrated use of accelerometers for monitoring the standard proband physical activity (PA) and also in special applications like respiration and mechanical heart activity, the so-called seismocardiography (SCG) monitoring, physiological activation monitoring and mechanomyography (MMG)

Level of agreement between methods for measuring moderate to vigorous physical activity and sedentary time in people with obstructive sleep apnea and obesity.

PubMed

Igelström, Helena; Emtner, Margareta; Lindberg, Eva; Asenlöf, Pernilla

2013-01-01

There is ambiguity about what measures to use to best identify physical activity and sedentary behavior, and agreement between methods for measuring physical activity and sedentary behavior in people with obstructive sleep apnea syndrome (OSAS) and obesity has not been evaluated. The objective of this study was to examine the level of agreement between an accelerometer and a self-report questionnaire (International Physical Activity Questionnaire [IPAQ]) or a logbook for measuring time spent on moderate to vigorous physical activity and time spent sedentary in people with OSAS and obesity. This prospective study was a psychometric evaluation of agreement between measurement methods. Thirty-nine people who were obese (body mass index: X=36.1 kg/m², SD=4.35) and had moderate to severe OSAS (apnea-hypopnea index of ≥15) were consecutively recruited from a sleep clinic in Sweden. All were treated with continuous positive airway pressure and were waiting for a follow-up sleep evaluation. Agreement between the measurement methods was limited. For physical activity, the mean difference between the accelerometer and the IPAQ was 47 minutes, and the mean difference between the accelerometer and the logbook was 32 minutes. Agreement was limited for sedentary time as well; the mean difference between the accelerometer and the IPAQ was 114 minutes, and the mean difference between the accelerometer and the logbook was 86 minutes. The small sample size may affect the interpretation and generalizability of the results. The results imply that the methods cannot be used interchangeably. A combination of an accelerometer and a daily logbook seems to provide a detailed description of physical activity and sedentary behavior.

Cognitive function and the agreement between self-reported and accelerometer-accessed physical activity.

PubMed

Herbolsheimer, Florian; Riepe, Matthias W; Peter, Richard

2018-02-21

Numerous studies have reported weak or moderate correlations between self-reported and accelerometer-assessed physical activity. One explanation is that self-reported physical activity might be biased by demographic, cognitive or other factors. Cognitive function is one factor that could be associated with either overreporting or underreporting of daily physical activity. Difficulties in remembering past physical activities might result in recall bias. Thus, the current study examines whether the cognitive function is associated with differences between self-reported and accelerometer-assessed physical activity. Cross-sectional data from the population-based Activity and Function in the Elderly in Ulm study (ActiFE) were used. A total of 1172 community-dwelling older adults (aged 65-90 years) wore a uniaxial accelerometer (activPAL unit) for a week. Additionally, self-reported physical activity was assessed using the LASA Physical Activity Questionnaire (LAPAQ). Cognitive function was measured with four items (immediate memory, delayed memory, recognition memory, and semantic fluency) from the Consortium to Establish a Registry for Alzheimer's Disease Total Score (CERAD-TS). Mean differences of self-reported and accelerometer-assessed physical activity (MPA) were associated with cognitive function in men (r s  = -.12, p = .002) but not in women. Sex-stratified multiple linear regression analyses showed that MPA declined with high cognitive function in men (β = -.13; p = .015). Results suggest that self-reported physical activity should be interpreted with caution in older populations, as cognitive function was one factor that explained the differences between objective and subjective physical activity measurements.

Increasing physician activity with treadmill desks.

PubMed

Thompson, Warren G; Koepp, Gabriel A; Levine, James A

2014-01-01

Prolonged sitting has been shown to increase mortality and obesity. We sought to determine whether physicians would use a treadmill desk, increase their daily physical activity and lose weight. 20 overweight and obese physicians aged 25 to 70 with Body Mass Index > 25. Participants used a treadmill desk, a triaxial accelerometer, and received exercise counseling in a randomized, cross-over trial over 24 weeks. Group 1 received exercise counseling, accelerometer feedback, and a treadmill desk for 12 weeks and then accelerometer only for 12 weeks. Group 2 received an accelerometer without feedback for 12 weeks followed by exercise counseling, accelerometer feedback, and the treadmill desk for 12 weeks. Daily physical activity increased while using the treadmill desk compared to not using the desk by 197 kcal per day (p=0.003). The difference in weight during the two 12 week periods was 1.85 kg (p=0.03). Percent body fat was 1.9% lower while using the treadmill desk (p=0.02). There were no differences in metabolic or well-being measures. This study suggests that physicians will use a treadmill desk, that it does increase their activity, and that it may help with weight loss. Further studies are warranted.

The Feasibility of Using Questionnaires and Accelerometers to Measure Physical Activity and Sedentary Behavior Among Inpatient Adults With Mental Illness.

PubMed

Fraser, Sarah J; Chapman, Justin J; Brown, Wendy J; Whiteford, Harvey A; Burton, Nicola W

2016-05-01

The aim of this study was to assess the feasibility of using questionnaires and accelerometers to measure physical activity and sedentary behavior among inpatient adults with mental illness. Participants completed a physical activity and sitting time questionnaire and wore an accelerometer for 7 consecutive days. Feasibility was assessed in terms of participant engagement, self-reported ease/ difficulty of completing study components, extreme self-report data values and adherence to accelerometer wear time criteria. Ease/difficulty ratings were examined by level of distress. 177 inpatients were invited to the study, 101 completed the questionnaires and 36 provided valid accelerometry data. Participants found it more difficult to complete sitting time and physical activity questionnaires than to wear the accelerometer during waking hours (z = 3.787, P < .001; z = 2.824, P = .005 respectively). No significant differences were found in ease/ difficulty ratings by level of distress for any of the study components. Extreme values for self-reported sitting time were identified in 27% of participants. Inpatient adults with mental illness can engage with self-report and objective methods of measuring physical activity and sedentary behavior. They were initially less willing to participate in objective measurement, which may however be more feasible than self-report measures.

Accelerometer use during field-based physical activity research in children and adolescents with intellectual disabilities: a systematic review.

PubMed

McGarty, Arlene M; Penpraze, Victoria; Melville, Craig A

2014-05-01

Many methodological questions and issues surround the use of accelerometers as a measure of physical activity during field-based research. To ensure overall research quality and the accuracy of results, methodological decisions should be based on study research questions. This paper aims to systematically review accelerometer use during field-based research in children and adolescents with intellectual disabilities. Medline, Embase, Cochrane Library, Web of Knowledge, PsycINFO, PubMed, and a thesis database (up to May 2013) were searched to identify relevant articles. Articles which used accelerometry-based monitors, quantified activity levels, and included ambulatory children and adolescents (≤ 18 years) with intellectual disabilities were included. Based on best practice guidelines, a form was developed to extract data based on 17 research components of accelerometer use. The search identified 429 articles. Ten full-text articles met the criteria and were included in the review. Many shortcomings in accelerometer use were identified, with the percentage of review criteria met ranging from 12% to 47%. Various methods of accelerometer use were reported, with most use decisions not based on population-specific research. However, a lack of measurement research, e.g., calibration/validation, for children and adolescents with intellectual disabilities is limiting the ability of field-based researchers to make to the most appropriate accelerometer use decisions. The methods of accelerometer use employed can have significant effects on the quality and validity of results produced, which researchers should be more aware of. To allow informed use decisions, there should be a greater focus on measurement research related to children and adolescents with intellectual disabilities. Copyright © 2014 Elsevier Ltd. All rights reserved.

Accelerometer-Derived Pattern of Sedentary and Physical Activity Time in Persons with Mobility Disability: National Health and Nutrition Examination Survey 2003 to 2006.

PubMed

Manns, Patricia; Ezeugwu, Victor; Armijo-Olivo, Susan; Vallance, Jeff; Healy, Genevieve N

2015-07-01

To describe objectively determined sedentary and activity outcomes (volume and pattern) and their associations with cardiometabolic risk biomarkers in individuals with and without mobility disability. Cross-sectional. Population based. Community-dwelling older adults (≥60) living in the United States who were participants in the 2003 to 2004 or 2005 to 2006 National Health and Nutrition Examination Survey. Participants were classified as with or without mobility disability according to responses to self-reported questions about ability to walk, climb stairs, and/or use of ambulatory aids. Accelerometer-derived sedentary and activity variables for volume (time in sedentary (<100 counts per minute (cpm)), very light- (100-759 cpm), light- (760-1,951 cpm), and moderate- to vigorous- (≥1,952 cpm) intensity activity and pattern (number of breaks from sedentary time, duration of sedentary bouts, duration of activity bouts). Survey-weighted regression models, adjusted for age, sex, ethnicity, education, and smoking, were used to examine the associations between pattern of activity and cardiometabolic health risk factors (blood pressure, waist circumference, high-density lipoprotein cholesterol). Of the 2,017 participants, 547 were classified as having a mobility disability. Participants with mobility disability had more sedentary time and less active time than those without. Sedentary bouts were longer and active bouts shorter in those with disability. The total number of sedentary breaks (transitions from sedentary to nonsedentary) differed between groups after adjustment for total sedentary time. Fewer breaks, longer sedentary bouts, and shorter activity bouts were associated with higher average waist circumference regardless of disability status. This study provides rationale for the development and testing of interventions to change the pattern of activity (e.g., include more breaks and longer activity bout durations) in older adults with mobility disability. © 2015, Copyright the Authors Journal compilation © 2015, The American Geriatrics Society.

Using Tri-Axial Accelerometry in Daily Elite Swim Training Practice.

PubMed

Ganzevles, Sander; Vullings, Rik; Beek, Peter Jan; Daanen, Hein; Truijens, Martin

2017-04-29

Background : Coaches in elite swimming carefully design the training programs of their swimmers and are keen on achieving strict adherence to those programs by their athletes. At present, coaches usually monitor the compliance of their swimmers to the training program with a stopwatch. However, this measurement clearly limits the monitoring possibilities and is subject to human error. Therefore, the present study was designed to examine the reliability and practical usefulness of tri-axial accelerometers for monitoring lap time, stroke count and stroke rate in swimming. Methods : In the first part of the study, a 1200 m warm-up swimming routine was measured in 13 elite swimmers using tri-axial accelerometers and synchronized video recordings. Reliability was determined using the typical error of measurement (TEM) as well as a Bland-Altman analysis. In the second part, training compliance both within and between carefully prescribed training sessions was assessed in four swimmers in order to determine the practical usefulness of the adopted accelerometric approach. In these sessions, targets were set for lap time and stroke count by the coach. Results : The results indicated high reliability for lap time (TEM = 0.26 s, bias = 0.74 [0.56 0.91] with limits of agreement (LoA) from -1.20 [-1.50 -0.90] to 2.70 [2.40 3.00]), stroke count (TEM 0.73 strokes, bias = 0.46 [0.32 0.60] with LoA from -1.70 [-1.94 -1.46] to 2.60 [2.36 2.84]) and stroke rate (TEM 0.72 str∙min -1 , bias = -0.13 [-0.20 -0.06] with LoA from -2.20 [-2.32 -2.08] to 1.90 [1.78 2.02]), while the results for the monitoring of training compliance demonstrated the practical usefulness of our approach in daily swimming training. Conclusions : The daily training of elite swimmers can be accurately and reliably monitored using tri-axial accelerometers. They provide the coach with more useful information to guide and control the training process than hand-clocked times.

Using Tri-Axial Accelerometry in Daily Elite Swim Training Practice

PubMed Central

Ganzevles, Sander; Vullings, Rik; Beek, Peter Jan; Daanen, Hein; Truijens, Martin

2017-01-01

Background: Coaches in elite swimming carefully design the training programs of their swimmers and are keen on achieving strict adherence to those programs by their athletes. At present, coaches usually monitor the compliance of their swimmers to the training program with a stopwatch. However, this measurement clearly limits the monitoring possibilities and is subject to human error. Therefore, the present study was designed to examine the reliability and practical usefulness of tri-axial accelerometers for monitoring lap time, stroke count and stroke rate in swimming. Methods: In the first part of the study, a 1200 m warm-up swimming routine was measured in 13 elite swimmers using tri-axial accelerometers and synchronized video recordings. Reliability was determined using the typical error of measurement (TEM) as well as a Bland-Altman analysis. In the second part, training compliance both within and between carefully prescribed training sessions was assessed in four swimmers in order to determine the practical usefulness of the adopted accelerometric approach. In these sessions, targets were set for lap time and stroke count by the coach. Results: The results indicated high reliability for lap time (TEM = 0.26 s, bias = 0.74 [0.56 0.91] with limits of agreement (LoA) from −1.20 [−1.50 −0.90] to 2.70 [2.40 3.00]), stroke count (TEM 0.73 strokes, bias = 0.46 [0.32 0.60] with LoA from −1.70 [−1.94 −1.46] to 2.60 [2.36 2.84]) and stroke rate (TEM 0.72 str∙min−1, bias = −0.13 [−0.20 −0.06] with LoA from −2.20 [−2.32 −2.08] to 1.90 [1.78 2.02]), while the results for the monitoring of training compliance demonstrated the practical usefulness of our approach in daily swimming training. Conclusions: The daily training of elite swimmers can be accurately and reliably monitored using tri-axial accelerometers. They provide the coach with more useful information to guide and control the training process than hand-clocked times. PMID:28468255

Measuring physical activity during pregnancy.

PubMed

Harrison, Cheryce L; Thompson, Russell G; Teede, Helena J; Lombard, Catherine B

2011-03-21

Currently, little is known about physical activity patterns in pregnancy with prior estimates predominantly based on subjective assessment measures that are prone to error. Given the increasing obesity rates and the importance of physical activity in pregnancy, we evaluated the relationship and agreement between subjective and objective physical activity assessment tools to inform researchers and clinicians on optimal assessment of physical activity in pregnancy. 48 pregnant women between 26-28 weeks gestation were recruited. The Yamax pedometer and Actigraph accelerometer were worn for 5-7 days under free living conditions and thereafter the International Physical Activity Questionnaire (IPAQ) was completed. IPAQ and pedometer estimates of activity were compared to the more robust and accurate accelerometer data. Of 48 women recruited, 30 women completed the study (mean age: 33.6 ± 4.7 years; mean BMI: 31.2 ± 5.1 kg/m(2)) and 18 were excluded (failure to wear [n = 8] and incomplete data [n = 10]). The accelerometer and pedometer correlated significantly on estimation of daily steps (ρ = 0.69, p < 0.01) and had good absolute agreement with low systematic error (mean difference: 505 ± 1498 steps/day). Accelerometer and IPAQ estimates of total, light and moderate Metabolic Equivalent minutes/day (MET min(-1) day(-1)) were not significantly correlated and there was poor absolute agreement. Relative to the accelerometer, the IPAQ under predicted daily total METs (105.76 ± 259.13 min(-1) day(-1)) and light METs (255.55 ± 128.41 min(-1) day(-1)) and over predicted moderate METs (-112.25 ± 166.41 min(-1) day(-1)). Compared with the accelerometer, the pedometer appears to provide a reliable estimate of physical activity in pregnancy, whereas the subjective IPAQ measure performed less accurately in this setting. Future research measuring activity in pregnancy should optimally encompass objective measures of physical activity. Australian New Zealand Clinical Trial Registry Number: ACTRN12608000233325. Registered 7/5/2008.

Measuring physical activity during pregnancy

PubMed Central

2011-01-01

Background Currently, little is known about physical activity patterns in pregnancy with prior estimates predominantly based on subjective assessment measures that are prone to error. Given the increasing obesity rates and the importance of physical activity in pregnancy, we evaluated the relationship and agreement between subjective and objective physical activity assessment tools to inform researchers and clinicians on optimal assessment of physical activity in pregnancy. Methods 48 pregnant women between 26-28 weeks gestation were recruited. The Yamax pedometer and Actigraph accelerometer were worn for 5-7 days under free living conditions and thereafter the International Physical Activity Questionnaire (IPAQ) was completed. IPAQ and pedometer estimates of activity were compared to the more robust and accurate accelerometer data. Results Of 48 women recruited, 30 women completed the study (mean age: 33.6 ± 4.7 years; mean BMI: 31.2 ± 5.1 kg/m2) and 18 were excluded (failure to wear [n = 8] and incomplete data [n = 10]). The accelerometer and pedometer correlated significantly on estimation of daily steps (ρ = 0.69, p < 0.01) and had good absolute agreement with low systematic error (mean difference: 505 ± 1498 steps/day). Accelerometer and IPAQ estimates of total, light and moderate Metabolic Equivalent minutes/day (MET min-1 day-1) were not significantly correlated and there was poor absolute agreement. Relative to the accelerometer, the IPAQ under predicted daily total METs (105.76 ± 259.13 min-1 day-1) and light METs (255.55 ± 128.41 min-1 day-1) and over predicted moderate METs (-112.25 ± 166.41 min-1 day-1). Conclusion Compared with the accelerometer, the pedometer appears to provide a reliable estimate of physical activity in pregnancy, whereas the subjective IPAQ measure performed less accurately in this setting. Future research measuring activity in pregnancy should optimally encompass objective measures of physical activity. Trial Registration Australian New Zealand Clinical Trial Registry Number: ACTRN12608000233325. Registered 7/5/2008. PMID:21418609

Measuring Physical Activity in a Cardiac Rehabilitation Population Using a Smartphone-Based Questionnaire

PubMed Central

Maddison, Ralph; Jiang, Yannan; Dalleck, Lance; Löf, Marie

2013-01-01

Background Questionnaires are commonly used to assess physical activity in large population-based studies because of their low cost and convenience. Many self-report physical activity questionnaires have been shown to be valid and reliable measures, but they are subject to measurement errors and misreporting, often due to lengthy recall periods. Mobile phones offer a novel approach to measure self-reported physical activity on a daily basis and offer real-time data collection with the potential to enhance recall. Objective The aims of this study were to determine the convergent validity of a mobile phone physical activity (MobilePAL) questionnaire against accelerometry in people with cardiovascular disease (CVD), and to compare how the MobilePAL questionnaire performed compared with the commonly used self-recall International Physical Activity Questionnaire (IPAQ). Methods Thirty adults aged 49 to 85 years with CVD were recruited from a local exercise-based cardiac rehabilitation clinic in Auckland, New Zealand. All participants completed a demographics questionnaire and underwent a 6-minute walk test at the first visit. Subsequently, participants were temporarily provided a smartphone (with the MobilePAL questionnaire preloaded that asked 2 questions daily) and an accelerometer, which was to be worn for 7 days. After 1 week, a follow-up visit was completed during which the smartphone and accelerometer were returned, and participants completed the IPAQ. Results Average daily physical activity level measured using the MobilePAL questionnaire showed moderate correlation (r=.45; P=.01) with daily activity counts per minute (Acc_CPM) and estimated metabolic equivalents (MET) (r=.45; P=.01) measured using the accelerometer. Both MobilePAL (beta=.42; P=.008) and age (beta=–.48, P=.002) were significantly associated with Acc_CPM (adjusted R2=.40). When IPAQ-derived energy expenditure, measured in MET-minutes per week (IPAQ_met), was considered in the predicted model, both IPAQ_met (beta=.51; P=.001) and age (beta=–.36; P=.016) made unique contributions (adjusted R2=.47, F 2,27=13.58; P<.001).There was also a significant association between the MobilePAL and IPAQ measures (r=.49, beta=.51; P=.007). Conclusions A mobile phone–delivered questionnaire is a relatively reliable and valid measure of physical activity in a CVD cohort. Reliability and validity measures in the present study are comparable to existing self-report measures. Given their ubiquitous use, mobile phones may be an effective method for physical activity surveillance data collection. PMID:23524251

Validating Pedometer-Based Physical Activity Time against Accelerometer in Middle School Physical Education

ERIC Educational Resources Information Center

Gao, Zan; Lee, Amelia M.; Solmon, Melinda A.; Kosma, Maria; Carson, Russell L.; Zhang, Tao; Domangue, Elizabeth; Moore, Delilah

2010-01-01

The purpose of this study was to validate physical activity time in middle school physical education as measured by pedometers in relation to a criterion measure, namely, students' accelerometer determined moderate to vigorous physical activity (MVPA). Participants were 155 sixth to eighth graders participating in regularly scheduled physical…

Accelerometer-Measured versus Self-Reported Physical Activity in College Students: Implications for Research and Practice

ERIC Educational Resources Information Center

Downs, Andrew; Van Hoomissen, Jacqueline; Lafrenz, Andrew; Julka, Deana L.

2014-01-01

Objective: To determine the level of moderate-vigorous-intensity physical activity (MVPA) assessed via self-report and accelerometer in the college population, and to examine intrapersonal and contextual variables associated with physical activity (PA). Participants: Participants were 77 college students at a university in the northwest sampled…

A new type of tri-axial accelerometers with high dynamic range MEMS for earthquake early warning

NASA Astrophysics Data System (ADS)

Peng, Chaoyong; Chen, Yang; Chen, Quansheng; Yang, Jiansi; Wang, Hongti; Zhu, Xiaoyi; Xu, Zhiqiang; Zheng, Yu

2017-03-01

Earthquake Early Warning System (EEWS) has shown its efficiency for earthquake damage mitigation. As the progress of low-cost Micro Electro Mechanical System (MEMS), many types of MEMS-based accelerometers have been developed and widely used in deploying large-scale, dense seismic networks for EEWS. However, the noise performance of these commercially available MEMS is still insufficient for weak seismic signals, leading to the large scatter of early-warning parameters estimation. In this study, we developed a new type of tri-axial accelerometer based on high dynamic range MEMS with low noise level using for EEWS. It is a MEMS-integrated data logger with built-in seismological processing. The device is built on a custom-tailored Linux 2.6.27 operating system and the method for automatic detecting seismic events is STA/LTA algorithms. When a seismic event is detected, peak ground parameters of all data components will be calculated at an interval of 1 s, and τc-Pd values will be evaluated using the initial 3 s of P wave. These values will then be organized as a trigger packet actively sent to the processing center for event combining detection. The output data of all three components are calibrated to sensitivity 500 counts/cm/s2. Several tests and a real field test deployment were performed to obtain the performances of this device. The results show that the dynamic range can reach 98 dB for the vertical component and 99 dB for the horizontal components, and majority of bias temperature coefficients are lower than 200 μg/°C. In addition, the results of event detection and real field deployment have shown its capabilities for EEWS and rapid intensity reporting.

Investigating children's physical activity and sedentary behavior using ecological momentary assessment with mobile phones.

PubMed

Dunton, Genevieve F; Liao, Yue; Intille, Stephen S; Spruijt-Metz, Donna; Pentz, Maryann

2011-06-01

The risk of obesity during childhood can be significantly reduced through increased physical activity and decreased sedentary behavior. Recent technological advances have created opportunities for the real-time measurement of these behaviors. Mobile phones are ubiquitous and easy to use, and thus have the capacity to collect data from large numbers of people. The present study tested the feasibility, acceptability, and validity of an electronic ecological momentary assessment (EMA) protocol using electronic surveys administered on the display screen of mobile phones to assess children's physical activity and sedentary behaviors. A total of 121 children (ages 9-13, 51% male, 38% at risk for overweight/overweight) participated in EMA monitoring from Friday afternoon to Monday evening during children's nonschool time, with 3-7 surveys/day. Items assessed current activity (e.g., watching TV/movies, playing video games, active play/sports/exercising). Children simultaneously wore an Actigraph GT2M accelerometer. EMA survey responses were time-matched to total step counts and minutes of moderate-to-vigorous physical activity (MVPA) occurring in the 30 min before each EMA survey prompt. No significant differences between answered and unanswered EMA surveys were found for total steps or MVPA. Step counts and the likelihood of 5+ min of MVPA were significantly higher during EMA-reported physical activity (active play/sports/exercising) vs. sedentary behaviors (reading/computer/homework, watching TV/movies, playing video games, riding in a car) (P < 0.001). Findings generally support the acceptability and validity of a 4-day EMA protocol using mobile phones to measure physical activity and sedentary behavior in children during leisure time.

Prediction of energy expenditure and physical activity in preschoolers.

PubMed

Butte, Nancy F; Wong, William W; Lee, Jong Soo; Adolph, Anne L; Puyau, Maurice R; Zakeri, Issa F

2014-06-01

Accurate, nonintrusive, and feasible methods are needed to predict energy expenditure (EE) and physical activity (PA) levels in preschoolers. Herein, we validated cross-sectional time series (CSTS) and multivariate adaptive regression splines (MARS) models based on accelerometry and heart rate (HR) for the prediction of EE using room calorimetry and doubly labeled water (DLW) and established accelerometry cut points for PA levels. Fifty preschoolers, mean ± SD age of 4.5 ± 0.8 yr, participated in room calorimetry for minute-by-minute measurements of EE, accelerometer counts (AC) (Actiheart and ActiGraph GT3X+), and HR (Actiheart). Free-living 105 children, ages 4.6 ± 0.9 yr, completed the 7-d DLW procedure while wearing the devices. AC cut points for PA levels were established using smoothing splines and receiver operating characteristic curves. On the basis of calorimetry, mean percent errors for EE were -2.9% ± 10.8% and -1.1% ± 7.4% for CSTS models and -1.9% ± 9.6% and 1.3% ± 8.1% for MARS models using the Actiheart and ActiGraph+HR devices, respectively. On the basis of DLW, mean percent errors were -0.5% ± 9.7% and 4.1% ± 8.5% for CSTS models and 3.2% ± 10.1% and 7.5% ± 10.0% for MARS models using the Actiheart and ActiGraph+HR devices, respectively. Applying activity EE thresholds, final accelerometer cut points were determined: 41, 449, and 1297 cpm for Actiheart x-axis; 820, 3908, and 6112 cpm for ActiGraph vector magnitude; and 240, 2120, and 4450 cpm for ActiGraph x-axis for sedentary/light, light/moderate, and moderate/vigorous PA (MVPA), respectively. On the basis of confusion matrices, correctly classified rates were 81%-83% for sedentary PA, 58%-64% for light PA, and 62%-73% for MVPA. The lack of bias and acceptable limits of agreement affirms the validity of the CSTS and MARS models for the prediction of EE in preschool-aged children. Accelerometer cut points are satisfactory for the classification of sedentary, light, and moderate/vigorous levels of PA in preschoolers.

Penguin head movement detected using small accelerometers: a proxy of prey encounter rate.

PubMed

Kokubun, Nobuo; Kim, Jeong-Hoon; Shin, Hyoung-Chul; Naito, Yasuhiko; Takahashi, Akinori

2011-11-15

Determining temporal and spatial variation in feeding rates is essential for understanding the relationship between habitat features and the foraging behavior of top predators. In this study we examined the utility of head movement as a proxy of prey encounter rates in medium-sized Antarctic penguins, under the presumption that the birds should move their heads actively when they encounter and peck prey. A field study of free-ranging chinstrap and gentoo penguins was conducted at King George Island, Antarctica. Head movement was recorded using small accelerometers attached to the head, with simultaneous monitoring for prey encounter or body angle. The main prey was Antarctic krill (>99% in wet mass) for both species. Penguin head movement coincided with a slow change in body angle during dives. Active head movements were extracted using a high-pass filter (5 Hz acceleration signals) and the remaining acceleration peaks (higher than a threshold acceleration of 1.0 g) were counted. The timing of head movements coincided well with images of prey taken from the back-mounted cameras: head movement was recorded within ±2.5 s of a prey image on 89.1±16.1% (N=7 trips) of images. The number of head movements varied largely among dive bouts, suggesting large temporal variations in prey encounter rates. Our results show that head movement is an effective proxy of prey encounter, and we suggest that the method will be widely applicable for a variety of predators.

Individual characteristics associated with mismatches between self-reported and accelerometer-measured physical activity.

PubMed

Tully, Mark A; Panter, Jenna; Ogilvie, David

2014-01-01

Accurate assessment tools are required for the surveillance of physical activity (PA) levels and the assessment of the effect of interventions. In addition, increasing awareness of PA is often used as the first step in pragmatic behavioural interventions, as discrepancies between the amount of activity an individual perceives they do and the amount actually undertaken may act as a barrier to change. Previous research has demonstrated differences in the amount of activity individuals report doing, compared to their level of physical activity when measured with an accelerometer. Understanding the characteristics of those whose PA level is ranked differently when measured with either self-report or accelerometry is important as it may inform the choice of instrument for future research. The aim of this project was to determine which individual characteristics are associated with differences between self-reported and accelerometer measured physical activity. Participant data from the 2009 wave of the Commuting and Health in Cambridge study were used. Quartiles of self-reported and accelerometer-measured PA were derived by ranking each measure from lowest to highest. These quartiles were compared to determine whether individuals' physical activity was ranked higher by either method. Multinomial logistic regression models were used to investigate the individual characteristics associated with different categories of mismatch. Data from 486 participants (70% female) were included in the analysis. In adjusted analyses, the physical activity of overweight or obese individuals was significantly more likely to be ranked higher by self-report than by accelerometer than that of normal-weight individuals (OR = 2.07, 95%CI = 1.28-3.34), particularly among women (OR = 3.97, 95%CI = 2.11-7.47). There was a greater likelihood of mismatch between self-reported and accelerometer measured physical activity levels in overweight or obese adults. Future studies in overweight or obese adults should consider employing both methods of measurement.

Comparison of accelerometer cut points for predicting activity intensity in youth.

PubMed

Trost, Stewart G; Loprinzi, Paul D; Moore, Rebecca; Pfeiffer, Karin A

2011-07-01

The absence of comparative validity studies has prevented researchers from reaching consensus regarding the application of intensity-related accelerometer cut points for children and adolescents. This study aimed to evaluate the classification accuracy of five sets of independently developed ActiGraph cut points using energy expenditure, measured by indirect calorimetry, as a criterion reference standard. A total of 206 participants between the ages of 5 and 15 yr completed 12 standardized activity trials. Trials consisted of sedentary activities (lying down, writing, computer game), lifestyle activities (sweeping, laundry, throw and catch, aerobics, basketball), and ambulatory activities (comfortable walk, brisk walk, brisk treadmill walk, running). During each trial, participants wore an ActiGraph GT1M, and V˙O2 was measured breath-by-breath using the Oxycon Mobile portable metabolic system. Physical activity intensity was estimated using five independently developed cut points: Freedson/Trost (FT), Puyau (PU), Treuth (TR), Mattocks (MT), and Evenson (EV). Classification accuracy was evaluated via weighted κ statistics and area under the receiver operating characteristic curve (ROC-AUC). Across all four intensity levels, the EV (κ=0.68) and FT (κ=0.66) cut points exhibited significantly better agreement than TR (κ=0.62), MT (κ=0.54), and PU (κ=0.36). The EV and FT cut points exhibited significantly better classification accuracy for moderate- to vigorous-intensity physical activity (ROC-AUC=0.90) than TR, PU, or MT cut points (ROC-AUC=0.77-0.85). Only the EV cut points provided acceptable classification accuracy for all four levels of physical activity intensity and performed well among children of all ages. The widely applied sedentary cut point of 100 counts per minute exhibited excellent classification accuracy (ROC-AUC=0.90). On the basis of these findings, we recommend that researchers use the EV ActiGraph cut points to estimate time spent in sedentary, light-, moderate-, and vigorous-intensity activity in children and adolescents.

Objective Quantification of Physical Activity in Bariatric Surgery Candidates and Normal-Weight Controls

PubMed Central

Bond, Dale S.; Jakicic, John M.; Vithiananthan, Sivamainthan; Thomas, J. Graham; Leahey, Tricia M.; Sax, Harry C.; Pohl, Dieter; Roye, G.D.; Ryder, Beth A.; Wing, Rena R.

2009-01-01

Background Physical activity (PA) is an important component of weight loss programs and may be encouraged for severely obese patients undergoing bariatric surgery. However, few studies have determined the amount and intensity of activities undertaken preoperatively by bariatric surgery patients using objective measures. Methods Using RT3 tri-axial accelerometers, this study compared 38 bariatric surgery candidates and 20 normal-weight controls on: 1) activity counts/hour; 2) minutes/day spent in moderate-to-vigorous intensity PA (MVPA) and vigorous intensity PA (VPA); and 3) level of compliance with national recommendations to accumulate 150 minutes/week of MVPA in bouts ≥ 10 minutes. Results Surgery candidates, compared to controls, recorded significantly (Ps < 0.01) fewer activity counts/hour (13799 ± 3758 vs 19462 ± 4259) and spent fewer minutes/day engaged in MVPA (26.4 ± 23.0 vs 52.4 ± 24.7) and VPA (1.2 ± 3.4 vs 11.8 ± 9.0). More than two-thirds (68%) of surgery candidates versus 13% of NW did not accumulate any MVPA in bouts ≥ 10 minutes and only 4.5% of Ob met the weekly MVPA recommendation compared to 40% of NW. Conclusion Bariatric surgery candidates have low PA levels and rarely engage in PA bouts of sufficient duration and intensity to maintain and improve health. Additional research is needed to determine how best to increase PA in bariatric surgery candidates. PMID:19837009

A sensitivity analysis on the variability in accelerometer data processing for monitoring physical activity.

PubMed

Lee, Paul H

2015-02-01

Accelerometers are gaining popularity for measuring physical activity, but there are many different ways to process accelerometer data. A sensitivity analysis was conducted to study the effect of varying accelerometer data processing protocols on estimating the association between PA level and socio-demographic characteristics using the National Health and Nutrition Examination Survey (NHANES) accelerometer data. The NHANES waves 2003-2004 and 2005-2006 accelerometer data (n=14,072) were used to investigate the effect of changing the accelerometer non-wearing time and valid day definitions on the demographic composition of the filtered datasets and the association between physical activity (PA) and socio-demographic characteristics (sex, age, race, educational level, marital status). Under different filtering rules (minimum number of valid day and definition of non-wear time), the demographic characteristics of the final sample varied. The proportion of participants aged 20-29 decreased from 18.9% to 15.8% when the minimum number of valid days required increased from 1 to 4 (p for trend<0.001), whereas that for aged ≥70 years increased from 18.9% to 20.6% (p for trend<0.001). Furthermore, with different filters, the effect of these demographic variables and PA varied, with some variables being significant under certain filtering rules but becoming insignificant under some other rules. The sensitivity analysis showed that the significance of the association between socio-demographic variables and PA could be varied with the definition of non-wearing time and minimum number of valid days. Copyright © 2014 Elsevier B.V. All rights reserved.

Validation of the ADAMO Care Watch for step counting in older adults.

PubMed

Magistro, Daniele; Brustio, Paolo Riccardo; Ivaldi, Marco; Esliger, Dale Winfield; Zecca, Massimiliano; Rainoldi, Alberto; Boccia, Gennaro

2018-01-01

Accurate measurement devices are required to objectively quantify physical activity. Wearable activity monitors, such as pedometers, may serve as affordable and feasible instruments for measuring physical activity levels in older adults during their normal activities of daily living. Currently few available accelerometer-based steps counting devices have been shown to be accurate at slow walking speeds, therefore there is still lacking appropriate devices tailored for slow speed ambulation, typical of older adults. This study aimed to assess the validity of step counting using the pedometer function of the ADAMO Care Watch, containing an embedded algorithm for measuring physical activity in older adults. Twenty older adults aged ≥ 65 years (mean ± SD, 75±7 years; range, 68-91) and 20 young adults (25±5 years, range 20-40), wore a care watch on each wrist and performed a number of randomly ordered tasks: walking at slow, normal and fast self-paced speeds; a Timed Up and Go test (TUG); a step test and ascending/descending stairs. The criterion measure was the actual number of steps observed, counted with a manual tally counter. Absolute percentage error scores, Intraclass Correlation Coefficients (ICC), and Bland-Altman plots were used to assess validity. ADAMO Care Watch demonstrated high validity during slow and normal speeds (range 0.5-1.5 m/s) showing an absolute error from 1.3% to 1.9% in the older adult group and from 0.7% to 2.7% in the young adult group. The percentage error for the 30-metre walking tasks increased with faster pace in both young adult (17%) and older adult groups (6%). In the TUG test, there was less error in the steps recorded for older adults (1.3% to 2.2%) than the young adults (6.6% to 7.2%). For the total sample, the ICCs for the ADAMO Care Watch for the 30-metre walking tasks at each speed and for the TUG test were ranged between 0.931 to 0.985. These findings provide evidence that the ADAMO Care Watch demonstrated highly accurate measurements of the steps count in all activities, particularly walking at normal and slow speeds. Therefore, these data support the inclusion of the ADAMO Care Watch in clinical applications for measuring the number of steps taken by older adults at normal, slow walking speeds.

Is physical behavior affected in fatigued persons with multiple sclerosis?

PubMed

Blikman, Lyan J; van Meeteren, Jetty; Horemans, Herwin L; Kortenhorst, Ilse C; Beckerman, Heleen; Stam, Henk J; Bussmann, Johannes B

2015-01-01

To study physical behavior in detail in fatigued persons with multiple sclerosis (MS). Case-control explorative study. Outpatient rehabilitation department and participants' daily environment. Fatigued persons with MS (n=23) were selected from a randomized controlled trial. Cases were matched by age and sex to healthy, nonfatigued controls (n=23). Eligible persons with MS were severely fatigued (Checklist Individual Strength fatigue domain mean score, 43.2±6.6) and ambulatory (Expanded Disability Status Scale mean score, 2.5±1.5). Not applicable. Measurements were performed using an accelerometer over 7 days. Outcomes included the following: amount of physical activity expressed in counts per day, counts per minute (CPM), and counts per day period (morning, afternoon, evening); duration of activity intensity categories (sedentary, light physical activity, moderate-to-vigorous physical activity [MVPA]); and distribution of MVPA and sedentary periods over the day. Persons with MS had fewer counts per day (mean difference, -156×10(3); 95% confidence interval [CI], -273×10(3) to -39×10(3); P=.010), had fewer CPM (mean difference, -135; 95% CI, -256 to -14; P=.030), and were less physically active in the morning (mean difference, -200; 95% CI, -389 to -11; P=.039) and evening (mean difference, -175; 95% CI, -336 to -14; P=.034) than controls. Persons with MS spent a higher percentage of their time sedentary (mean difference, 5.6; 95% CI, .1-11.1; P=.045) and spent less time at the higher MVPA intensity (mean difference, -2.4; 95% CI, -4.7 to -0.09; P=.042). They had fewer MVPA periods (mean difference, 29; 95% CI, -56.2 to -2.6; P=.032) and a different distribution of sedentary (mean difference, .033; 95% CI, .002 to .064; P=.039) and MVPA periods (mean difference, -.08; 95% CI, -.15 to -.01; P=.023). Detailed analyses of physical behavior showed that ambulatory fatigued persons with MS do differ from healthy controls not only in physical activity level, but also in other physical behavior dimensions (eg, day patterns, intensity, distribution). Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Comparisons of four methods of estimating physical activity in adult women.

PubMed

Leenders NYJM; Sherman, W M; Nagaraja, H N

2000-07-01

To compare four different methods of measuring physical activity (PA) in adult women under free-living conditions. Twelve women participated in a 7-d period during which PA was assessed via self-report, accelerometry and step-counting. Subjects wore at the waist a Tritrac-R3D accelerometer, a Computer Science Application Inc. activity monitor (CSA), both of which measure bodily accelerations in various planes, and a Yamax Digi-Walker-500 that records steps. After the 7-d period subjects responded to a 7-d Physical Activity Recall interview (PAR). Physical activity-related energy expenditure (PAEE) determined from PAR was significantly higher than PAEE estimated from either the Tritrac, CSA, or the Yamax data. Time spent in light, moderate, and hard physical activity was not significantly different between PAR, CSA, and Tritrac. Log-transformed activity counts from CSA were highly correlated with log-transformed Tritrac results (r > 0.90). Number of steps recorded by the Yamax was significantly correlated with untransformed Tritrac and CSA results. Based upon comparisons with PAR, Tritrac, CSA, and Yamax underestimate the amount of PAEE by 25, 46, and 48%, respectively. The correspondence between the Tritrac and CSA results suggests that both devices produce similar estimates of bodily movement in free-living women. The relationships among results for Tritrac, CSA, and Yamax indicate that the number of steps recorded by the Yamax is representative of the amount of physical activity performed during the day as estimated by Tritrac and CSA. These results should be useful when selecting a method to measure PA in individuals under free-living conditions.

Physical Activity Inventory for Patients with Spinal Cord Injury

PubMed Central

Butler, Jolene A.; Miller, Terrya; O’Connell, Susan; Jelinek, Christine; Collins, Eileen G.

2010-01-01

Objectives To test the reliability and validity of a physical activity instrument adapted for individuals with spinal cord injuries (SCI), the Physical Activity Instrument-SCI (PAI-SCI). Methods Eligible participants completed the adapted PAI-SCI questionnaire at baseline and 1 week later. At baseline, they were also given an Actical accelerometer to wear on their wrist for 1 week. Results Forty-three male subjects completed the study. There was a moderate relationship between total score on the PAI-SCI and total activity count determined by accelerometry (r = 0.42, P = 0.036). The PAI-SCI was able to differentiate between people with upper and lower level injuries (P = 0.05). Test-retest reliability was supported for the exercise and the general activity/self care subscales and not supported for the light household or the outdoor/gardening subscales. Conclusion The PAI-SCI was able to distinguish between physical activity amongst those with upper level and lower level injuries. More research is needed before the PAI-SCI can be recommended for use in clinical trials. PMID:25190905

Accelerometer's position independent physical activity recognition system for long-term activity monitoring in the elderly.

PubMed

Khan, Adil Mehmood; Lee, Young-Koo; Lee, Sungyoung; Kim, Tae-Seong

2010-12-01

Mobility is a good indicator of health status and thus objective mobility data could be used to assess the health status of elderly patients. Accelerometry has emerged as an effective means for long-term physical activity monitoring in the elderly. However, the output of an accelerometer varies at different positions on a subject's body, even for the same activity, resulting in high within-class variance. Existing accelerometer-based activity recognition systems thus require firm attachment of the sensor to a subject's body. This requirement makes them impractical for long-term activity monitoring during unsupervised free-living as it forces subjects into a fixed life pattern and impede their daily activities. Therefore, we introduce a novel single-triaxial-accelerometer-based activity recognition system that reduces the high within-class variance significantly and allows subjects to carry the sensor freely in any pocket without its firm attachment. We validated our system using seven activities: resting (lying/sitting/standing), walking, walking-upstairs, walking-downstairs, running, cycling, and vacuuming, recorded from five positions: chest pocket, front left trousers pocket, front right trousers pocket, rear trousers pocket, and inner jacket pocket. Its simplicity, ability to perform activities unimpeded, and an average recognition accuracy of 94% make our system a practical solution for continuous long-term activity monitoring in the elderly.

Evaluation of two-dimensional accelerometers to monitor behavior of beef calves after castration.

PubMed

White, Brad J; Coetzee, Johann F; Renter, David G; Babcock, Abram H; Thomson, Daniel U; Andresen, Daniel

2008-08-01

To determine the accuracy of accelerometers for measuring behavior changes in calves and to determine differences in beef calf behavior from before to after castration. 3 healthy Holstein calves and 12 healthy beef calves. 2-dimensional accelerometers were placed on 3 calves, and data were logged simultaneous to video recording of animal behavior. Resulting data were used to generate and validate predictive models to classify posture (standing or lying) and type of activity (standing in place, walking, eating, getting up, lying awake, or lying sleeping). The algorithms developed were used to conduct a prospective trial to compare calf behavior in the first 24 hours after castration (n = 6) with behavior of noncastrated control calves (6) and with presurgical readings from the same castrated calves. On the basis of the analysis of the 2-dimensional accelerometer signal, posture was classified with a high degree of accuracy (98.3%) and the specific activity was estimated with a reasonably low misclassification rate (23.5%). Use of the system to compare behavior after castration revealed that castrated calves spent a significantly larger amount of time standing (82.2%), compared with presurgical readings (46.2%). 2-dimensional accelerometers provided accurate classification of posture and reasonable classification of activity. Applying the system in a castration trial illustrated the usefulness of accelerometers for measuring behavioral changes in individual calves.

Validity of a Questionnaire to Assess the Physical Activity Level in Coronary Artery Disease Patients

ERIC Educational Resources Information Center

Guiraud, Thibaut; Granger, Richard; Bousquet, Marc; Gremeaux, Vincent

2012-01-01

The aim of the study is to compare, in coronary artery disease patients, physical activity (PA) assessed with the Dijon Physical Activity Questionnaire (DPAQ) and the true PA objectively measured using an accelerometer. Seventy patients wore an accelerometer (MyWellness Key actimeter) throughout 1 week after a cardiac rehabilitation program that…

Intensity Classification Accuracy of Accelerometer-Measured Physical Activities in Chinese Children and Youth

ERIC Educational Resources Information Center

Zhu, Zheng; Chen, Peijie; Zhuang, Jie

2013-01-01

Purpose: Many ActiGraph accelerometer cutoff points and equations have been developed to classify children and youth's physical activity (PA) into different intensity levels. Using a sample from the Chinese City Children and Youth Physical Activity Study, this study was to develop new ActiGraph cutoff points for moderate-to-vigorous physical…

Convergent Validity of Four Accelerometer Cutpoints with Direct Observation of Preschool Children's Outdoor Physical Activity

ERIC Educational Resources Information Center

Kahan, David; Nicaise, Virginie; Reuben, Karen

2013-01-01

Purpose: More than one fifth of American preschool-aged children are classified as overweight/obese. Increasing physical activity is one means of slowing/reversing progression to overweight or obesity. Measurement of physical activity in this age group relies heavily on motion sensors such as accelerometers. Output is typically interpreted through…

A feasibility study on smartphone accelerometer-based recognition of household activities and influence of smartphone position.

PubMed

Della Mea, Vincenzo; Quattrin, Omar; Parpinel, Maria

2017-12-01

Obesity and physical inactivity are the most important risk factors for chronic diseases. The present study aimed at (i) developing and testing a method for classifying household activities based on a smartphone accelerometer; (ii) evaluating the influence of smartphone position; and (iii) evaluating the acceptability of wearing a smartphone for activity recognition. An Android application was developed to record accelerometer data and calculate descriptive features on 5-second time blocks, then classified with nine algorithms. Household activities were: sitting, working at the computer, walking, ironing, sweeping the floor, going down stairs with a shopping bag, walking while carrying a large box, and climbing stairs with a shopping bag. Ten volunteers carried out the activities for three times, each one with a smartphone in a different position (pocket, arm, and wrist). Users were then asked to answer a questionnaire. 1440 time blocks were collected. Three algorithms demonstrated an accuracy greater than 80% for all smartphone positions. While for some subjects the smartphone was uncomfortable, it seems that it did not really affect activity. Smartphones can be used to recognize household activities. A further development is to measure metabolic equivalent tasks starting from accelerometer data only.

Identifying Active Travel Behaviors in Challenging Environments Using GPS, Accelerometers, and Machine Learning Algorithms.

PubMed

Ellis, Katherine; Godbole, Suneeta; Marshall, Simon; Lanckriet, Gert; Staudenmayer, John; Kerr, Jacqueline

2014-01-01

Active travel is an important area in physical activity research, but objective measurement of active travel is still difficult. Automated methods to measure travel behaviors will improve research in this area. In this paper, we present a supervised machine learning method for transportation mode prediction from global positioning system (GPS) and accelerometer data. We collected a dataset of about 150 h of GPS and accelerometer data from two research assistants following a protocol of prescribed trips consisting of five activities: bicycling, riding in a vehicle, walking, sitting, and standing. We extracted 49 features from 1-min windows of this data. We compared the performance of several machine learning algorithms and chose a random forest algorithm to classify the transportation mode. We used a moving average output filter to smooth the output predictions over time. The random forest algorithm achieved 89.8% cross-validated accuracy on this dataset. Adding the moving average filter to smooth output predictions increased the cross-validated accuracy to 91.9%. Machine learning methods are a viable approach for automating measurement of active travel, particularly for measuring travel activities that traditional accelerometer data processing methods misclassify, such as bicycling and vehicle travel.

Accelerometry: A feasible method to monitor physical activity during sub-acute rehabilitation of persons with stroke.

PubMed

Joseph, Conran; Strömbäck, Björn; Hagströmer, Maria; Conradsson, David

2018-05-08

To investigate the feasibility of using accelerometers to monitor physical activity in persons with stroke admitted to inpatient rehabilitation. Longitudinal observational study. Persons with stroke admitted to a specialized rehabilitation centre for sub-acute rehabilitation were recruited between August and December 2016. Volume and intensity of physical activity were assessed with accelerometers throughout the rehabilitation period. Indicators of feasibility included processes (recruitment, protocol adherence and participants' experiences) and scientific feasibility, which assessed the accelerometers' ability to detect change in physical activity among stroke survivors who ambulate independently and those who are dependent on a mobility device. Twenty-seven out of 31 eligible individuals took part in this study, with 23 (85%) completing it. In total, 432 days of rehabilitation were monitored and valid physical activity data were obtained for 408 days (94%). There were no indications that the measurement interfered with participants' ability to participate in rehabilitation. Despite the subjects' ambulation status, the number of steps and time spent in moderate-to-vigorous physical activity increased significantly across the first 18 days of rehabilitation, whereas sedentary time was unchanged. This study supports the feasibility of using accelerometers to capture physical activity behaviour in survivors of stroke during inpatient rehabilitation.

Accelerometer thresholds: Accounting for body mass reduces discrepancies between measures of physical activity for individuals with overweight and obesity.

PubMed

Raiber, Lilian; Christensen, Rebecca A G; Jamnik, Veronica K; Kuk, Jennifer L

2017-01-01

The objective of this study was to explore whether accelerometer thresholds that are adjusted to account for differences in body mass influence discrepancies between self-report and accelerometer-measured physical activity (PA) volume for individuals with overweight and obesity. We analyzed 6164 adults from the National Health and Nutrition Examination Survey between 2003-2006. Established accelerometer thresholds were adjusted to account for differences in body mass to produce a similar energy expenditure (EE) rate as individuals with normal weight. Moderate-, vigorous-, and moderate- to vigorous-intensity PA (MVPA) durations were measured using established and adjusted accelerometer thresholds and compared with self-report. Durations of self-report were longer than accelerometer-measured MVPA using established thresholds (normal weight: 57.8 ± 2.4 vs 9.0 ± 0.5 min/day, overweight: 56.1 ± 2.7 vs 7.4 ± 0.5 min/day, and obesity: 46.5 ± 2.2 vs 3.7 ± 0.3 min/day). Durations of subjective and objective PA were negatively associated with body mass index (BMI) (P < 0.05). Using adjusted thresholds increased MVPA durations, and reduced discrepancies between accelerometer and self-report measures for overweight and obese groups by 6.0 ± 0.3 min/day and 17.7 ± 0.8 min/day, respectively (P < 0.05). Using accelerometer thresholds that represent equal EE rates across BMI categories reduced the discrepancies between durations of subjective and objective PA for overweight and obese groups. However, accelerometer-measured PA generally remained shorter than durations of self-report within all BMI categories. Further research may be necessary to improve analytical approaches when using objective measures of PA for individuals with overweight or obesity.

Actogram analysis of free-flying migratory birds: new perspectives based on acceleration logging.

PubMed

Bäckman, Johan; Andersson, Arne; Pedersen, Lykke; Sjöberg, Sissel; Tøttrup, Anders P; Alerstam, Thomas

2017-07-01

The use of accelerometers has become an important part of biologging techniques for large-sized birds with accelerometer data providing information about flight mode, wing-beat pattern, behaviour and energy expenditure. Such data show that birds using much energy-saving soaring/gliding flight like frigatebirds and swifts can stay airborne without landing for several months. Successful accelerometer studies have recently been conducted also for free-flying small songbirds during their entire annual cycle. Here we review the principles and possibilities for accelerometer studies in bird migration. We use the first annual actograms (for red-backed shrike Lanius collurio) to explore new analyses and insights that become possible with accelerometer data. Actogram data allow precise estimates of numbers of flights, flight durations as well as departure/landing times during the annual cycle. Annual and diurnal rhythms of migratory flights, as well as prolonged nocturnal flights across desert barriers are illustrated. The shifting balance between flight, rest and different intensities of activity throughout the year as revealed by actogram data can be used to analyse exertion levels during different phases of the life cycle. Accelerometer recording of the annual activity patterns of individual birds will open up a new dimension in bird migration research.

Comparison of accelerometer-measured sedentary behavior, and light- and moderate-to-vigorous-intensity physical activity in white- and blue-collar workers in a Japanese manufacturing plant.

PubMed

Fukushima, Noritoshi; Kitabayashi, Makiko; Kikuchi, Hiroyuki; Sasai, Hiroyuki; Oka, Koichiro; Nakata, Yoshio; Tanaka, Shigeho; Inoue, Shigeru

2018-05-25

The times spent in sedentary behavior (SB) and moderate-to-vigorous physical activity (MVPA) are independently associated with health outcomes; however, objective data on physical activity levels including SB among different occupations is limited. We compared accelerometer-measured times spent in SB, light-intensity physical activity (LPA), and MVPA, and the patterns associated with prolonged bouts of SB between white- and blue-collar workers. The study population consisted of 102 full-time plant workers (54 white-collar and 48 blue-collar) who wore a triaxial accelerometer during waking hours for 5 working days. Accelerometer-measured activity levels were categorized as SB (≤1.5 metabolic equivalents (METs)), LPA (1.6-2.9 METs), and MVPA (≥3.0 METs). A sedentary bout was defined as consecutive minutes during which the accelerometer registered less than ≤1.5 METs. Accelerometer variables were compared between white- and blue-collar workers through analysis of covariance. During working hours, white-collar workers spent significantly more time in SB and less time in LPA than blue-collar workers (SB: 6.4 h vs. 4.8 h, 73% vs. 55% of total work time; LPA: 1.9 h vs. 3.5 h, 22% vs. 40% of total work time, p<.001), whereas the MVPA time was similar between the groups. White-collar workers spent significantly more SB time in prolonged sedentary bouts (≥30 min) compared to blue-collar workers. During leisure time, the SB, LPA, and MVPA times were similar between the groups. White-collar workers have significantly longer SB times than blue-collar workers during work hours, and do not compensate for their excess SB during work by reducing SB during leisure time.

Quantifying Human Movement Using the Movn Smartphone App: Validation and Field Study

PubMed Central

2017-01-01

Background The use of embedded smartphone sensors offers opportunities to measure physical activity (PA) and human movement. Big data—which includes billions of digital traces—offers scientists a new lens to examine PA in fine-grained detail and allows us to track people’s geocoded movement patterns to determine their interaction with the environment. Objective The objective of this study was to examine the validity of the Movn smartphone app (Moving Analytics) for collecting PA and human movement data. Methods The criterion and convergent validity of the Movn smartphone app for estimating energy expenditure (EE) were assessed in both laboratory and free-living settings, compared with indirect calorimetry (criterion reference) and a stand-alone accelerometer that is commonly used in PA research (GT1m, ActiGraph Corp, convergent reference). A supporting cross-validation study assessed the consistency of activity data when collected across different smartphone devices. Global positioning system (GPS) and accelerometer data were integrated with geographical information software to demonstrate the feasibility of geospatial analysis of human movement. Results A total of 21 participants contributed to linear regression analysis to estimate EE from Movn activity counts (standard error of estimation [SEE]=1.94 kcal/min). The equation was cross-validated in an independent sample (N=42, SEE=1.10 kcal/min). During laboratory-based treadmill exercise, EE from Movn was comparable to calorimetry (bias=0.36 [−0.07 to 0.78] kcal/min, t82=1.66, P=.10) but overestimated as compared with the ActiGraph accelerometer (bias=0.93 [0.58-1.29] kcal/min, t89=5.27, P<.001). The absolute magnitude of criterion biases increased as a function of locomotive speed (F1,4=7.54, P<.001) but was relatively consistent for the convergent comparison (F1,4=1.26, P<.29). Furthermore, 95% limits of agreement were consistent for criterion and convergent biases, and EE from Movn was strongly correlated with both reference measures (criterion r=.91, convergent r=.92, both P<.001). Movn overestimated EE during free-living activities (bias=1.00 [0.98-1.02] kcal/min, t6123=101.49, P<.001), and biases were larger during high-intensity activities (F3,6120=1550.51, P<.001). In addition, 95% limits of agreement for convergent biases were heterogeneous across free-living activity intensity levels, but Movn and ActiGraph measures were strongly correlated (r=.87, P<.001). Integration of GPS and accelerometer data within a geographic information system (GIS) enabled creation of individual temporospatial maps. Conclusions The Movn smartphone app can provide valid passive measurement of EE and can enrich these data with contextualizing temporospatial information. Although enhanced understanding of geographic and temporal variation in human movement patterns could inform intervention development, it also presents challenges for data processing and analytics. PMID:28818819

Occupational Physical Activity Habits of UK Office Workers: Cross-Sectional Data from the Active Buildings Study.

PubMed

Smith, Lee; Sawyer, Alexia; Gardner, Benjamin; Seppala, Katri; Ucci, Marcella; Marmot, Alexi; Lally, Pippa; Fisher, Abi

2018-06-09

Habitual behaviours are learned responses that are triggered automatically by associated environmental cues. The unvarying nature of most workplace settings makes workplace physical activity a prime candidate for a habitual behaviour, yet the role of habit strength in occupational physical activity has not been investigated. Aims of the present study were to: (i) document occupational physical activity habit strength; and (ii) investigate associations between occupational activity habit strength and occupational physical activity levels. A sample of UK office-based workers ( n = 116; 53% female, median age 40 years, SD 10.52) was fitted with activPAL accelerometers worn for 24 h on five consecutive days, providing an objective measure of occupational step counts, stepping time, sitting time, standing time and sit-to-stand transitions. A self-report index measured the automaticity of two occupational physical activities (“being active” (e.g., walking to printers and coffee machines) and “stair climbing”). Adjusted linear regression models investigated the association between occupational activity habit strength and objectively-measured occupational step counts, stepping time, sitting time, standing time and sit-to-stand transitions. Eighty-one per cent of the sample reported habits for “being active”, and 62% reported habits for “stair climbing”. In adjusted models, reported habit strength for “being active” were positively associated with average occupational sit-to-stand transitions per hour (B = 0.340, 95% CI: 0.053 to 0.627, p = 0.021). “Stair climbing” habit strength was unexpectedly negatively associated with average hourly stepping time (B = −0.01, 95% CI: −0.01 to −0.00, p = 0.006) and average hourly occupational step count (B = −38.34, 95% CI: −72.81 to −3.88, p = 0.030), which may reflect that people with stronger stair-climbing habits compensate by walking fewer steps overall. Results suggest that stair-climbing and office-based occupational activity can be habitual. Interventions might fruitfully promote habitual workplace activity, although, in light of potential compensation effects, such interventions should perhaps focus on promoting moderate-intensity activity.

How many days of accelerometer monitoring predict weekly physical activity behaviour in obese youth?

PubMed

Vanhelst, Jérémy; Fardy, Paul S; Duhamel, Alain; Béghin, Laurent

2014-09-01

The aim of this study was to determine the type and the number of accelerometer monitoring days needed to predict weekly sedentary behaviour and physical activity in obese youth. Fifty-three obese youth wore a triaxial accelerometer for 7 days to measure physical activity in free-living conditions. Analyses of variance for repeated measures, Intraclass coefficient (ICC) and regression linear analyses were used. Obese youth spent significantly less time in physical activity on weekends or free days compared with school days. ICC analyses indicated a minimum of 2 days is needed to estimate physical activity behaviour. ICC were 0·80 between weekly physical activity and weekdays and 0·92 between physical activity and weekend days. The model has to include a weekday and a weekend day. Using any combination of one weekday and one weekend day, the percentage of variance explained is >90%. Results indicate that 2 days of monitoring are needed to estimate the weekly physical activity behaviour in obese youth with an accelerometer. Our results also showed the importance of taking into consideration school day versus free day and weekday versus weekend day in assessing physical activity in obese youth. © 2013 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Validation of mercury tip-switch and accelerometer activity sensors for identifying resting and active behavior in bears

USGS Publications Warehouse

Jasmine Ware,; Rode, Karyn D.; Pagano, Anthony M.; Bromaghin, Jeffrey F.; Robbins, Charles T.; Joy Erlenbach,; Shannon Jensen,; Amy Cutting,; Nicole Nicassio-Hiskey,; Amy Hash,; Owen, Megan A.; Heiko Jansen,

2015-01-01

Activity sensors are often included in wildlife transmitters and can provide information on the behavior and activity patterns of animals remotely. However, interpreting activity-sensor data relative to animal behavior can be difficult if animals cannot be continuously observed. In this study, we examined the performance of a mercury tip-switch and a tri-axial accelerometer housed in collars to determine whether sensor data can be accurately classified as resting and active behaviors and whether data are comparable for the 2 sensor types. Five captive bears (3 polar [Ursus maritimus] and 2 brown [U. arctos horribilis]) were fitted with a collar specially designed to internally house the sensors. The bears’ behaviors were recorded, classified, and then compared with sensor readings. A separate tri-axial accelerometer that sampled continuously at a higher frequency and provided raw acceleration values from 3 axes was also mounted on the collar to compare with the lower resolution sensors. Both accelerometers more accurately identified resting and active behaviors at time intervals ranging from 1 minute to 1 hour (≥91.1% accuracy) compared with the mercury tip-switch (range = 75.5–86.3%). However, mercury tip-switch accuracy improved when sampled at longer intervals (e.g., 30–60 min). Data from the lower resolution accelerometer, but not the mercury tip-switch, accurately predicted the percentage of time spent resting during an hour. Although the number of bears available for this study was small, our results suggest that these activity sensors can remotely identify resting versus active behaviors across most time intervals. We recommend that investigators consider both study objectives and the variation in accuracy of classifying resting and active behaviors reported here when determining sampling interval.

Integrated Solution for Physical Activity Monitoring Based on Mobile Phone and PC.

PubMed

Lee, Mi Hee; Kim, Jungchae; Jee, Sun Ha; Yoo, Sun Kook

2011-03-01

This study is part of the ongoing development of treatment methods for metabolic syndrome (MS) project, which involves monitoring daily physical activity. In this study, we have focused on detecting walking activity from subjects which includes many other physical activities such as standing, sitting, lying, walking, running, and falling. Specially, we implemented an integrated solution for various physical activities monitoring using a mobile phone and PC. We put the iPod touch has built in a tri-axial accelerometer on the waist of the subjects, and measured change in acceleration signal according to change in ambulatory movement and physical activities. First, we developed of programs that are aware of step counts, velocity of walking, energy consumptions, and metabolic equivalents based on iPod. Second, we have developed the activity recognition program based on PC. iPod synchronization with PC to transmit measured data using iPhoneBrowser program. Using the implemented system, we analyzed change in acceleration signal according to the change of six activity patterns. We compared results of the step counting algorithm with different positions. The mean accuracy across these tests was 99.6 ± 0.61%, 99.1 ± 0.87% (right waist location, right pants pocket). Moreover, six activities recognition was performed using Fuzzy c means classification algorithm recognized over 98% accuracy. In addition we developed of programs that synchronization of data between PC and iPod for long-term physical activity monitoring. This study will provide evidence on using mobile phone and PC for monitoring various activities in everyday life. The next step in our system will be addition of a standard value of various physical activities in everyday life such as household duties and a health guideline how to select and plan exercise considering one's physical characteristics and condition.

Moving through Life-Space Areas and Objectively Measured Physical Activity of Older People.

PubMed

Portegijs, Erja; Tsai, Li-Tang; Rantanen, Taina; Rantakokko, Merja

2015-01-01

Physical activity-an important determinant of health and function in old age-may vary according to the life-space area reached. Our aim was to study how moving through greater life-space areas is associated with greater physical activity of community-dwelling older people. The association between objectively measured physical activity and life-space area reached on different days by the same individual was studied using one-week longitudinal data, to provide insight in causal relationships. One-week surveillance of objectively assessed physical activity of community-dwelling 70-90-year-old people in central Finland from the "Life-space mobility in old age" cohort substudy (N = 174). In spring 2012, participants wore an accelerometer for 7 days and completed a daily diary including the largest life-space area reached (inside home, outside home, neighborhood, town, and beyond town). The daily step count, and the time in moderate (incl. walking) and low activity and sedentary behavior were assessed. Differences in physical activity between days on which different life-space areas were reached were tested using Generalized Estimation Equation models (within-group comparison). Participants' mean age was 80.4±4.2 years and 63.5% were female. Participants had higher average step counts (p < .001) and greater moderate and low activity time (p < .001) on days when greater life-space areas were reached, from the home to the town area. Only low activity time continued to increase when moving beyond the town. Community-dwelling older people were more physically active on days when they moved through greater life-space areas. While it is unknown whether physical activity was a motivator to leave the home, intervention studies are needed to determine whether facilitation of daily outdoor mobility, regardless of the purpose, may be beneficial in terms of promoting physical activity.

Relationship between tactics and energy expenditure according to level of experience in badminton.

PubMed

Dieu, Olivier; Blondeau, Thomas; Vanhelst, Jérémy; Fardy, Paul S; Bui-Xuân, Gilles; Mikulovic, Jacques

2014-10-01

Research on racket sports has traditionally focused on expert players and has treated energy expenditure and tactics as independent factors. These prior studies could not assess how energy expenditure and tactics changed as a function of experience and skill. Here, the specific relationship between playing tactics and energy expenditure in badminton were assessed. Participants were classified into five stages of badminton experience on the basis of conative criteria: structural (physical abilities), technical (technical skills), and functional (tactics). The physical activity of 99 players (47 beginners, 15 intermediates, 30 advanced, and 7 experts) was measured using a three-axis accelerometer during a badminton set (21 points, no extra scoring). The results showed that physical activity (counts/sec.) ranged between about 115 (Stage 1) and 155 (Stage 5), and differed significantly across the conative stages. For Stages 2 and 4, defined by an increase in use of tactics, physical activity increased substantially. For Stage 3, defined by a decrease in use of tactics, physical activity decreased significantly. Thus, tactically-oriented play appears to be closely related to physical activity.

Causes and consequences of timing errors associated with global positioning system collar accelerometer activity monitors

Treesearch

Adam J. Gaylord; Dana M. Sanchez

2014-01-01

Direct behavioral observations of multiple free-ranging animals over long periods of time and large geographic areas is prohibitively difficult. However, recent improvements in technology, such as Global Positioning System (GPS) collars equipped with motion-sensitive activity monitors, create the potential to remotely monitor animal behavior. Accelerometer-equipped...

Comparison of Activity Type Classification Accuracy from Accelerometers Worn on the Hip, Wrists, and Thigh in Young, Apparently Healthy Adults

ERIC Educational Resources Information Center

Montoye, Alexander H. K.; Pivarnik, James M.; Mudd, Lanay M.; Biswas, Subir; Pfeiffer, Karin A.

2016-01-01

The purpose of this article is to compare accuracy of activity type prediction models for accelerometers worn on the hip, wrists, and thigh. Forty-four adults performed sedentary, ambulatory, lifestyle, and exercise activities (14 total, 10 categories) for 3-10 minutes each in a 90-minute semi-structured laboratory protocol. Artificial neural…

Self Diagnostic Accelerometer Testing on the C-17 Aircraft

NASA Technical Reports Server (NTRS)

Tokars, Roger P.; Lekki, John D.

2013-01-01

The self diagnostic accelerometer (SDA) developed by the NASA Glenn Research Center was tested for the first time in an aircraft engine environment as part of the Vehicle Integrated Propulsion Research (VIPR) program. The VIPR program includes testing multiple critical flight sensor technologies. One such sensor, the accelerometer, measures vibrations to detect faults in the engine. In order to rely upon the accelerometer, the health of the accelerometer must be ensured. The SDA is a sensor system designed to actively determine the accelerometer structural health and attachment condition, in addition to vibration measurements. The SDA uses a signal conditioning unit that sends an electrical chirp to the accelerometer and recognizes changes in the response due to changes in the accelerometer health and attachment condition. To demonstrate the SDAs flight worthiness and robustness, multiple SDAs were mounted and tested on a C-17 aircraft engine. The engine test conditions varied from engine off, to idle, to maximum power. The SDA attachment conditions were varied from fully tight to loose. The newly developed SDA health algorithm described herein uses cross correlation pattern recognition to discriminate a healthy from a faulty SDA. The VIPR test results demonstrate for the first.

The Physical Activity Scale for Individuals with Physical Disabilities: test-retest reliability and comparison with an accelerometer.

PubMed

van der Ploeg, Hidde P; Streppel, Kitty R M; van der Beek, Allard J; van der Woude, Luc H V; Vollenbroek-Hutten, Miriam; van Mechelen, Willem

2007-01-01

The objective was to determine the test-retest reliability and criterion validity of the Physical Activity Scale for Individuals with Physical Disabilities (PASIPD). Forty-five non-wheelchair dependent subjects were recruited from three Dutch rehabilitation centers. Subjects' diagnoses were: stroke, spinal cord injury, whiplash, and neurological-, orthopedic- or back disorders. The PASIPD is a 7-d recall physical activity questionnaire that was completed twice, 1 wk apart. During this week, physical activity was also measured with an Actigraph accelerometer. The test-retest reliability Spearman correlation of the PASIPD was 0.77. The criterion validity Spearman correlation was 0.30 when compared to the accelerometer. The PASIPD had test-retest reliability and criterion validity that is comparable to well established self-report physical activity questionnaires from the general population.

Identifying Active Travel Behaviors in Challenging Environments Using GPS, Accelerometers, and Machine Learning Algorithms

PubMed Central

Ellis, Katherine; Godbole, Suneeta; Marshall, Simon; Lanckriet, Gert; Staudenmayer, John; Kerr, Jacqueline

2014-01-01

Background: Active travel is an important area in physical activity research, but objective measurement of active travel is still difficult. Automated methods to measure travel behaviors will improve research in this area. In this paper, we present a supervised machine learning method for transportation mode prediction from global positioning system (GPS) and accelerometer data. Methods: We collected a dataset of about 150 h of GPS and accelerometer data from two research assistants following a protocol of prescribed trips consisting of five activities: bicycling, riding in a vehicle, walking, sitting, and standing. We extracted 49 features from 1-min windows of this data. We compared the performance of several machine learning algorithms and chose a random forest algorithm to classify the transportation mode. We used a moving average output filter to smooth the output predictions over time. Results: The random forest algorithm achieved 89.8% cross-validated accuracy on this dataset. Adding the moving average filter to smooth output predictions increased the cross-validated accuracy to 91.9%. Conclusion: Machine learning methods are a viable approach for automating measurement of active travel, particularly for measuring travel activities that traditional accelerometer data processing methods misclassify, such as bicycling and vehicle travel. PMID:24795875

Comparative evaluation of features and techniques for identifying activity type and estimating energy cost from accelerometer data

PubMed Central

Kate, Rohit J.; Swartz, Ann M.; Welch, Whitney A.; Strath, Scott J.

2016-01-01

Wearable accelerometers can be used to objectively assess physical activity. However, the accuracy of this assessment depends on the underlying method used to process the time series data obtained from accelerometers. Several methods have been proposed that use this data to identify the type of physical activity and estimate its energy cost. Most of the newer methods employ some machine learning technique along with suitable features to represent the time series data. This paper experimentally compares several of these techniques and features on a large dataset of 146 subjects doing eight different physical activities wearing an accelerometer on the hip. Besides features based on statistics, distance based features and simple discrete features straight from the time series were also evaluated. On the physical activity type identification task, the results show that using more features significantly improve results. Choice of machine learning technique was also found to be important. However, on the energy cost estimation task, choice of features and machine learning technique were found to be less influential. On that task, separate energy cost estimation models trained specifically for each type of physical activity were found to be more accurate than a single model trained for all types of physical activities. PMID:26862679

Outdoor time, physical activity and sedentary time among young children: The 2012-2013 Canadian Health Measures Survey.

PubMed

Larouche, Richard; Garriguet, Didier; Tremblay, Mark S

2017-03-01

Previous studies have shown that children who spend more time outdoors are more active and spend less time sedentary, but these studies were limited by the use of small convenience samples. We examined the relationship between outdoor time and measures of physical activity (PA), screen time and sedentary time in a nationally-representative sample of young children. Parental reports of outdoor time were obtained for 594 children aged 3-6 years (47.8% girls) who participated in the 2012-2013 Canadian Health Measures Survey. Participants were asked to wear an Actical accelerometer for seven consecutive days. Outdoor time and screen time were assessed by parent reports. The relationships between outdoor time and measures of PA, screen time and sedentary time were examined with linear regression models. Adherence to PA guidelines was estimated based on a betabinomial distribution, and adherence with the screen time guidelines was assessed through logistic regression models. All analyses were stratified by age group (3-4 and 5-6 year olds) and adjusted for sex, parental education and household income. Among 5-6 year olds, each additional hour spent outdoors was associated with an additional 10 minutes of moderate-to-vigorous PA (95% CI: 6-14), 27,455 more accelerometer counts/day (95% CI: 11,929-42,980) and an increased likelihood of meeting the PA guidelines (OR = 2.53; 95% CI: 1.68-3.82). No significant relationships were observed among 3-4 year olds. Outdoor time has a large effect on PA among 5-6 year olds at a population level. Future studies should examine the correlates of outdoor time to inform novel PA promotion interventions.

Accuracy of physical activity monitors in pregnant women.

PubMed

Connolly, Christopher P; Coe, Dawn P; Kendrick, Jo M; Bassett, David R; Thompson, Dixie L

2011-06-01

To determine the step count accuracy of three pedometers and one accelerometer in pregnant women during treadmill walking. Participants were 30 women in the second or third trimester (20-34 wk) who were screened for pregnancy-related risk factors. Each participant was fitted with a belt containing three physical activity monitors: Yamax Digiwalker SW-200 (DW), New Lifestyles NL 2000 (NL), and GT3X ActiGraph accelerometer (ACT). The Omron HJ-720ITC (HJ) was placed in the pants' front pocket. Participants walked at 54, 67, 80, and 94 m · min for 2 min each. Actual steps were determined by an investigator using a hand-tally counter. The mean percent of steps recorded was calculated for each device at each speed and compared. Pearson correlations were used to determine the effect of body mass index and tilt angle on pedometer accuracy. There was a significant interaction between speed and device (F9,20 = 7.574, P < 0.001). Across all speeds, the NL and HJ had the lowest error. The ACT and DW underestimated the actual steps taken, particularly at the slower walking speeds. At 54 m · min, the ACT averaged 77.5% of steps and the DW averaged 56.9% of steps. Significant differences in the mean percent of steps recorded were found between devices at all speeds. Body mass index was only significantly correlated with percent of steps recorded by the NL, and there were no significant correlations between steps recorded and tilt angle. In pregnant women, the ACT and DW had more error than the NL and HJ. On the basis of these results, the NL and HJ should be considered for use in further research studies and physical activity programs that focus on walking during pregnancy.

Associations of Accelerometer-Measured and Self-Reported Sedentary Time With Leukocyte Telomere Length in Older Women

PubMed Central

Shadyab, Aladdin H.; Macera, Caroline A.; Shaffer, Richard A.; Jain, Sonia; Gallo, Linda C.; LaMonte, Michael J.; Reiner, Alexander P.; Kooperberg, Charles; Carty, Cara L.; Di, Chongzhi; Manini, Todd M.; Hou, Lifang; LaCroix, Andrea Z.

2017-01-01

Abstract Few studies have assessed the association of sedentary time with leukocyte telomere length (LTL). In a cross-sectional study conducted in 2012–2013, we examined associations of accelerometer-measured and self-reported sedentary time with LTL in a sample of 1,481 older white and African-American women from the Women's Health Initiative and determined whether associations varied by level of moderate- to vigorous-intensity physical activity (MVPA). The association between sedentary time and LTL was evaluated using multiple linear regression models. Women were aged 79.2 (standard deviation, 6.7) years, on average. Self-reported sedentary time was not associated with LTL. In a model adjusting for demographic characteristics, lifestyle behaviors, and health-related factors, among women at or below the median level of accelerometer-measured MVPA, those in the highest quartile of accelerometer-measured sedentary time had significantly shorter LTL than those in the lowest quartile, with an average difference of 170 base pairs (95% confidence interval: 4, 340). Accelerometer-measured sedentary time was not associated with LTL in women above the median level of MVPA. Findings suggest that, on the basis of accelerometer measurements, higher sedentary time may be associated with shorter LTL among less physically active women. PMID:28100466

Objectively Measured Sedentary Time and Cardiometabolic Biomarkers in US Hispanic/Latino Adults: The Hispanic Community Health Study/Study of Latinos (HCHS/SOL).

PubMed

Qi, Qibin; Strizich, Garrett; Merchant, Gina; Sotres-Alvarez, Daniela; Buelna, Christina; Castañeda, Sheila F; Gallo, Linda C; Cai, Jianwen; Gellman, Marc D; Isasi, Carmen R; Moncrieft, Ashley E; Sanchez-Johnsen, Lisa; Schneiderman, Neil; Kaplan, Robert C

2015-10-20

Sedentary behavior is recognized as a distinct construct from lack of moderate-vigorous physical activity and is associated with deleterious health outcomes. Previous studies have primarily relied on self-reported data, whereas data on the relationship between objectively measured sedentary time and cardiometabolic biomarkers are sparse, especially among US Hispanics/Latinos. We examined associations of objectively measured sedentary time (via Actical accelerometers for 7 days) and multiple cardiometabolic biomarkers among 12 083 participants, aged 18 to 74 years, from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL). Hispanics/Latinos of diverse backgrounds (Central American, Cuban, Dominican, Mexican, Puerto Rican, and South American) were recruited from 4 US cities between 2008 and 2011. Sedentary time (<100 counts/min) was standardized to 16 hours/d of wear time. The mean sedentary time was 11.9 hours/d (74% of accelerometer wear time). After adjustment for moderate-vigorous physical activity and confounding variables, prolonged sedentary time was associated with decreased high-density lipoprotein cholesterol (P=0.04), and increased triglycerides, 2-hour glucose, fasting insulin, and homeostatic model assessment of insulin resistance (all P<0.0001). These associations were generally consistent across age, sex, Hispanic/Latino backgrounds, and physical activity levels. Even among individuals meeting physical activity guidelines, sedentary time was detrimentally associated with several cardiometabolic biomarkers (diastolic blood pressure, high-density lipoprotein cholesterol, fasting and 2-hour glucose, fasting insulin and homeostatic model assessment of insulin resistance; all P<0.05). Our large population-based, objectively derived data showed deleterious associations between sedentary time and cardiometabolic biomarkers, independent of physical activity, in US Hispanics/Latinos. Our findings emphasize the importance of reducing sedentary behavior for the prevention of cardiometabolic diseases, even in those who meet physical activity recommendations. © 2015 American Heart Association, Inc.

Accelerometer-determined physical activity level among government employees in Penang, Malaysia.

PubMed

Hazizi, A S; Aina, Mardiah B; Mohd, Nasir M T; Zaitun, Y; Hamid, Jan J M; Tabata, I

2012-04-01

A cross-sectional study was carried out to investigate accelerometer-determined physical activity level of 233 Malay government employees (104 men, 129 women) working in the Federal Government Building Penang, Malaysia. Body weight, height, waist and hip circumference, body fat percentage and blood pressure were measured for each respondent. All the respondents were asked to wear an accelerometer for 3 days. Body mass index (BMI) and waist-hip ratio (WHR) were calculated using a standard formulas. Fasting blood sample was obtained to determine the lipid profile and glucose levels of the respondents. Based on the accelerometer-determined physical activity level, almost 65% of the respondents were categorised as sedentary. Approximately 50.2% of the respondents were overweight or obese. There were negative but significant relationships between body mass index (BMI) (r = -0.353, p < 0.05), body fat percentage (r = -0.394, p < 0.05), waist circumference (WC) (r = -0.198, p < 0.05) and physical activity level. Sedentary individuals had a higher risk than moderate to active individuals of having a BMI more than or equal to 25 kg/m2 (OR = 2.80, 95% CI 1.55-5.05), an-risk classified WC (OR = 1.79, 95% CI 1.01-3.20), and a body fat percentage classified as unhealthy (OR = 3.01, 95% CI 1.41-6.44). The results of this study suggest that accelerometer-determined physical activity level is a significant factor associated with obesity in this study. The high prevalence of physical inactivity and obesity found among respondents of this study indicate a need for implementing intervention programmes among this population.

Accelerometer measured daily physical activity and sedentary pursuits--comparison between two models of the Actigraph and the importance of data reduction.

PubMed

Tanha, Tina; Tornberg, Åsa; Dencker, Magnus; Wollmer, Per

2013-10-31

Very few validation studies have been performed between different generations of the commonly used Actigraph accelerometers. We compared daily physical activity data generated from the old generation Actigraph model 7164 with the new generation Actigraph GT1M accelerometer in 15 young females for eight consecutive days. We also investigated if different wear time thresholds had any impact on the findings. Minutes per day of moderate and vigorous physical activity (MVPA), vigorous physical activity (VPA) and very vigorous physical activity (VVPA) were calculated. Moreover, minutes of sedentary pursuits per day were calculated. There were significant (P < 0.05) differences between the Actigraph 7164 and the GT1M concerning MVPA (61 ± 21vs. 56 ± 23 min/day), VPA (12 ± 8 vs. 9 ± 3 min/day) and VVPA (3.2 ± 3.0 vs. 0.3 ± 1.1 min/day). The different wear time thresholds had little impact on minutes per day in different intensities. Median minutes of sedentary pursuits per day ranged from 159 to 438 minutes depending on which wear time threshold was used (i.e. 10, 30 or 60 minutes), whereas very small differences were observed between the two different models. Data from the old generation Actigraph 7164 and the new generation Actigraph GT1M accelerometers differ, where the Actigraph GT1M generates lower minutes spent in free living physical activity. Median minutes of sedentary pursuits per day are highly dependent on which wear time threshold that is used, and not by accelerometer model.

Distance from public transportation and physical activity in Japanese older adults: The moderating role of driving status.

PubMed

Harada, Kazuhiro; Lee, Sangyoon; Lee, Sungchul; Bae, Seongryu; Anan, Yuya; Harada, Kenji; Shimada, Hiroyuki

2018-04-01

Although previous studies have shown that good access to public transportation is positively related with physical activity, the moderators of this relationship have not been explored sufficiently in older adults. It is possible that driving status could moderate this relationship. The present study examined whether the objectively measured distance between public transportation and the home was associated with physical activity levels, and whether this association was moderated by driving status among Japanese older adults. In this cross-sectional study, participants (n = 2,878) completed questionnaires and wore accelerometers for at least 7 days, to measure their average daily step counts and minutes spent engaging in moderate-to-vigorous physical activity. Road network distances between the home and the nearest bus stop or train station were measured using geographic information systems. Driving status was assessed using questionnaires. Multiple regression analyses stratified by driving status revealed that, among nondrivers, living further away from public transportation was associated with higher step counts (β = 0.08, p < .001) and moderate-to-vigorous physical activity (β = 0.06, p = .029). Among drivers, living closer to public transportation was significantly associated with higher moderate-to-vigorous physical activity levels (β = -0.05, p = .042). Despite the small effect sizes, the direction of the association between distance from public transportation and physical activity was different for current drivers and nondrivers. These findings imply that good access to public transportation does not positively relate with greater engagement in physical activity among nondriving older adults. Shorter distances to public transportation might reduce opportunities for engaging in physical activity for them. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Physical activity, sedentary behavior, and academic performance in Finnish children.

PubMed

Syväoja, Heidi J; Kantomaa, Marko T; Ahonen, Timo; Hakonen, Harto; Kankaanpää, Anna; Tammelin, Tuija H

2013-11-01

This study aimed to determine the relationships between objectively measured and self-reported physical activity, sedentary behavior, and academic performance in Finnish children. Two hundred and seventy-seven children from five schools in the Jyväskylä school district in Finland (58% of the 475 eligible students, mean age = 12.2 yr, 56% girls) participated in the study in the spring of 2011. Self-reported physical activity and screen time were evaluated with questions used in the WHO Health Behavior in School-Aged Children study. Children's physical activity and sedentary time were measured objectively by using an ActiGraph GT1M/GT3X accelerometer for seven consecutive days. A cutoff value of 2296 counts per minute was used for moderate-to-vigorous physical activity (MVPA) and 100 counts per minute for sedentary time. Grade point averages were provided by the education services of the city of Jyväskylä. ANOVA and linear regression analysis were used to analyze the relationships among physical activity, sedentary behavior, and academic performance. Objectively measured MVPA (P = 0.955) and sedentary time (P = 0.285) were not associated with grade point average. However, self-reported MVPA had an inverse U-shaped curvilinear association with grade point average (P = 0.001), and screen time had a linear negative association with grade point average (P = 0.002), after adjusting for sex, children's learning difficulties, highest level of parental education, and amount of sleep. In this study, self-reported physical activity was directly, and screen time inversely, associated with academic achievement. Objectively measured physical activity and sedentary time were not associated with academic achievement. Objective and subjective measures may reflect different constructs and contexts of physical activity and sedentary behavior in association with academic outcomes.

Estimation of physical activity levels using cell phone questionnaires: a comparison with accelerometry for evaluation of between-subject and within-subject variations.

PubMed

Bexelius, Christin; Sandin, Sven; Trolle Lagerros, Ylva; Litton, Jan-Eric; Löf, Marie

2011-09-25

Physical activity promotes health and longevity. Further elaboration of the role of physical activity for human health in epidemiological studies on large samples requires accurate methods that are easy to use, cheap, and possible to repeat. The use of telecommunication technologies such as cell phones is highly interesting in this respect. In an earlier report, we showed that physical activity level (PAL) assessed using a cell phone procedure agreed well with corresponding estimates obtained using the doubly labeled water method. However, our earlier study indicated high within-subject variation in relation to between-subject variations in PAL using cell phones, but we could not assess if this was a true variation of PAL or an artifact of the cell phone technique. Our objective was to compare within- and between-subject variations in PAL by means of cell phones with corresponding estimates using an accelerometer. In addition, we compared the agreement of daily PAL values obtained using the cell phone questionnaire with corresponding data obtained using an accelerometer. PAL was measured both with the cell phone questionnaire and with a triaxial accelerometer daily during a 2-week study period in 21 healthy Swedish women (20 to 45 years of age and BMI from 17.7 kg/m² to 33.6 kg/m²). The results were evaluated by fitting linear mixed effect models and descriptive statistics and graphs. With the accelerometer, 57% (95% confidence interval [CI] 40%-66%) of the variation was within subjects, while with the cell phone, within-subject variation was 76% (95% CI 59%-83%). The day-to-day variations in PAL observed using the cell phone questions agreed well with the corresponding accelerometer results. Both the cell phone questionnaire and the accelerometer showed high within-subject variations. Furthermore, day-to-day variations in PAL within subjects assessed using the cell phone agreed well with corresponding accelerometer values. Consequently, our cell phone questionnaire is a promising tool for assessing levels of physical activity. The tool may be useful for large-scale prospective studies.

Unobtrusive measurement of indoor energy expenditure using an infrared sensor-based activity monitoring system.

PubMed

Hwang, Bosun; Han, Jonghee; Choi, Jong Min; Park, Kwang Suk

2008-11-01

The purpose of this study was to develop an unobtrusive energy expenditure (EE) measurement system using an infrared (IR) sensor-based activity monitoring system to measure indoor activities and to estimate individual quantitative EE. IR-sensor activation counts were measured with a Bluetooth-based monitoring system and the standard EE was calculated using an established regression equation. Ten male subjects participated in the experiment and three different EE measurement systems (gas analyzer, accelerometer, IR sensor) were used simultaneously in order to determine the regression equation and evaluate the performance. As a standard measurement, oxygen consumption was simultaneously measured by a portable metabolic system (Metamax 3X, Cortex, Germany). A single room experiment was performed to develop a regression model of the standard EE measurement from the proposed IR sensor-based measurement system. In addition, correlation and regression analyses were done to compare the performance of the IR system with that of the Actigraph system. We determined that our proposed IR-based EE measurement system shows a similar correlation to the Actigraph system with the standard measurement system.

Daily step count predicts acute exacerbations in a US cohort with COPD.

PubMed

Moy, Marilyn L; Teylan, Merilee; Weston, Nicole A; Gagnon, David R; Garshick, Eric

2013-01-01

COPD is characterized by variability in exercise capacity and physical activity (PA), and acute exacerbations (AEs). Little is known about the relationship between daily step count, a direct measure of PA, and the risk of AEs, including hospitalizations. In an observational cohort study of 169 persons with COPD, we directly assessed PA with the StepWatch Activity Monitor, an ankle-worn accelerometer that measures daily step count. We also assessed exercise capacity with the 6-minute walk test (6MWT) and patient-reported PA with the St. George's Respiratory Questionnaire Activity Score (SGRQ-AS). AEs and COPD-related hospitalizations were assessed and validated prospectively over a median of 16 months. Mean daily step count was 5804±3141 steps. Over 209 person-years of observation, there were 263 AEs (incidence rate 1.3±1.6 per person-year) and 116 COPD-related hospitalizations (incidence rate 0.56±1.09 per person-year). Adjusting for FEV1 % predicted and prednisone use for AE in previous year, for each 1000 fewer steps per day walked at baseline, there was an increased rate of AEs (rate ratio 1.07; 95%CI = 1.003-1.15) and COPD-related hospitalizations (rate ratio 1.24; 95%CI = 1.08-1.42). There was a significant linear trend of decreasing daily step count by quartiles and increasing rate ratios for AEs (P = 0.008) and COPD-related hospitalizations (P = 0.003). Each 30-meter decrease in 6MWT distance was associated with an increased rate ratio of 1.07 (95%CI = 1.01-1.14) for AEs and 1.18 (95%CI = 1.07-1.30) for COPD-related hospitalizations. Worsening of SGRQ-AS by 4 points was associated with an increased rate ratio of 1.05 (95%CI = 1.01-1.09) for AEs and 1.10 (95%CI = 1.02-1.17) for COPD-related hospitalizations. Lower daily step count, lower 6MWT distance, and worse SGRQ-AS predict future AEs and COPD-related hospitalizations, independent of pulmonary function and previous AE history. These results support the importance of assessing PA in patients with COPD, and provide the rationale to promote PA as part of exacerbation-prevention strategies.

New Validated Thresholds for Various Intensities of Physical Activity in Adolescents Using the Actigraph Accelerometer

ERIC Educational Resources Information Center

Vanhelst, Jeremy; Beghin, Laurent; Turck, Dominique; Gottrand, Frederic

2011-01-01

The aim of this study was to determine and validate the new thresholds for various intensities of physical activity in adolescents using the Actigraph accelerometer. Sixty healthy participants aged 10-16 years were recruited. Forty participants participated in the calibration study whereas the others participated in the validation study.…

Using tri-axial accelerometers to identify wild polar bear behaviors

USGS Publications Warehouse

Pagano, Anthony M.; Rode, Karyn D.; Cutting, A.; Owen, M.A.; Jensen, S.; Ware, J.V.; Robbins, C.T.; Durner, George M.; Atwood, Todd C.; Obbard, M.E.; Middel, K.R.; Thiemann, G.W.; Williams, T.M.

2017-01-01

Tri-axial accelerometers have been used to remotely identify the behaviors of a wide range of taxa. Assigning behaviors to accelerometer data often involves the use of captive animals or surrogate species, as their accelerometer signatures are generally assumed to be similar to those of their wild counterparts. However, this has rarely been tested. Validated accelerometer data are needed for polar bears Ursus maritimus to understand how habitat conditions may influence behavior and energy demands. We used accelerometer and water conductivity data to remotely distinguish 10 polar bear behaviors. We calibrated accelerometer and conductivity data collected from collars with behaviors observed from video-recorded captive polar bears and brown bears U. arctos, and with video from camera collars deployed on free-ranging polar bears on sea ice and on land. We used random forest models to predict behaviors and found strong ability to discriminate the most common wild polar bear behaviors using a combination of accelerometer and conductivity sensor data from captive or wild polar bears. In contrast, models using data from captive brown bears failed to reliably distinguish most active behaviors in wild polar bears. Our ability to discriminate behavior was greatest when species- and habitat-specific data from wild individuals were used to train models. Data from captive individuals may be suitable for calibrating accelerometers, but may provide reduced ability to discriminate some behaviors. The accelerometer calibrations developed here provide a method to quantify polar bear behaviors to evaluate the impacts of declines in Arctic sea ice.

An intensive longitudinal examination of daily physical activity and sleep in midlife women.

PubMed

Kishida, Moé; Elavsky, Steriani

2016-03-01

Previous research examining physical activity (PA) and sleep link has largely ignored the day-to-day variability that is present in these 2 health behaviors, and few studies have addressed this relation using objective assessments of PA and sleep. Through an intensive longitudinal design, the present study aimed: (1) to elucidate the reciprocal associations between PA and sleep; and (2) to better understand the role of body mass index (BMI) in these 2 health behaviors. Community-dwelling midlife women (N = 103; M = 53, age range= 40-60 years) wore an accelerometer for the objective assessment of PA and sleep for 21 days. A series of multilevel models were estimated to test concurrent and lagged associations between PA (activity counts, moderate-to-vigorous PA) and sleep (total sleep time [TST], sleep efficiency, sleep fragmentation indices). In concurrent, same-day analyses, a positive association emerged between PA and sleep such that as activity counts increased during the day, TST at night also increased (P < .05). In lagged analyses examining next-day effect of sleep on PA, a negative association was found such that greater TST on a given night was associated with less moderate-to-vigorous PA the subsequent day (P < .05). A moderation effect by BMI was also observed such that women with a high BMI engaging in overall lower levels of PA demonstrated poorer-quality sleep. The data suggest that leading a physically active lifestyle may have protective effects on sleep, particularly for overweight and obese women. Published by Elsevier Inc.

Assessing Daily Physical Activity in Older Adults: Unraveling the Complexity of Monitors, Measures, and Methods

PubMed Central

Cooper, Rachel; Koster, Annemarie; Shiroma, Eric J.; Murabito, Joanne M.; Rejeski, W. Jack; Ferrucci, Luigi; Harris, Tamara B.

2016-01-01

At the 67th Gerontological Society of America Annual Meeting, a preconference workshop was convened to discuss the challenges of accurately assessing physical activity in older populations. The advent of wearable technology (eg, accelerometers) to monitor physical activity has created unprecedented opportunities to observe, quantify, and define physical activity in the real-world setting. These devices enable researchers to better understand the associations of physical activity with aging, and subsequent health outcomes. However, a consensus on proper methodological use of these devices in older populations has not been established. To date, much of the validation research regarding device type, placement, and data interpretation has been performed in younger, healthier populations, and translation of these methods to older populations remains problematic. A better understanding of these devices, their measurement properties, and the data generated is imperative to furthering our understanding of daily physical activity, its effects on the aging process, and vice versa. The purpose of this article is to provide an overview of the highlights of the preconference workshop, including properties of the different types of accelerometers, the methodological challenges of employing accelerometers in older study populations, a brief summary of ongoing aging-related research projects that utilize different types of accelerometers, and recommendations for future research directions. PMID:26957472

Strategies for Dealing with Missing Accelerometer Data.

PubMed

Stephens, Samantha; Beyene, Joseph; Tremblay, Mark S; Faulkner, Guy; Pullnayegum, Eleanor; Feldman, Brian M

2018-05-01

Missing data is a universal research problem that can affect studies examining the relationship between physical activity measured with accelerometers and health outcomes. Statistical techniques are available to deal with missing data; however, available techniques have not been synthesized. A scoping review was conducted to summarize the advantages and disadvantages of identified methods of dealing with missing data from accelerometers. Missing data poses a threat to the validity and interpretation of trials using physical activity data from accelerometry. Imputation using multiple imputation techniques is recommended to deal with missing data and improve the validity and interpretation of studies using accelerometry. Copyright © 2018 Elsevier Inc. All rights reserved.

Machine learning methods for classifying human physical activity from on-body accelerometers.

PubMed

Mannini, Andrea; Sabatini, Angelo Maria

2010-01-01

The use of on-body wearable sensors is widespread in several academic and industrial domains. Of great interest are their applications in ambulatory monitoring and pervasive computing systems; here, some quantitative analysis of human motion and its automatic classification are the main computational tasks to be pursued. In this paper, we discuss how human physical activity can be classified using on-body accelerometers, with a major emphasis devoted to the computational algorithms employed for this purpose. In particular, we motivate our current interest for classifiers based on Hidden Markov Models (HMMs). An example is illustrated and discussed by analysing a dataset of accelerometer time series.

Dog ownership and adolescent physical activity.

PubMed

Sirard, John R; Patnode, Carrie D; Hearst, Mary O; Laska, Melissa N

2011-03-01

Positive associations between dog ownership and adult health outcomes have been observed, but research involving youth is lacking. The purpose of this study was to assess the relationship of family dog ownership to adolescent physical activity. Data were collected on dog ownership in 618 adolescent/parent pairs between 9/2006 and 6/2008 and analyzed in 2010. Adolescent physical activity was assessed by ActiGraph accelerometers. Adolescents' mean age was 14.6±1.8 years and 49% were male. White and higher-SES adolescents were more likely to own a dog. In models adjusted for age, puberty, gender, race, total household members, and SES, adolescent physical activity (mean counts·min(-1)day(-1)) remained significantly associated with dog ownership (β=24.3, SE=12.4, p=0.05), whereas the association with minutes of moderate to vigorous physical activity per day became nonsignificant (β=2.2, SE=1.2, p=0.07). No significant results were observed for other adolescent characteristics. Dog ownership was associated with more physical activity among adolescents. Further research using longitudinal data will help clarify the role that dog ownership may have on adolescent physical activity. Copyright © 2011 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Validity and reliability of International Physical Activity Questionnaire-Short Form in Chinese youth.

PubMed

Wang, Chao; Chen, Peijie; Zhuang, Jie

2013-12-01

The psychometric profiles of the widely used International Physical Activity Questionnaire-Short Form (IPAQ-SF) in Chinese youth have not been reported. The purpose of this study was to examine the validity and reliability of the IPAQ-SF using a sample of Chinese youth. One thousand and twenty-one youth (M(age) = 14.26 +/- 1.63 years, 52.8% boys) from 11 cities in China wore accelerometers for 7 consecutive days and completed the IPAQ-SF on the 8th day to recall their physical activity (PA) during accelerometer-wearing days. A subsample of 92 youth (M(age) = 15.90 +/- 1.35 years, 46.7% boys) completed the IPAQ-SF again a week later to recall their PA during accelerometer-wearing days. Differences in PA estimated by the IPAQ-SF and accelerometer were examined by paired-sample t test. Spearman correlation coefficients were used to examine the correlation between the IPAQ-SF and accelerometer. Test-retest reliability of the IPAQ-SF was determined by the intraclass correlation coefficient (ICC). Compared with accelerometer, the IPAQ-SF overestimated sedentary time, moderate PA (MPA), vigorous PA (VPA), and moderate-to-vigorous PA (MVPA). Correlations between PA (total PA, MPA, VPA, and MVPA) and sedentary time measured by 2 instruments ranged from "none" to "low" (p = .08-.31). Test-retest ICC of the IPAQ-SF ranged from "moderate" to "high" (ICC = .43-.83), except for sitting in boys (ICC = .06), sitting for the whole sample (ICC = .32), and VPA in girls (ICC = .35). The IPAQ-SF was not a valid instrument for measuring PA and sedentary behavior in Chinese youth.

Predicting adult pulmonary ventilation volume and wearing complianceby on-board accelerometry during personal level exposure assessments

NASA Astrophysics Data System (ADS)

Rodes, C. E.; Chillrud, S. N.; Haskell, W. L.; Intille, S. S.; Albinali, F.; Rosenberger, M. E.

2012-09-01

BackgroundMetabolic functions typically increase with human activity, but optimal methods to characterize activity levels for real-time predictions of ventilation volume (l min-1) during exposure assessments have not been available. Could tiny, triaxial accelerometers be incorporated into personal level monitors to define periods of acceptable wearing compliance, and allow the exposures (μg m-3) to be extended to potential doses in μg min-1 kg-1 of body weight? ObjectivesIn a pilot effort, we tested: 1) whether appropriately-processed accelerometer data could be utilized to predict compliance and in linear regressions to predict ventilation volumes in real-time as an on-board component of personal level exposure sensor systems, and 2) whether locating the exposure monitors on the chest in the breathing zone, provided comparable accelerometric data to other locations more typically utilized (waist, thigh, wrist, etc.). MethodsPrototype exposure monitors from RTI International and Columbia University were worn on the chest by a pilot cohort of adults while conducting an array of scripted activities (all <10 METS), spanning common recumbent, sedentary, and ambulatory activity categories. Referee Wocket accelerometers that were placed at various body locations allowed comparison with the chest-located exposure sensor accelerometers. An Oxycon Mobile mask was used to measure oral-nasal ventilation volumes in-situ. For the subset of participants with complete data (n = 22), linear regressions were constructed (processed accelerometric variable versus ventilation rate) for each participant and exposure monitor type, and Pearson correlations computed to compare across scenarios. ResultsTriaxial accelerometer data were demonstrated to be adequately sensitive indicators for predicting exposure monitor wearing compliance. Strong linear correlations (R values from 0.77 to 0.99) were observed for all participants for both exposure sensor accelerometer variables against ventilation volume for recumbent, sedentary, and ambulatory activities with MET values ˜<6. The RTI monitors mean R value of 0.91 was slightly higher than the Columbia monitors mean of 0.86 due to utilizing a 20 Hz data rate instead of a slower 1 Hz rate. A nominal mean regression slope was computed for the RTI system across participants and showed a modest RSD of +/-36.6%. Comparison of the correlation values of the exposure monitors with the Wocket accelerometers at various body locations showed statistically identical regressions for all sensors at alternate hip, ankle, upper arm, thigh, and pocket locations, but not for the Wocket accelerometer located at the dominant side wrist location (R = 0.57; p = 0.016). ConclusionsEven with a modest number of adult volunteers, the consistency and linearity of regression slopes for all subjects were very good with excellent within-person Pearson correlations for the accelerometer versus ventilation volume data. Computing accelerometric standard deviations allowed good sensitivity for compliance assessments even for sedentary activities. These pilot findings supported the hypothesis that a common linear regression is likely to be usable for a wider range of adults to predict ventilation volumes from accelerometry data over a range of low to moderate energy level activities. The predicted volumes would then allow real-time estimates of potential dose, enabling more robust panel studies. The poorer correlation in predicting ventilation rate for an accelerometer located on the wrist suggested that this location should not be considered for predictions of ventilation volume.

Accelerometer-based wireless body area network to estimate intensity of therapy in post-acute rehabilitation

PubMed Central

Choquette, Stéphane; Hamel, Mathieu; Boissy, Patrick

2008-01-01

Background It has been suggested that there is a dose-response relationship between the amount of therapy and functional recovery in post-acute rehabilitation care. To this day, only the total time of therapy has been investigated as a potential determinant of this dose-response relationship because of methodological and measurement challenges. The primary objective of this study was to compare time and motion measures during real life physical therapy with estimates of active time (i.e. the time during which a patient is active physically) obtained with a wireless body area network (WBAN) of 3D accelerometer modules positioned at the hip, wrist and ankle. The secondary objective was to assess the differences in estimates of active time when using a single accelerometer module positioned at the hip. Methods Five patients (77.4 ± 5.2 y) with 4 different admission diagnoses (stroke, lower limb fracture, amputation and immobilization syndrome) were recruited in a post-acute rehabilitation center and observed during their physical therapy sessions throughout their stay. Active time was recorded by a trained observer using a continuous time and motion analysis program running on a Tablet-PC. Two WBAN configurations were used: 1) three accelerometer modules located at the hip, wrist and ankle (M3) and 2) one accelerometer located at the hip (M1). Acceleration signals from the WBANs were synchronized with the observations. Estimates of active time were computed based on the temporal density of the acceleration signals. Results A total of 62 physical therapy sessions were observed. Strong associations were found between WBANs estimates of active time and time and motion measures of active time. For the combined sessions, the intraclass correlation coefficient (ICC) was 0.93 (P ≤ 0.001) for M3 and 0.79 (P ≤ 0.001) for M1. The mean percentage of differences between observation measures and estimates from the WBAN of active time was -8.7% ± 2.0% using data from M3 and -16.4% ± 10.4% using data from M1. Conclusion WBANs estimates of active time compare favorably with results from observation-based time and motion measures. While the investigation on the association between active time and outcomes of rehabilitation needs to be studied in a larger scale study, the use of an accelerometer-based WBAN to measure active time is a promising approach that offers a better overall precision than methods relying on work sampling. Depending on the accuracy needed, the use of a single accelerometer module positioned on the hip may still be an interesting alternative to using multiple modules. PMID:18764954

Parent-child interactions and objectively measured child physical activity: a cross-sectional study

PubMed Central

2010-01-01

Background Parents influence their children's behaviors directly through specific parenting practices and indirectly through their parenting style. Some practices such as logistical and emotional support have been shown to be positively associated with child physical activity (PA) levels, while for others (e.g. monitoring) the relationship is not clear. The objectives of this study were to determine the relationship between parent's PA-related practices, general parenting style, and children's PA level. Methods During the spring of 2007 a diverse group of 99 parent-child dyads (29% White, 49% Black, 22% Hispanic; 89% mothers) living in low-income rural areas of the US participated in a cross-sectional study. Using validated questionnaires, parents self-reported their parenting style (authoritative, authoritarian, permissive, and uninvolved) and activity-related parenting practices. Height and weight were measured for each dyad and parents reported demographic information. Child PA was measured objectively through accelerometers and expressed as absolute counts and minutes engaged in intensity-specific activity. Results Seventy-six children had valid accelerometer data. Children engaged in 113.4 ± 37.0 min. of moderate-vigorous physical activity (MVPA) per day. Children of permissive parents accumulated more minutes of MVPA than those of uninvolved parents (127.5 vs. 97.1, p < 0.05), while parents who provided above average levels of support had children who participated in more minutes of MVPA (114.2 vs. 98.3, p = 0.03). While controlling for known covariates, an uninvolved parenting style was the only parenting behavior associated with child physical activity. Parenting style moderated the association between two parenting practices - reinforcement and monitoring - and child physical activity. Specifically, post-hoc analyses revealed that for the permissive parenting style group, higher levels of parental reinforcement or monitoring were associated with higher levels of child physical activity. Conclusions This work extends the current literature by demonstrating the potential moderating role of parenting style on the relationship between activity-related parenting practices and children's objectively measured physical activity, while controlling for known covariates. Future studies in this area are warranted and, if confirmed, may help to identify the mechanism by which parents influence their child's physical activity behavior. PMID:20929570

Parent-child interactions and objectively measured child physical activity: a cross-sectional study.

PubMed

Hennessy, Erin; Hughes, Sheryl O; Goldberg, Jeanne P; Hyatt, Raymond R; Economos, Christina D

2010-10-07

Parents influence their children's behaviors directly through specific parenting practices and indirectly through their parenting style. Some practices such as logistical and emotional support have been shown to be positively associated with child physical activity (PA) levels, while for others (e.g. monitoring) the relationship is not clear. The objectives of this study were to determine the relationship between parent's PA-related practices, general parenting style, and children's PA level. During the spring of 2007 a diverse group of 99 parent-child dyads (29% White, 49% Black, 22% Hispanic; 89% mothers) living in low-income rural areas of the US participated in a cross-sectional study. Using validated questionnaires, parents self-reported their parenting style (authoritative, authoritarian, permissive, and uninvolved) and activity-related parenting practices. Height and weight were measured for each dyad and parents reported demographic information. Child PA was measured objectively through accelerometers and expressed as absolute counts and minutes engaged in intensity-specific activity. Seventy-six children had valid accelerometer data. Children engaged in 113.4 ± 37.0 min. of moderate-vigorous physical activity (MVPA) per day. Children of permissive parents accumulated more minutes of MVPA than those of uninvolved parents (127.5 vs. 97.1, p < 0.05), while parents who provided above average levels of support had children who participated in more minutes of MVPA (114.2 vs. 98.3, p = 0.03). While controlling for known covariates, an uninvolved parenting style was the only parenting behavior associated with child physical activity. Parenting style moderated the association between two parenting practices - reinforcement and monitoring - and child physical activity. Specifically, post-hoc analyses revealed that for the permissive parenting style group, higher levels of parental reinforcement or monitoring were associated with higher levels of child physical activity. This work extends the current literature by demonstrating the potential moderating role of parenting style on the relationship between activity-related parenting practices and children's objectively measured physical activity, while controlling for known covariates. Future studies in this area are warranted and, if confirmed, may help to identify the mechanism by which parents influence their child's physical activity behavior.

Validation of Accelerometer-Based Energy Expenditure Prediction Models in Structured and Simulated Free-Living Settings

ERIC Educational Resources Information Center

Montoye, Alexander H. K.; Conger, Scott A.; Connolly, Christopher P.; Imboden, Mary T.; Nelson, M. Benjamin; Bock, Josh M.; Kaminsky, Leonard A.

2017-01-01

This study compared accuracy of energy expenditure (EE) prediction models from accelerometer data collected in structured and simulated free-living settings. Twenty-four adults (mean age 45.8 years, 50% female) performed two sessions of 11 to 21 activities, wearing four ActiGraph GT9X Link activity monitors (right hip, ankle, both wrists) and a…

A Comparison of Self-Report Scales and Accelerometer-Determined Moderate to Vigorous Physical Activity Scores of Finnish School Students

ERIC Educational Resources Information Center

Gråstén, Arto; Watt, Anthony

2016-01-01

The current article provides an important insight into measurement differences between two commonly used self-reports and accelerometer-determined moderate to vigorous physical activity (MVPA) scores within matched samples across 1 school year. Participants were 998 fifth- through eighth-grade students who completed self-reports and 76 fifth- and…

Multisensor data fusion for physical activity assessment.

PubMed

Liu, Shaopeng; Gao, Robert X; John, Dinesh; Staudenmayer, John W; Freedson, Patty S

2012-03-01

This paper presents a sensor fusion method for assessing physical activity (PA) of human subjects, based on support vector machines (SVMs). Specifically, acceleration and ventilation measured by a wearable multisensor device on 50 test subjects performing 13 types of activities of varying intensities are analyzed, from which activity type and energy expenditure are derived. The results show that the method correctly recognized the 13 activity types 88.1% of the time, which is 12.3% higher than using a hip accelerometer alone. Also, the method predicted energy expenditure with a root mean square error of 0.42 METs, 22.2% lower than using a hip accelerometer alone. Furthermore, the fusion method was effective in reducing the subject-to-subject variability (standard deviation of recognition accuracies across subjects) in activity recognition, especially when data from the ventilation sensor were added to the fusion model. These results demonstrate that the multisensor fusion technique presented is more effective in identifying activity type and energy expenditure than the traditional accelerometer-alone-based methods.

A triaxial accelerometer-based physical-activity recognition via augmented-signal features and a hierarchical recognizer.

PubMed

Khan, Adil Mehmood; Lee, Young-Koo; Lee, Sungyoung Y; Kim, Tae-Seong

2010-09-01

Physical-activity recognition via wearable sensors can provide valuable information regarding an individual's degree of functional ability and lifestyle. In this paper, we present an accelerometer sensor-based approach for human-activity recognition. Our proposed recognition method uses a hierarchical scheme. At the lower level, the state to which an activity belongs, i.e., static, transition, or dynamic, is recognized by means of statistical signal features and artificial-neural nets (ANNs). The upper level recognition uses the autoregressive (AR) modeling of the acceleration signals, thus, incorporating the derived AR-coefficients along with the signal-magnitude area and tilt angle to form an augmented-feature vector. The resulting feature vector is further processed by the linear-discriminant analysis and ANNs to recognize a particular human activity. Our proposed activity-recognition method recognizes three states and 15 activities with an average accuracy of 97.9% using only a single triaxial accelerometer attached to the subject's chest.

Validation of Questionnaire-Assessed Physical Activity in Comparison With Objective Measures Using Accelerometers and Physical Performance Measures Among Community-Dwelling Adults Aged ≥85 Years in Tokyo, Japan.

PubMed

Oguma, Yuko; Osawa, Yusuke; Takayama, Michiyo; Abe, Yukiko; Tanaka, Shigeho; Lee, I-Min; Arai, Yasumichi

2017-04-01

To date, there is no physical activity (PA) questionnaire with convergent and construct validity for the oldest-old. The aim of the current study was to investigate the validity of questionnaire-assessed PA in comparison with objective measures determined by uniaxial and triaxial accelerometers and physical performance measures in the oldest-old. Participants were 155 elderly (mean age 90 years) who were examined at the university and agreed to wear an accelerometer for 7 days in the 3-year-follow-up survey of the Tokyo Oldest-Old Survey of Total Health. Fifty-nine participants wore a uniaxial and triaxial accelerometer simultaneously. Self-rated walking, exercise, and household PA were measured using a modified Zutphen PA Questionnaire (PAQ). Several physical performance tests were done, and the associations among PAQ, accelerometer-assessed PA, and physical performances were compared by Spearman's correlation coefficients. Significant, low to moderate correlations between PA measures were seen on questionnaire and accelerometer assessments (ρ = 0.19 to 0.34). Questionnaireassessed PA measure were correlated with a range of lower extremity performance (ρ = 0.21 to 0.29). This PAQ demonstrated convergent and construct validity. Our findings suggest that the PAQ can reasonably be used in this oldest-old population to rank their PA level.

Does school physical education really contribute to accelerometer-measured daily physical activity and non sedentary behaviour in high school students?

PubMed

Mayorga-Vega, Daniel; Martínez-Baena, Alejandro; Viciana, Jesús

2018-09-01

Physical education has been highlighted as an important environment for physical activity promotion, however, to our knowledge there are no previous studies examining the contribution of physical education to daily accelerometer-measured physical activity and non sedentary behaviour. The purpose was to compare the accelerometer-measured physical activity and sedentary behaviour between physical education, non-physical education and weekend days in adolescents. Of the 394 students from a Spanish high school that were invited to participate, 158 students (83 boys and 75 girls) aged 13-16 years were analyzed (wear time ≥ 600 min). Participants' physical activity and sedentary behaviour were objectively-measured by GT3X+ accelerometers during physical education (one session), non-physical education and weekend days. Results indicated that overall adolescents had statistically significant greater physical activity levels and lower values of sedentary behaviour on physical education days than on non-physical education and weekend days (e.g., moderate-to-vigorous physical activity = 71, 54 and 57 min; sedentary = 710, 740 and 723 min) (p < 0.05). Physical education contributes significantly to reducing students' daily physical inactivity and sedentary behaviour. Increasing the number of physical education classes seems to be an effective strategy to reduce the high current prevalence of physical inactivity and sedentary behaviour in adolescence.

Physical Activity Measurement by Accelerometry Among Older Malay Adults Living in Semi-Rural Areas-A Feasibility Study.

PubMed

Zainol Abidin, Nurdiana; Brown, Wendy J; Clark, Bronwyn; Muhamed, Ahmad Munir Che; Singh, Rabindarjeet

2016-10-01

We evaluated feasibility of physical activity measurement by accelerometry among older Malay adults living in semi-rural areas in Malaysia. Results showed that 95% of 146 participants (aged [SD] 67.6 [6.4] years) were compliant in wearing the accelerometer for at least five days. Fifteen participants were asked for re-wear the accelerometer because they did not have enough valid days during the first assessment. Participants wore the accelerometer an average of 15.3 hr in a 24-hr day, with 6.5 (1.2) valid wear days. No significant difference in valid wear day and time was found between men and women. Participants who are single provide more valid wear days compared with married participants (p < .05), and participants with higher levels of education provide longer periods of accelerometer wearing hours (p < .01). Eighty-seven percent of participants reported 'no issues' with wearing the meter. This study suggests that accelerometry is a feasible method to assess the physical activity level among older Malay adults living in semi-rural areas.

Comparison of accelerometer data calibration methods used in thermospheric neutral density estimation

NASA Astrophysics Data System (ADS)

Vielberg, Kristin; Forootan, Ehsan; Lück, Christina; Löcher, Anno; Kusche, Jürgen; Börger, Klaus

2018-05-01

Ultra-sensitive space-borne accelerometers on board of low Earth orbit (LEO) satellites are used to measure non-gravitational forces acting on the surface of these satellites. These forces consist of the Earth radiation pressure, the solar radiation pressure and the atmospheric drag, where the first two are caused by the radiation emitted from the Earth and the Sun, respectively, and the latter is related to the thermospheric density. On-board accelerometer measurements contain systematic errors, which need to be mitigated by applying a calibration before their use in gravity recovery or thermospheric neutral density estimations. Therefore, we improve, apply and compare three calibration procedures: (1) a multi-step numerical estimation approach, which is based on the numerical differentiation of the kinematic orbits of LEO satellites; (2) a calibration of accelerometer observations within the dynamic precise orbit determination procedure and (3) a comparison of observed to modeled forces acting on the surface of LEO satellites. Here, accelerometer measurements obtained by the Gravity Recovery And Climate Experiment (GRACE) are used. Time series of bias and scale factor derived from the three calibration procedures are found to be different in timescales of a few days to months. Results are more similar (statistically significant) when considering longer timescales, from which the results of approach (1) and (2) show better agreement to those of approach (3) during medium and high solar activity. Calibrated accelerometer observations are then applied to estimate thermospheric neutral densities. Differences between accelerometer-based density estimations and those from empirical neutral density models, e.g., NRLMSISE-00, are observed to be significant during quiet periods, on average 22 % of the simulated densities (during low solar activity), and up to 28 % during high solar activity. Therefore, daily corrections are estimated for neutral densities derived from NRLMSISE-00. Our results indicate that these corrections improve model-based density simulations in order to provide density estimates at locations outside the vicinity of the GRACE satellites, in particular during the period of high solar/magnetic activity, e.g., during the St. Patrick's Day storm on 17 March 2015.

Parent and child physical activity and sedentary time: do active parents foster active children?

PubMed

Jago, Russell; Fox, Kenneth R; Page, Angie S; Brockman, Rowan; Thompson, Janice L

2010-04-15

Physical activity has many positive effects on children's health while TV viewing has been associated with adverse health outcomes. Many children do not meet physical activity recommendations and exceed TV viewing guidelines. Parents are likely to be an important influence on their children's behaviour. There is an absence of information about the associations between parents' and children's physical activity and TV viewing. Year 6 children and their parent were recruited from 40 primary schools. Results are presented for the 340 parent-child dyads with accelerometer data that met a > or = 3 day inclusion criteria and the 431 parent-child dyads with complete self-reported TV viewing. Over 80% of the dyads with valid TV viewing data included mothers and their child. Mean minutes of moderate to vigorous physical activity (MVPA), minutes of sedentary time per day and counts per minute were assessed by accelerometer. Self-reported hours of TV viewing were coded into 3 groups (< 2 hours per day, 2-4 hours per day and >4 hours per day. Linear and multi-nominal regression models were run by child gender to examine parent-child associations. In linear regression models there was an association for the overall sedentary time of girls and their parents (t = 2.04. p = .020) but there was no association between girls' and parents' physical activity. There were no associations between parents' and boys' sedentary or physical activity time. For girls, the risk of watching more than 4 hours of TV per day, (reference = 2 hours of TV per day), was 3.67 times higher if the girl's parent watched 2-4 hours of TV per day (p = 0.037). For boys, the risk of watching more than 4 hours of TV per day, was 10.47 times higher if the boy's parent watched more than 4 hours of TV per day (p = 0.038). There are associations in the sedentary time of parents and daughters. Higher parental TV viewing was associated with an increased risk of high levels of TV viewing for both boys and girls. There were no associations between the time that parents and children spend engaged in physical activity.

Evaluation of physical activity measures used in middle-aged women.

PubMed

Pettee Gabriel, Kelley; McClain, James J; Lee, Chong D; Swan, Pamela D; Alvar, Brent A; Mitros, Melanie R; Ainsworth, Barbara E

2009-07-01

To evaluate the reliability and validity of five commonly used physical activity questionnaires (PAQ) in women aged 45-65 yr with varying physical activity (PA) levels. Data were obtained from the Evaluation of Physical Activity Measures in Middle-aged Women (PAW) Study and included 66 women (aged 52.6 +/- 5.4 yr). PAQ evaluated include Modifiable Activity Questionnaire (past week and past month version), Nurses' Health Study PAQ, Active Australia Survey, and Women's Health Initiative PAQ. Intraclass correlation coefficients (ICC) between administrations of the PAQ were used to assess test-retest reliability. Spearman rank-order correlation coefficients were used to examine the associations of PA and physical fitness data with PAQ summary estimates. Accelerometer-determined median (25th, 75th percentiles) times (min.d) spent in moderate-lifestyle [760-1951 counts (ct)], moderate-walk (1952-5724 ct), vigorous (> or =5725 ct), and combined moderate and vigorous PA (MVPA > or = 1952 ct) during the 35 d of observation were 66.0 (51.2, 81.3), 23.1 (14.1, 34.6), 0.4 (0.0, 2.3), and 24.3 (15.9, 41.6) min, respectively. The PAQ were shown to be reproducible and relatively stable over time (ICC = 0.32 to 0.91) and were associated with total counts per day (ct.d, 0.46 to 0.60, all P < 0.001), and most were associated with many facets of physical fitness, including cardiorespiratory fitness (0.36 to 0.46, P < 0.01), body composition (-0.27 to -0.34, P < 0.05), and muscular fatigue (-0.25 to -0.44, P < 0.05). The PAQ evaluated in this study were shown to be reliable and associated with PA and physical fitness measures. Current findings support the utility of these PAQ for PA assessment in research studies of middle-aged women.

Validation of the Actigraph GT3X and ActivPAL Accelerometers for the Assessment of Sedentary Behavior

ERIC Educational Resources Information Center

Kim, Youngdeok; Barry, Vaughn W.; Kang, Minsoo

2015-01-01

This study examined (a) the validity of two accelerometers (ActiGraph GT3X [ActiGraph LLC, Pensacola, FL, USA] and activPAL [PAL Technologies Ltd., Glasgow, Scotland]) for the assessment of sedentary behavior; and (b) the variations in assessment accuracy by setting minimum sedentary bout durations against a proxy for direct observation using an…

Prediction of activity type in preschool children using machine learning techniques.

PubMed

Hagenbuchner, Markus; Cliff, Dylan P; Trost, Stewart G; Van Tuc, Nguyen; Peoples, Gregory E

2015-07-01

Recent research has shown that machine learning techniques can accurately predict activity classes from accelerometer data in adolescents and adults. The purpose of this study is to develop and test machine learning models for predicting activity type in preschool-aged children. Participants completed 12 standardised activity trials (TV, reading, tablet game, quiet play, art, treasure hunt, cleaning up, active game, obstacle course, bicycle riding) over two laboratory visits. Eleven children aged 3-6 years (mean age=4.8±0.87; 55% girls) completed the activity trials while wearing an ActiGraph GT3X+ accelerometer on the right hip. Activities were categorised into five activity classes: sedentary activities, light activities, moderate to vigorous activities, walking, and running. A standard feed-forward Artificial Neural Network and a Deep Learning Ensemble Network were trained on features in the accelerometer data used in previous investigations (10th, 25th, 50th, 75th and 90th percentiles and the lag-one autocorrelation). Overall recognition accuracy for the standard feed forward Artificial Neural Network was 69.7%. Recognition accuracy for sedentary activities, light activities and games, moderate-to-vigorous activities, walking, and running was 82%, 79%, 64%, 36% and 46%, respectively. In comparison, overall recognition accuracy for the Deep Learning Ensemble Network was 82.6%. For sedentary activities, light activities and games, moderate-to-vigorous activities, walking, and running recognition accuracy was 84%, 91%, 79%, 73% and 73%, respectively. Ensemble machine learning approaches such as Deep Learning Ensemble Network can accurately predict activity type from accelerometer data in preschool children. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

[Accelerometry does not match with self-reported physical activity and sedentary behaviors in Mexican children].

PubMed

Ayala-Guzmán, César Iván; Ramos-Ibáñez, Norma; Ortiz-Hernández, Luis

An accurate assessment of physical activity in schoolchildren is necessary to implement strategies that promote active lifestyles. The objective of this study was to validate a self-administered questionnaire to assess physical activity and sedentary behaviors and to analyze differences in the validity according to nutritional status in Mexican schoolchildren. Schoolchildren of 8-12 years of age answered a self-report physical activity and sedentary behaviors questionnaire to evaluate sedentary and light physical activity (SLPA) and moderate to vigorous physical activity (MVPA). The data of children who wore a triaxial accelerometer days was analyzed. Concordance between both methods to determine the time schoolchildren spend watching television was assessed using intraclass correlation coefficients and Bland-Altman method. The estimation of MVPA by questionnaires was higher than that of accelerometers by 117.6minutes per week, and the estimation of SLPA was lower by 1,924.7minutes per week. No correlation between the time assessed by accelerometers and the time reported in the questionnaires for SLPA and MVPA was detected. In normal-weighted children, a low correlation between the time dedicated to play videogames with sedentary activities (r ic =0.29, p=0.031) assessed by accelerometers was observed. Schoolchildren over-estimate MVPA and under-estimate SLPA. Body weight can be a factor influencing such bias. Copyright © 2017 Hospital Infantil de México Federico Gómez. Publicado por Masson Doyma México S.A. All rights reserved.

Measuring the Daily Activity of Lying Down, Sitting, Standing and Stepping of Obese Children Using the ActivPALTM Activity Monitor.

PubMed

Wafa, Sharifah Wajihah; Aziz, Nur Nadzirah; Shahril, Mohd Razif; Halib, Hasmiza; Rahim, Marhasiyah; Janssen, Xanne

2017-04-01

This study describes the patterns of objectively measured sitting, standing and stepping in obese children using the activPALTM and highlights possible differences in sedentary levels and patterns during weekdays and weekends. Sixty-five obese children, aged 9-11 years, were recruited from primary schools in Terengganu, Malaysia. Sitting, standing and stepping were objectively measured using an activPALTM accelerometer over a period of 4-7 days. Obese children spent an average of 69.6% of their day sitting/lying, 19.1% standing and 11.3% stepping. Weekdays and weekends differed significantly in total time spent sitting/lying, standing, stepping, step count, number of sedentary bouts and length of sedentary bouts (p < 0.05, respectively). Obese children spent a large proportion of their time sedentarily, and they spent more time sedentarily during weekends compared with weekdays. This study on sedentary behaviour patterns presents valuable information for designing and implementing strategies to decrease sedentary time among obese children, particularly during weekends. © The Author [2016]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Classification of accelerometer wear and non-wear events in seconds for monitoring free-living physical activity

PubMed Central

Zhou, Shang-Ming; Hill, Rebecca A; Morgan, Kelly; Stratton, Gareth; Gravenor, Mike B; Bijlsma, Gunnar; Brophy, Sinead

2015-01-01

Objective To classify wear and non-wear time of accelerometer data for accurately quantifying physical activity in public health or population level research. Design A bi-moving-window-based approach was used to combine acceleration and skin temperature data to identify wear and non-wear time events in triaxial accelerometer data that monitor physical activity. Setting Local residents in Swansea, Wales, UK. Participants 50 participants aged under 16 years (n=23) and over 17 years (n=27) were recruited in two phases: phase 1: design of the wear/non-wear algorithm (n=20) and phase 2: validation of the algorithm (n=30). Methods Participants wore a triaxial accelerometer (GeneActiv) against the skin surface on the wrist (adults) or ankle (children). Participants kept a diary to record the timings of wear and non-wear and were asked to ensure that events of wear/non-wear last for a minimum of 15 min. Results The overall sensitivity of the proposed method was 0.94 (95% CI 0.90 to 0.98) and specificity 0.91 (95% CI 0.88 to 0.94). It performed equally well for children compared with adults, and females compared with males. Using surface skin temperature data in combination with acceleration data significantly improved the classification of wear/non-wear time when compared with methods that used acceleration data only (p<0.01). Conclusions Using either accelerometer seismic information or temperature information alone is prone to considerable error. Combining both sources of data can give accurate estimates of non-wear periods thus giving better classification of sedentary behaviour. This method can be used in population studies of physical activity in free-living environments. PMID:25968000

Gender and Age Differences in Levels, Types and Locations of Physical Activity among Older Adults Living in Car-Dependent Neighborhoods.

PubMed

Li, W; Procter-Gray, E; Churchill, L; Crouter, S E; Kane, K; Tian, J; Franklin, P D; Ockene, J K; Gurwitz, J

2017-01-01

A thorough understanding of gender differences in physical activity is critical to effective promotion of active living in older adults. To examine gender and age differences in levels, types and locations of physical activity. Cross-sectional observation. Car-dependent urban and rural neighborhoods in Worcester County, Massachusetts, USA. 111 men and 103 women aged 65 years and older. From 2012 to 2014, participants were queried on type, frequency and location of physical activity. Participants wore an accelerometer for 7 consecutive days. Compared to women, men had a higher mean daily step count (mean (SD) 4385 (2122) men vs. 3671(1723) women, p=0.008). Men reported higher frequencies of any physical activity and moderate-to-vigorous physical activity, and a lower frequency of physical activity inside the home. Mean daily step counts and frequency of physical activity outside the home decreased progressively with age for both men and women. Women had a sharper decline in frequencies of self-reported physical activity. Men had a significant decrease in utilitarian walking, which women did not (p=0.07). Among participants who reported participation in any physical activity (n=190), more women indicated exercising indoors more often (59% vs. 44%, p=0.04). The three most commonly cited locations for physical activity away from home for both genders were streets or sidewalks, shopping malls, and membership-only facilities (e.g., YMCA or YWCA). The most common types of physical activity, performed at least once in a typical month, with over 40% of both genders reporting, included light housework, brisk walking, leisurely walking, and stretching. Levels, types and location preferences of physical activity differed substantially by gender. Levels of physical activity decreased progressively with age, with greater decline among women. Consideration of these gender differences is necessary to improve the effectiveness of active living promotion programs among older adults.

The Webcam system: a simple, automated, computer-based video system for quantitative measurement of movement in nonhuman primates.

PubMed

Togasaki, Daniel M; Hsu, Albert; Samant, Meghana; Farzan, Bijan; DeLanney, Louis E; Langston, J William; Di Monte, Donato A; Quik, Maryka

2005-06-30

Investigations using models of neurologic disease frequently involve quantifying animal motor activity. We developed a simple method for measuring motor activity using a computer-based video system (the Webcam system) consisting of an inexpensive video camera connected to a personal computer running customized software. Images of the animals are captured at half-second intervals and movement is quantified as the number of pixel changes between consecutive images. The Webcam system allows measurement of motor activity of the animals in their home cages, without devices affixed to their bodies. Webcam quantification of movement was validated by correlation with measures simultaneously obtained by two other methods: measurement of locomotion by interruption of infrared beams; and measurement of general motor activity using portable accelerometers. In untreated squirrel monkeys, correlations of Webcam and locomotor activity exceeded 0.79, and correlations with general activity counts exceeded 0.65. Webcam activity decreased after the monkeys were rendered parkinsonian by treatment with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), but the correlations with the other measures of motor activity were maintained. Webcam activity also correlated with clinical ratings of parkinsonism. These results indicate that the Webcam system is reliable under both untreated and experimental conditions and is an excellent method for quantifying motor activity in animals.

Statistical approaches to account for missing values in accelerometer data: Applications to modeling physical activity.

PubMed

Yue Xu, Selene; Nelson, Sandahl; Kerr, Jacqueline; Godbole, Suneeta; Patterson, Ruth; Merchant, Gina; Abramson, Ian; Staudenmayer, John; Natarajan, Loki

2018-04-01

Physical inactivity is a recognized risk factor for many chronic diseases. Accelerometers are increasingly used as an objective means to measure daily physical activity. One challenge in using these devices is missing data due to device nonwear. We used a well-characterized cohort of 333 overweight postmenopausal breast cancer survivors to examine missing data patterns of accelerometer outputs over the day. Based on these observed missingness patterns, we created psuedo-simulated datasets with realistic missing data patterns. We developed statistical methods to design imputation and variance weighting algorithms to account for missing data effects when fitting regression models. Bias and precision of each method were evaluated and compared. Our results indicated that not accounting for missing data in the analysis yielded unstable estimates in the regression analysis. Incorporating variance weights and/or subject-level imputation improved precision by >50%, compared to ignoring missing data. We recommend that these simple easy-to-implement statistical tools be used to improve analysis of accelerometer data.

Are physical activity studies in Hispanics meeting reporting guidelines for continuous monitoring technology? A systematic review.

PubMed

Layne, Charles S; Parker, Nathan H; Soltero, Erica G; Rosales Chavez, José; O'Connor, Daniel P; Gallagher, Martina R; Lee, Rebecca E

2015-09-18

Continuous monitoring technologies such as accelerometers and pedometers are the gold standard for physical activity (PA) measurement. However, inconsistencies in use, analysis, and reporting limit the understanding of dose-response relationships involving PA and the ability to make comparisons across studies and population subgroups. These issues are particularly detrimental to the study of PA across different ethnicities with different PA habits. This systematic review examined the inclusion of published guidelines involving data collection, processing, and reporting among articles using accelerometers or pedometers in Hispanic or Latino populations. English (PubMed; EbscoHost) and Spanish (SCIELO; Biblioteca Virtual en Salud) articles published between 2000 and 2013 using accelerometers or pedometers to measure PA among Hispanics or Latinos were identified through systematic literature searches. Of the 253 abstracts which were initially reviewed, 57 met eligibility criteria (44 accelerometer, 13 pedometer). Articles were coded and reviewed to evaluate compliance with recommended guidelines (N = 20), and the percentage of accelerometer and pedometer articles following each guideline were computed and reported. On average, 57.1 % of accelerometer and 62.2 % of pedometer articles reported each recommended guideline for data collection. Device manufacturer and model were reported most frequently, and provision of instructions for device wear in Spanish was reported least frequently. On average, 29.6 % of accelerometer articles reported each guideline for data processing. Definitions of an acceptable day for inclusion in analyses were reported most frequently, and definitions of an acceptable hour for inclusion in analyses were reported least frequently. On average, 18.8 % of accelerometer and 85.7 % of pedometer articles included each guideline for data reporting. Accelerometer articles most frequently included average number of valid days and least frequently included percentage of wear time. Inclusion of standard collection and reporting procedures in studies using continuous monitoring devices in Hispanic or Latino population is generally low. Lack of reporting consistency in continuous monitoring studies limits researchers' ability to compare studies or draw meaningful conclusions concerning amounts, quality, and benefits of PA among Hispanic or Latino populations. Reporting data collection, computation, and decision-making standards should be required. Improved interpretability would allow practitioners and researchers to apply scientific findings to promote PA.

Off-the-shelf mobile handset environments for deploying accelerometer based gait and activity analysis algorithms.

PubMed

Hynes, Martin; Wang, Han; Kilmartin, Liam

2009-01-01

Over the last decade, there has been substantial research interest in the application of accelerometry data for many forms of automated gait and activity analysis algorithms. This paper introduces a summary of new "of-the-shelf" mobile phone handset platforms containing embedded accelerometers which support the development of custom software to implement real time analysis of the accelerometer data. An overview of the main software programming environments which support the development of such software, including Java ME based JSR 256 API, C++ based Motion Sensor API and the Python based "aXYZ" module, is provided. Finally, a sample application is introduced and its performance evaluated in order to illustrate how a standard mobile phone can be used to detect gait activity using such a non-intrusive and easily accepted sensing platform.

Rural–Urban Differences in Objective and Subjective Measures of Physical Activity: Findings From the National Health and Nutrition Examination Survey (NHANES) 2003–2006

PubMed Central

Wen, Ming; Kowaleski-Jones, Lori

2014-01-01

Introduction Lower levels of physical activity among rural relative to urban residents have been suggested as an important contributor to rural–urban health disparity; however, empirical evidence is sparse. Methods We examined rural–urban differences in 4 objective physical activity measures (2 intensity thresholds by 2 bout lengths) and 4 subjective measures (total, leisure, household, and transportation) in a nationally representative sample of participants in the National Health and Nutrition Examination Survey (NHANES) 2003–2006. The sample comprised 5,056 adults aged 20 to 75 years. Rural-Urban Commuting Area (RUCA) codes were matched with NHANES subjects to identify urban status and 2 types of rural status. Rural–urban and within–rural differences in physical activity were estimated without and with controls for demographic and socioeconomic variables. Results Rural residents were less active than urban residents in high-intensity long bout (2,020 counts per minute threshold and 10 miniutes or longer bout length) accelerometer-measured physical activity (42.5 ± 6.2 min/wk vs 55.9 ± 2.8 min/wk) but the difference disappeared with a lower-intensity threshold (760 counts per minute). Rural residents reported more total physical activity than urban residents (438.3 ± 35.3min/wk vs 371.2 ± 12.5 min/wk), with differences primarily attributable to household physical activity. Within rural areas, micropolitan residents were less active than residents in smaller rural areas. Controlling for other variables reduced the size of the differences. Conclusion The direction and significance of rural–urban difference in physical activity varied by the method of physical activity measurement, likely related to rural residents spending more time in low-intensity household physical activity but less time in high-intensity physical activity. Micropolitan residents were substantially less active than residents in smaller rural areas, indicating that physical activity did not vary unidirectionally with degree of urbanization. PMID:25144676

Rural-urban differences in objective and subjective measures of physical activity: findings from the National Health and Nutrition Examination Survey (NHANES) 2003-2006.

PubMed

Fan, Jessie X; Wen, Ming; Kowaleski-Jones, Lori

2014-08-21

Lower levels of physical activity among rural relative to urban residents have been suggested as an important contributor to rural-urban health disparity; however, empirical evidence is sparse. We examined rural-urban differences in 4 objective physical activity measures (2 intensity thresholds by 2 bout lengths) and 4 subjective measures (total, leisure, household, and transportation) in a nationally representative sample of participants in the National Health and Nutrition Examination Survey (NHANES) 2003-2006. The sample comprised 5,056 adults aged 20 to 75 years. Rural-Urban Commuting Area (RUCA) codes were matched with NHANES subjects to identify urban status and 2 types of rural status. Rural-urban and within-rural differences in physical activity were estimated without and with controls for demographic and socioeconomic variables. Rural residents were less active than urban residents in high-intensity long bout (2,020 counts per minute threshold and 10 miniutes or longer bout length) accelerometer-measured physical activity (42.5 ± 6.2 min/wk vs 55.9 ± 2.8 min/wk) but the difference disappeared with a lower-intensity threshold (760 counts per minute). Rural residents reported more total physical activity than urban residents (438.3 ± 35.3min/wk vs 371.2 ± 12.5 min/wk), with differences primarily attributable to household physical activity. Within rural areas, micropolitan residents were less active than residents in smaller rural areas. Controlling for other variables reduced the size of the differences. The direction and significance of rural-urban difference in physical activity varied by the method of physical activity measurement, likely related to rural residents spending more time in low-intensity household physical activity but less time in high-intensity physical activity. Micropolitan residents were substantially less active than residents in smaller rural areas, indicating that physical activity did not vary unidirectionally with degree of urbanization.

A comparison of self-reported leisure-time physical activity and measured moderate-to-vigorous physical activity in adolescents and adults.

PubMed

Garriguet, Didier; Colley, Rachel C

2014-07-01

Systematic reviews and results of Statistics Canada surveys have shown a discrepancy between self-reported and measured physical activity. This study compares these two methods and examines specific activities to explain the limitations of each method. Data are from cycle 1 (2007 to 2009) and cycle 2 (2009 to 2011) of the Canadian Health Measures Survey. The survey involved an interview in the respondent's home and a visit to a mobile examination centre (MEC) for physical measurements. In a questionnaire, respondents were asked about 21 leisure-time physical activities. They were requested to wear an Actical accelerometer for seven days after the MEC visit. The analysis pertains to respondents aged 12 to 79 who wore the accelerometer for 10 or more hours on at least four days (n = 7,158). Averages of self-reported leisure-time physical activity and moderate-to-vigorous physical activity measured by accelerometer were within a couple of minutes of each other. However, at the individual level, the difference between estimates could exceed 37.5 minutes per day in one direction or the other, and around 40% of the population met physical activity thresholds according to one measurement method, but not according to the other. The disagreement is supported by weak observed correlations. The lack of a systematic trend in the relationship between the two methods of measuring physical activity precludes the creation of correction factors or being confident in using one method instead of the other. Accelerometers and questionnaires measure different aspects of physical activity.

Capturing Ultraviolet Radiation Exposure and Physical Activity: Feasibility Study and Comparison Between Self-Reports, Mobile Apps, Dosimeters, and Accelerometers

PubMed Central

Allen, Martin; Nathan, Andrea; Lowe, John; Janda, Monika

2018-01-01

Background Skin cancer is the most prevalent cancer in Australia. Skin cancer prevention programs aim to reduce sun exposure and increase sun protection behaviors. Effectiveness is usually assessed through self-report. Objective It was the aim of this study to test the acceptance and validity of a newly developed ultraviolet radiation (UVR) exposure app, designed to reduce the data collection burden to research participants. Physical activity data was collected because a strong focus on sun avoidance may result in unhealthy reductions in physical activity. This paper provides lessons learned from collecting data from participants using paper diaries, a mobile app, dosimeters, and accelerometers for measuring end-points of UVR exposure and physical activity. Methods Two participant groups were recruited through social and traditional media campaigns 1) Group A—UVR Diaries and 2) Group B—Physical Activity. In Group A, nineteen participants wore an UVR dosimeter wristwatch (University of Canterbury, New Zealand) when outside for 7 days. They also recorded their sun exposure and physical activity levels using both 1) the UVR diary app and 2) a paper UVR diary. In Group B, 55 participants wore an accelerometer (Actigraph, Pensacola, FL, USA) for 14 days and completed the UVR diary app. Data from the UVR diary app were compared with UVR dosimeter wristwatch, accelerometer, and paper UVR diary data. Cohen kappa coefficient score was used to determine if there was agreement between categorical variables for different UVR data collection methods and Spearman rank correlation coefficient was used to determine agreement between continuous accelerometer data and app-collected self-report physical activity. Results The mean age of participants in Groups A (n=19) and B (n=55) was 29.3 and 25.4 years, and 63% (12/19) and 75% (41/55) were females, respectively. Self-reported sun exposure data in the UVR app correlated highly with UVR dosimetry (κ=0.83, 95% CI 0.64-1.00, P<.001). Correlation between self-reported UVR app and accelerometer-collected moderate to vigorous physical activity data was low (ρ=0.23, P=.10), while agreement for low-intensity physical activity was significantly different (ρ=-0.49, P<.001). Seventy-nine percent of participants preferred the app over the paper diary for daily self-report of UVR exposure and physical activity. Conclusions This feasibility study highlights self-report using an UVR app can reliably collect personal UVR exposure, but further improvements are required before the app can also be used to collect physical activity data. PMID:29666044

A National Survey of Physical Activity and Sedentary Behavior of Chinese City Children and Youth Using Accelerometers

ERIC Educational Resources Information Center

Wang, Chao; Chen, Peijie; Zhuang, Jie

2013-01-01

Purpose: The purpose of this study was to objectively assess levels of physical activity (PA) and sedentary behavior (SB) of Chinese city children and youth aged 9 to 17 years old using accelerometers and to examine their differences by gender, age, grade, and weight status. Method: The PA and SB of 2,163 students in 4th grade through 11th grade…

Evaluation of the MyWellness Key accelerometer.

PubMed

Herrmann, S D; Hart, T L; Lee, C D; Ainsworth, B E

2011-02-01

to examine the concurrent validity of the Technogym MyWellness Key accelerometer against objective and subjective physical activity (PA) measures. randomised, cross-sectional design with two phases. The laboratory phase compared the MyWellness Key with the ActiGraph GT1M and the Yamax SW200 Digiwalker pedometer during graded treadmill walking, increasing speed each minute. The free-living phase compared the MyWellness Key with the ActiGraph, Digiwalker, Bouchard Activity cord (BAR) and Global Physical Activity Questionnaire (GPAQ) for seven continuous days. Data were analysed using Spearman rank-order correlation coefficients for all comparisons. laboratory and free-living phases. sixteen participants randomly stratified from 41 eligible respondents by sex (n=8 men; n=8 women) and PA levels (n=4 low, n=8 middle and n=4 high active). there was a strong association between the MyWellness Key and the ActiGraph accelerometer during controlled graded treadmill walking (r=0.91, p<0.01) and in free-living settings (r=0.73-0.76 for light to vigorous PA, respectively, p<0.01). No associations were observed between the MyWellness Key and the BAR and GPAQ (p>0.05). the MyWellness Key has a high concurrent validity with the ActiGraph accelerometer to detect PA in both controlled laboratory and free-living settings.

Combining GPS, GIS, and accelerometry: methodological issues in the assessment of location and intensity of travel behaviors.

PubMed

Oliver, Melody; Badland, Hannah; Mavoa, Suzanne; Duncan, Mitch J; Duncan, Scott

2010-01-01

Global positioning systems (GPS), geographic information systems (GIS), and accelerometers are powerful tools to explain activity within a built environment, yet little integration of these tools has taken place. This study aimed to assess the feasibility of combining GPS, GIS, and accelerometry to understand transport-related physical activity (TPA) in adults. Forty adults wore an accelerometer and portable GPS unit over 7 consecutive days and completed a demographics questionnaire and 7-day travel log. Accelerometer and GPS data were extracted for commutes to/from workplace and integrated into a GIS database. GIS maps were generated to visually explore physical activity intensity, GPS speeds and routes traveled. GPS, accelerometer, and survey data were collected for 37 participants. Loss of GPS data was substantial due to a range of methodological issues, such as low battery life, signal drop out, and participant noncompliance. Nonetheless, greater travel distances and significantly higher speeds were observed for motorized trips when compared with TPA. Pragmatic issues of using GPS monitoring to understand TPA behaviors and methodological recommendations for future research were identified. Although methodologically challenging, the combination of GPS monitoring, accelerometry and GIS technologies holds promise for understanding TPA within the built environment.

[Validity of a standard questionnaire to assess physical activity for specific medical checkups and health guidance].

PubMed

Kawakami, Ryoko; Miyachi, Motohiko

2010-10-01

This study aimed to determine the validity of a standard questionnaire to assess amount of physical activity (PA) and cardiorespiratory fitness (VO2peak). A total of 483 men and women, aged 20 to 69 years, participated. The standard questionnaire included 3 items about exercise, PA, and walking speed. All questions were designed to require an answer of Yes or No. Subjects were classified into one of four groups regarding the number of Yes answers to the three questions, giving activity levels of 0 to 3. The amount of PA was measured objectively with a tn-axial accelerometer which could also calculate daily step counts, and the amounts of PA under 3 metabolic equivalents (METs) and at 3 METs or more. VO2peak. was measured by incremental cycle exercise tests with indirect calorimetry. The daily step counts, the amount of PA at 3 METs or more, and the VO2peak. were significantly higher in subjects who answered Yes to each question than in those who answered No. Sensitivity and specificity of each question were 62-73% and 45-71% for the amount of PA established with the "Exercise and Physical Activity Reference for Health Promotion 2006 (EPAR2006)". The sum of sensitivity and specificity was the highest when the cutoff value was activity level 2 (sensitivity 73%, specificity 68%). Sensitivity and specificity for VO2max established by EPAR2006 were lower than those for the amount of PA. These results suggest that only answering simple questions with a standard questionnaire is sufficient for estimation of PA levels for specific medical checkups and health guidance, even though the accuracy is somewhat limited.

Exploring the feasibility and use of acceleromters before, during, and after a camp-based CIMT program for children with cerebral palsy.

PubMed

Coker-Bolt, Patty; Downey, Ryan J; Connolly, Jacqueline; Hoover, Reagin; Shelton, Daniel; Seo, Na Jin

2017-01-01

The aim of this pilot study was to determine the feasibility and use accelerometers before, during, and after a camp-based constraint-induced movement therapy (CIMT) program for children with hemiplegic cerebral palsy. A pre-test post-test design was used for 12 children with CP (mean = 4.9 yrs) who completed a 30-hour camp-based CIMT program. The accelerometer data were collected using ActiGraph GT9X Link. Children wore accelerometers on both wrists one day before and after the camp and on the affected limb during each camp day. Three developmental assessments were administered pre-post CIMT program. Accelerometers were successfully worn before, during, and directly after the CIMT program to collect upper limb data. Affected upper limb accelerometer activity significantly increased during the CIMT camp compared to baseline (p< 0.05). Significant improvements were seen in all twelve children on all assessments of affected upper limb function (p< 0.05) measuring capacity and quality of affected upper limb functioning. Accelerometers can be worn during high intensity pediatric CIMT programs to collect data about affected upper limb function. Further study is required to determine the relationship between accelerometer data, measure of motor capacity, and real-world performance post-CIMT.

SVM-based multi-sensor fusion for free-living physical activity assessment.

PubMed

Liu, Shaopeng; Gao, Robert X; John, Dinesh; Staudenmayer, John; Freedson, Patty S

2011-01-01

This paper presents a sensor fusion method for assessing physical activity (PA) of human subjects, based on the support vector machines (SVMs). Specifically, acceleration and ventilation measured by a wearable multi-sensor device on 50 test subjects performing 13 types of activities of varying intensities are analyzed, from which the activity types and related energy expenditures are derived. The result shows that the method correctly recognized the 13 activity types 84.7% of the time, which is 26% higher than using a hip accelerometer alone. Also, the method predicted the associated energy expenditure with a root mean square error of 0.43 METs, 43% lower than using a hip accelerometer alone. Furthermore, the fusion method was effective in reducing the subject-to-subject variability (standard deviation of recognition accuracies across subjects) in activity recognition, especially when data from the ventilation sensor was added to the fusion model. These results demonstrate that the multi-sensor fusion technique presented is more effective in assessing activities of varying intensities than the traditional accelerometer-alone based methods.

Deriving a GPS Monitoring Time Recommendation for Physical Activity Studies of Adults.

PubMed

Holliday, Katelyn M; Howard, Annie Green; Emch, Michael; Rodríguez, Daniel A; Rosamond, Wayne D; Evenson, Kelly R

2017-05-01

Determining locations of physical activity (PA) is important for surveillance and intervention development, yet recommendations for using location recording tools like global positioning system (GPS) units are lacking. Specifically, no recommendation exists for the number of days study participants should wear a GPS to reliably estimate PA time spent in locations. This study used data from participants (N = 224, age = 18-85 yr) in five states who concurrently wore an ActiGraph GT1M accelerometer and a Qstarz BT-Q1000X GPS for three consecutive weeks to construct monitoring day recommendations through variance partitioning methods. PA bouts ≥10 min were constructed from accelerometer counts, and the location of GPS points was determined using a hand-coding protocol. Monitoring day recommendations varied by the type of location (e.g., participant homes vs parks) and the intensity of PA bouts considered (low and medium cut point moderate to vigorous PA [MVPA] bouts or high cut point vigorous PA [VPA] bouts). In general, minutes of all PA intensities spent in a given location could be measured with ≥80% reliability using 1-3 d of GPS monitoring for fitness facilities, schools, and footpaths. MVPA bout minutes in parks and roads required longer monitoring periods of 5-12 d. PA in homes and commercial areas required >19 d of monitoring. Twelve days of monitoring was found to reliably estimate minutes in both low and medium threshold MVPA as well as VPA bouts for many important built environment locations that can be targeted to increase PA at the population level. Minutes of PA in the home environment and commercial locations may be best assessed through other means given the lengthy estimated monitoring time required.

Physical activity of adults with mental retardation: review and research needs.

PubMed

Temple, Viviene A; Frey, Georgia C; Stanish, Heidi I

2006-01-01

To characterize physical activity levels of adults with mental retardation and identify limitations in published research. Key word searches for "mental retardation," "intellectual disability," "learning disability," or "developmental disability" combined with "physical activity" or "habitual exercise" identified articles from MEDLINE, Academic Search Elite, Psych Articles, Health Source, and SPORT Discus. This produced a total of 801 citations. Published English-language literature that quantitatively measured physical activity levels of adults with mental retardation was included in this review. Fourteen articles met this criterion. Characteristics of participants, study design, outcome measures, methods of analyses, and findings in terms of percentages, step counts, and accelerometer output were extracted. Data were synthesized to identify the percentage of adults with mental retardation who met published health-related physical activity criteria and compare them with adults without mental retardation and to examine study limitations. The studies with the greatest rigor indicate that one-third of adults or fewer with mental retardation were sufficiently active to achieve health benefits. However, data are insufficient to determine whether adults with mental retardation are less active than the general community. Future research would be enhanced by including appropriately powered representative samples, by including comparison groups, by validating physical activity questionnaires, and by determining the accuracy of proxy respondents.

Accuracy of the Yamax CW-701 Pedometer for measuring steps in controlled and free-living conditions

PubMed Central

Coffman, Maren J; Reeve, Charlie L; Butler, Shannon; Keeling, Maiya; Talbot, Laura A

2016-01-01

Objective The Yamax Digi-Walker CW-701 (Yamax CW-701) is a low-cost pedometer that includes a 7-day memory, a 2-week cumulative memory, and automatically resets to zero at midnight. To date, the accuracy of the Yamax CW-701 has not been determined. The purpose of this study was to assess the accuracy of steps recorded by the Yamax CW-701 pedometer compared with actual steps and two other devices. Methods The study was conducted in a campus-based lab and in free-living settings with 22 students, faculty, and staff at a mid-sized university in the Southeastern US. While wearing a Yamax CW-701, Yamax Digi-Walker SW-200, and an ActiGraph GTX3 accelerometer, participants engaged in activities at variable speeds and conditions. To assess accuracy of each device, steps recorded were compared with actual step counts. Statistical tests included paired sample t-tests, percent accuracy, intraclass correlation coefficient, and Bland–Altman plots. Results The Yamax CW-701 demonstrated reliability and concurrent validity during walking at a fast pace and walking on a track, and in free-living conditions. Decreased accuracy was noted walking at a slow pace. Conclusions These findings are consistent with prior research. With most pedometers and accelerometers, adequate force and intensity must be present for a step to register. The Yamax CW-701 is accurate in recording steps taken while walking at a fast pace and in free-living settings. PMID:29942555

Accuracy of the Yamax CW-701 Pedometer for measuring steps in controlled and free-living conditions.

PubMed

Coffman, Maren J; Reeve, Charlie L; Butler, Shannon; Keeling, Maiya; Talbot, Laura A

2016-01-01

The Yamax Digi-Walker CW-701 (Yamax CW-701) is a low-cost pedometer that includes a 7-day memory, a 2-week cumulative memory, and automatically resets to zero at midnight. To date, the accuracy of the Yamax CW-701 has not been determined. The purpose of this study was to assess the accuracy of steps recorded by the Yamax CW-701 pedometer compared with actual steps and two other devices. The study was conducted in a campus-based lab and in free-living settings with 22 students, faculty, and staff at a mid-sized university in the Southeastern US. While wearing a Yamax CW-701, Yamax Digi-Walker SW-200, and an ActiGraph GTX3 accelerometer, participants engaged in activities at variable speeds and conditions. To assess accuracy of each device, steps recorded were compared with actual step counts. Statistical tests included paired sample t -tests, percent accuracy, intraclass correlation coefficient, and Bland-Altman plots. The Yamax CW-701 demonstrated reliability and concurrent validity during walking at a fast pace and walking on a track, and in free-living conditions. Decreased accuracy was noted walking at a slow pace. These findings are consistent with prior research. With most pedometers and accelerometers, adequate force and intensity must be present for a step to register. The Yamax CW-701 is accurate in recording steps taken while walking at a fast pace and in free-living settings.

Physical activity discrimination improvement using accelerometers and wireless sensor network localization - biomed 2013.

PubMed

Bashford, Gregory R; Burnfield, Judith M; Perez, Lance C

2013-01-01

Automating documentation of physical activity data (e.g., duration and speed of walking or propelling a wheelchair) into the electronic medical record (EMR) offers promise for improving efficiency of documentation and understanding of best practices in the rehabilitation and home health settings. Commercially available devices which could be used to automate documentation of physical activities are either cumbersome to wear or lack the specificity required to differentiate activities. We have designed a novel system to differentiate and quantify physical activities, using inexpensive accelerometer-based biomechanical data technology and wireless sensor networks, a technology combination that has not been used in a rehabilitation setting to date. As a first step, a feasibility study was performed where 14 healthy young adults (mean age = 22.6 ± 2.5 years, mean height = 173 ± 10.0 cm, mean mass = 70.7 ± 11.3 kg) carried out eight different activities while wearing a biaxial accelerometer sensor. Activities were performed at each participant’s self-selected pace during a single testing session in a controlled environment. Linear discriminant analysis was performed by extracting spectral parameters from the subjects’ accelerometer patterns. It is shown that physical activity classification alone results in an average accuracy of 49.5%, but when combined with rule-based constraints using a wireless sensor network with localization capabilities in an in silico simulated room, accuracy improves to 99.3%. When fully implemented, our technology package is expected to improve goal setting, treatment interventions and patient outcomes by enhancing clinicians’ understanding of patients’ physical performance within a day and across the rehabilitation program.

Sedentary Behavior in Preschoolers: How Many Days of Accelerometer Monitoring Is Needed?

PubMed Central

Byun, Wonwoo; Beets, Michael W.; Pate, Russell R.

2015-01-01

The reliability of accelerometry for measuring sedentary behavior in preschoolers has not been determined, thus we determined how many days of accelerometry monitoring are necessary to reliably estimate daily time spent in sedentary behavior in preschoolers. In total, 191 and 150 preschoolers (three to five years) wore ActiGraph accelerometers (15-s epoch) during the in-school (≥4 days) and the total-day (≥6 days) period respectively. Accelerometry data were summarized as time spent in sedentary behavior (min/h) using three different cutpoints developed for preschool-age children (<37.5, <200, and <373 counts/15 s). The intraclass correlations (ICCs) and Spearman-Brown prophecy formula were used to estimate the reliability of accelerometer for measuring sedentary behavior. Across different cutpoints, the ICCs ranged from 0.81 to 0.92 for in-school sedentary behavior, and from 0.75 to 0.81 for total-day sedentary behavior, respectively. To achieve an ICC of ≥0.8, two to four days or six to nine days of monitoring were needed for in-school sedentary behavior and total-day sedentary behavior, respectively. These findings provide important guidance for future research on sedentary behavior in preschool children using accelerometry. Understanding the reliability of accelerometry will facilitate the conduct of research designed to inform policies and practices aimed at reducing sedentary behavior in preschool children. PMID:26492261

Long-term synchronized electrophysiological and behavioral wireless monitoring of freely moving animals

PubMed Central

Grand, Laszlo; Ftomov, Sergiu; Timofeev, Igor

2012-01-01

Parallel electrophysiological recording and behavioral monitoring of freely moving animals is essential for a better understanding of the neural mechanisms underlying behavior. In this paper we describe a novel wireless recording technique, which is capable of synchronously recording in vivo multichannel electrophysiological (LFP, MUA, EOG, EMG) and activity data (accelerometer, video) from freely moving cats. The method is based on the integration of commercially available components into a simple monitoring system and is complete with accelerometers and the needed signal processing tools. LFP activities of freely moving group-housed cats were recorded from multiple intracortical areas and from the hippocampus. EMG, EOG, accelerometer and video were simultaneously acquired with LFP activities 24-h a day for 3 months. These recordings confirm the possibility of using our wireless method for 24-h long-term monitoring of neurophysiological and behavioral data of freely moving experimental animals such as cats, ferrets, rabbits and other large animals. PMID:23099345

Multiple-stage integrating accelerometer

DOEpatents

Devaney, H.F.

1984-06-27

An accelerometer assembly is provided for use in activating a switch in response to multiple acceleration pulses in series. The accelerometer includes a housing forming a chamber. An inertial mass or piston is slidably disposed in the chamber and spring biased toward a first or reset position. A damping system is also provided to damp piston movement in response to first and subsequent acceleration pulses. Additionally, a cam, including a Z-shaped slot, and cooperating follower pin slidably received therein are mounted to the piston and the housing. The middle or cross-over leg of the Z-shaped slot cooperates with the follower pin to block or limit piston movement and prevent switch activation in response to a lone acceleration pulse. The switch of the assembly is only activated after two or more separate acceleration pulses are sensed and the piston reaches the end of the chamber opposite the reset position.

Physical Activity Level and Sedentary Behaviors among Public School Children in Dakar (Senegal) Measured by PAQ-C and Accelerometer: Preliminary Results

PubMed Central

Diouf, Adama; Thiam, Mbeugué; Idohou-Dossou, Nicole; Diongue, Ousmane; Mégné, Ndé; Diallo, Khady; Sembène, Pape Malick; Wade, Salimata

2016-01-01

Background: Physical inactivity and sedentary lifestyles are major risk factors of childhood obesity. This study aimed to measure physical activity (PA) levels by accelerometer and Physical Activity Questionnaire for Older Children (PAQ-C) among Senegalese school children and the relation with Body Mass Index (BMI) and body composition. Methodology: 156 pupils 8–11 years old were randomly selected in four elementary public schools of Dakar. BMI z-score was used to categorize children according to their weight status. PA was measured by PAQ-C in the 156 pupils and by accelerometer (Actigraph GT3X+, Pensacola, FL, USA) in a subsample of 42 children. Body composition was determined by deuterium dilution method. Results: PAQ-C results were comparable in the 156 and 42 pupils. The 42 pupils presented a light activity measured by accelerometer, while PAQ-C classified the majority of them (57%; n = 24) in the moderate PA level. Children spent most of their time (min/day) in sedentary activities and light activities than in moderate and intense activity levels. Accumulation of 60 min/day Moderate-to-Vigorous Physical Activity (MVPA) was achieved by 54.8% (n = 23) of the pupils. MVPA decreased in girls in relation to their body fatness. There was a significant difference in MVPA between boys and girls. Similarly, overweight/obese (45 ± 16 min/day) children had lower MVPA than their normal and underweight peers (88 ± 34 and 74 ± 36 min/day, respectively; p = 0.004). Conclusions: The two methods are inconsistent for measuring light and moderate PA levels. Although PAQ-C is an uncomplicated routine method, various activities were not adapted for genuine activities in Senegalese children and therefore needs to be validated in African children. PMID:27735876

Physical Activity Level and Sedentary Behaviors among Public School Children in Dakar (Senegal) Measured by PAQ-C and Accelerometer: Preliminary Results.

PubMed

Diouf, Adama; Thiam, Mbeugué; Idohou-Dossou, Nicole; Diongue, Ousmane; Mégné, Ndé; Diallo, Khady; Sembène, Pape Malick; Wade, Salimata

2016-10-10

Background : Physical inactivity and sedentary lifestyles are major risk factors of childhood obesity. This study aimed to measure physical activity (PA) levels by accelerometer and Physical Activity Questionnaire for Older Children (PAQ-C) among Senegalese school children and the relation with Body Mass Index (BMI) and body composition. Methodology : 156 pupils 8-11 years old were randomly selected in four elementary public schools of Dakar. BMI z -score was used to categorize children according to their weight status. PA was measured by PAQ-C in the 156 pupils and by accelerometer (Actigraph GT3X+, Pensacola, FL, USA) in a subsample of 42 children. Body composition was determined by deuterium dilution method. Results : PAQ-C results were comparable in the 156 and 42 pupils. The 42 pupils presented a light activity measured by accelerometer, while PAQ-C classified the majority of them (57%; n = 24) in the moderate PA level. Children spent most of their time (min/day) in sedentary activities and light activities than in moderate and intense activity levels. Accumulation of 60 min/day Moderate-to-Vigorous Physical Activity (MVPA) was achieved by 54.8% ( n = 23) of the pupils. MVPA decreased in girls in relation to their body fatness. There was a significant difference in MVPA between boys and girls. Similarly, overweight/obese (45 ± 16 min/day) children had lower MVPA than their normal and underweight peers (88 ± 34 and 74 ± 36 min/day, respectively; p = 0.004). Conclusions : The two methods are inconsistent for measuring light and moderate PA levels. Although PAQ-C is an uncomplicated routine method, various activities were not adapted for genuine activities in Senegalese children and therefore needs to be validated in African children.

Association between depressive symptoms and objectively measured daily step count in individuals at high risk of cardiovascular disease in South London, UK: a cross-sectional study.

PubMed

Ludwig, Vera M; Bayley, Adam; Cook, Derek G; Stahl, Daniel; Treasure, Janet L; Asthworth, Mark; Greenough, Anne; Winkley, Kirsty; Bornstein, Stefan R; Ismail, Khalida

2018-04-12

Depressive symptoms are common but rarely considered a risk factor for unhealthy lifestyles associated with cardiovascular disease (CVD). This study investigates whether depressive symptoms are associated with reduced physical activity (PA) in individuals at high risk of developing CVD. Secondary analysis of the cross-sectional baseline data from a randomised controlled trial of an intensive lifestyle intervention. 135 primary care practices in South London, UK. 1742 adults, 49-74 years, 86% male at high (≥20%) risk of developing CVD in the next 10 years as defined via QRISK2 score. The main explanatory variable was depressive symptoms measured via the Patient Health Questionnaire-9 (PHQ-9). The main outcome was daily step count measured with an accelerometer (ActiGraph GT3X) stratified by weekdays and weekend days. The median daily step count of the total sample was 6151 (IQR 3510) with significant differences (P<0.001) in mean daily step count between participants with low (PHQ-9 score: 0-4), mild (PHQ-9 score: 5-9) and moderate to severe depressive symptoms (PHQ-9 score: ≥10). Controlling for age, gender, ethnicity, education level, body mass index (BMI), smoking, consumption of alcohol, day of the week and season, individuals with mild depressive symptoms and those with moderate to severe depressive symptoms walked 13.3% (95% CI 18.8% to 7.9%) and 15.6% (95% CI 23.7% to 6.5%) less than non-depressed individuals, respectively. Furthermore, male gender, white ethnicity, higher education level, lower BMI, non-smoking, moderate alcohol intake, weekdays and summer season were independently associated with higher step count. People at high risk of CVD with depressive symptoms have lower levels of PA. ISRCTN84864870; Pre-results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Superconducting Rebalance Accelerometer

NASA Technical Reports Server (NTRS)

Torti, R. P.; Gerver, M.; Leary, K. J.; Jagannathan, S.; Dozer, D. M.

1996-01-01

A multi-axis accelerometer which utilizes a magnetically-suspended, high-TC proof mass is under development. The design and performance of a single axis device which is stabilized actively in the axial direction but which utilizes ring magnets for passive radial stabilization is discussed. The design of a full six degree-of-freedom device version is also described.

Nicotine Dependence, Physical Activity, and Sedentary Behavior among Adult Smokers.

PubMed

Loprinzi, Paul D; Walker, Jerome F

2015-03-01

Research has previously demonstrated an inverse association between smoking status and physical activity; however, few studies have examined the association between nicotine dependence and physical activity or sedentary behavior. This study examined the association between nicotine dependence and accelerometer-determined physical activity and sedentary behavior. Data from the 2003-2006 National Health and Nutrition Examination Survey (NHANES) were used. A total of 851 adult (≥20 years) smokers wore an accelerometer for ≥4 days and completed the Fagerstrom Test for Nicotine Dependence scale. Regression models were used to examine the association between nicotine dependence and physical activity/sedentary behavior. After adjusting for age, gender, race-ethnicity, poverty level, hypertension, emphysema, bronchitis, body mass index (BMI), cotinine, and accelerometer wear time, smokers 50 + years of age with greater nicotine dependence engaged in more sedentary behavior (β = 11.4, P = 0.02) and less light-intensity physical activity (β = -9.6, P = 0.03) and moderate-to-vigorous physical activity (MVPA; β = -0.14, P = 0.003) than their less nicotine dependent counterparts. Older adults who are more nicotine dependent engage in less physical activity (both MVPA and light-intensity) and more sedentary behavior than their less nicotine dependent counterparts.

Activity recognition using a single accelerometer placed at the wrist or ankle.

PubMed

Mannini, Andrea; Intille, Stephen S; Rosenberger, Mary; Sabatini, Angelo M; Haskell, William

2013-11-01

Large physical activity surveillance projects such as the UK Biobank and NHANES are using wrist-worn accelerometer-based activity monitors that collect raw data. The goal is to increase wear time by asking subjects to wear the monitors on the wrist instead of the hip, and then to use information in the raw signal to improve activity type and intensity estimation. The purposes of this work was to obtain an algorithm to process wrist and ankle raw data and to classify behavior into four broad activity classes: ambulation, cycling, sedentary, and other activities. Participants (N = 33) wearing accelerometers on the wrist and ankle performed 26 daily activities. The accelerometer data were collected, cleaned, and preprocessed to extract features that characterize 2-, 4-, and 12.8-s data windows. Feature vectors encoding information about frequency and intensity of motion extracted from analysis of the raw signal were used with a support vector machine classifier to identify a subject's activity. Results were compared with categories classified by a human observer. Algorithms were validated using a leave-one-subject-out strategy. The computational complexity of each processing step was also evaluated. With 12.8-s windows, the proposed strategy showed high classification accuracies for ankle data (95.0%) that decreased to 84.7% for wrist data. Shorter (4 s) windows only minimally decreased performances of the algorithm on the wrist to 84.2%. A classification algorithm using 13 features shows good classification into the four classes given the complexity of the activities in the original data set. The algorithm is computationally efficient and could be implemented in real time on mobile devices with only 4-s latency.

[Validity of four questionnaires to assess physical activity in Spanish adolescents].

PubMed

Martínez-Gómez, David; Martínez-De-Haro, Vicente; Del-Campo, Juan; Zapatera, Belén; Welk, Gregory J; Villagra, Ariel; Marcos, Ascensión; Veiga, Oscar L

2009-01-01

The physical activity (PA) levels of Spanish adolescents must be determined to assess how the lack of PA may affect the increasing prevalence of obesity. Thus, to assess PA in this age range valid measurement instruments are essential. The aim of this study was to evaluate the validity of four easily applied questionnaires (the enKid and FITNESSGRAM questions, the Patient-Centered Assessment and Counselling [PACE] questionnaire, and an activity rating) to assess PA in Spanish adolescents by using an accelerometer as the criterion instrument. A total of 232 adolescents (113 girls) completed the questionnaires and wore an ActiGraph accelerometer for 7 consecutive days. Spearman's correlation coefficient (rho) was used to compare the questionnaires and total PA, moderate PA, vigorous PA and moderate-to-vigorous PA (MVPA) assessed by the accelerometer. All the questionnaires showed moderate correlations when compared against total PA (rho=0.36-0.43) and MVPA (rho=0.34-0.46) obtained by the accelerometer in the total sample. Higher correlations were found when comparing the questionnaires against vigorous PA (rho=0.42-0.51) than against moderate PA (rho=0.15-0.17). The FITNESSGRAM question and the PACE questionnaire obtained weak correlations in girls and the enKid question and activity rating were moderately correlated for boys and girls. The four questionnaires evaluated showed acceptable validity in the assessment of PA in the Spanish adolescent population.

Accelerometer-measured dose-response for physical activity, sedentary time, and mortality in US adults.

PubMed

Matthews, Charles E; Keadle, Sarah Kozey; Troiano, Richard P; Kahle, Lisa; Koster, Annemarie; Brychta, Robert; Van Domelen, Dane; Caserotti, Paolo; Chen, Kong Y; Harris, Tamara B; Berrigan, David

2016-11-01

Moderate-to-vigorous-intensity physical activity is recommended to maintain and improve health, but the mortality benefits of light activity and risk for sedentary time remain uncertain. Using accelerometer-based measures, we 1) described the mortality dose-response for sedentary time and light- and moderate-to-vigorous-intensity activity using restricted cubic splines, and 2) estimated the mortality benefits associated with replacing sedentary time with physical activity, accounting for total activity. US adults (n = 4840) from NHANES (2003-2006) wore an accelerometer for ≤7 d and were followed prospectively for mortality. Proportional hazards models were used to estimate adjusted HRs and 95% CIs for mortality associations with time spent sedentary and in light- and moderate-to-vigorous-intensity physical activity. Splines were used to graphically present behavior-mortality relation. Isotemporal models estimated replacement associations for sedentary time, and separate models were fit for low- (<5.8 h total activity/d) and high-active participants to account for nonlinear associations. Over a mean of 6.6 y, 700 deaths occurred. Compared with less-sedentary adults (6 sedentary h/d), those who spent 10 sedentary h/d had 29% greater risk (HR: 1.29; 95% CI: 1.1, 1.5). Compared with those who did less light activity (3 h/d), those who did 5 h of light activity/d had 23% lower risk (HR: 0.77; 95% CI: 0.6, 1.0). There was no association with mortality for sedentary time or light or moderate-to-vigorous activity in highly active adults. In less-active adults, replacing 1 h of sedentary time with either light- or moderate-to-vigorous-intensity activity was associated with 18% and 42% lower mortality, respectively. Health promotion efforts for physical activity have mostly focused on moderate-to-vigorous activity. However, our findings derived from accelerometer-based measurements suggest that increasing light-intensity activity and reducing sedentary time are also important, particularly for inactive adults. © 2016 American Society for Nutrition.

Evaluation of the Environmental Bias on Accelerometer-Measured Total Daily Activity Counts and Owner Survey Responses in Dogs with Osteoarthritis.

PubMed

Katz, Erin M; Scott, Ruth M; Thomson, Christopher B; Mesa, Eileen; Evans, Richard; Conzemius, Michael G

2017-11-01

Objective  To determine if environmental variables affect the average daily activity counts (AC) of dogs with osteoarthritis (OA) and/or owners' perception of their dog's clinical signs or quality of life. Methods  The AC and Canine Brief Pain Inventory (CBPI) owner questionnaires of 62 dogs with OA were compared with daily environmental variables including the following: average temperature (°C), high temperature (°C), low temperature (°C), relative humidity (%), total precipitation (mm), average barometric pressure (hPa) and total daylight hours. Results  Daily AC significantly correlated with average temperature and total daylight hours, but average temperature and total daylight hours accounted for less than 1% of variation in AC. No other significant relationships were found between daily AC and daily high temperature, low temperature, relative humidity, total precipitation or average barometric pressure. No statistical relationship was found between daily AC and the CBPI, nor between environmental variables and the CBPI. Canine Brief Pain Inventory scores for pain severity and pain interference decreased significantly over the test period. Clinical Significance  The relationship between daily AC and average temperature and total daylight hours was significant, but unlikely to be clinically significant. Thus, environmental variables do not appear to have a clinically relevant bias on AC or owner CBPI questionnaires. The decrease over time in CBPI pain severity and pain interference values suggests owners completing the CBPI in this study were influenced by a caregiver placebo effect. Schattauer GmbH Stuttgart.

Effect and cost of an after-school dance programme on the physical activity of 11-12 year old girls: The Bristol Girls Dance Project, a school-based cluster randomised controlled trial.

PubMed

Jago, Russell; Edwards, Mark J; Sebire, Simon J; Tomkinson, Keeley; Bird, Emma L; Banfield, Kathryn; May, Thomas; Kesten, Joanna M; Cooper, Ashley R; Powell, Jane E; Blair, Peter S

2015-10-06

The aim of this study was to examine the effectiveness and cost of an after-school dance intervention at increasing the physical activity levels of Year 7 girls (age 11-12). A cluster randomised controlled trial was conducted in 18 secondary schools. Participants were Year 7 girls attending a study school. The Bristol Girls Dance Project (BGDP) intervention consisted of up to forty, 75-minute dance sessions delivered in the period immediately after school by experienced dance instructors over 20-weeks. The pre-specified primary outcome was accelerometer assessed mean minutes of weekday moderate to vigorous physical activity (MVPA) at time 2 (52 weeks are T0 baseline assessments). Secondary outcomes included accelerometer assessed mean minutes of weekday MVPA at time 1 (while the intervention was still running) and psychosocial outcomes. Intervention costs were assessed. 571 girls participated. Valid accelerometer data were collected from 549 girls at baseline with 508 girls providing valid accelerometer data at baseline and time 2. There were no differences between the intervention and control group for accelerometer assessed physical activity at either time 1 or time 2. Only one third of the girls in the intervention arm met the pre-set adherence criteria of attending two thirds of the dance sessions that were available to them. Instrumental variable regression analyses using complier average causal effects provided no evidence of a difference between girls who attended the sessions and the control group. The average cost of the intervention was £73 per girl, which was reduced to £63 when dance instructor travel expenses were excluded. This trial showed no evidence that an after-school dance programme can increase the physical activity of Year 7 girls. The trial highlighted the difficulty encountered in maintaining attendance in physical activity programmes delivered in secondary schools. There is a need to find new ways to help adolescent girls to be physically active via identifying ways to support and encourage sustained engagement in physical activity over the life course. ISRCTN52882523.

Capturing Ultraviolet Radiation Exposure and Physical Activity: Feasibility Study and Comparison Between Self-Reports, Mobile Apps, Dosimeters, and Accelerometers.

PubMed

Hacker, Elke; Horsham, Caitlin; Allen, Martin; Nathan, Andrea; Lowe, John; Janda, Monika

2018-04-17

Skin cancer is the most prevalent cancer in Australia. Skin cancer prevention programs aim to reduce sun exposure and increase sun protection behaviors. Effectiveness is usually assessed through self-report. It was the aim of this study to test the acceptance and validity of a newly developed ultraviolet radiation (UVR) exposure app, designed to reduce the data collection burden to research participants. Physical activity data was collected because a strong focus on sun avoidance may result in unhealthy reductions in physical activity. This paper provides lessons learned from collecting data from participants using paper diaries, a mobile app, dosimeters, and accelerometers for measuring end-points of UVR exposure and physical activity. Two participant groups were recruited through social and traditional media campaigns 1) Group A-UVR Diaries and 2) Group B-Physical Activity. In Group A, nineteen participants wore an UVR dosimeter wristwatch (University of Canterbury, New Zealand) when outside for 7 days. They also recorded their sun exposure and physical activity levels using both 1) the UVR diary app and 2) a paper UVR diary. In Group B, 55 participants wore an accelerometer (Actigraph, Pensacola, FL, USA) for 14 days and completed the UVR diary app. Data from the UVR diary app were compared with UVR dosimeter wristwatch, accelerometer, and paper UVR diary data. Cohen kappa coefficient score was used to determine if there was agreement between categorical variables for different UVR data collection methods and Spearman rank correlation coefficient was used to determine agreement between continuous accelerometer data and app-collected self-report physical activity. The mean age of participants in Groups A (n=19) and B (n=55) was 29.3 and 25.4 years, and 63% (12/19) and 75% (41/55) were females, respectively. Self-reported sun exposure data in the UVR app correlated highly with UVR dosimetry (κ=0.83, 95% CI 0.64-1.00, P<.001). Correlation between self-reported UVR app and accelerometer-collected moderate to vigorous physical activity data was low (ρ=0.23, P=.10), while agreement for low-intensity physical activity was significantly different (ρ=-0.49, P<.001). Seventy-nine percent of participants preferred the app over the paper diary for daily self-report of UVR exposure and physical activity. This feasibility study highlights self-report using an UVR app can reliably collect personal UVR exposure, but further improvements are required before the app can also be used to collect physical activity data. ©Elke Hacker, Caitlin Horsham, Martin Allen, Andrea Nathan, John Lowe, Monika Janda. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 17.04.2018.

[Reliability and validity of the PAQ-A questionnaire to assess physical activity in Spanish adolescents].

PubMed

Martínez-Gómez, David; Martínez-de-Haro, Vicente; Pozo, Tamara; Welk, Gregory J; Villagra, Ariel; Calle, Marisa E; Marcos, Ascensión; Veiga, Oscar L

2009-01-01

Questionnaires are feasible instruments to assess physical activity (PA) in large samples. The aim of the current study was to evaluate the reliability and validity of the PAQ-A questionnaire in Spanish adolescents using the measurement of PA by accelerometer as criterion. In a sample of 82 adolescents, aged 12 to 17 years, 1-week PAQ-A test-retest was administered. Reliability was analyzed by the Intraclass Correlation Coefficient (ICC) and the internal consistency by the Cronbach's alpha Coefficient. Two hundred thirty-two adolescents, aged 13-17 years, completed the PAQ-A and wore the ActiGraph GT1M accelerometer during 7-days. The PAQ-A was compared against total PA and moderate to vigorous PA (MVPA) obtained by the accelerometer. Test-retest reliability showed ICC = 0.71 for the final score of PAQ-A. Internal consistency was alpha = 0.65 in the first self-report, alpha = 0.67 in the retest in 82 adolescents sample, and alpha = 0.74 in the 232 adolescents sample. The PAQ-A was moderately correlated with total PA (rho = 0.39) and MVPA (rho= 0.34) assessed by the accelerometer. The PAQ-A obtained significantly moderate correlations in boys but not in girls against the accelerometer. The PAQ-A questionnaire shows an adequate reliability and a reasonable validity for assessing PA in Spanish adolescents.

Classification of accelerometer wear and non-wear events in seconds for monitoring free-living physical activity.

PubMed

Zhou, Shang-Ming; Hill, Rebecca A; Morgan, Kelly; Stratton, Gareth; Gravenor, Mike B; Bijlsma, Gunnar; Brophy, Sinead

2015-05-11

To classify wear and non-wear time of accelerometer data for accurately quantifying physical activity in public health or population level research. A bi-moving-window-based approach was used to combine acceleration and skin temperature data to identify wear and non-wear time events in triaxial accelerometer data that monitor physical activity. Local residents in Swansea, Wales, UK. 50 participants aged under 16 years (n=23) and over 17 years (n=27) were recruited in two phases: phase 1: design of the wear/non-wear algorithm (n=20) and phase 2: validation of the algorithm (n=30). Participants wore a triaxial accelerometer (GeneActiv) against the skin surface on the wrist (adults) or ankle (children). Participants kept a diary to record the timings of wear and non-wear and were asked to ensure that events of wear/non-wear last for a minimum of 15 min. The overall sensitivity of the proposed method was 0.94 (95% CI 0.90 to 0.98) and specificity 0.91 (95% CI 0.88 to 0.94). It performed equally well for children compared with adults, and females compared with males. Using surface skin temperature data in combination with acceleration data significantly improved the classification of wear/non-wear time when compared with methods that used acceleration data only (p<0.01). Using either accelerometer seismic information or temperature information alone is prone to considerable error. Combining both sources of data can give accurate estimates of non-wear periods thus giving better classification of sedentary behaviour. This method can be used in population studies of physical activity in free-living environments. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Accurate prediction of energy expenditure using a shoe-based activity monitor.

PubMed

Sazonova, Nadezhda; Browning, Raymond C; Sazonov, Edward

2011-07-01

The aim of this study was to develop and validate a method for predicting energy expenditure (EE) using a footwear-based system with integrated accelerometer and pressure sensors. We developed a footwear-based device with an embedded accelerometer and insole pressure sensors for the prediction of EE. The data from the device can be used to perform accurate recognition of major postures and activities and to estimate EE using the acceleration, pressure, and posture/activity classification information in a branched algorithm without the need for individual calibration. We measured EE via indirect calorimetry as 16 adults (body mass index=19-39 kg·m) performed various low- to moderate-intensity activities and compared measured versus predicted EE using several models based on the acceleration and pressure signals. Inclusion of pressure data resulted in better accuracy of EE prediction during static postures such as sitting and standing. The activity-based branched model that included predictors from accelerometer and pressure sensors (BACC-PS) achieved the lowest error (e.g., root mean squared error (RMSE)=0.69 METs) compared with the accelerometer-only-based branched model BACC (RMSE=0.77 METs) and nonbranched model (RMSE=0.94-0.99 METs). Comparison of EE prediction models using data from both legs versus models using data from a single leg indicates that only one shoe needs to be equipped with sensors. These results suggest that foot acceleration combined with insole pressure measurement, when used in an activity-specific branched model, can accurately estimate the EE associated with common daily postures and activities. The accuracy and unobtrusiveness of a footwear-based device may make it an effective physical activity monitoring tool.

Weather, day length and physical activity in older adults: Cross-sectional results from the European Prospective Investigation into Cancer and Nutrition (EPIC) Norfolk Cohort.

PubMed

Wu, Yu-Tzu; Luben, Robert; Wareham, Nicholas; Griffin, Simon; Jones, Andy P

2017-01-01

A wide range of environmental factors have been related to active ageing, but few studies have explored the impact of weather and day length on physical activity in older adults. We investigate the cross-sectional association between weather conditions, day length and activity in older adults using a population-based cohort in England, the European Prospective Investigation into Cancer and Nutrition (EPIC) Norfolk study. Physical activity was measured objectively over 7 days using an accelerometer and this was used to calculate daily total physical activity (counts per minute), daily minutes of sedentary behaviour and light, moderate and vigorous physical activity (LMVPA). Day length and two types of weather conditions, precipitation and temperature, were obtained from a local weather station. The association between these variables and physical activity was examined by multilevel first-order autoregressive modelling. After adjusting for individual factors, short day length and poor weather conditions, including high precipitation and low temperatures, were associated with up to 10% lower average physical activity (p<0.01) and 8 minutes less time spent in LMVPA but 15 minutes more sedentary time, compared to the best conditions. Day length and weather conditions appear to be an important factor related to active ageing. Future work should focus on developing potential interventions to reduce their impact on physical activity behaviours in older adults.

Association of Accelerometry-Measured Physical Activity and Cardiovascular Events in Mobility-Limited Older Adults: The LIFE (Lifestyle Interventions and Independence for Elders) Study.

PubMed

Cochrane, Shannon K; Chen, Shyh-Huei; Fitzgerald, Jodi D; Dodson, John A; Fielding, Roger A; King, Abby C; McDermott, Mary M; Manini, Todd M; Marsh, Anthony P; Newman, Anne B; Pahor, Marco; Tudor-Locke, Catrine; Ambrosius, Walter T; Buford, Thomas W

2017-12-02

Data are sparse regarding the value of physical activity (PA) surveillance among older adults-particularly among those with mobility limitations. The objective of this study was to examine longitudinal associations between objectively measured daily PA and the incidence of cardiovascular events among older adults in the LIFE (Lifestyle Interventions and Independence for Elders) study. Cardiovascular events were adjudicated based on medical records review, and cardiovascular risk factors were controlled for in the analysis. Home-based activity data were collected by hip-worn accelerometers at baseline and at 6, 12, and 24 months postrandomization to either a physical activity or health education intervention. LIFE study participants (n=1590; age 78.9±5.2 [SD] years; 67.2% women) at baseline had an 11% lower incidence of experiencing a subsequent cardiovascular event per 500 steps taken per day based on activity data (hazard ratio, 0.89; 95% confidence interval, 0.84-0.96; P =0.001). At baseline, every 30 minutes spent performing activities ≥500 counts per minute (hazard ratio, 0.75; confidence interval, 0.65-0.89 [ P =0.001]) were also associated with a lower incidence of cardiovascular events. Throughout follow-up (6, 12, and 24 months), both the number of steps per day (per 500 steps; hazard ratio, 0.90, confidence interval, 0.85-0.96 [ P =0.001]) and duration of activity ≥500 counts per minute (per 30 minutes; hazard ratio, 0.76; confidence interval, 0.63-0.90 [ P =0.002]) were significantly associated with lower cardiovascular event rates. Objective measurements of physical activity via accelerometry were associated with cardiovascular events among older adults with limited mobility (summary score >10 on the Short Physical Performance Battery) both using baseline and longitudinal data. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01072500. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Energy Expenditure and Intensity of Active Video Games in Children and Adolescents.

PubMed

Canabrava, Karina L R; Faria, Fernanda R; Lima, Jorge R P de; Guedes, Dartagnan P; Amorim, Paulo R S

2018-03-01

This study aimed to compare the energy expenditure and intensity of active video games to that of treadmill walking in children and adolescents. Seventy-two boys and girls (aged 8-13 years) were recruited from local public schools. Energy expenditure and heart rate were measured during rest, during 3-km/hr, 4-km/hr, and 5-km/hr walks, and during active games (Adventure, Boxing I, Boxing II, and Dance). During walking and active games, we also assessed physical activity using an accelerometer. The energy expenditure of the active games Adventure, Boxing I, Boxing II, and Dance was similar to that of treadmill walking at 5 km/hr in boys and girls. Heart rate was significantly higher for the game Adventure compared with walking at 3 km/hr, 4 km/hr, and 5 km/hr and the game Dance in both genders. The heart rate of girls during the games Adventure and Dance was significantly higher compared with boys. There was a statistically significant difference (p < .05, with an effect size ranging from 0.40 to 3.54) in the counts·min -1 , measured through accelerometry, between activities. XBOX 360 Kinect games provide energy expenditure and physical activity of moderate intensity for both genders. The use of active video games can be an interesting alternative to increase physical activity levels.

Comparison of linear and non-linear models for predicting energy expenditure from raw accelerometer data.

PubMed

Montoye, Alexander H K; Begum, Munni; Henning, Zachary; Pfeiffer, Karin A

2017-02-01

This study had three purposes, all related to evaluating energy expenditure (EE) prediction accuracy from body-worn accelerometers: (1) compare linear regression to linear mixed models, (2) compare linear models to artificial neural network models, and (3) compare accuracy of accelerometers placed on the hip, thigh, and wrists. Forty individuals performed 13 activities in a 90 min semi-structured, laboratory-based protocol. Participants wore accelerometers on the right hip, right thigh, and both wrists and a portable metabolic analyzer (EE criterion). Four EE prediction models were developed for each accelerometer: linear regression, linear mixed, and two ANN models. EE prediction accuracy was assessed using correlations, root mean square error (RMSE), and bias and was compared across models and accelerometers using repeated-measures analysis of variance. For all accelerometer placements, there were no significant differences for correlations or RMSE between linear regression and linear mixed models (correlations: r  =  0.71-0.88, RMSE: 1.11-1.61 METs; p  >  0.05). For the thigh-worn accelerometer, there were no differences in correlations or RMSE between linear and ANN models (ANN-correlations: r  =  0.89, RMSE: 1.07-1.08 METs. Linear models-correlations: r  =  0.88, RMSE: 1.10-1.11 METs; p  >  0.05). Conversely, one ANN had higher correlations and lower RMSE than both linear models for the hip (ANN-correlation: r  =  0.88, RMSE: 1.12 METs. Linear models-correlations: r  =  0.86, RMSE: 1.18-1.19 METs; p  <  0.05), and both ANNs had higher correlations and lower RMSE than both linear models for the wrist-worn accelerometers (ANN-correlations: r  =  0.82-0.84, RMSE: 1.26-1.32 METs. Linear models-correlations: r  =  0.71-0.73, RMSE: 1.55-1.61 METs; p  <  0.01). For studies using wrist-worn accelerometers, machine learning models offer a significant improvement in EE prediction accuracy over linear models. Conversely, linear models showed similar EE prediction accuracy to machine learning models for hip- and thigh-worn accelerometers and may be viable alternative modeling techniques for EE prediction for hip- or thigh-worn accelerometers.

Comparability and feasibility of wrist- and hip-worn accelerometers in free-living adolescents.

PubMed

Scott, Joseph J; Rowlands, Alex V; Cliff, Dylan P; Morgan, Philip J; Plotnikoff, Ronald C; Lubans, David R

2017-12-01

To determine the comparability and feasibility of wrist- and hip-worn accelerometers among free-living adolescents. 89 adolescents (age=13-14years old) from eight secondary schools in New South Wales (NSW), Australia wore wrist-worn GENEActiv and hip-worn ActiGraph (GT3X+) accelerometers simultaneously for seven days and completed an accelerometry behavior questionnaire. Bivariate correlations between the wrist- and hip-worn out-put were used to determine concurrent validity. Paired samples t-test were used to compare minutes per day in moderate-to-vigorous physical activity (MVPA). Group means and paired sample t-tests were used to analyze participants' perceptions of the wrist- and hip-worn monitoring protocols to assist with determining the feasibility. Wrist-worn accelerometry compared favorably with the hip-worn in average activity (r=0.88, p<0.001) and MVPA (r=0.84 p<0.001, mean difference=3.54min/day, SD=12.37). The wrist-worn accelerometer had 50% fewer non-valid days (75 days, 12%) than the hip-worn accelerometer (n=152, 24.4%). Participants reported they liked to wear the device on the wrist (p<0.01), and that it was less uncomfortable (p=0.02) and less embarrassing to wear on the wrist (p<0.01). Furthermore, that they would be more willing to wear the device again on the wrist over the hip (p<0.01). Our findings reveal there is a strong linear relationship between wrist- and hip-worn accelerometer out-put among adolescents in free-living conditions. Adolescent compliance was significantly higher with wrist placement, with participants reporting that it was more comfortable and less embarrassing to wear on the wrist. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Moderate-to-Vigorous Physical Activity But Not Sedentary Time Is Associated With Musculoskeletal Health Outcomes in a Cohort of Australian Middle-Aged Women.

PubMed

Wu, Feitong; Wills, Karen; Laslett, Laura L; Oldenburg, Brian; Jones, Graeme; Winzenberg, Tania

2017-04-01

Associations between physical activity and time spent sedentary and musculoskeletal outcomes remain unclear in middle-aged adults. This study aimed to describe associations between objectively-measured physical activity and sedentary time and musculoskeletal health outcomes in middle-aged women. This cross-sectional study from a population-based sample of 309 women (age 36 to 57 years) examined associations of total physical activity (accelerometer counts/min of wear time), and time spent sedentary, in light physical activities and moderate-to-vigorous physical activities (MVPA) (by Actigraph GT1M accelerometer) with lumbar spine (LS) and femoral neck (FN) bone mineral density (BMD) (by dual-energy X-ray absorptiometry), lower limb muscle strength (LMS), and functional mobility and balance tests (timed up and go test [TUG], functional reach test [FRT], lateral reach test [LRT], and step test [ST]) using linear regression. Total physical activity was beneficially associated with FN BMD (values are β; 95% CI) (0.011 g/cm 2 ; 95% CI, 0.003 to 0.019 g/cm 2 ), LMS (2.13 kg; 95% CI, 0.21 to 4.06 kg), and TUG (-0.080 s; 95% CI, -0.129 to -0.030 s), after adjustment for confounders. MVPA was also beneficially associated with FN BMD (0.0050 g/cm 2 ; 95% CI, 0.0007 to 0.0094 g/cm 2 ), LMS (1.48 kg; 95% CI, 0.45 to 2.52 kg), ST (0.12 steps; 95% CI, 0.02 to 0.23 steps), and TUG (-0.043 s; 95% CI, -0.070 to -0.016 s). Associations between MVPA and LMS, TUG and ST persisted after further adjustment for sedentary time. Only TUG was associated with sedentary time, with a detrimental effect (0.075 s; 95% CI, 0.013 to 0.137 s) and this did not persist after further adjustment for MVPA. Light physical activity was not associated with any outcome. MVPA appears more important than light physical activity or sedentary time for many musculoskeletal outcomes in middle-aged women. This needs to be considered when developing interventions to improve habitual physical activity that aim to improve musculoskeletal health. © 2016 American Society for Bone and Mineral Research. © 2016 American Society for Bone and Mineral Research.

Exercise Therapy for Management of Type 2 Diabetes Mellitus: Superior Efficacy of Activity Monitors over Pedometers.

PubMed

Miyauchi, Masaaki; Toyoda, Masao; Kaneyama, Noriko; Miyatake, Han; Tanaka, Eitaro; Kimura, Moritsugu; Umezono, Tomoya; Fukagawa, Masafumi

2016-01-01

We compared the efficacy of activity monitor (which displays exercise intensity and number of steps) versus that of pedometer in exercise therapy for patients with type 2 diabetes. The study subjects were divided into the activity monitor group ( n = 92) and pedometer group ( n = 95). The primary goal was improvement in hemoglobin A1c (HbA1c). The exercise target was set at 8,000 steps/day and 20 minutes of moderate-intensity exercise (≥3.5 metabolic equivalents). The activity monitor is equipped with a triple-axis accelerometer sensor capable of measuring medium-intensity walking duration, number of steps, walking distance, calorie consumption, and total calorie consumption. The pedometer counts the number of steps. Blood samples for laboratory tests were obtained during the visits. The first examination was conducted at the start of the study and repeated at 2 and 6 months. A significant difference in the decrease in HbA1c level was observed between the two groups at 2 months. The results suggest that the use of activity level monitor that displays information on exercise intensity, in addition to the number of steps, is useful in exercise therapy as it enhances the concept of exercise therapy and promotes lowering of HbA1c in diabetic patients.

Recovery of peripheral muscle function from fatiguing exercise and daily physical activity level in patients with multiple sclerosis: a case-control study.

PubMed

Ickmans, Kelly; Simoens, Fauve; Nijs, Jo; Kos, Daphne; Cras, Patrick; Willekens, Barbara; Meeus, Mira

2014-07-01

Delayed recovery of muscle function following exercise has been demonstrated in the lower limbs of patients with multiple sclerosis (MS). However, studies examining this in the upper limbs are currently lacking. This study compared physical activity level (PAL) and recovery of upper limb muscle function following exercise between MS patients and healthy inactive controls. Furthermore, the relationship between PAL and muscle recovery was examined. PAL of 19 MS patients and 32 controls was measured using an accelerometer for 7 consecutive days. Afterwards, recovery of muscle function was assessed by performing a fatiguing upper limb exercise test with subsequent recovery measures. Muscle recovery of the upper limb muscles was similar in both groups. Average activity counts were significantly lower in MS patients than in the control group. MS patients spent significantly more time being sedentary and less time on activities of moderate intensity compared with the control group. No significant correlation between PAL and recovery of muscle function was found in MS patients. Recovery of upper limb muscle function following exercise is normal in MS patients. MS patients are less physically active than healthy inactive controls. PAL and recovery of upper limb muscle function appear unrelated in MS patients. Copyright © 2014 Elsevier B.V. All rights reserved.

Day length is associated with physical activity and sedentary behavior among older women.

PubMed

Schepps, Mitchell A; Shiroma, Eric J; Kamada, Masamitsu; Harris, Tamara B; Lee, I-Min

2018-04-26

Physical activity may be influenced by one's physical environment, including day length and weather. Studies of physical activity, day length, and weather have primarily used self-reported activity, broad meteorological categorization, and limited geographic regions. We aim to examine the association of day length and physical activity in a large cohort of older women, covering a wide geographic range. Participants (N = 16,741; mean (SD) age = 72.0 (SD = 5.7) years) were drawn from the Women's Health Study and lived throughout the United States. Physical activity was assessed by accelerometer (ActiGraph GT3X+) between 2011 and 2015. Day length and weather information were obtained by matching weather stations to the participants' location using National Oceanic and Atmospheric Administration databases. Women who experienced day lengths greater than 14 hours had 5.5% more steps, 9.4% more moderate-to-vigorous physical activity, and 1.6% less sedentary behavior, compared to women who experienced day lengths less than 10 hours, after adjusting for age, accelerometer wear, temperature, and precipitation. Day length is associated with physical activity and sedentary behavior in older women, and needs to be considered in programs promoting physical activity as well as in the analyses of accelerometer data covering wide geographic regions.

Performance of Activity Classification Algorithms in Free-living Older Adults

PubMed Central

Sasaki, Jeffer Eidi; Hickey, Amanda; Staudenmayer, John; John, Dinesh; Kent, Jane A.; Freedson, Patty S.

2015-01-01

Purpose To compare activity type classification rates of machine learning algorithms trained on laboratory versus free-living accelerometer data in older adults. Methods Thirty-five older adults (21F and 14M ; 70.8 ± 4.9 y) performed selected activities in the laboratory while wearing three ActiGraph GT3X+ activity monitors (dominant hip, wrist, and ankle). Monitors were initialized to collect raw acceleration data at a sampling rate of 80 Hz. Fifteen of the participants also wore the GT3X+ in free-living settings and were directly observed for 2-3 hours. Time- and frequency- domain features from acceleration signals of each monitor were used to train Random Forest (RF) and Support Vector Machine (SVM) models to classify five activity types: sedentary, standing, household, locomotion, and recreational activities. All algorithms were trained on lab data (RFLab and SVMLab) and free-living data (RFFL and SVMFL) using 20 s signal sampling windows. Classification accuracy rates of both types of algorithms were tested on free-living data using a leave-one-out technique. Results Overall classification accuracy rates for the algorithms developed from lab data were between 49% (wrist) to 55% (ankle) for the SVMLab algorithms, and 49% (wrist) to 54% (ankle) for RFLab algorithms. The classification accuracy rates for SVMFL and RFFL algorithms ranged from 58% (wrist) to 69% (ankle) and from 61% (wrist) to 67% (ankle), respectively. Conclusion Our algorithms developed on free-living accelerometer data were more accurate in classifying activity type in free-living older adults than our algorithms developed on laboratory accelerometer data. Future studies should consider using free-living accelerometer data to train machine-learning algorithms in older adults. PMID:26673129

Performance of Activity Classification Algorithms in Free-Living Older Adults.

PubMed

Sasaki, Jeffer Eidi; Hickey, Amanda M; Staudenmayer, John W; John, Dinesh; Kent, Jane A; Freedson, Patty S

2016-05-01

The objective of this study is to compare activity type classification rates of machine learning algorithms trained on laboratory versus free-living accelerometer data in older adults. Thirty-five older adults (21 females and 14 males, 70.8 ± 4.9 yr) performed selected activities in the laboratory while wearing three ActiGraph GT3X+ activity monitors (in the dominant hip, wrist, and ankle; ActiGraph, LLC, Pensacola, FL). Monitors were initialized to collect raw acceleration data at a sampling rate of 80 Hz. Fifteen of the participants also wore GT3X+ in free-living settings and were directly observed for 2-3 h. Time- and frequency-domain features from acceleration signals of each monitor were used to train random forest (RF) and support vector machine (SVM) models to classify five activity types: sedentary, standing, household, locomotion, and recreational activities. All algorithms were trained on laboratory data (RFLab and SVMLab) and free-living data (RFFL and SVMFL) using 20-s signal sampling windows. Classification accuracy rates of both types of algorithms were tested on free-living data using a leave-one-out technique. Overall classification accuracy rates for the algorithms developed from laboratory data were between 49% (wrist) and 55% (ankle) for the SVMLab algorithms and 49% (wrist) to 54% (ankle) for the RFLab algorithms. The classification accuracy rates for SVMFL and RFFL algorithms ranged from 58% (wrist) to 69% (ankle) and from 61% (wrist) to 67% (ankle), respectively. Our algorithms developed on free-living accelerometer data were more accurate in classifying the activity type in free-living older adults than those on our algorithms developed on laboratory accelerometer data. Future studies should consider using free-living accelerometer data to train machine learning algorithms in older adults.

Physical functioning in patients with ankylosing spondylitis: comparing approaches of experienced ability with self-reported and objectively measured physical activity.

PubMed

van Genderen, Simon; van den Borne, Carlie; Geusens, Piet; van der Linden, Sjef; Boonen, Annelies; Plasqui, Guy

2014-04-01

Physical functioning can be assessed by different approaches that are characterized by increasing levels of individual appraisal. There is insufficient insight into which approach is the most informative in patients with ankylosing spondylitis (AS) compared with control subjects. The objective of this study was to compare patients with AS and control subjects regarding 3 approaches of functioning: experienced ability to perform activities (Bath Ankylosing Spondylitis Functional Index [BASFI]), self-reported amount of physical activity (PA) (Baecke questionnaire), and the objectively measured amount of PA (triaxial accelerometer). This case-control study included 24 AS patients and 24 control subjects (matched for age, gender, and body mass index). Subjects completed the BASFI and Baecke questionnaire and wore a triaxial accelerometer. Subjects also completed other self-reported measures on disease activity (Bath AS Disease Activity Index), fatigue (Multidimensional Fatigue Inventory), and overall health (EuroQol visual analog scale). Both groups included 14 men (58%), and the mean age was 48 years. Patients scored significantly worse on the BASFI (3.9 vs 0.2) than their healthy peers, whereas PA assessed by Baecke and the accelerometer did not differ between groups. Correlations between approaches of physical functioning were low to moderate. Bath Ankylosing Spondylitis Functional Index was associated with disease activity (r = 0.49) and physical fatigue (0.73) and Baecke with physical and activity related fatigue (r = 0.54 and r = 0.54), but total PA assessed by accelerometer was not associated with any of these experience-based health outcomes. Different approaches of the concept physical functioning in patients with AS provide different information. Compared with matched control subjects, patients with AS report more difficulties but report and objectively perform the same amount of PA.

Physical Activity in Hemodialysis Patients Measured by Triaxial Accelerometer

PubMed Central

Gomes, Edimar Pedrosa; Reboredo, Maycon Moura; Carvalho, Erich Vidal; Teixeira, Daniel Rodrigues; Carvalho, Laís Fernanda Caldi d'Ornellas; Filho, Gilberto Francisco Ferreira; de Oliveira, Julio César Abreu; Sanders-Pinheiro, Helady; Chebli, Júlio Maria Fonseca; de Paula, Rogério Baumgratz; Pinheiro, Bruno do Valle

2015-01-01

Different factors can contribute to a sedentary lifestyle among hemodialysis (HD) patients, including the period they spend on dialysis. The aim of this study was to evaluate characteristics of physical activities in daily life in this population by using an accurate triaxial accelerometer and to correlate these characteristics with physiological variables. Nineteen HD patients were evaluated using the DynaPort accelerometer and compared to nineteen control individuals, regarding the time spent in different activities and positions of daily life and the number of steps taken. HD patients were more sedentary than control individuals, spending less time walking or standing and spending more time lying down. The sedentary behavior was more pronounced on dialysis days. According to the number of steps taken per day, 47.4% of hemodialysis patients were classified as sedentary against 10.5% in control group. Hemoglobin level, lower extremity muscle strength, and physical functioning of SF-36 questionnaire correlated significantly with the walking time and active time. Looking accurately at the patterns of activity in daily life, HDs patients are more sedentary, especially on dialysis days. These patients should be motivated to enhance the physical activity. PMID:26090432

A Web-Based Physical Activity Intervention for Spanish-Speaking Latinas: A Costs and Cost-Effectiveness Analysis.

PubMed

Larsen, Britta; Marcus, Bess; Pekmezi, Dori; Hartman, Sheri; Gilmer, Todd

2017-02-22

Latinas report particularly low levels of physical activity and suffer from greater rates of lifestyle-related conditions such as obesity and diabetes. Interventions are needed that can increase physical activity in this growing population in a large-scale, cost-effective manner. Web-based interventions may have potential given the increase in Internet use among Latinas and the scalability of Web-based programs. To examine the costs and cost-effectiveness of a Web-based, Spanish-language physical activity intervention for Latinas compared to a wellness contact control. Healthy adult Latina women (N=205) were recruited from the community and randomly assigned to receive a Spanish-language, Web-based, individually tailored physical activity intervention (intervention group) or were given access to a website with content on wellness topics other than physical activity (control group). Physical activity was measured using the 7-Day Physical Activity Recall interview and ActiGraph accelerometers at baseline, 6 months (ie, postintervention), and 12 months (ie, maintenance phase). Costs were estimated from a payer perspective and included all features necessary to implement the intervention in a community setting, including staff time (ie, wages, benefits, and overhead), materials, hardware, website hosting, and routine website maintenance. At 6 months, the costs of running the intervention and control groups were US $17 and US $8 per person per month, respectively. These costs fell to US $12 and US $6 per person per month at 12 months, respectively. Linear interpolation showed that intervention participants increased their physical activity by 1362 total minutes at 6 months (523 minutes by accelerometer) compared to 715 minutes for control participants (186 minutes by accelerometer). At 6 months, each minute increase in physical activity for the intervention group cost US $0.08 (US $0.20 by accelerometer) compared to US $0.07 for control participants (US $0.26 by accelerometer). Incremental cost-per-minute increases associated with the intervention were US $0.08 at 6 months and US $0.04 at 12 months (US $0.16 and US $0.08 by accelerometer, respectively). Sensitivity analyses showed variations in staffing costs or intervention effectiveness yielded only modest changes in incremental costs. While the Web-based physical activity intervention was more expensive than the wellness control, both were quite low cost compared to face-to-face or mail-delivered interventions. Cost-effectiveness ranged markedly based on physical activity measure and was similar between the two conditions. Overall, the Web-based intervention was effective and low cost, suggesting a promising channel for increasing physical activity on a large scale in this at-risk population. Clinicaltrials.gov NCT01834287; https://clinicaltrials.gov/ct2/show/NCT01834287 (Archived by WebCite at http://www.webcitation.org/6nyjX9Jrh). ©Britta Larsen, Bess Marcus, Dori Pekmezi, Sheri Hartman, Todd Gilmer. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 22.02.2017.

A Web-Based Physical Activity Intervention for Spanish-Speaking Latinas: A Costs and Cost-Effectiveness Analysis

PubMed Central

Marcus, Bess; Pekmezi, Dori; Hartman, Sheri; Gilmer, Todd

2017-01-01

Background Latinas report particularly low levels of physical activity and suffer from greater rates of lifestyle-related conditions such as obesity and diabetes. Interventions are needed that can increase physical activity in this growing population in a large-scale, cost-effective manner. Web-based interventions may have potential given the increase in Internet use among Latinas and the scalability of Web-based programs. Objective To examine the costs and cost-effectiveness of a Web-based, Spanish-language physical activity intervention for Latinas compared to a wellness contact control. Methods Healthy adult Latina women (N=205) were recruited from the community and randomly assigned to receive a Spanish-language, Web-based, individually tailored physical activity intervention (intervention group) or were given access to a website with content on wellness topics other than physical activity (control group). Physical activity was measured using the 7-Day Physical Activity Recall interview and ActiGraph accelerometers at baseline, 6 months (ie, postintervention), and 12 months (ie, maintenance phase). Costs were estimated from a payer perspective and included all features necessary to implement the intervention in a community setting, including staff time (ie, wages, benefits, and overhead), materials, hardware, website hosting, and routine website maintenance. Results At 6 months, the costs of running the intervention and control groups were US $17 and US $8 per person per month, respectively. These costs fell to US $12 and US $6 per person per month at 12 months, respectively. Linear interpolation showed that intervention participants increased their physical activity by 1362 total minutes at 6 months (523 minutes by accelerometer) compared to 715 minutes for control participants (186 minutes by accelerometer). At 6 months, each minute increase in physical activity for the intervention group cost US $0.08 (US $0.20 by accelerometer) compared to US $0.07 for control participants (US $0.26 by accelerometer). Incremental cost-per-minute increases associated with the intervention were US $0.08 at 6 months and US $0.04 at 12 months (US $0.16 and US $0.08 by accelerometer, respectively). Sensitivity analyses showed variations in staffing costs or intervention effectiveness yielded only modest changes in incremental costs. Conclusions While the Web-based physical activity intervention was more expensive than the wellness control, both were quite low cost compared to face-to-face or mail-delivered interventions. Cost-effectiveness ranged markedly based on physical activity measure and was similar between the two conditions. Overall, the Web-based intervention was effective and low cost, suggesting a promising channel for increasing physical activity on a large scale in this at-risk population. ClinicalTrial Clinicaltrials.gov NCT01834287; https://clinicaltrials.gov/ct2/show/NCT01834287 (Archived by WebCite at http://www.webcitation.org/6nyjX9Jrh) PMID:28228368

Accelerometer-based step initiation control for gait-assist neuroprostheses.

PubMed

Foglyano, Kevin M; Schnellenberger, John R; Kobetic, Rudi; Lombardo, Lisa; Pinault, Gilles; Selkirk, Stephen; Makowski, Nathaniel S; Triolo, Ronald J

2016-01-01

Electrical activation of paralyzed musculature can generate or augment joint movements required for walking after central nervous system trauma. Proper timing of stimulation relative to residual volitional control is critical to usefully affecting ambulation. This study evaluates three-dimensional accelerometers and customized algorithms to detect the intent to step from voluntary movements to trigger stimulation during walking in individuals with significantly different etiologies, mobility limitations, manual dexterities, and walking aids. Three individuals with poststroke hemiplegia or partial spinal cord injury exhibiting varying gait deficits were implanted with multichannel pulse generators to provide joint motions at the hip, knee, and ankle. An accelerometer integrated into the external control unit was used to detect heel strike or walker movement, and wireless accelerometers were used to detect crutch strike. Algorithms were developed for each sensor location to detect intent to step to progress through individualized stimulation patterns. Testing these algorithms produced detection accuracies of at least 90% on both level ground and uneven terrain. All participants use their accelerometer-triggered implanted gait systems in the community; the validation/system testing was completed in the hospital. The results demonstrated that safe, reliable, and convenient accelerometer-based step initiation can be achieved regardless of specific gait deficits, manual dexterities, and walking aids.

Accelerometer Assessment of Physical Activity and Its Association with Physical Function in Older Adults Residing at Assisted Care Facilities.

PubMed

Corcoran, M P; Chui, K K H; White, D K; Reid, K F; Kirn, D; Nelson, M E; Sacheck, J M; Folta, S C; Fielding, R A

2016-01-01

To describe levels of physical activity among older adults residing at assisted care facilities and their association with physical function. Cross-sectional analysis. Assisted care facilities within the greater Boston, MA area. Older adults aged 65 years and older (N = 65). Physical Activity Level (PAL) as defined by quartiles from accelerometry (counts and steps), Short Physical Performance Battery (SPPB) Score, gait speed, and handgrip strength. Participants in the most active accelerometry quartile engaged in 25 minutes/week of moderate to vigorous physical activity (MVPA) and walked 2,150 steps/day. These individuals had an SPPB score, 400 meter walk speed, and handgrip strength that was 3.7-3.9 points, 0.3-0.4 meters/second, and 4.5-5.1 kg greater respectively, than individuals in the lowest activity quartile, who engaged in less than 5 min/wk of MVPA or took fewer than 460 steps/day. Despite engaging in physical activity levels far below current recommendations (150 min/week of MVPA or > 7000 steps/day), the most active older adults in this study exhibited clinically significant differences in physical function relative to their less active peers. While the direction of causality cannot be determined from this cross-sectional study, these findings suggest a strong association between PAL and physical function among older adults residing in an assisted care facility.

Intensity and duration of physical efforts in Physical Education classes.

PubMed

Kremer, Marina Marques; Reichert, Felipe Fossati; Hallal, Pedro Curi

2012-04-01

To evaluate the intensity and duration of physical efforts in Physical Education classes in primary and secondary school. School-based cross-sectional study carried out by means of the observation of 218 Physical Education classes, including a total of 272 students (each one of the students was evaluated three times). The study was carried out in the city of Pelotas (Southern Brazil), between August and December 2009. In order to evaluate the intensity of the efforts, accelerometers were used and the following cut-off points were adopted (in counts per minute): sedentary activities (0-100), light activities (101-2,000), moderate (2,001-4,999), vigorous (5,000-7,999), and very vigorous activities (>8000). The mean duration of the classes was 35.6 minutes (SD 6.0). The mean proportion of time spent in moderate to vigorous physical activity was 32.7% (SD 25.2). Boys (44.1%) were involved significantly more in moderate to vigorous physical activity as compared to girls (21.0%; p<0.01). Students who practice physical activities outside the classes participated more in moderate to vigorous physical activity in the Physical Education classes. Besides the fact that Physical Education classes have a short duration, students practice moderate to vigorous physical activity during one third of the class, with a poor significant contribution to students' level of physical activity.

Three-axis accelerometer package for slimhole and microhole seismic monitoring and surveys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hunter, S.L.; Harben, P.E.

1997-01-07

The development of microdrilling technology, nominally defined as drilling technology for 1-in.-diameter boreholes, shows potential for reducing the cost of drilling monitoring wells. A major question that arises in drilling microholes is if downhole logging and monitoring in general--and downhole seismic surveying in particular--can be conducted in such small holes since the inner working diameter of such a seismic tool could be as small as 0.31 in. A downhole three-component accelerometer package that fits within a 031-in. inner diameter tube has been designed, built, and tested. The package consists of three orthogonally mounted Entran EGA-125-5g piezoresistive silicon micromachined accelerometers withmore » temperature compensation circuitry, downhole amplification, and line drivers mounted in a thin-walled aluminum tube. Accelerometers are commercially available in much smaller package sizes than conventional geophones, but the noise floor is significantly higher than that for the geophones. Cross-well tests using small explosives showed good signal-to-noise ratio in the recorded waveform at various receiver depths with a 1,50-ft source-receiver well separation. For some active downhole surveys, the accelerometer unit would clearly be adequate. It can be reasonably assumed, however, that for less energetic sources and for greater well separations, the high accelerometer noise floor is not acceptable. By expanding the inner working diameter of a microhole seismic tool to 0.5 in., other commercial accelerometers can be used with substantially lower noise floors.« less

Active transportation and public transportation use to achieve physical activity recommendations? A combined GPS, accelerometer, and mobility survey study.

PubMed

Chaix, Basile; Kestens, Yan; Duncan, Scott; Merrien, Claire; Thierry, Benoît; Pannier, Bruno; Brondeel, Ruben; Lewin, Antoine; Karusisi, Noëlla; Perchoux, Camille; Thomas, Frédérique; Méline, Julie

2014-09-27

Accurate information is lacking on the extent of transportation as a source of physical activity, on the physical activity gains from public transportation use, and on the extent to which population shifts in the use of transportation modes could increase the percentage of people reaching official physical activity recommendations. In 2012-2013, 234 participants of the RECORD GPS Study (French Paris region, median age = 58) wore a portable GPS receiver and an accelerometer for 7 consecutive days and completed a 7-day GPS-based mobility survey (participation rate = 57.1%). Information on transportation modes and accelerometry data aggregated at the trip level [number of steps taken, energy expended, moderate to vigorous physical activity (MVPA), and sedentary time] were available for 7,644 trips. Associations between transportation modes and accelerometer-derived physical activity were estimated at the trip level with multilevel linear models. Participants spent a median of 1 h 58 min per day in transportation (8.2% of total time). Thirty-eight per-cent of steps taken, 31% of energy expended, and 33% of MVPA over 7 days were attributable to transportation. Walking and biking trips but also public transportation trips with all four transit modes examined were associated with greater steps, MVPA, and energy expenditure when compared to trips by personal motorized vehicle. Two simulated scenarios, implying a shift of approximately 14% and 33% of all motorized trips to public transportation or walking, were associated with a predicted 6 point and 13 point increase in the percentage of participants achieving the current physical activity recommendation. Collecting data with GPS receivers, accelerometers, and a GPS-based electronic mobility survey of activities and transportation modes allowed us to investigate relationships between transportation modes and physical activity at the trip level. Our findings suggest that an increase in active transportation participation and public transportation use may have substantial impacts on the percentage of people achieving physical activity recommendations.

Classification of motor activities through derivative dynamic time warping applied on accelerometer data.

PubMed

Muscillo, Rossana; Conforto, Silvia; Schmid, Maurizio; Caselli, Paolo; D'Alessio, Tommaso

2007-01-01

In the context of tele-monitoring, great interest is presently devoted to physical activity, mainly of elderly or people with disabilities. In this context, many researchers studied the recognition of activities of daily living by using accelerometers. The present work proposes a novel algorithm for activity recognition that considers the variability in movement speed, by using dynamic programming. This objective is realized by means of a matching and recognition technique that determines the distance between the signal input and a set of previously defined templates. Two different approaches are here presented, one based on Dynamic Time Warping (DTW) and the other based on the Derivative Dynamic Time Warping (DDTW). The algorithm was applied to the recognition of gait, climbing and descending stairs, using a biaxial accelerometer placed on the shin. The results on DDTW, obtained by using only one sensor channel on the shin showed an average recognition score of 95%, higher than the values obtained with DTW (around 85%). Both DTW and DDTW consistently show higher classification rate than classical Linear Time Warping (LTW).

Validity and reliability of the International Physical Activity Questionnaire among adults in Mexico.

PubMed

Medina, Catalina; Barquera, Simón; Janssen, Ian

2013-07-01

To determine the test-retest reliability and validity of the Spanish version of the short-form International Physical Activity Questionnaire (IPAQ) among adults in Mexico. This was a cross-sectional study of a convenience sample of 267 adult factory workers in Mexico City. Participants were 19 - 68 years of age; 48% were female. Participants wore an accelerometer for 9 consecutive days and were administered the Spanish version of the short form IPAQ on two occasions (IPAQ1 and IPAQ2, separated by 9 days). The relation and differences between moderate-to-vigorous physical activity (MVPA) measures obtained from IPAQ1, IPAQ2, and the accelerometer were determined using correlations, linear regression, and paired t-tests. IPAQ1 and IPAQ2 measures of MVPA were significantly correlated to each other (r = 0.55, P < 0.01). However, MVPA was 44 ± 408 minutes/week lower in IPAQ1 than in IPAQ2, although this difference did not reach statistical significance (P = 0.08). The (min/week) measures from IPAQ1 and IPAQ2 were only modestly correlated with the accelerometer measures (r = 0.26 and r = 0.31, P < 0.01), and by comparison to accelerometer measures, MVPA values were higher when based on IPAQ1 (174 ± 357 min/week, P < 0.01) than for IPAQ2 (135 ± 360 min/week, P < 0.01). The percentage of participants who were classified as physically inactive according to the World Health Organization guidelines was 18.0% in IPAQ1, 25.1% in IPAQ2, and 28.2% based on the accelerometer. Similar to what has been observed in other populations, the short form IPAQ has a modest reliability and poor validity for assessing MVPA among Mexican adults.

Self Diagnostic Accelerometer Ground Testing on a C-17 Aircraft Engine

NASA Technical Reports Server (NTRS)

Tokars, Roger P.; Lekki, John D.

2013-01-01

The self diagnostic accelerometer (SDA) developed by the NASA Glenn Research Center was tested for the first time in an aircraft engine environment as part of the Vehicle Integrated Propulsion Research (VIPR) program. The VIPR program includes testing multiple critical flight sensor technologies. One such sensor, the accelerometer, measures vibrations to detect faults in the engine. In order to rely upon the accelerometer, the health of the accelerometer must be ensured. Sensor system malfunction is a significant contributor to propulsion in flight shutdowns (IFSD) which can lead to aircraft accidents when the issue is compounded with an inappropriate crew response. The development of the SDA is important for both reducing the IFSD rate, and hence reducing the rate at which this component failure type can put an aircraft in jeopardy, and also as a critical enabling technology for future automated malfunction diagnostic systems. The SDA is a sensor system designed to actively determine the accelerometer structural health and attachment condition, in addition to making vibration measurements. The SDA uses a signal conditioning unit that sends an electrical chirp to the accelerometer and recognizes changes in the response due to changes in the accelerometer health and attachment condition. In an effort toward demonstrating the SDAs flight worthiness and robustness, multiple SDAs were mounted and tested on a C-17 aircraft engine. The engine test conditions varied from engine off, to idle, to maximum power. The two SDA attachment conditions used were fully tight and loose. The newly developed SDA health algorithm described herein uses cross correlation pattern recognition to discriminate a healthy from a faulty SDA. The VIPR test results demonstrate for the first time the robustness of the SDA in an engine environment characterized by high vibration levels.

Self diagnostic accelerometer ground testing on a C-17 aircraft engine

NASA Astrophysics Data System (ADS)

Tokars, Roger P.; Lekki, John D.

The self diagnostic accelerometer (SDA) developed by the NASA Glenn Research Center was tested for the first time in an aircraft engine environment as part of the Vehicle Integrated Propulsion Research (VIPR) program. The VIPR program includes testing multiple critical flight sensor technologies. One such sensor, the accelerometer, measures vibrations to detect faults in the engine. In order to rely upon the accelerometer, the health of the accelerometer must be ensured. Sensor system malfunction is a significant contributor to propulsion in flight shutdowns (IFSD) which can lead to aircraft accidents when the issue is compounded with an inappropriate crew response. The development of the SDA is important for both reducing the IFSD rate, and hence reducing the rate at which this component failure type can put an aircraft in jeopardy, and also as a critical enabling technology for future automated malfunction diagnostic systems. The SDA is a sensor system designed to actively determine the accelerometer structural health and attachment condition, in addition to making vibration measurements. The SDA uses a signal conditioning unit that sends an electrical chirp to the accelerometer and recognizes changes in the response due to changes in the accelerometer health and attachment condition. In an effort toward demonstrating the SDA's flight worthiness and robustness, multiple SDAs were mounted and tested on a C-17 aircraft engine. The engine test conditions varied from engine off, to idle, to maximum power. The two SDA attachment conditions used were fully tight and loose. The newly developed SDA health algorithm described herein uses cross correlation pattern recognition to discriminate a healthy from a faulty SDA. The VIPR test results demonstrate for the first time the robustness of the SDA in an engine environment characterized by high vibration levels.

The reliability, validity, and feasibility of physical activity measurement in adults with traumatic brain injury: an observational study.

PubMed

Hassett, Leanne; Moseley, Anne; Harmer, Alison; van der Ploeg, Hidde P

2015-01-01

To determine the reliability and validity of the Physical Activity Scale for Individuals with a Physical Disability (PASIPD) in adults with severe traumatic brain injury (TBI) and estimate the proportion of the sample participants who fail to meet the World Health Organization guidelines for physical activity. A single-center observational study recruited a convenience sample of 30 community-based ambulant adults with severe TBI. Participants completed the PASIPD on 2 occasions, 1 week apart, and wore an accelerometer (ActiGraph GT3X; ActiGraph LLC, Pensacola, Florida) for the 7 days between these 2 assessments. The PASIPD test-retest reliability was substantial (intraclass correlation coefficient = 0.85; 95% confidence interval, 0.70-0.92), and the correlation with the accelerometer ranged from too low to be meaningful (R = 0.09) to moderate (R = 0.57). From device-based measurement of physical activity, 56% of participants failed to meet the World Health Organization physical activity guidelines. The PASIPD is a reliable measure of the type of physical activity people with severe TBI participate in, but it is not a valid measure of the amount of moderate to vigorous physical activity in which they engage. Accelerometers should be used to quantify moderate to vigorous physical activity in people with TBI.

Comparing the validity of 2 physical activity questionnaire formats in African-American and Hispanic women.

PubMed

Mâsse, Louise C; Fulton, Janet E; Watson, Kathleen B; Tortolero, Susan; Kohl, Harold W; Meyers, Michael C; Blair, Steven N; Wong, William W

2012-02-01

The purpose of this study was to compare the validity of 2 physical activity questionnaire formats--one that lists activities (Checklist questionnaire) and one that assesses overall activities (Global questionnaire) by domain. Two questionnaire formats were validated among 260 African-American and Hispanic women (age 40-70) using 3 validation standards: 1) accelerometers to validate activities of ambulation; 2) diaries to validate physical activity domains (occupation, household, exercise, yard, family, volunteer/church work, and transportation); and 3) doubly-labeled water to validate physical activity energy expenditure (DLW-PAEE). The proportion of total variance explained by the Checklist questionnaire was 38.4% with diaries, 9.0% with accelerometers, and 6.4% with DLW-PAEE. The Global questionnaire explained 17.6% of the total variance with diaries and about 5% with both accelerometers and with DLWPAEE. Overall, associations with the 3 validation standards were slightly better with the Checklist questionnaire. However, agreement with DLW-PAEE was poor with both formats and the Checklist format resulted in greater overestimation. Validity results also indicated the Checklist format was better suited to recall household, family, and transportation activities. Overall, the Checklist format had slightly better measurement properties than the Global format. Both questionnaire formats are better suited to rank individuals.

Acceptability and Feasibility of Physical Activity Assessment Methods for an Appalachian Population

PubMed Central

Tarasenko, Yelena N.; Howell, Britteny M.; Studts, Christina R.; Strath, Scott J.; Schoenberg, Nancy E.

2015-01-01

Nowhere is improving understanding and accurate assessment of physical activity more important for disease prevention and health promotion than among health disparities populations such as those residing in rural and Appalachian regions. To enhance accurate assessment of physical activity and potentially improve intervention capacity, we conducted a mixed-methods study examining the acceptability and feasibility of self-report physical activity questionnaires, pedometers, and accelerometers among rural Appalachian children, adolescents, and adults. Most participants reported positive experiences with all three physical activity assessment tools. Several acceptability ratings differed by age group and by sex within each age group. With very few exceptions, no significant differences in acceptability were found by race, education, employment status, health status, BMI categories, income levels, or insurance status within age groups or overall. Several factors may impact the choice of the physical activity assessment method, including target population age, equipment cost, researcher burden, and potential influence on physical activity levels. Children and adolescents appear to have more constraints on when they can wear pedometers and accelerometers. While pedometers are inexpensive and convenient, they may influence physical activity levels, rather than simply measure them. Accelerometers, while less influential on behavior, consume extensive resources, including high purchase costs and researcher burden. PMID:25608476

Nicotine Dependence, Physical Activity, and Sedentary Behavior among Adult Smokers

PubMed Central

Loprinzi, Paul D.; Walker, Jerome F.

2015-01-01

Background: Research has previously demonstrated an inverse association between smoking status and physical activity; however, few studies have examined the association between nicotine dependence and physical activity or sedentary behavior. Aim: This study examined the association between nicotine dependence and accelerometer-determined physical activity and sedentary behavior. Materials and Methods: Data from the 2003-2006 National Health and Nutrition Examination Survey (NHANES) were used. A total of 851 adult (≥20 years) smokers wore an accelerometer for ≥4 days and completed the Fagerstrom Test for Nicotine Dependence scale. Regression models were used to examine the association between nicotine dependence and physical activity/sedentary behavior. Results: After adjusting for age, gender, race-ethnicity, poverty level, hypertension, emphysema, bronchitis, body mass index (BMI), cotinine, and accelerometer wear time, smokers 50 + years of age with greater nicotine dependence engaged in more sedentary behavior (β = 11.4, P = 0.02) and less light-intensity physical activity (β = −9.6, P = 0.03) and moderate-to-vigorous physical activity (MVPA; β = −0.14, P = 0.003) than their less nicotine dependent counterparts. Conclusion: Older adults who are more nicotine dependent engage in less physical activity (both MVPA and light-intensity) and more sedentary behavior than their less nicotine dependent counterparts. PMID:25839000

Criterion-related validity of the short form of the international physical activity questionnaire in adults who are Deaf.

PubMed

Menezes, Diogo; Laranjo, Luís; Marmeleira, José

2017-01-01

To implement appropriate programs for promoting physical activity (PA) in people who are Deaf, it is important to have valid instruments for assessing PA in this population. The main purpose of this study was to examine the criterion validity of the short form of the International Physical Activity Questionnaire (IPAQ-S) in Deaf adults. This study included 44 adults (18-65 years) of both genders (63.6% were females) who met the inclusion criteria. Objective measures of PA were collected using accelerometers, which were worn by each participant during one week. After using the accelerometer, the IPAQ-S was applied to assess participants' physical activity during the last 7 days. There was no significant correlation between the average time spent in moderate to vigorous physical activity (MVPA) as measured by the accelerometer (40.1 ± 24.5 min/day) and by the IPAQ-S (41.3 ± 57.5 min/day). The IPAQ-S significantly underestimated the time spent in sedentary behavior (7.6 ± 2.7 h/day vs. 10.1 ± 1.6 h/day). Sedentary behavior and MVPA as measured by the accelerometer and the IPAQ-S showed limited agreement. Our results show some limitations on the use of IPAQ-S for quantifying PA among adults who are Deaf. The IPAQ-S tends to overestimate the MVPA and to underestimate sedentary behavior in adults who are Deaf. Copyright © 2016 Elsevier Inc. All rights reserved.

Estimating Energy Expenditure with the RT3 Triaxial Accelerometer

ERIC Educational Resources Information Center

Maddison, Ralph; Jiang, Yannan; Vander Hoorn, Stephen; Mhurchu, Cliona Ni; Lawes, Carlene M. M.; Rodgers, Anthony; Rush, Elaine

2009-01-01

The RT3 is a relatively new triaxial accelerometer that has replaced the TriTrac. The aim of this study was to validate the RT3 against doubly labeled water (DLW) in a free-living, mixed weight sample of adults. Total energy expenditure (TEE) was measured over a 15-day period using DLW. Activity-related energy expenditure (AEE) was estimated by…

Prediction models discriminating between nonlocomotive and locomotive activities in children using a triaxial accelerometer with a gravity-removal physical activity classification algorithm.

PubMed

Hikihara, Yuki; Tanaka, Chiaki; Oshima, Yoshitake; Ohkawara, Kazunori; Ishikawa-Takata, Kazuko; Tanaka, Shigeho

2014-01-01

The aims of our study were to examine whether a gravity-removal physical activity classification algorithm (GRPACA) is applicable for discrimination between nonlocomotive and locomotive activities for various physical activities (PAs) of children and to prove that this approach improves the estimation accuracy of a prediction model for children using an accelerometer. Japanese children (42 boys and 26 girls) attending primary school were invited to participate in this study. We used a triaxial accelerometer with a sampling interval of 32 Hz and within a measurement range of ±6 G. Participants were asked to perform 6 nonlocomotive and 5 locomotive activities. We measured raw synthetic acceleration with the triaxial accelerometer and monitored oxygen consumption and carbon dioxide production during each activity with the Douglas bag method. In addition, the resting metabolic rate (RMR) was measured with the subject sitting on a chair to calculate metabolic equivalents (METs). When the ratio of unfiltered synthetic acceleration (USA) and filtered synthetic acceleration (FSA) was 1.12, the rate of correct discrimination between nonlocomotive and locomotive activities was excellent, at 99.1% on average. As a result, a strong linear relationship was found for both nonlocomotive (METs = 0.013×synthetic acceleration +1.220, R2 = 0.772) and locomotive (METs = 0.005×synthetic acceleration +0.944, R2 = 0.880) activities, except for climbing down and up. The mean differences between the values predicted by our model and measured METs were -0.50 to 0.23 for moderate to vigorous intensity (>3.5 METs) PAs like running, ball throwing and washing the floor, which were regarded as unpredictable PAs. In addition, the difference was within 0.25 METs for sedentary to mild moderate PAs (<3.5 METs). Our specific calibration model that discriminates between nonlocomotive and locomotive activities for children can be useful to evaluate the sedentary to vigorous PAs intensity of both nonlocomotive and locomotive activities.

Quantifying functional mobility progress for chronic disease management.

PubMed

Boyle, Justin; Karunanithi, Mohan; Wark, Tim; Chan, Wilbur; Colavitti, Christine

2006-01-01

A method for quantifying improvements in functional mobility is presented based on patient-worn accelerometer devices. For patients with cardiovascular, respiratory, or other chronic disease, increasing the amount of functional mobility is a large component of rehabilitation programs. We have conducted an observational trial on the use of accelerometers for quantifying mobility improvements in a small group of chronic disease patients (n=15, 48 - 86 yrs). Cognitive impairments precluded complex instrumentation of patients, and movement data was obtained from a single 2-axis accelerometer device worn at the hip. In our trial, movement data collected from accelerometer devices was classified into Lying vs Sitting/Standing vs Walking/Activity movements. This classification enabled the amount of walking to be quantified and graphically presented to clinicians and carers for feedback on exercise efficacy. Presenting long term trends in this data to patients also provides valuable feedback for self managed care and assisting with compliance.

Objectively Assessed Physical Activity and its Association with Balance, Physical Function and Dyskinesia in Parkinson's Disease.

PubMed

Nero, Håkan; Benka Wallén, Martin; Franzén, Erika; Conradsson, David; Ståhle, Agneta; Hagströmer, Maria

2016-10-19

The desirable effects of physical activity in individuals with Parkinson's disease are well-known, although according to results from previous studies factors associated with objectively assessed physical activity are not fully investigated. To investigate demographic, disease-related and mobility-related factors that associate with objectively measured physical activity, in a sample of older adults with mild to moderate Parkinson's disease. Demographic, disease-related and mobility-related factors were gathered by interview from a total of 91 older adults with Parkinson's disease, followed by an evaluation of balance control using the Mini-BESTest. After initial testing, participants wore a tri-axial accelerometer during a week of free-living. Correlation analysis and multiple linear regression was used to investigate factors associated with total PA, represented by total activity counts, and time in brisk walking. Motor impairment, physical function, body mass index and dyskinesia contributed to the variance of total physical activity, explaining 34 % of the variance, while physical function and balance control were significant factors associated with brisk walking, explaining 22 %. This study identified factors that have not been shown to associate with objectively measured physical activity previously, such as dyskinesia, balance control and self-rated physical function. The findings also demonstrated that associated factors differ, depending on the activity behavior being investigated. However, other factors than those included in this study may also be of importance.

Association of physical activity in the past year and immediately after in vitro fertilization on pregnancy.

PubMed

Evenson, Kelly R; Calhoun, Kathryn C; Herring, Amy H; Pritchard, David; Wen, Fang; Steiner, Anne Z

2014-04-01

To estimate the association of physical activity on in vitro fertilization (IVF). Prospective cohort study. Academic infertility clinic. Women (n = 121) undergoing nondonor IVF embryo transfer (fresh or frozen). The women completed a questionnaire on past year physical activity and wore an accelerometer from embryo transfer to serum pregnancy testing. Implantation, intrauterine gestation, and live birth. Based on self-reported past year physical activity, the adjusted odds of intrauterine gestation was higher among those that had higher continuous active living (odds ratio [OR] 1.96, 95% confidence interval [CI] 1.09-3.50), sports/exercise (OR 1.48, CI 1.02-2.15), and total activity (OR 1.52, 95%CI 1.15-2.01) indices. After embryo transfer, women did almost no vigorous activity (median 0 min/d) as measured by the accelerometer. More of their time was spent in light activity (median 3.0 h/d) and sedentary behaviors (median 9.3 h/d). Accelerometer-measured physical activity and sedentary behavior after embryo transfer were not associated with any IVF outcome. An active lifestyle in the preceding year favorably impacted the IVF outcome. After embryo transfer, women engaged in mostly light physical activity and sedentary behaviors; therefore, the impact of vigorous physical activity on implantation could not be determined. Copyright © 2014 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Disparity between functional recovery and daily use of the upper and lower extremities during subacute stroke rehabilitation

PubMed Central

Rand, Debbie; Eng, Janice J.

2011-01-01

Background Although inpatient rehabilitation may enhance an individual’s functional ability after stroke, it is not known whether these improvements are accompanied by an increase in daily use of the arms and legs. Objective To determine the change in daily use of the upper and lower extremities of stroke patients during rehabilitation and to compare these values with that of community-dwelling older adults. Methods A total of 60 stroke patients underwent functional assessments and also wore 3 accelerometers for 3 consecutive weekdays on admission to rehabilitation and 3 weeks later prior to hospital discharge. The number of steps and upper-extremity activity counts were measured over the waking hours and during daily use for occupational therapy and physical therapy (PT) sessions. Healthy older adults (n = 40) also wore 3 accelerometers for 5 consecutive days. Results Stroke patients demonstrated a significant increase in mobility function, and this was accompanied by an increase in daily walking over the entire day as well as in PT. However, increases in daily walking were found predominantly in patients who were wheelchair users (and not walkers) at the time of admission. Control walking values (5202 steps) were more than 17 times that of stroke patients. Despite significant improvements in paretic hand function, no increase in daily use of the paretic or nonparetic hand was found over the entire day or in PT. Conclusions. A disparity between functional recovery and increases in daily use of the upper and lower extremities was found during inpatient stroke rehabilitation. PMID:21693771

Health Monitors for Chronic Disease by Gait Analysis with Mobile Phones

PubMed Central

Juen, Joshua; Cheng, Qian; Prieto-Centurion, Valentin; Krishnan, Jerry A.

2014-01-01

Abstract We have developed GaitTrack, a phone application to detect health status while the smartphone is carried normally. GaitTrack software monitors walking patterns, using only accelerometers embedded in phones to record spatiotemporal motion, without the need for sensors external to the phone. Our software transforms smartphones into health monitors, using eight parameters of phone motion transformed into body motion by the gait model. GaitTrack is designed to detect health status while the smartphone is carried during normal activities, namely, free-living walking. The current method for assessing free-living walking is medical accelerometers, so we present evidence that mobile phones running our software are more accurate. We then show our gait model is more accurate than medical pedometers for counting steps of patients with chronic disease. Our gait model was evaluated in a pilot study involving 30 patients with chronic lung disease. The six-minute walk test (6MWT) is a major assessment for chronic heart and lung disease, including congestive heart failure and especially chronic obstructive pulmonary disease (COPD), affecting millions of persons. The 6MWT consists of walking back and forth along a measured distance for 6 minutes. The gait model using linear regression performed with 94.13% accuracy in measuring walk distance, compared with the established standard of direct observation. We also evaluated a different statistical model using the same gait parameters to predict health status through lung function. This gait model has high accuracy when applied to demographic cohorts, for example, 89.22% accuracy testing the cohort of 12 female patients with ages 50–64 years. PMID:24694291

Rates of attrition, non-compliance and missingness in randomized controlled trials of child physical activity interventions using accelerometers: A brief methodological review.

PubMed

Howie, Erin K; Straker, Leon M

2016-10-01

The purpose of this brief review was to describe the missingness, from both attrition and non-compliance, during physical activity randomized controlled trials among children which have used accelerometers to measure physical activity. Systematic review. Using a previously published search strategy, an updated search of the literature was performed in the MEDLINE database for articles published from 1996 to February 2015 identifying physical activity RCTs in children (ages 2-18) measuring physical activity using accelerometers. Rates of attrition and non-compliance were extracted from identified articles. Twenty-three independent studies provided complete attrition and non-compliance data and were included. The mean attrition rate was 11.5% (SD 10.1%, range 0-30.9%). The mean accelerometer non-compliance rate at baseline was 22.7% (SD 16.4%, range 1.7-67.8%) and 29.6% (SD 19.4%, range 3.3-70.1%) at follow-up. The mean total study missingness was 37.4% (SD 20.2%, range 3.3-75.4%) and ranged from 3.3% to 75.4%. There was large variation in how missingness was accounted for between studies. There were no statistically significant differences in missingness between study characteristics including sample size, participant age, intervention setting, duration of follow-up, whether physical activity was the primary outcome, and weartime compliance criteria. Missingness is common among randomized controlled trials using accelerometry in children and is currently handled inconsistently. Researchers must plan for high levels of missingness in study design and account for missingness in reporting and analyses of trial outcomes. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Impaired chronotropic response to physical activities in heart failure patients.

PubMed

Shen, Hong; Zhao, Jianrong; Zhou, Xiaohong; Li, Jingbo; Wan, Qing; Huang, Jing; Li, Hui; Wu, Liqun; Yang, Shungang; Wang, Ping

2017-05-25

While exercise-based cardiac rehabilitation has a beneficial effect on heart failure hospitalization and mortality, it is limited by the presence of chronotropic incompetence (CI) in some patients. This study explored the feasibility of using wearable devices to assess impaired chronotropic response in heart failure patients. Forty patients with heart failure (left ventricular ejection fraction, LVEF: 44.6 ± 5.8; age: 54.4 ± 11.7) received ECG Holter and accelerometer to monitor heart rate (HR) and physical activities during symptom-limited treadmill exercise testing, 6-min hall walk (6MHW), and 24-h daily living. CI was defined as maximal HR during peak exercise testing failing to reach 70% of age-predicted maximal HR (APMHR, 220 - age). The correlation between HR and physical activities in Holter-accelerometer recording was analyzed. Of 40 enrolled patients, 26 were able to perform treadmill exercise testing. Based on exercise test reports, 13 (50%) of 26 patients did not achieve at least 70% of APMHR (CI patients). CI patients achieved a lower % APMHR (62.0 ± 6.3%) than non-CI patients who achieved 72.0 ± 1.2% of APMHR (P < 0.0001). When Holter-accelerometer recording was used to assess chronotropic response, the percent APMHR achieved during 6MHW and physical activities was significantly lower in CI patients than in non-CI patients. CI patients had a significantly shorter 6MHW distance and less physical activity intensity than non-CI patients. The study found impaired chronotropic response in 50% of heart failure patients who took treadmill exercise testing. The wearable Holter-accelerometer recording could help to identify impaired chronotropic response to physical activities in heart failure patients. ClinicalTrials.gov ID NCT02358603 . Registered 16 May 2014.

Accelerometer-Measured Physical Activity and Sedentary Time Differ According to Education Level in Young Adults

PubMed Central

Kantomaa, Marko T.; Tikanmäki, Marjaana; Kankaanpää, Anna; Vääräsmäki, Marja; Sipola-Leppänen, Marika; Ekelund, Ulf; Hakonen, Harto; Järvelin, Marjo-Riitta; Kajantie, Eero; Tammelin, Tuija H.

2016-01-01

This study examined the association of education level with objectively measured physical activity and sedentary time in young adults. Data from the Finnish ESTER study (2009–2011) (n = 538) was used to examine the association between educational attainment and different subcomponents of physical activity and sedentary time measured using hip-worn accelerometers (ActiGraph GT1M) for seven consecutive days. Overall physical activity, moderate-to-vigorous physical activity (MVPA), light-intensity physical activity and sedentary time were calculated separately for weekdays and weekend days. A latent profile analysis was conducted to identify the different profiles of sedentary time and the subcomponents of physical activity. The educational differences in accelerometer-measured physical activity and sedentary time varied according to the subcomponents of physical activity, and between weekdays and weekend days. A high education level was associated with high MVPA during weekdays and weekend days in both sexes, high sedentary time during weekdays in both sexes, and a low amount of light-intensity physical activity during weekdays in males and during weekdays and weekend days in females. The results indicate different challenges related to unhealthy behaviours in young adults with low and high education: low education is associated with a lack of MVPA, whereas high education is associated with a lack of light-intensity physical activity and high sedentary time especially during weekdays. PMID:27403958

Effects of message framing on self-report and accelerometer-assessed physical activity across age and gender groups.

PubMed

Li, Kin-Kit; Cheng, Sheung-Tak; Fung, Helene H

2014-02-01

This study compared message-framing effects on physical activity (PA) across age and gender groups. Participants included 111 younger and 100 older adults (68% were women), randomly assigned to read gain-framed or loss-framed PA messages in promotion pamphlets, and who wore accelerometers for the following 14 days. Using regression analyses controlling for demographic and health factors, we found significant age-by-gender-by-framing interactions predicting self-report (B = -4.39, p = .01) and accelerometer-assessed PA (B = -2.44, p = .02) during the follow-up period. Gain-framed messages were more effective than loss-framed messages in promoting PA behaviors only among older men. We speculated that the age-related positivity effect, as well as the age and gender differences in issue involvement, explained the group differences in framing. In addition, more time availability and higher self-efficacy among older men might have contributed to the results.

Classification of Sporting Activities Using Smartphone Accelerometers

PubMed Central

Mitchell, Edmond; Monaghan, David; O'Connor, Noel E.

2013-01-01

In this paper we present a framework that allows for the automatic identification of sporting activities using commonly available smartphones. We extract discriminative informational features from smartphone accelerometers using the Discrete Wavelet Transform (DWT). Despite the poor quality of their accelerometers, smartphones were used as capture devices due to their prevalence in today's society. Successful classification on this basis potentially makes the technology accessible to both elite and non-elite athletes. Extracted features are used to train different categories of classifiers. No one classifier family has a reportable direct advantage in activity classification problems to date; thus we examine classifiers from each of the most widely used classifier families. We investigate three classification approaches; a commonly used SVM-based approach, an optimized classification model and a fusion of classifiers. We also investigate the effect of changing several of the DWT input parameters, including mother wavelets, window lengths and DWT decomposition levels. During the course of this work we created a challenging sports activity analysis dataset, comprised of soccer and field-hockey activities. The average maximum F-measure accuracy of 87% was achieved using a fusion of classifiers, which was 6% better than a single classifier model and 23% better than a standard SVM approach. PMID:23604031

Association of diabetic peripheral arterial disease and objectively-measured physical activity: NHANES 2003-2004

PubMed Central

2014-01-01

Background Although much is known about the management of peripheral arterial disease among adults in the general population, the management of this disease among those with diabetes, and the effects of diabetic-induced peripheral arterial disease on objectively-measured physical activity, is unclear. Here, we examined the association between accelerometer-assessed physical activity and peripheral arterial disease among a national sample of U.S. adults with diabetes. Methods Data from the 2003–2004 National Health and Nutrition Examination Survey were used. Physical activity was measured using an accelerometer in 254 adults with diabetes. Peripheral arterial disease was assessed via ankle brachial index. Negative binomial regression analysis was used to examine the association between physical activity and peripheral arterial disease. Results Results were adjusted for age, gender, race-ethnicity, comorbidity index, smoking, HgbA1C, C-reactive protein, homocysteine, glomerular filtration rate, microalbuminuria, peripheral neuropathy, physical functioning, and medication use. After adjustments, participants with peripheral arterial disease engaged in 23% less physical activity (RR = 0.77, 95% CI: 0.62-0.96) than those without peripheral arterial disease. Conclusions These findings demonstrate an inverse association between accelerometer-assessed physical activity and peripheral arterial disease in a national sample of U.S adults with diabetes. PMID:24967220

Physical activity monitoring in stroke: SenseWear Pro2 activity accelerometer versus Yamax Digi-Walker SW-200 pedometer.

PubMed

Vanroy, Christel; Vissers, Dirk; Cras, Patrick; Beyne, Saskia; Feys, Hilde; Vanlandewijck, Yves; Truijen, Steven

2014-01-01

Determine validity and reliability of SenseWear Pro2 Armband (SWP2A) and Yamax Digi-Walker SW-200 Pedometer (YDWP) in stroke and healthy adults. Fifteen stroke patients and 15 healthy participants wore SWP2A on upper arm and YDWP at hip/knee. Different activities were performed: treadmill walking, walking up/down a step, cycling and walking on an even surface. Steps and Energy Expenditure (EE) were measured and compared to steps counted manually and indirect calorimetry. Repeated measurements were compared to determine reliability of both devices. Spearman correlation coefficients between knee-worn YDWP and counted steps while walking on an even surface was ≥0.89 in healthy and ≥0.95 in stroke. Treadmill walking revealed high Spearman correlation coefficients in healthy individuals (rs ≥ 0.90) and at 1.5 km/h in stroke (rs = 0.69). During other activities YDWP often underestimated steps. SWP2A data revealed inconsistent results in EE and steps. Reliability tested by repeated measurements varied between 0.66 and 0.98 for YDWP and 0.61 and 0.97 for SWP2A. YDWP and SWP2A are both reliable. Only knee-worn YDWP is a valid device to measure steps except high intensity walking in stroke. YDWP systematically undercounts steps during other activities of short duration. This study could not demonstrate valid measurement of steps/EE in stroke using SWP2A. Implications for Rehabilitation Stroke is a disabling disease with residual neurologic deficits, which impairs mobility and predisposes them to sedentary behavior. A Yamax Digi-Walker SW-200 knee-worn pedometer showed to be a valid and reliable technique to measure ambulatory activity in stroke. A valid instrument to measure energy expenditure in stroke needs to be explored.

Objective Longitudinal Measures of Physical Activity and Bone Health in Older Japanese: the Nakanojo Study.

PubMed

Shephard, Roy J; Park, Hyuntae; Park, Sungjin; Aoyagi, Yukitoshi

2017-04-01

To examine dose/response relationships between habitual physical activity and bone health in the elderly. Longitudinal. Community of Nakanojo. Community-living Japanese aged 65 to 84 (212 men, 284 women). Daily 24-h pedometer/accelerometer data were collected continuously for 5 years. A quantitative calcaneal osteosonic index (OSI) was determined annually. Year-end OSI values were higher in those with greater daily step counts and especially a greater duration of activity >3 metabolic equivalents (METs). However, after controlling for baseline OSI, age and body mass, final OSI values were not significantly greater in the fourth than in the third activity quartile, where men and women, respectively, took means of 7,700 and 7,500 steps/day and/or exercised at an intensity >3 METs for means of 19 and 17 min/day. A multivariate-adjusted proportional hazards model predicted that the OSI values of men and women were, respectively, 2.6 (1.4-4.4) and 3.3 (2.1-5.2) and/or 2.8 (1.5-5.6) and 3.9 (2.4-6.7) times more likely to drop below the OSI fracture threshold over 5 years in the two lowest activity quartiles (<7,000 and <6,900 steps/day and/or <18 and <17 min/day at >3 METs) than in the highest quartile (>9,100 and >8,800 steps/day and/or >30 and >25 min/day at >3 METs). After adjustment for potential confounders, the calcaneal health of seniors is associated with both the daily step count and the duration of activity at an intensity >3 METs. The bone health is optimal in elderly people who take at least 7,000-8,000 steps/day and/or spend at least 15-20 min/day at an intensity >3 METs. © 2016, Copyright the Authors Journal compilation © 2016, The American Geriatrics Society.

School travel mode, parenting practices and physical activity among UK Year 5 and 6 children

PubMed Central

2014-01-01

Background School travel mode and parenting practices have been associated with children’s physical activity (PA). The current study sought to examine whether PA parenting practices differ by school travel mode and whether school travel mode and PA parenting practices are associated with PA. Methods 469 children (aged 9-11) wore accelerometers from which mean weekday and after-school (3.30 to 8.30 pm) minutes of moderate-to-vigorous intensity PA (MVPA) and counts per minute (CPM) were derived. Mode of travel to and from school (passive vs. active) and PA parenting practices (maternal and paternal logistic support and modelling behaviour) were child-reported. Results Children engaged in an average of 59.7 minutes of MVPA per weekday. Active travel to school by girls was associated with 5.9 more minutes of MVPA per day compared with those who travelled to school passively (p = 0.004). After-school CPM and MVPA did not differ by school travel mode. There was no evidence that physical activity parenting practices were associated with school travel mode. Conclusions For girls, encouraging active travel to school is likely to be important for overall PA. Further formative research may be warranted to understand how both parental logistic support and active travel decisions are operationalized in families as a means of understanding how to promote increased PA among pre-adolescent children. PMID:24739338

The association between physical activity and sleep characteristics in people with multiple sclerosis.

PubMed

Aburub, Aseel; Khalil, Hanan; Al-Sharman, Alham; Alomari, Mahmoud; Khabour, Omar

2017-02-01

The majority of individuals with multiple sclerosis (MS) suffer from sleep disorders. In this study, we investigated the relationship between physical activity and sleep characteristics in MS patients. Sixty MS patients were recruited in the study. Sleep characteristics were assessed using the Actisleep device while physical activity levels were assessed using mobility accelerometer. The results showed that means (±SD) of sleep latency (SL) and sleep efficiency (ES) for MS patients were 23.89±13.23min and 87.52±76.89% respectively. The participants' total time in sleep (TST) and wake after sleep onset (WASO) were 353.25±63.98min and 83.84±42.23min respectively. With respect to physical activity levels, means (±SD) of light (LA), moderate (MA), vigorous (VA) activities and moderate to vigorous physical activity (MVPA) were 11,660.15±18,145, 212.04±148.67, 9.70±9.26 and 222.88±154.60 counts per minute, respectively. Pearson's correlation analysis showed that WASO correlated significantly with LA, MA and MVPA (P<0.05). These correlations remained significant even after accounting for age, body weight and disease severity (P<0.05). The results show a positive relationship of physical activity with sleep parameters in individuals with MS. Copyright © 2017 Elsevier B.V. All rights reserved.

Objectively assessing treadmill walking during the second and third pregnancy trimesters.

PubMed

DiNallo, Jennifer M; Downs, Danielle Symons; Le Masurier, Guy

2012-01-01

To effectively promote physical activity (PA) and quantify the effects of PA interventions for pregnant women, PA measurement during pregnancy needs improvement. The purpose of this study was to assess PA monitor output during a controlled, treadmill walking protocol among pregnant women at 20- and 32-weeks gestation. Women (N = 43) wore an Actigraph accelerometer, NL1000, and Yamax pedometer during a 20-minute treadmill walking test [5-minute periods at 4 different speeds (54, 67, 80, and 94 m·min(-1))] at 20- and 32-weeks gestation. Repeated-measures ANOVAs indicated that Actigraph total counts/minute and minutes of moderate-vigorous PA (MVPA), NL1000 steps and minutes MVPA, and Yamax steps decreased from 20- to 32-weeks gestation (P ≤ .05), while body girth circumference and activity monitor tilt increased (P ≤ .05). Repeated measures ANCOVAs, controlling for changes in body girth and monitor tilt, yielded no significant differences in any outcome measures from 20- to 32-weeks gestation. Preliminary results suggest physical changes during pregnancy impact activity monitor output in controlled settings. Accurately measuring and statistically controlling for changes in body girth at monitor placement site and monitor tilt may improve the accuracy of activity monitors for use with pregnant populations.

Building spatial layout that supports healthier behavior of office workers: a new performance mandate for sustainable buildings.

PubMed

Hua, Ying; Yang, Eunhwa

2014-01-01

The pursuit of efficiency and the permeation of communication technologies in modern workplace have increased prolonged sitting and physical inactivity among the white-collar workforce. Physical inactivity is a major risk factor for developing various chronic diseases and obesity. This study intends to understand the impact of physical environment on both voluntary and imperative physical activity levels in an office building, and to collect evidence for design suggestions to encourage office workers' activity level on a daily basis. This study examined how proximity from individual workstations to various shared service and amenity spaces in the workplace (e.g., meeting spaces, copy areas, kitchens, restrooms, elevators, and stairs) is associated with office workers' physical activity level (e.g., sedentary and non-sedentary behavior) and their environmental and job satisfaction. To objectively measure physical activity, twenty-six office workers, in a three-story office building, wore accelerometers for three consecutive days at work. Environmental and job satisfaction of office workers was measured by a questionnaire. Proximity variables were measured using the floor plans of the subject building. Participants on average were sedentary for 80% of the time during the study. Proximity to several service and amenity areas was positively associated with step counts and job satisfaction.

Comparing accelerometer, pedometer and a questionnaire for measuring physical activity in bronchiectasis: a validity and feasibility study?

PubMed

O'Neill, B; McDonough, S M; Wilson, J J; Bradbury, I; Hayes, K; Kirk, A; Kent, L; Cosgrove, D; Bradley, J M; Tully, M A

2017-01-14

There are challenges for researchers and clinicians to select the most appropriate physical activity tool, and a balance between precision and feasibility is needed. Currently it is unclear which physical activity tool should be used to assess physical activity in Bronchiectasis. The aim of this research is to compare assessment methods (pedometer and IPAQ) to our criterion method (ActiGraph) for the measurement of physical activity dimensions in Bronchiectasis (BE), and to assess their feasibility and acceptability. Patients in this analysis were enrolled in a cross-sectional study. The ActiGraph and pedometer were worn for seven consecutive days and the IPAQ was completed for the same period. Statistical analyses were performed using SPSS 20 (IBM). Descriptive statistics were used; the percentage agreement between ActiGraph and the other measures were calculated using limits of agreement. Feedback about the feasibility of the activity monitors and the IPAQ was obtained. There were 55 (22 male) data sets available. For step count there was no significant difference between the ActiGraph and Pedometer, however, total physical activity time (mins) as recorded by the ActiGraph was significantly higher than the pedometer (mean ± SD, 232 (75) vs. 63 (32)). Levels of agreement between the two devices was very good for step count (97% agreement); and variation in the levels of agreement were within accepted limits of ±2 standard deviations from the mean value. IPAQ reported more bouted- moderate - vigorous physical activity (MVPA) [mean, SD; 167(170) vs 6(9) mins/day], and significantly less sedentary time than ActiGraph [mean, SD; 362(115) vs 634(76) vmins/day]. There were low levels of agreement between the two tools (57% sedentary behaviour; 0% MVPA 10+ ), with IPAQ under-reporting sedentary behaviour and over-reporting MVPA 10+ compared to ActiGraph. The monitors were found to be feasible and acceptable by participants and researchers; while the IPAQ was accepta ble to use, most patients required assistance to complete it. Accurate measurement of physical activity is feasible in BE and will be valuable for future trials of therapeutic interventions. ActiGraph or pedometer could be used to measure simple daily step counts, but ActiGraph was superior as it measured intensity of physical activity and was a more precise measure of time spent walking. The IPAQ does not appear to represent an accurate measure of physical activity in this population. Clinical Trials Registration Number NCT01569009 : Physical Activity in Bronchiectasis.

How many days of monitoring predict physical activity and sedentary behaviour in older adults?

PubMed Central

2011-01-01

Background The number of days of pedometer or accelerometer data needed to reliably assess physical activity (PA) is important for research that examines the relationship with health. While this important research has been completed in young to middle-aged adults, data is lacking in older adults. Further, data determining the number of days of self-reports PA data is also void. The purpose of this study was to examine the number of days needed to predict habitual PA and sedentary behaviour across pedometer, accelerometer, and physical activity log (PA log) data in older adults. Methods Participants (52 older men and women; age = 69.3 ± 7.4 years, range= 55-86 years) wore a Yamax Digiwalker SW-200 pedometer and an ActiGraph 7164 accelerometer while completing a PA log for 21 consecutive days. Mean differences each instrument and intensity between days of the week were examined using separate repeated measures analysis of variance for with pairwise comparisons. Spearman-Brown Prophecy Formulae based on Intraclass Correlations of .80, .85, .90 and .95 were used to predict the number of days of accelerometer or pedometer wear or PA log daily records needed to represent total PA, light PA, moderate-to-vigorous PA, and sedentary behaviour. Results Results of this study showed that three days of accelerometer data, four days of pedometer data, or four days of completing PA logs are needed to accurately predict PA levels in older adults. When examining time spent in specific intensities of PA, fewer days of data are needed for accurate prediction of time spent in that activity for ActiGraph but more for the PA log. To accurately predict average daily time spent in sedentary behaviour, five days of ActiGraph data are needed. Conclusions The number days of objective (pedometer and ActiGraph) and subjective (PA log) data needed to accurately estimate daily PA in older adults was relatively consistent. Despite no statistical differences between days for total PA by the pedometer and ActiGraph, the magnitude of differences between days suggests that day of the week cannot be completely ignored in the design and analysis of PA studies that involve < 7-day monitoring protocols for these instruments. More days of accelerometer data were needed to determine typical sedentary behaviour than PA level in this population of older adults. PMID:21679426

How many days of monitoring predict physical activity and sedentary behaviour in older adults?

PubMed

Hart, Teresa L; Swartz, Ann M; Cashin, Susan E; Strath, Scott J

2011-06-16

The number of days of pedometer or accelerometer data needed to reliably assess physical activity (PA) is important for research that examines the relationship with health. While this important research has been completed in young to middle-aged adults, data is lacking in older adults. Further, data determining the number of days of self-reports PA data is also void. The purpose of this study was to examine the number of days needed to predict habitual PA and sedentary behaviour across pedometer, accelerometer, and physical activity log (PA log) data in older adults. Participants (52 older men and women; age = 69.3 ± 7.4 years, range= 55-86 years) wore a Yamax Digiwalker SW-200 pedometer and an ActiGraph 7164 accelerometer while completing a PA log for 21 consecutive days. Mean differences each instrument and intensity between days of the week were examined using separate repeated measures analysis of variance for with pairwise comparisons. Spearman-Brown Prophecy Formulae based on Intraclass Correlations of .80, .85, .90 and .95 were used to predict the number of days of accelerometer or pedometer wear or PA log daily records needed to represent total PA, light PA, moderate-to-vigorous PA, and sedentary behaviour. Results of this study showed that three days of accelerometer data, four days of pedometer data, or four days of completing PA logs are needed to accurately predict PA levels in older adults. When examining time spent in specific intensities of PA, fewer days of data are needed for accurate prediction of time spent in that activity for ActiGraph but more for the PA log. To accurately predict average daily time spent in sedentary behaviour, five days of ActiGraph data are needed. The number days of objective (pedometer and ActiGraph) and subjective (PA log) data needed to accurately estimate daily PA in older adults was relatively consistent. Despite no statistical differences between days for total PA by the pedometer and ActiGraph, the magnitude of differences between days suggests that day of the week cannot be completely ignored in the design and analysis of PA studies that involve < 7-day monitoring protocols for these instruments. More days of accelerometer data were needed to determine typical sedentary behaviour than PA level in this population of older adults.

Characterizing performance of ultra-sensitive accelerometers

NASA Technical Reports Server (NTRS)

Sebesta, Henry

1990-01-01

An overview is given of methodology and test results pertaining to the characterization of ultra sensitive accelerometers. Two issues are of primary concern. The terminology ultra sensitive accelerometer is used to imply instruments whose noise floors and resolution are at the state of the art. Hence, the typical approach of verifying an instrument's performance by measuring it with a yet higher quality instrument (or standard) is not practical. Secondly, it is difficult to find or create an environment with sufficiently low background acceleration. The typical laboratory acceleration levels will be at several orders of magnitude above the noise floor of the most sensitive accelerometers. Furthermore, this background must be treated as unknown since the best instrument available is the one to be tested. A test methodology was developed in which two or more like instruments are subjected to the same but unknown background acceleration. Appropriately selected spectral analysis techniques were used to separate the sensors' output spectra into coherent components and incoherent components. The coherent part corresponds to the background acceleration being measured by the sensors being tested. The incoherent part is attributed to sensor noise and data acquisition and processing noise. The method works well for estimating noise floors that are 40 to 50 dB below the motion applied to the test accelerometers. The accelerometers being tested are intended for use as feedback sensors in a system to actively stabilize an inertial guidance component test platform.

Are Currently Available Wearable Devices for Activity Tracking and Heart Rate Monitoring Accurate, Precise, and Medically Beneficial?

PubMed Central

El-Amrawy, Fatema

2015-01-01

Objectives The new wave of wireless technologies, fitness trackers, and body sensor devices can have great impact on healthcare systems and the quality of life. However, there have not been enough studies to prove the accuracy and precision of these trackers. The objective of this study was to evaluate the accuracy, precision, and overall performance of seventeen wearable devices currently available compared with direct observation of step counts and heart rate monitoring. Methods Each participant in this study used three accelerometers at a time, running the three corresponding applications of each tracker on an Android or iOS device simultaneously. Each participant was instructed to walk 200, 500, and 1,000 steps. Each set was repeated 40 times. Data was recorded after each trial, and the mean step count, standard deviation, accuracy, and precision were estimated for each tracker. Heart rate was measured by all trackers (if applicable), which support heart rate monitoring, and compared to a positive control, the Onyx Vantage 9590 professional clinical pulse oximeter. Results The accuracy of the tested products ranged between 79.8% and 99.1%, while the coefficient of variation (precision) ranged between 4% and 17.5%. MisFit Shine showed the highest accuracy and precision (along with Qualcomm Toq), while Samsung Gear 2 showed the lowest accuracy, and Jawbone UP showed the lowest precision. However, Xiaomi Mi band showed the best package compared to its price. Conclusions The accuracy and precision of the selected fitness trackers are reasonable and can indicate the average level of activity and thus average energy expenditure. PMID:26618039

Are Currently Available Wearable Devices for Activity Tracking and Heart Rate Monitoring Accurate, Precise, and Medically Beneficial?

PubMed

El-Amrawy, Fatema; Nounou, Mohamed Ismail

2015-10-01

The new wave of wireless technologies, fitness trackers, and body sensor devices can have great impact on healthcare systems and the quality of life. However, there have not been enough studies to prove the accuracy and precision of these trackers. The objective of this study was to evaluate the accuracy, precision, and overall performance of seventeen wearable devices currently available compared with direct observation of step counts and heart rate monitoring. Each participant in this study used three accelerometers at a time, running the three corresponding applications of each tracker on an Android or iOS device simultaneously. Each participant was instructed to walk 200, 500, and 1,000 steps. Each set was repeated 40 times. Data was recorded after each trial, and the mean step count, standard deviation, accuracy, and precision were estimated for each tracker. Heart rate was measured by all trackers (if applicable), which support heart rate monitoring, and compared to a positive control, the Onyx Vantage 9590 professional clinical pulse oximeter. The accuracy of the tested products ranged between 79.8% and 99.1%, while the coefficient of variation (precision) ranged between 4% and 17.5%. MisFit Shine showed the highest accuracy and precision (along with Qualcomm Toq), while Samsung Gear 2 showed the lowest accuracy, and Jawbone UP showed the lowest precision. However, Xiaomi Mi band showed the best package compared to its price. The accuracy and precision of the selected fitness trackers are reasonable and can indicate the average level of activity and thus average energy expenditure.

A step-defined sedentary lifestyle index: <5000 steps/day.

PubMed

Tudor-Locke, Catrine; Craig, Cora L; Thyfault, John P; Spence, John C

2013-02-01

Step counting (using pedometers or accelerometers) is widely accepted by researchers, practitioners, and the general public. Given the mounting evidence of the link between low steps/day and time spent in sedentary behaviours, how few steps/day some populations actually perform, and the growing interest in the potentially deleterious effects of excessive sedentary behaviours on health, an emerging question is "How many steps/day are too few?" This review examines the utility, appropriateness, and limitations of using a reoccurring candidate for a step-defined sedentary lifestyle index: <5000 steps/day. Adults taking <5000 steps/day are more likely to have a lower household income and be female, older, of African-American vs. European-American heritage, a current vs. never smoker, and (or) living with chronic disease and (or) disability. Little is known about how contextual factors (e.g., built environment) foster such low levels of step-defined physical activity. Unfavorable indicators of body composition and cardiometabolic risk have been consistently associated with taking <5000 steps/day. The acute transition (3-14 days) of healthy active young people from higher (>10 000) to lower (<5000 or as low as 1500) daily step counts induces reduced insulin sensitivity and glycemic control, increased adiposity, and other negative changes in health parameters. Although few alternative values have been considered, the continued use of <5000 steps/day as a step-defined sedentary lifestyle index for adults is appropriate for researchers and practitioners and for communicating with the general public. There is little evidence to advocate any specific value indicative of a step-defined sedentary lifestyle index in children and adolescents.

Non-intrusive Shock Measurements Using Laser Doppler Vibrometers

NASA Technical Reports Server (NTRS)

Statham, Shannon M.; Kolaini, Ali R.

2012-01-01

Stud mount accelerometers are widely used by the aerospace industry to measure shock environments during hardware qualification. The commonly used contact-based sensors, however, interfere with the shock waves and distort the acquired signature, which is a concern not actively discussed in the community. To alleviate these interference issues, engineers at the Jet Propulsion Laboratory are investigating the use of non-intrusive sensors, specifically Laser Doppler Vibrometers, as alternatives to the stud mounted accelerometers. This paper will describe shock simulation tests completed at the Jet Propulsion Laboratory, compare the measurements from stud mounted accelerometers and Laser Doppler Vibrometers, and discuss the advantages and disadvantages of introducing Laser Doppler Vibrometers as alternative sensors for measuring shock environments.

Optimal Sensor Placement for Measuring Physical Activity with a 3D Accelerometer

PubMed Central

Boerema, Simone T.; van Velsen, Lex; Schaake, Leendert; Tönis, Thijs M.; Hermens, Hermie J.

2014-01-01

Accelerometer-based activity monitors are popular for monitoring physical activity. In this study, we investigated optimal sensor placement for increasing the quality of studies that utilize accelerometer data to assess physical activity. We performed a two-staged study, focused on sensor location and type of mounting. Ten subjects walked at various walking speeds on a treadmill, performed a deskwork protocol, and walked on level ground, while simultaneously wearing five ProMove2 sensors with a snug fit on an elastic waist belt. We found that sensor location, type of activity, and their interaction-effect affected sensor output. The most lateral positions on the waist belt were the least sensitive for interference. The effect of mounting was explored, by making two subjects repeat the experimental protocol with sensors more loosely fitted to the elastic belt. The loose fit resulted in lower sensor output, except for the deskwork protocol, where output was higher. In order to increase the reliability and to reduce the variability of sensor output, researchers should place activity sensors on the most lateral position of a participant's waist belt. If the sensor hampers free movement, it may be positioned slightly more forward on the belt. Finally, sensors should be fitted tightly to the body. PMID:24553085

What is the relation between fear of falling and physical activity in older adults?

PubMed

Hornyak, Victoria; Brach, Jennifer S; Wert, David M; Hile, Elizabeth; Studenski, Stephanie; Vanswearingen, Jessie M

2013-12-01

To describe the association between fear of falling (FOF) and total daily activity in older adults. Cross-sectional observational study. Ambulatory clinical research training center. Community-dwelling older adults aged ≥64 years (N=78), who were independent in ambulation with or without an assistive device. Not applicable. FOF was defined by self-reported fear ratings using the Survey of Activities and Fear of Falling in the Elderly and self-reported fear status determined by response to the following question: Are you afraid of falling? Physical function was assessed using the Late Life Function and Disability Instrument. Physical activity was recorded using an accelerometer worn on the waist for 7 consecutive days, and mean daily counts of activity per minute were averaged over the 7-day period. Fear ratings were related to total daily activity (r=-.26, P=.02). The relation was not as strong as the relation of function and physical activity (r=.45, P<.001). When stratified by exercise status or functional status, fear was no longer related to total daily activity. Physical function explained 19% of the variance in physical activity, whereas the addition of fear status did not add to the explained variance in physical activity. FOF is related to total daily physical activity; however, FOF was not independently associated with physical activity when accounting for physical function. Some FOF may be reported as a limitation in function. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Validity of the occupational sitting and physical activity questionnaire.

PubMed

Chau, Josephine Y; Van Der Ploeg, Hidde P; Dunn, Scott; Kurko, John; Bauman, Adrian E

2012-01-01

Sitting at work is an emerging occupational health risk. Few instruments designed for use in population-based research measure occupational sitting and standing as distinct behaviors. This study aimed to develop and validate brief measure of occupational sitting and physical activity. A convenience sample (n = 99, 61% female) was recruited from two medium-sized workplaces and by word-of-mouth in Sydney, Australia. Participants completed the newly developed Occupational Sitting and Physical Activity Questionnaire (OSPAQ) and a modified version of the MONICA Optional Study on Physical Activity Questionnaire (modified MOSPA-Q) twice, 1 wk apart. Participants also wore an ActiGraph accelerometer for the 7 d in between the test and retest. Analyses determined test-retest reliability with intraclass correlation coefficients and assessed criterion validity against accelerometers using the Spearman ρ. The test-retest intraclass correlation coefficients for occupational sitting, standing, and walking for OSPAQ ranged from 0.73 to 0.90, while that for the modified MOSPA-Q ranged from 0.54 to 0.89. Comparison of sitting measures with accelerometers showed higher Spearman correlations for the OSPAQ (r = 0.65) than for the modified MOSPA-Q (r = 0.52). Criterion validity correlations for occupational standing and walking measures were comparable for both instruments with accelerometers (standing: r = 0.49; walking: r = 0.27-0.29). The OSPAQ has excellent test-retest reliability and moderate validity for estimating time spent sitting and standing at work and is comparable to existing occupational physical activity measures for assessing time spent walking at work. The OSPAQ brief instrument measures sitting and standing at work as distinct behaviors and would be especially suitable in national health surveys, prospective cohort studies, and other studies that are limited by space constraints for questionnaire items.

Using wireless technology in clinical practice: does feedback of daily walking activity improve walking outcomes of individuals receiving rehabilitation post-stroke? Study protocol for a randomized controlled trial

PubMed Central

2013-01-01

Background Regaining independent ambulation is the top priority for individuals recovering from stroke. Thus, physical rehabilitation post-stroke should focus on improving walking function and endurance. However, the amount of walking completed by individuals with stroke attending rehabilitation is far below that required for independent community ambulation. There has been increased interest in accelerometer-based monitoring of walking post-stroke. Walking monitoring could be integrated within the goal-setting process for those with ambulation goals in rehabilitation. The feedback from these devices can be downloaded to a computer to produce reports. The purpose of this study is to determine the effect of accelerometer-based feedback of daily walking activity during rehabilitation on the frequency and duration of walking post-stroke. Methods Participants will be randomly assigned to one of two groups: feedback or no feedback. Participants will wear accelerometers daily during in- and out-patient rehabilitation and, for participants in the feedback group, the participants’ treating physiotherapist will receive regular reports of walking activity. The primary outcome measures are the amount of daily walking completed, as measured using the accelerometers, and spatio-temporal characteristics of walking (e.g. walking speed). We will also examine goal attainment, satisfaction with progress towards goals, stroke self-efficacy, and community-integration. Discussion Increased walking activity during rehabilitation is expected to improve walking function and community re-integration following discharge. In addition, a focus on altering walking behaviour within the rehabilitation setting may lead to altered behaviour and increased activity patterns after discharge. Trial registration ClinicalTrials.gov NCT01521234 PMID:23865593

Declared and real physical activity in patients with type 2 diabetes mellitus as assessed by the International Physical Activity Questionnaire and Caltrac accelerometer monitor: a potential tool for physical activity assessment in patients with type 2 diabetes mellitus.

PubMed

Mynarski, W; Psurek, A; Borek, Z; Rozpara, M; Grabara, M; Strojek, K

2012-10-01

The aims of this study were to assess and compare declared and real volume of physical activity (PA), and to evaluate correlations of these measurements with glycemic control (HbA1c) and body mass index (BMI), in patients with type 2 diabetes mellitus (T2DM). A group of 31 (16 women and 15 men) type 2 diabetic patients treated with insulin monotherapy, from (mean age=54 ± 3.6 years, BMI=29.7 ± 4.8 kg/m(2), T2DM treatment=9 ± 8 years, HbA1c 7 ± 1%) and not professionally active (unemployed or retired) was recruited. An assessment of energy cost (EC) of their weekly PA using International Physical Activity Questionnaire (IPAQ), and an accelerometer assessment was performed. Total energy expenditure of the declared weekly PA, calculated from the IPAQ (DPA) was 2513 ± 1349 METmin/week, and 2428 ± 1348, for male and female participants, respectively (p > 0.05). EC of the real PA (RPA), registered with the accelerometer was 4552 ± 2028 kcal/week, and 4032 ± 2288 kcal/week, for males, and females, respectively. Patients who demonstrated a high DPA, based on their IPAQ score, showed a significantly higher RPA, as registered by the accelerometer (p < 0.05). HbA1c and BMI did not correlate with their PA measurements. Our findings indicate that the IPAQ may serve as a potential tool for physical activity assessment with no further requirement for more sophisticated methods. Our results suggest that habitual physical activity has no impact on glycemic control and BMI in type 2 diabetic patients. However, further studies on a larger population are needed to explore these issues. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Feasibility and Performance Test of a Real-Time Sensor-Informed Context-Sensitive Ecological Momentary Assessment to Capture Physical Activity.

PubMed

Dunton, Genevieve Fridlund; Dzubur, Eldin; Intille, Stephen

2016-06-01

Objective physical activity monitors (eg, accelerometers) have high rates of nonwear and do not provide contextual information about behavior. This study tested performance and value of a mobile phone app that combined objective and real-time self-report methods to measure physical activity using sensor-informed context-sensitive ecological momentary assessment (CS-EMA). The app was programmed to prompt CS-EMA surveys immediately after 3 types of events detected by the mobile phone's built-in motion sensor: (1) Activity (ie, mobile phone movement), (2) No-Activity (ie, mobile phone nonmovement), and (3) No-Data (ie, mobile phone or app powered off). In addition, the app triggered random (ie, signal-contingent) ecological momentary assessment (R-EMA) prompts (up to 7 per day). A sample of 39 ethnically diverse high school students in the United States (aged 14-18, 54% female) tested the app over 14 continuous days during nonschool time. Both CS-EMA and R-EMA prompts assessed activity type (eg, reading or doing homework, eating or drinking, sports or exercising) and contextual characteristics of the activity (eg, location, social company, purpose). Activity was also measured with a waist-worn Actigraph accelerometer. The average CS-EMA + R-EMA prompt compliance and survey completion rates were 80.5% and 98.5%, respectively. More moderate-to-vigorous intensity physical activity was recorded by the waist-worn accelerometer in the 30 minutes before CS-EMA activity prompts (M=5.84 minutes) than CS-EMA No-Activity (M=1.11 minutes) and CS-EMA No-Data (M=0.76 minute) prompts (P's<.001). Participants were almost 5 times as likely to report going somewhere (ie, active or motorized transit) in the 30 minutes before CS-EMA Activity than R-EMA prompts (odds ratio=4.91, 95% confidence interval=2.16-11.12). Mobile phone apps using motion sensor-informed CS-EMA are acceptable among high school students and may be used to augment objective physical activity data collected from traditional waist-worn accelerometers.

Web-Based Physical Activity Intervention for Latina Adolescents: Feasibility, Acceptability, and Potential Efficacy of the Niñas Saludables Study.

PubMed

Larsen, Britta; Benitez, Tanya; Cano, Mayra; Dunsiger, Shira S; Marcus, Bess H; Mendoza-Vasconez, Andrea; Sallis, James F; Zive, Michelle

2018-05-09

Physical activity is markedly low in Latina adolescents, yet few physical activity interventions have been attempted in this population. Web-based interventions can incorporate theory-based components, be appealing to adolescents, and have potential for low-cost dissemination. This study aimed to assess the feasibility, acceptability, and potential efficacy of a Web-based physical activity intervention for Latina adolescents in a single-arm pilot trial. A total of 21 Latina adolescents (aged 12-18 years) who could read and write in English and were underactive (<90 min/week) participated in a 12-week, theory-informed Web-based physical activity intervention. The intervention website was modified from a previous Web-based intervention for Latina adults. Web content was individually tailored based on the responses to monthly questionnaires. Feasibility was measured by recruitment, retention, and adherence/engagement, and acceptability was measured by satisfaction surveys. Physical activity was measured at baseline and follow-up (12 weeks) using the 7-day physical activity recall (PAR) interview and accelerometers. Baseline activity as measured by the 7-day PAR and accelerometers was 24.7 (SD 26.11) and 24.8 (SD 38.3) min/week, respectively. At 12 weeks, 19 participants (90%, 19/21) returned. Adherence and engagement with materials were low, but 72% (15/21) of the participants indicated that they were satisfied with the intervention. Activity at 12 weeks increased by 58.8 (SD 11.33) min/week measured by the 7-day PAR (P<.001). Accelerometer-measured activity did not increase. Activities reported at follow-up were more varied than at baseline, including some activities measured poorly by accelerometers (eg, biking and swimming). Participants suggested simplifying the website and incorporating other technologies. Good retention and increases in self-reported activity suggest a promising approach to delivering a physical activity intervention to Latina adolescents. Incorporating other technologies, such as smartphone apps, could make the intervention more engaging, acceptable, and effective. ©Britta Larsen, Tanya Benitez, Mayra Cano, Shira S Dunsiger, Bess H Marcus, Andrea Mendoza-Vasconez, James F Sallis, Michelle Zive. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 09.05.2018.

Feasibility and Performance Test of a Real-Time Sensor-Informed Context-Sensitive Ecological Momentary Assessment to Capture Physical Activity

PubMed Central

Dzubur, Eldin; Intille, Stephen

2016-01-01

Background Objective physical activity monitors (eg, accelerometers) have high rates of nonwear and do not provide contextual information about behavior. Objective This study tested performance and value of a mobile phone app that combined objective and real-time self-report methods to measure physical activity using sensor-informed context-sensitive ecological momentary assessment (CS-EMA). Methods The app was programmed to prompt CS-EMA surveys immediately after 3 types of events detected by the mobile phone’s built-in motion sensor: (1) Activity (ie, mobile phone movement), (2) No-Activity (ie, mobile phone nonmovement), and (3) No-Data (ie, mobile phone or app powered off). In addition, the app triggered random (ie, signal-contingent) ecological momentary assessment (R-EMA) prompts (up to 7 per day). A sample of 39 ethnically diverse high school students in the United States (aged 14-18, 54% female) tested the app over 14 continuous days during nonschool time. Both CS-EMA and R-EMA prompts assessed activity type (eg, reading or doing homework, eating or drinking, sports or exercising) and contextual characteristics of the activity (eg, location, social company, purpose). Activity was also measured with a waist-worn Actigraph accelerometer. Results The average CS-EMA + R-EMA prompt compliance and survey completion rates were 80.5% and 98.5%, respectively. More moderate-to-vigorous intensity physical activity was recorded by the waist-worn accelerometer in the 30 minutes before CS-EMA activity prompts (M=5.84 minutes) than CS-EMA No-Activity (M=1.11 minutes) and CS-EMA No-Data (M=0.76 minute) prompts (P’s<.001). Participants were almost 5 times as likely to report going somewhere (ie, active or motorized transit) in the 30 minutes before CS-EMA Activity than R-EMA prompts (odds ratio=4.91, 95% confidence interval=2.16-11.12). Conclusions Mobile phone apps using motion sensor–informed CS-EMA are acceptable among high school students and may be used to augment objective physical activity data collected from traditional waist-worn accelerometers. PMID:27251313

Weather, day length and physical activity in older adults: Cross-sectional results from the European Prospective Investigation into Cancer and Nutrition (EPIC) Norfolk Cohort

PubMed Central

Wu, Yu-Tzu; Luben, Robert; Wareham, Nicholas; Griffin, Simon; Jones, Andy P.

2017-01-01

Background A wide range of environmental factors have been related to active ageing, but few studies have explored the impact of weather and day length on physical activity in older adults. We investigate the cross-sectional association between weather conditions, day length and activity in older adults using a population-based cohort in England, the European Prospective Investigation into Cancer and Nutrition (EPIC) Norfolk study. Methods Physical activity was measured objectively over 7 days using an accelerometer and this was used to calculate daily total physical activity (counts per minute), daily minutes of sedentary behaviour and light, moderate and vigorous physical activity (LMVPA). Day length and two types of weather conditions, precipitation and temperature, were obtained from a local weather station. The association between these variables and physical activity was examined by multilevel first-order autoregressive modelling. Results After adjusting for individual factors, short day length and poor weather conditions, including high precipitation and low temperatures, were associated with up to 10% lower average physical activity (p<0.01) and 8 minutes less time spent in LMVPA but 15 minutes more sedentary time, compared to the best conditions. Conclusion Day length and weather conditions appear to be an important factor related to active ageing. Future work should focus on developing potential interventions to reduce their impact on physical activity behaviours in older adults. PMID:28562613

Physical Activity Is Positively Associated with Episodic Memory in Aging.

PubMed

Hayes, Scott M; Alosco, Michael L; Hayes, Jasmeet P; Cadden, Margaret; Peterson, Kristina M; Allsup, Kelly; Forman, Daniel E; Sperling, Reisa A; Verfaellie, Mieke

2015-11-01

Aging is associated with performance reductions in executive function and episodic memory, although there is substantial individual variability in cognition among older adults. One factor that may be positively associated with cognition in aging is physical activity. To date, few studies have objectively assessed physical activity in young and older adults, and examined whether physical activity is differentially associated with cognition in aging. Young (n=29, age 18-31 years) and older adults (n=31, ages 55-82 years) completed standardized neuropsychological testing to assess executive function and episodic memory capacities. An experimental face-name relational memory task was administered to augment assessment of episodic memory. Physical activity (total step count and step rate) was objectively assessed using an accelerometer, and hierarchical regressions were used to evaluate relationships between cognition and physical activity. Older adults performed more poorly on tasks of executive function and episodic memory. Physical activity was positively associated with a composite measure of visual episodic memory and face-name memory accuracy in older adults. Physical activity associations with cognition were independent of sedentary behavior, which was negatively correlated with memory performance. Physical activity was not associated with cognitive performance in younger adults. Physical activity is positively associated with episodic memory performance in aging. The relationship appears to be strongest for face-name relational memory and visual episodic memory, likely attributable to the fact that these tasks make strong demands on the hippocampus. The results suggest that physical activity relates to cognition in older, but not younger adults.

Correlates of US adult physical activity and sedentary behavior patterns.

PubMed

Jones, Sydney A; Wen, Fang; Herring, Amy H; Evenson, Kelly R

2016-12-01

Physical activity and sedentary behavior patterns may be differentially associated with socio-demographic and health measures. We explored correlates of day-to-day patterns over a week in accelerometer measured physical activity and sedentary behavior to inform intervention development. Cross-sectional study. National Health and Nutrition Examination Survey (NHANES) adult participants (≥20 years) in 2003-2006 wore an accelerometer for 1 week. Accelerometer data from 7236 participants were used to derive latent classes describing day-to-day patterns over a week of physical activity and sedentary behavior. Correlates of each pattern were identified using multinomial logistic regression from 21 potential variables grouped into four domains: socio-demographic, acculturation, cardiovascular, and health history. Older age, female sex, higher body mass index, and history of chronic disease were consistently associated with lower odds of being in a more active compared to the least active class. In contrast, being employed, speaking Spanish at home, and having better self-rated health were associated with higher odds of being in a more active compared to the least active class. Correlates of physical activity and sedentary behavior patterns were identified from all domains (socio-demographic, acculturation, cardiovascular, and health history). Most correlates that were positively associated with physical activity were negatively associated with sedentary behavior. Better understanding of the correlates of physical activity and sedentary behavior patterns can inform interventions to promote physical activity and reduce sedentary behavior. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

High performance, accelerometer-based control of the Mini-MAST structure at Langley Research Center

NASA Technical Reports Server (NTRS)

Collins, Emmanuel G., Jr.; King, James A.; Phillips, Douglas J.; Hyland, David C.

1991-01-01

Many large space system concepts will require active vibration control to satisfy critical performance requirements such as line of sight pointing accuracy and constraints on rms surface roughness. In order for these concepts to become operational, it is imperative that the benefits of active vibration control be shown to be practical in ground based experiments. The results of an experiment shows the successful application of the Maximum Entropy/Optimal Projection control design methodology to active vibration control for a flexible structure. The testbed is the Mini-Mast structure at NASA-Langley and has features dynamically traceable to future space systems. To maximize traceability to real flight systems, the controllers were designed and implemented using sensors (four accelerometers and one rate gyro) that are actually mounted to the structure. Ground mounted displacement sensors that could greatly ease the control design task were available but were used only for performance evaluation. The use of the accelerometers increased the potential of destabilizing the system due to spillover effects and motivated the use of precompensation strategy to achieve sufficient compensator roll-off.

High performance, accelerometer-based control of the Mini-MAST structure

NASA Technical Reports Server (NTRS)

Collins, Emmanuel G., Jr.; King, James A.; Phillips, Douglas J.; Hyland, David C.

1992-01-01

Many large space system concepts will require active vibration control to satisfy critical performance requirements such as line of sight pointing accuracy and constraints on rms surface roughness. In order for these concepts to become operational, it is imperative that the benefits of active vibration control be shown to be practical in ground based experiments. The results of an experiment shows the successful application of the Maximum Entropy/Optical Projection control design methodology to active vibration control for a flexible structure. The testbed is the Mini-Mast structure at NASA-Langley and has features dynamically traceable to future space systems. To maximize traceability to real flight systems, the controllers were designed and implemented using sensors (four accelerometers and one rate gyro) that are actually mounted to the structure. Ground mounted displacement sensors that could greatly ease the control design task were available but were used only for performance evaluation. The use of the accelerometers increased the potential of destabilizing the system due to spillover effects and motivated the use of precompensation strategy to achieve sufficient compensator roll-off.

Predicting Chinese Children and Youth's Energy Expenditure Using ActiGraph Accelerometers: A Calibration and Cross-Validation Study

ERIC Educational Resources Information Center

Zhu, Zheng; Chen, Peijie; Zhuang, Jie

2013-01-01

Purpose: The purpose of this study was to develop and cross-validate an equation based on ActiGraph accelerometer GT3X output to predict children and youth's energy expenditure (EE) of physical activity (PA). Method: Participants were 367 Chinese children and youth (179 boys and 188 girls, aged 9 to 17 years old) who wore 1 ActiGraph GT3X…

A Novel Inexpensive Use of Smartphone Technology for Ecological Momentary Assessment in Middle-Aged Women.

PubMed

Ehlers, Diane K; Huberty, Jennifer; Buman, Matthew; Hooker, Steven; Todd, Michael; de Vreede, Gert-Jan

2016-03-01

Commercially available mobile and Internet technologies present a promising opportunity to feasibly conduct ecological momentary assessment (EMA). The purpose of this study was to describe a novel EMA protocol administered on middle-aged women's smartphones via text messaging and mobile Internet. Women (N = 9; mean age = 46.2 ± 8.2 y) received 35 text message prompts to a mobile survey assessing activity, self-worth, and self-efficacy over 14 days. Prompts were scheduled and surveys were administered using commercial, Internet-based programs. Prompting was tailored to each woman's daily wake/sleep schedule. Women concurrently wore a wrist-worn accelerometer. Feasibility was assessed via survey completion, accelerometer wear, participant feedback, and researcher notes. Of 315 prompted surveys, 287 responses were valid (91.1%). Average completion time was 1.52 ± 1.03 minutes. One participant's activity data were excluded due to accelerometer malfunction, resulting in complete data from 8 participants (n = 252 [80.0%] valid observations). Women reported the survey was easily and quickly read/completed. However, most thought the accelerometer was inconvenient. High completion rates and perceived usability suggest capitalizing on widely available technology and tailoring prompting schedules may optimize EMA in middle-aged women. However, researchers may need to carefully select objective monitors to maintain data validity while limiting participant burden.

Development and validation of a very brief questionnaire measure of physical activity in adults with coronary heart disease.

PubMed

Orrell, Alison; Doherty, Patrick; Miles, Jeremy; Lewin, Robert

2007-10-01

The aim of this study was to validate the Total Activity Measure, a brief questionnaire, to measure physical activity in an older adult population with heart disease. Two versions of the Total Activity Measure were administered twice, 7 days apart. The Total Activity Measure 1 asked respondents for the frequency and average duration of bouts of physical activity at three different intensity levels per week, whereas the Total Activity Measure 2 asked respondents for the total time spent in activity at each activity level per week. Questionnaire accuracy was studied in 62 men and 15 women aged 47-84 years, by repeatability and comparison of both administrations of the Total Activity Measure 1 and Total Activity Measure 2 with 7-day RT3 accelerometer data. Seventy-three adults (58 men, 15 women) were used for all statistical analyses. Intraclass correlation coefficients for the Total Activity Measure 1 and Total Activity Measure 2 total activity scores (metabolic equivalent per minute) were r=0.73 (95% confidence intervals, 0.56-0.83) and r=0.82 (95% confidence intervals, 0.71-0.88), respectively. Correlations between the Total Activity Measure 1 and RT3 accelerometer for total activity score (metabolic equivalent per minute) were significant, r=0.26 at time 1 and r=0.27 at time 2 for moderate intensity activities. Correlations between the Total Activity Measure 2 and RT3 accelerometer for total activity score (metabolic equivalent per minute) were also significant, r=0.38 at time 1 and r=0.36 at time 2, r=0.31 at time 2 for strenuous intensity activities and r=0.29 at time 1 and r=0.25 at time 2 for moderate intensity activities. Participants overestimated the amount of physical activity on both questionnaires as compared with the RT3 accelerometer. The Total Activity Measure 2 was reasonably accurate in assessing total and moderate intensity activity over a 7-day period and demonstrated good test-retest reliability. The Total Activity Measure 1 was less accurate. The Total Activity Measure 2 is a suitable measure of total or moderate intensity physical activity for surveys and audits in an adult cardiac population.

Evaluation of Thermal Protection Tile Transmissibility for Ground Vibration Test

NASA Technical Reports Server (NTRS)

Chung, Y. T.; Fowler, Samuel B.; Lo, Wenso; Towner, Robert

2005-01-01

Transmissibility analyses and tests were conducted on a composite panel with thermal protection system foams to evaluate the quality of the measured frequency response functions. Both the analysis and the test results indicate that the vehicle dynamic responses are fully transmitted to the accelerometers mounted on the thermal protection system in the normal direction below a certain frequency. In addition, the in-plane motions of the accelerometer mounted on the top surface of the thermal protection system behave more actively than those on the composite panel due to the geometric offset of the accelerometer from the panel in the test set-up. The transmissibility tests and analyses show that the frequency response functions measured from the accelerometers mounted on the TPS will provide accurate vehicle responses below 120 Hz for frequency and mode shape identification. By confirming that accurate dynamic responses below a given frequency can be obtained, this study increases the confidence needed for conducting the modal testing, model correlation, and model updating for a vehicle installed with TPS. '

Carotid femoral pulse wave velocity in type 2 diabetes and hypertension: capturing arterial health effects of step counts

PubMed Central

Dasgupta, Kaberi; Rosenberg, Ellen; Joseph, Lawrence; Trudeau, Luc; Garfield, Natasha; Chan, Deborah; Sherman, Mark; Rabasa-Lhoret, Rémi; Daskalopoulou, Stella S.

2017-01-01

Objective: Optimal medication use obscures the impact of physical activity on traditional cardiometabolic risk factors. We evaluated the relationship between step counts and carotid-femoral pulse wave velocity (cfPWV), a summative risk indicator, in patients with type 2 diabetes and/or hypertension. Research design and methods: Three hundred and sixty-nine participants were recruited (outpatient clinics; Montreal, Quebec; 2011–2015). Physical activity (pedometer/accelerometer), cfPWV (applanation tonometry), and risk factors (A1C, Homeostatic Model Assessment–Insulin Resistance, blood pressure, lipid profiles) were evaluated. Linear regression models were constructed to quantify the relationship of steps/day with cfPWV. Results: The study population comprised 191 patients with type 2 diabetes and hypertension, 39 with type 2 diabetes, and 139 with hypertension (mean ± SD: age 59.6 ± 11.2 years; BMI 31.3 ± 4.8 kg/m2; 54.2% women). Blood pressure (125/77 ± 15/9 mmHg), A1C (diabetes: 7.7 ± 1.3%; 61 mmol/mol), and low-density lipoprotein cholesterol (diabetes: 2.19 ± 0.8 mmol/l; without diabetes: 3.13 ± 1.1mmol/l) were close to target. Participants averaged 5125 ± 2722 steps/day. Mean cfPWV was 9.8 ± 2.2 m/s. Steps correlated with cfPWV, but not with other risk factors. A 1000 steps/day increment was associated with a 0.1 m/s cfPWV decrement across adjusted models and in subgroup analysis by diabetes status. In a model adjusted for age, sex, BMI, ethnicity, immigrant status, employment, education, diabetes, hypertension, medication classes, the mean cfPWV decrement was 0.11 m/s (95% confidence interval −0.2, −0.02). Conclusions: cfPWV is responsive to step counts in patients who are well controlled on cardioprotective medications. This ability to capture the ‘added value’ of physical activity supports the emerging role of cfPWV in arterial health monitoring. PMID:28129250

Field evaluation of a random forest activity classifier for wrist-worn accelerometer data.

PubMed

Pavey, Toby G; Gilson, Nicholas D; Gomersall, Sjaan R; Clark, Bronwyn; Trost, Stewart G

2017-01-01

Wrist-worn accelerometers are convenient to wear and associated with greater wear-time compliance. Previous work has generally relied on choreographed activity trials to train and test classification models. However, validity in free-living contexts is starting to emerge. Study aims were: (1) train and test a random forest activity classifier for wrist accelerometer data; and (2) determine if models trained on laboratory data perform well under free-living conditions. Twenty-one participants (mean age=27.6±6.2) completed seven lab-based activity trials and a 24h free-living trial (N=16). Participants wore a GENEActiv monitor on the non-dominant wrist. Classification models recognising four activity classes (sedentary, stationary+, walking, and running) were trained using time and frequency domain features extracted from 10-s non-overlapping windows. Model performance was evaluated using leave-one-out-cross-validation. Models were implemented using the randomForest package within R. Classifier accuracy during the 24h free living trial was evaluated by calculating agreement with concurrently worn activPAL monitors. Overall classification accuracy for the random forest algorithm was 92.7%. Recognition accuracy for sedentary, stationary+, walking, and running was 80.1%, 95.7%, 91.7%, and 93.7%, respectively for the laboratory protocol. Agreement with the activPAL data (stepping vs. non-stepping) during the 24h free-living trial was excellent and, on average, exceeded 90%. The ICC for stepping time was 0.92 (95% CI=0.75-0.97). However, sensitivity and positive predictive values were modest. Mean bias was 10.3min/d (95% LOA=-46.0 to 25.4min/d). The random forest classifier for wrist accelerometer data yielded accurate group-level predictions under controlled conditions, but was less accurate at identifying stepping verse non-stepping behaviour in free living conditions Future studies should conduct more rigorous field-based evaluations using observation as a criterion measure. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

The validation of a self-report measure and physical activity of Australian Aboriginal and Torres Strait Islander and non-Indigenous rural children.

PubMed

Gwynn, Josephine D; Hardy, Louise L; Wiggers, John H; Smith, Wayne T; D'Este, Catherine A; Turner, Nicole; Cochrane, Janine; Barker, Daniel J; Attia, John R

2010-07-01

To validate a self-report measure of physical activity for both Australian Aboriginal and Torres Strait Islander and non-Indigenous rural children, and to describe their physical activity participation. In this cross-sectional study, 84 Aboriginal and Torres Strait Islander and 146 non-Indigenous children aged 10-12 years old completed the Many Rivers Physical Activity Recall Questionnaire (MRPARQ), a modified version of the Adolescent Physical Activity Recall Questionnaire (APARQ). A sub-group (n=86) wore an accelerometer for seven consecutive days in order to validate the instrument. Pearson and Intra Class Correlation coefficients between the survey and acceleromtery for weekdays only are 0.31 and 0.16, respectively, for Aboriginal and Torres Strait Islander children, and 0.38 and 0.31, respectively, for non-Indigenous children, and demonstrate a modest (p<0.05) correlation. Self-reported MVPA for Aboriginal and Torres Strait Islander children is between 162 and 172 minutes/day, and is 125 minutes by accelerometer; for non-Indigenous children MVPA is between 123 and 149 minutes (survey) and 107 minutes (accelerometer). Australian Aboriginal and Torres Strait Islander children's self-report of physical activity is at least as valid as non-Indigenous children, given culturally appropriate support; they tend to be more active than non-Indigenous children. The MRPARQ can be administered with Aboriginal and Torres Strait Islander and non-Indigenous children.

Monitoring walking and cycling of middle-aged to older community dwellers using wireless wearable accelerometers.

PubMed

Zhang, Yuting; Beenakker, Karel G M; Butala, Pankil M; Lin, Cheng-Chieh; Little, Thomas D C; Maier, Andrea B; Stijntjes, Marjon; Vartanian, Richard; Wagenaar, Robert C

2012-01-01

Changes in gait parameters have been shown to be an important indicator of several age-related cognitive and physical declines of older adults. In this paper we propose a method to monitor and analyze walking and cycling activities based on a triaxial accelerometer worn on one ankle. We use an algorithm that can (1) distinguish between static and dynamic functional activities, (2) detect walking and cycling events, (3) identify gait parameters, including step frequency, number of steps, number of walking periods, and total walking duration per day, and (4) evaluate cycling parameters, including cycling frequency, number of cycling periods, and total cycling duration. Our algorithm is evaluated against the triaxial accelerometer data obtained from a group of 297 middle-aged to older adults wearing an activity monitor on the right ankle for approximately one week while performing unconstrained daily activities in the home and community setting. The correlation coefficients between each of detected gait and cycling parameters on two weekdays are all statistically significant, ranging from 0.668 to 0.873. These results demonstrate good test-retest reliability of our method in monitoring walking and cycling activities and analyzing gait and cycling parameters. This algorithm is efficient and causal in time and thus implementable for real-time monitoring and feedback.

PACE-UP (Pedometer and consultation evaluation--UP)--a pedometer-based walking intervention with and without practice nurse support in primary care patients aged 45-75 years: study protocol for a randomised controlled trial.

PubMed

Harris, Tess; Kerry, Sally M; Victor, Christina R; Shah, Sunil M; Iliffe, Steve; Ussher, Michael; Ekelund, Ulf; Fox-Rushby, Julia; Whincup, Peter; David, Lee; Brewin, Debbie; Ibison, Judith; DeWilde, Stephen; Limb, Elizabeth; Anokye, Nana; Furness, Cheryl; Howard, Emma; Dale, Rebecca; Cook, Derek G

2013-12-05

Most adults do not achieve the 150 minutes weekly of at least moderate intensity activity recommended for health. Adults' most common physical activity (PA) is walking, light intensity if strolling, moderate if brisker. Pedometers can increase walking; however, most trials have been short-term, have combined pedometer and support effects, and have not reported PA intensity. This trial will investigate whether pedometers, with or without nurse support, can help less active 45-75 year olds to increase their PA over 12 months. Primary care-based 3-arm randomized controlled trial with 12-month follow-up and health economic and qualitative evaluations. Less active 45-75 year olds (n = 993) will be recruited by post from six South West London general practices, maximum of two per household and households randomised into three groups. Step-count and time spent at different PA intensities will be assessed for 7 days at baseline, 3 and 12 months by accelerometer. Questionnaires and anthropometric assessments will be completed. The pedometer-alone group will be posted a pedometer (Yamax Digi-Walker SW-200), handbook and diary detailing a 12-week pedometer-based walking programme, using targets from their baseline assessment. The pedometer-plus-support group will additionally receive three practice nurse PA consultations. The handbook, diary and consultations include behaviour change techniques (e.g., self-monitoring, goal-setting, relapse prevention planning). The control group will receive usual care. Changes in average daily step-count (primary outcome), time spent sedentary and in at least moderate intensity PA weekly at 12 months, measured by accelerometry. Other outcomes include change in body mass index, body fat, self-reported PA, quality of life, mood and adverse events. Cost-effectiveness will be assessed by the incremental cost of the intervention to the National Health Service and incremental cost per change in step-count and per quality adjusted life year. Qualitative evaluations will explore reasons for trial non-participation and the interventions' acceptability. The PACE-UP trial will determine the effectiveness and cost-effectiveness of a pedometer-based walking intervention delivered by post or practice nurse to less active primary care patients aged 45-75 years old. Approaches to minimise bias and challenges anticipated in delivery will be discussed. ISRCTN98538934.

Hierarchical classifier approach to physical activity recognition via wearable smartphone tri-axial accelerometer.

PubMed

Yusuf, Feridun; Maeder, Anthony; Basilakis, Jim

2013-01-01

Physical activity recognition has emerged as an active area of research which has drawn increasing interest from researchers in a variety of fields. It can support many different applications such as safety surveillance, fraud detection, and clinical management. Accelerometers have emerged as the most useful and extensive tool to capture and assess human physical activities in a continuous, unobtrusive and reliable manner. The need for objective physical activity data arises strongly in health related research. With the shift to a sedentary lifestyle, where work and leisure tend to be less physically demanding, research on the health effects of low physical activity has become a necessity. The increased availability of small, inexpensive components has led to the development of mobile devices such as smartphones, providing platforms for new opportunities in healthcare applications. In this study 3 subjects performed directed activity routines wearing a smartphone with a built in tri-axial accelerometer, attached on a belt around the waist. The data was collected to classify 11 basic physical activities such as sitting, lying, standing, walking, and the transitions in between them. A hierarchical classifier approach was utilised with Artificial Neural Networks integrated in a rule-based system, to classify the activities. Based on our evaluation, recognition accuracy of over 89.6% between subjects and over 91.5% within subject was achieved. These results show that activities such as these can be recognised with a high accuracy rate; hence the approach is promising for use in future work.

Weight status in US youth: the role of activity, diet, and sedentary behaviors.

PubMed

Peart, Tasha; Velasco Mondragon, H Eduardo; Rohm-Young, Deborah; Bronner, Yvonne; Hossain, Mian B

2011-11-01

To assess associations of physical activity, diet, and sedentary behaviors with overweight and obesity. Analyses of the NHANES 2003-06 were conducted among 2368 US adolescents, ages 12-19. Self-reported diet and sedentary behavior measures were used; physical activity was assessed using accelerometers. Television/video viewing (OR=1.84; CI=1.24, 2.69), physical activity (OR=0.75; CI=0.59, 0.95), and fiber intake (OR=0.96; CI=0.92, 0.99) were associated with obesity whereas television/video viewing was a risk factor for overweight (OR=1.57; CI=1.1, 2.63). Findings using accelerometer-measured physical activity are consistent with results from other studies using self-reported measurements. No interactions with ethnicity and gender were found.

Associations between children's social functioning and physical activity participation are not mediated by social acceptance: a cross-sectional study.

PubMed

Sebire, Simon J; Jago, Russell; Fox, Kenneth R; Page, Angie S; Brockman, Rowan; Thompson, Janice L

2011-09-30

Physical activity (PA) during childhood often occurs in social contexts. As such, children's ability to develop and maintain friendship groups may be important in understanding their PA. This paper investigates the associations among children's social functioning, and physical activity and whether perceptions of social acceptance mediate any social functioning-PA association. A cross sectional survey in which 652 10-11 year olds self-reported their peer (e.g. difficulties with friends) and conduct (e.g. anger/aggression) problems, prosocial behaviours (e.g. being kind to others) and perceptions of social acceptance. Physical activity was objectively assessed by Actigraph GT1M accelerometers to estimate counts per minute, (CPM) and minutes of moderate-to-vigorous physical activity (MVPA). Linear regression analyses were conducted to investigate associations between social functioning and PA. Indirect effects were analysed to explore mediation by social acceptance. Among boys, peer problems were negatively associated with CPM and MVPA and conduct problems were positively associated with CPM and MVPA. Prosocial behaviour was unrelated to PA in boys. Social functioning was not associated with PA among girls. Social acceptance did not mediate the social functioning-PA relationship. Boys' conduct and peer problems were associated positively and negatively respectively with their PA but this relationship was not mediated by perceptions of social acceptance. Future research should study alternative mediators to understand the processes underpinning this relationship.

Prediction Models Discriminating between Nonlocomotive and Locomotive Activities in Children Using a Triaxial Accelerometer with a Gravity-removal Physical Activity Classification Algorithm

PubMed Central

Hikihara, Yuki; Tanaka, Chiaki; Oshima, Yoshitake; Ohkawara, Kazunori; Ishikawa-Takata, Kazuko; Tanaka, Shigeho

2014-01-01

The aims of our study were to examine whether a gravity-removal physical activity classification algorithm (GRPACA) is applicable for discrimination between nonlocomotive and locomotive activities for various physical activities (PAs) of children and to prove that this approach improves the estimation accuracy of a prediction model for children using an accelerometer. Japanese children (42 boys and 26 girls) attending primary school were invited to participate in this study. We used a triaxial accelerometer with a sampling interval of 32 Hz and within a measurement range of ±6 G. Participants were asked to perform 6 nonlocomotive and 5 locomotive activities. We measured raw synthetic acceleration with the triaxial accelerometer and monitored oxygen consumption and carbon dioxide production during each activity with the Douglas bag method. In addition, the resting metabolic rate (RMR) was measured with the subject sitting on a chair to calculate metabolic equivalents (METs). When the ratio of unfiltered synthetic acceleration (USA) and filtered synthetic acceleration (FSA) was 1.12, the rate of correct discrimination between nonlocomotive and locomotive activities was excellent, at 99.1% on average. As a result, a strong linear relationship was found for both nonlocomotive (METs = 0.013×synthetic acceleration +1.220, R2 = 0.772) and locomotive (METs = 0.005×synthetic acceleration +0.944, R2 = 0.880) activities, except for climbing down and up. The mean differences between the values predicted by our model and measured METs were −0.50 to 0.23 for moderate to vigorous intensity (>3.5 METs) PAs like running, ball throwing and washing the floor, which were regarded as unpredictable PAs. In addition, the difference was within 0.25 METs for sedentary to mild moderate PAs (<3.5 METs). Our specific calibration model that discriminates between nonlocomotive and locomotive activities for children can be useful to evaluate the sedentary to vigorous PAs intensity of both nonlocomotive and locomotive activities. PMID:24755646

Use of electronic games by young children and fundamental movement skills?

PubMed

Barnett, Lisa M; Hinkley, Trina; Okely, Anthony D; Hesketh, Kylie; Salmon, Jo

2012-06-01

This study investigated associations between pre-school children's time spent playing electronic games and their fundamental movement skills. In 2009, 53 children had physical activity (Actigraph accelerometer counts per minute), parent proxy-report of child's time in interactive and non-interactive electronic games (min./week), and movement skill (Test of Gross Motor Development-2) assessed. Hierarchical linear regression, adjusting for age (range = 3-6 years), sex (Step 1), and physical activity (cpm; M=687, SD=175.42; Step 2), examined the relationship between time in (a) non-interactive and (b) interactive electronic games and locomotor and object control skill. More than half (59%, n=31) of the children were female. Adjusted time in interactive game use was associated with object control but not locomotor skill. Adjusted time in non-interactive game use had no association with object control or locomotor skill. Greater time spent playing interactive electronic games is associated with higher object control skill proficiency in these young children. Longitudinal and experimental research is required to determine if playing these games improves object control skills or if children with greater object control skill proficiency prefer and play these games.

Comparison of the Effects of Stable and Dynamic Furniture on Physical Activity and Learning in Children.

PubMed

Garcia, Jeanette M; Huang, Terry T; Trowbridge, Matthew; Weltman, Arthur; Sirard, John R

2016-12-01

We compared the effects of traditional (stable) and non-traditional (dynamic) school furniture on children's physical activity (PA), energy expenditure (EE), information retention, and math skills. Participants were 12 students (8.3 years, 58 % boys) in grades 1-5. Participants wore an Actigraph GT3X+ accelerometer (to assess PA), and an Oxycon Mobile indirect calorimetry device (to assess EE) for 40 min (20 min for each session). Each session consisted of a nutrition lecture, multiple choice questions related to the lecture, and grade-appropriate math problems. We used paired t tests to examine differences between the stable and dynamic furniture conditions. Average activity counts were significantly greater in the dynamic than the stable furniture condition (40.82 vs. 9.81, p < 0.05). We found no significant differences between conditions for average oxygen uptake (p = 0.34), percentage of nutrition questions (p = 0.5), or math problems (p = 0.93) answered correctly. Movement was significantly greater in the dynamic than the stable furniture condition, and did not impede information acquisition or concentration. Future studies should compare the long-term effects of traditional and dynamic furniture on health and academic outcomes in schools and other settings.

Self-Care Posters Serve as a Low-Cost Option for Physical Activity Promotion of Hospital Nurses.

PubMed

Raney, Marcella; Van Zanten, Erin

2018-03-01

Hospital nurses play an important role in the nation's short- and long-term patient care. At the same time, nurses often experience high levels of occupational stress and participate in low levels of physical activity (PA). The purpose of this study was to examine the impact of self-monitoring and a poster campaign on the PA behaviors of hospital nurses. Motivational and instructional exercise posters were hung in break rooms of experimental units and replaced biweekly for 8 weeks. A total of 26 nurses (control: n = 13; experimental: n = 13) wore accelerometers for 3 workdays pre-, mid-, and postintervention. Participants were provided a step counter at baseline and a PA report at each stage. Moderate to vigorous PA (MVPA) and step count (SC) increased pre- to midintervention for control (MVPA: 14.8 ± 7.6%; SC: 19.1 ± 7.8%) and experimental (MVPA: 26.7 ± 18.5%, SC: 17.6 ± 8.3%) participants. Physical activity levels returned to baseline postintervention for control ( p > .05) and increased mid- to postintervention for experimental (MVPA: 16.2 ± 5.2%, SC: 10.7 ± 4.7%, p < .05) participants. In conclusion, a low-cost, self-care poster campaign may increase PA levels of hospital nurses when combined with personalized PA feedback.

Reliability and Validity of a Chinese-Translated Version of a Pregnancy Physical Activity Questionnaire.

PubMed

Xiang, Mi; Konishi, Massayuki; Hu, Huanhuan; Takahashi, Masaki; Fan, Wenbi; Nishimaki, Mio; Ando, Karina; Kim, Hyeon-Ki; Tabata, Hiroki; Arao, Takashi; Sakamoto, Shizuo

2016-09-01

Objectives The objectives of the present study were to translate the English version of the Pregnancy Physical Activity Questionnaire into Chinese (PPAQ-C) and to determine its reliability and validity for use by pregnant Chinese women. Methods The study included 224 pregnant women during their first, second, or third trimesters of pregnancy who completed the PPAQ-C on their first visit and wore a uniaxial accelerometer (Lifecorder; Suzuken Co. Ltd) for 7 days. One week after the first visit, we collected the data from the uniaxial accelerometer records, and the women were asked to complete the PPAQ-C again. Results We used intraclass correlation coefficients to determine the reliability of the PPAQ-C. The intraclass correlation coefficients were 0.77 for total activity (light and above), 0.76 for sedentary activity, 0.75 for light activity, 0.59 for moderate activity, and 0.28 for vigorous activity. The intraclass correlation coefficients were 0.74 for "household and caregiving", 0.75 for "occupational" activities, and 0.34 for "sports/exercise". Validity between the PPAQ-C and accelerometer data was determined by Spearman correlation coefficients. Although there were no significant correlations for moderate activity (r = 0.19, P > 0.05) or vigorous activity (r = 0.15, P > 0.05), there were significant correlations for total activity [light and above; r = 0.35, P < 0.01)] and for light activity (r = 0.33, P < 0.01). Conclusions for Practice The PPAQ-C is reliable and moderately accurate for measuring physical activity in pregnant Chinese women.

Using internet and mobile phone technology to deliver an automated physical activity program: randomized controlled trial.

PubMed

Hurling, Robert; Catt, Michael; Boni, Marco De; Fairley, Bruce William; Hurst, Tina; Murray, Peter; Richardson, Alannah; Sodhi, Jaspreet Singh

2007-04-27

The Internet has potential as a medium for health behavior change programs, but no controlled studies have yet evaluated the impact of a fully automated physical activity intervention over several months with real-time objective feedback from a monitor. The aim was to evaluate the impact of a physical activity program based on the Internet and mobile phone technology provided to individuals for 9 weeks. A single-center, randomized, stratified controlled trial was conducted from September to December 2005 in Bedfordshire, United Kingdom, with 77 healthy adults whose mean age was 40.4 years (SD = 7.6) and mean body mass index was 26.3 (SD = 3.4). Participants were randomized to a test group that had access to an Internet and mobile phone-based physical activity program (n = 47) or to a control group (n = 30) that received no support. The test group received tailored solutions for perceived barriers, a schedule to plan weekly exercise sessions with mobile phone and email reminders, a message board to share their experiences with others, and feedback on their level of physical activity. Both groups were issued a wrist-worn accelerometer to monitor their level of physical activity; only the test group received real-time feedback via the Internet. The main outcome measures were accelerometer data and self-report of physical activity. At the end of the study period, the test group reported a significantly greater increase over baseline than did the control group for perceived control (P < .001) and intention/expectation to exercise (P < .001). Intent-to-treat analyses of both the accelerometer data (P = .02) and leisure time self-report data (P = .03) found a higher level of moderate physical activity in the test group. The average increase (over the control group) in accelerometer-measured moderate physical activity was 2 h 18 min per week. The test group also lost more percent body fat than the control group (test group: -2.18, SD = 0.59; control group: -0.17, SD = 0.81; P = .04). A fully automated Internet and mobile phone-based motivation and action support system can significantly increase and maintain the level of physical activity in healthy adults.

Validation of five minimally obstructive methods to estimate physical activity energy expenditure in young adults in semi-standardized settings.

PubMed

Schneller, Mikkel B; Pedersen, Mogens T; Gupta, Nidhi; Aadahl, Mette; Holtermann, Andreas

2015-03-13

We compared the accuracy of five objective methods, including two newly developed methods combining accelerometry and activity type recognition (Acti4), against indirect calorimetry, to estimate total energy expenditure (EE) of different activities in semi-standardized settings. Fourteen participants performed a standardized and semi-standardized protocol including seven daily life activity types, while having their EE measured by indirect calorimetry. Simultaneously, physical activity was quantified by an ActivPAL3, two ActiGraph GT3X+'s and an Actiheart. EE was estimated by the standard ActivPAL3 software (ActivPAL), ActiGraph GT3X+ (ActiGraph) and Actiheart (Actiheart), and by a combination of activity type recognition via Acti4 software and activity counts per minute (CPM) of either a hip- or thigh-worn ActiGraph GT3X+ (AGhip + Acti4 and AGthigh + Acti4). At group level, estimated physical activities EE by Actiheart (MSE = 2.05) and AGthigh + Acti4 (MSE = 0.25) were not significantly different from measured EE by indirect calorimetry, while significantly underestimated by ActiGraph, ActivPAL and AGhip + Acti4. AGthigh + Acti4 and Actiheart explained 77% and 45%, of the individual variations in measured physical activity EE by indirect calorimetry, respectively. This study concludes that combining accelerometer data from a thigh-worn ActiGraph GT3X+ with activity type recognition improved the accuracy of activity specific EE estimation against indirect calorimetry in semi-standardized settings compared to previously validated methods using CPM only.

Analysis of Movement, Orientation and Rotation-Based Sensing for Phone Placement Recognition

PubMed Central

Durmaz Incel, Ozlem

2015-01-01

Phone placement, i.e., where the phone is carried/stored, is an important source of information for context-aware applications. Extracting information from the integrated smart phone sensors, such as motion, light and proximity, is a common technique for phone placement detection. In this paper, the efficiency of an accelerometer-only solution is explored, and it is investigated whether the phone position can be detected with high accuracy by analyzing the movement, orientation and rotation changes. The impact of these changes on the performance is analyzed individually and both in combination to explore which features are more efficient, whether they should be fused and, if yes, how they should be fused. Using three different datasets, collected from 35 people from eight different positions, the performance of different classification algorithms is explored. It is shown that while utilizing only motion information can achieve accuracies around 70%, this ratio increases up to 85% by utilizing information also from orientation and rotation changes. The performance of an accelerometer-only solution is compared to solutions where linear acceleration, gyroscope and magnetic field sensors are used, and it is shown that the accelerometer-only solution performs as well as utilizing other sensing information. Hence, it is not necessary to use extra sensing information where battery power consumption may increase. Additionally, I explore the impact of the performed activities on position recognition and show that the accelerometer-only solution can achieve 80% recognition accuracy with stationary activities where movement data are very limited. Finally, other phone placement problems, such as in-pocket and on-body detections, are also investigated, and higher accuracies, ranging from 88% to 93%, are reported, with an accelerometer-only solution. PMID:26445046

Analysis of Movement, Orientation and Rotation-Based Sensing for Phone Placement Recognition.

PubMed

Incel, Ozlem Durmaz

2015-10-05

Phone placement, i.e., where the phone is carried/stored, is an important source of information for context-aware applications. Extracting information from the integrated smart phone sensors, such as motion, light and proximity, is a common technique for phone placement detection. In this paper, the efficiency of an accelerometer-only solution is explored, and it is investigated whether the phone position can be detected with high accuracy by analyzing the movement, orientation and rotation changes. The impact of these changes on the performance is analyzed individually and both in combination to explore which features are more efficient, whether they should be fused and, if yes, how they should be fused. Using three different datasets, collected from 35 people from eight different positions, the performance of different classification algorithms is explored. It is shown that while utilizing only motion information can achieve accuracies around 70%, this ratio increases up to 85% by utilizing information also from orientation and rotation changes. The performance of an accelerometer-only solution is compared to solutions where linear acceleration, gyroscope and magnetic field sensors are used, and it is shown that the accelerometer-only solution performs as well as utilizing other sensing information. Hence, it is not necessary to use extra sensing information where battery power consumption may increase. Additionally, I explore the impact of the performed activities on position recognition and show that the accelerometer-only solution can achieve 80% recognition accuracy with stationary activities where movement data are very limited. Finally, other phone placement problems, such as in-pocket and on-body detections, are also investigated, and higher accuracies, ranging from 88% to 93%, are reported, with an accelerometer-only solution.

Performance of thigh-mounted triaxial accelerometer algorithms in objective quantification of sedentary behaviour and physical activity in older adults

PubMed Central

Verschueren, Sabine M. P.; Degens, Hans; Morse, Christopher I.; Onambélé, Gladys L.

2017-01-01

Accurate monitoring of sedentary behaviour and physical activity is key to investigate their exact role in healthy ageing. To date, accelerometers using cut-off point models are most preferred for this, however, machine learning seems a highly promising future alternative. Hence, the current study compared between cut-off point and machine learning algorithms, for optimal quantification of sedentary behaviour and physical activity intensities in the elderly. Thus, in a heterogeneous sample of forty participants (aged ≥60 years, 50% female) energy expenditure during laboratory-based activities (ranging from sedentary behaviour through to moderate-to-vigorous physical activity) was estimated by indirect calorimetry, whilst wearing triaxial thigh-mounted accelerometers. Three cut-off point algorithms and a Random Forest machine learning model were developed and cross-validated using the collected data. Detailed analyses were performed to check algorithm robustness, and examine and benchmark both overall and participant-specific balanced accuracies. This revealed that the four models can at least be used to confidently monitor sedentary behaviour and moderate-to-vigorous physical activity. Nevertheless, the machine learning algorithm outperformed the cut-off point models by being robust for all individual’s physiological and non-physiological characteristics and showing more performance of an acceptable level over the whole range of physical activity intensities. Therefore, we propose that Random Forest machine learning may be optimal for objective assessment of sedentary behaviour and physical activity in older adults using thigh-mounted triaxial accelerometry. PMID:29155839

Performance of thigh-mounted triaxial accelerometer algorithms in objective quantification of sedentary behaviour and physical activity in older adults.

PubMed

Wullems, Jorgen A; Verschueren, Sabine M P; Degens, Hans; Morse, Christopher I; Onambélé, Gladys L

2017-01-01

Accurate monitoring of sedentary behaviour and physical activity is key to investigate their exact role in healthy ageing. To date, accelerometers using cut-off point models are most preferred for this, however, machine learning seems a highly promising future alternative. Hence, the current study compared between cut-off point and machine learning algorithms, for optimal quantification of sedentary behaviour and physical activity intensities in the elderly. Thus, in a heterogeneous sample of forty participants (aged ≥60 years, 50% female) energy expenditure during laboratory-based activities (ranging from sedentary behaviour through to moderate-to-vigorous physical activity) was estimated by indirect calorimetry, whilst wearing triaxial thigh-mounted accelerometers. Three cut-off point algorithms and a Random Forest machine learning model were developed and cross-validated using the collected data. Detailed analyses were performed to check algorithm robustness, and examine and benchmark both overall and participant-specific balanced accuracies. This revealed that the four models can at least be used to confidently monitor sedentary behaviour and moderate-to-vigorous physical activity. Nevertheless, the machine learning algorithm outperformed the cut-off point models by being robust for all individual's physiological and non-physiological characteristics and showing more performance of an acceptable level over the whole range of physical activity intensities. Therefore, we propose that Random Forest machine learning may be optimal for objective assessment of sedentary behaviour and physical activity in older adults using thigh-mounted triaxial accelerometry.

Intervention Effects on Adolescent Physical Activity in the Multicomponent SPACE Study: A Cluster Randomized Controlled Trial

PubMed Central

Toftager, Mette; Christiansen, Lars B.; Ersbøll, Annette K.; Kristensen, Peter L.; Due, Pernille; Troelsen, Jens

2014-01-01

Background Multicomponent school-based interventions have the potential to reduce the age-related decline in adolescents' physical activity (PA), yet there is not consistent evidence to guide non-curricular and school environment interventions. The aim of this study was to assess the effectiveness of a multicomponent environmental school-based intervention, designed to reduce the age-related decline in PA among adolescents. Methods A cluster randomized controlled trial was conducted with 7 intervention and 7 control schools. Baseline measurements were carried out in spring 2010 with 2 years of follow-up. A total of 1,348 students (11–13 years, in grade 5 and 6) enrolled in the study at baseline. The 14 schools included in the study were located in the Region of Southern Denmark. The intervention consisted of organizational and physical changes in the school environment with a total of 11 intervention components. The primary outcome measure was overall PA (cpm, counts per minute) and was supported by analyses of time spent in MVPA, and time spent sedentary. Furthermore, a secondary outcome measure was PA in school time and during recess. PA was measured using accelerometer (Actigraph GT3X). Results A total of 797 students completed the trial and had valid accelerometer data. No significant difference was found for overall PA with an adjusted difference of −19.1 cpm (95% CI: −93, 53) or for school time activity with an adjusted difference of 6 cpm (95% CI: −73, 85). A sensitivity analysis revealed a positive significant intervention effect of PA in recess with an adjusted difference of 95 cpm. Conclusions No evidence was found of the overall effect of a non-curricular multicomponent school-based intervention on PA among Danish adolescents. The intervention was positively associated with PA during school time and recess, however, with small estimates. Lack of effect on overall PA could be due to both program theory and different degrees of implementation. Trial Registration www.Controlled-Trials.com ISRCTN79122411 PMID:24921948

Physical Activity and Falls in Older Men: The Critical Role of Mobility Limitations

PubMed Central

JEFFERIS, BARBARA J.; MEROM, DAFNA; SARTINI, CLAUDIO; WANNAMETHEE, S. GOYA; ASH, SARAH; LENNON, LUCY T.; ILIFFE, STEVE; KENDRICK, DENISE; WHINCUP, PETER H.

2015-01-01

ABSTRACT Background Physical activity (PA) has many health benefits but may increase falls risk among older adults. We study how objectively measured habitual daily PA is related to falls by exploring the modifying effect of mobility limitations and the mediating roles of fitness and lower-limb strength. Methods One thousand six hundred fifty-five (53%) of 3137 surviving participants (men age 71–91 yr) in an ongoing UK-population-based cohort study wore an ActiGraph GT3x accelerometer over the hip for 1 wk in 2010–2012 to measure PA (exposure) and reported demographic and health status, including mobility limitations. One year later, 825 men reported falls history (outcome). Results Seven hundred of 825 men had ≥600 min·d−1 of accelerometer wear for ≥3 d. Nineteen percent (n = 128) reported falls 1 yr later. Associations between PA and falls differed by presence of mobility limitations. Among 66% (n = 471) of men without mobility limitations, number of falls increased incrementally (for every 30 min of moderate to vigorous PA [MVPA]: incidence rate ratio [IRR], 1.50; 95% confidence interval [CI], 1.10–2.03, adjusted for falls risk factors). Step count was not related to number of falls below 9000 steps per day but was related to number of falls ≥9000 steps per day (for every additional 1000 steps per day: IRR, 1.59; 95% CI, 1.16–2.18). Among 33% (n = 229) of men with mobility limitations, falls risk declined with increasing activity (for every 1000 steps per day: IRR, 0.80; 95% CI, 0.70–0.91; for every 30 min of MVPA: IRR, 0.61; 95% CI, 0.42–0.89; for every additional 30 min of sedentary behavior ≥600 min·d−1: IRR, 1.22; 95% CI, 1.07–1.40). Conclusions Interventions to promote MVPA in older men should incorporate falls prevention strategies. Among adults with mobility limitations, trials should investigate whether increasing MVPA levels can reduce falls risk. PMID:25668406

Relationship between physical activity and markers of oxidative stress in independent community-living elderly individuals.

PubMed

Fraile-Bermúdez, A B; Kortajarena, M; Zarrazquin, I; Maquibar, A; Yanguas, J J; Sánchez-Fernández, C E; Gil, J; Irazusta, A; Ruiz-Litago, F

2015-10-01

The aim of the present study was to examine the relationship between objective data of physical activity and markers of oxidative stress in older men and women. Participants were old adults, aged≥60years (61 women and 34 men) who were all capable of performing basic daily activities by themselves and lived on their own. To describe physical activity we used objective data measured by accelerometers which record active and sedentary periods during everyday life for five days. Determination of oxidative stress was conducted from three perspectives: determination plasma total antioxidant status (TAS), plasma antioxidant enzyme activities, i.e., glutathione peroxidase (GPx), catalase (CAT) and superoxide dismutase (SOD), and membrane lipid peroxidation (TBARS). In the group of women, those who met physical activity recommendations (WR) had lower level of TAS. In addition, the moderate to vigorous physical activity (MVPA) was negatively correlated with TAS. Simultaneously, MVPA was correlated with increase in the GPx antioxidant enzyme activity, and the counts per minute were positively correlated with CAT activity. In the group of men, the cpm and the MVPA were negatively correlated with lipid peroxidation while lifestyle physical activity was positively correlated with CAT activity. These findings suggest that MVPA in the elderly although it is related to a decrease in the TAS in women, induces adaptive increase in antioxidant enzyme activity and decreases lipid peroxidation in both women and men. These results suggest that at this time of life, it is not only the amount of physical activity performed that is important but also its intensity. Copyright © 2015 Elsevier Inc. All rights reserved.

Determinants of physical activity in minimally impaired people with multiple sclerosis.

PubMed

Kahraman, Turhan; Savci, Sema; Coskuner-Poyraz, Esra; Ozakbas, Serkan; Idiman, Egemen

2015-11-01

Despite the commonly known benefits of physical activity, evidence shows that people with multiple sclerosis (pwMS) are relatively inactive. There are several studies about factors affecting physical activity in pwMS. However, these factors have not investigated in minimally impaired pwMS who do not have remarkable symptoms and walking disturbance. The objective was to determine factors affecting physical activity in minimally impaired pwMS. We recruited 52 minimally impaired pwMS and measured physical activity with Godin Leisure-Time Exercise Questionnaire (GLTEQ) and an accelerometer used for the 7-day period. Demographic data were recorded. Walking (speed, endurance, dexterity, and quality), fatigue, depression, and quality of life were measured. We recruited 52 minimally impaired pwMS and measured physical activity with Godin Leisure-Time Exercise Questionnaire (GLTEQ) and an accelerometer used for the 7-day period. Demographic data were recorded. Walking (speed, endurance, dexterity, and quality), fatigue, depression, and quality of life were measured. The walking speed assessed by the Timed 25-Foot Walk and gender were found the determinants of physical activity level assessed by the GLTEQ and accelerometer, respectively. Walking (speed, endurance, and dexterity), gender, employment status, and quality of life were associated with physical activity. Either female or unemployed participants had significantly less physical activity. There were no significant difference between physical activity levels and the other subgroups. Either to be a female or to have slower walking speed was associated with less physical activity. Strategies to improve walking should be focused on female pwMS with minimal impairment. Copyright © 2015 Elsevier B.V. All rights reserved.

Compressor surge counter

DOEpatents

Castleberry, Kimberly N.

1983-01-01

A surge counter for a rotating compressor is provided which detects surging by monitoring the vibration signal from an accelerometer mounted on the shaft bearing of the compressor. The circuit detects a rapid increase in the amplitude envelope of the vibration signal, e.g., 4 dB or greater in less than one second, which is associated with a surge onset and increments a counter. The circuit is rendered non-responsive for a period of about 5 seconds following the detection which corresponds to the duration of the surge condition. This prevents multiple registration of counts during the surge period due to rapid swings in vibration amplitude during the period.

Examining Incentives to Promote Physical Activity Maintenance Among Hospital Employees Not Achieving 10,000 Daily Steps: A Web-Based Randomized Controlled Trial Protocol

PubMed Central

White, Lauren; Oh, Paul; Kwan, Matthew; Gove, Peter; Leahey, Tricia; Faulkner, Guy

2016-01-01

Background The economic burden of physical inactivity in Canada is estimated at Can $6.8 billion (US $5 billion) per year. Employers bear a substantial proportion of the economic costs, as they pay more for inactive workers in health care and other organizational costs. In response, many Canadian employers offer wellness programs, though these are often underutilized. While financial health incentives have been proposed as one way of increasing participation, their longer term effects (ie postintervention effects) are not clear. Objective The objective of this paper is to outline the methodology for a randomized control trial (RCT) examining the longer term impact of an existing physical activity promotion program that is enhanced by adding guaranteed rewards (Can $1 [US $0.74] per day step goal met) in a lower active hospital employee population (less than 10,000 steps per day). Methods A 12-week, parallel-arm RCT (with a 12-week postintervention follow-up) will be employed. Employees using Change4Life (a fully automated, incentive-based wellness program) and accumulating fewer than 10,000 steps per day at baseline (weeks 1 to 2) will be randomly allocated (1:1) to standard care (wellness program, accelerometer) or an intervention group (standard care plus guaranteed incentives). All study participants will be asked to wear the accelerometer and synchronize it to Change4Life daily, although only intervention group participants will receive guaranteed incentives for reaching tailored daily step count goals (Can $1 [US $0.74] per day; weeks 3 to 12). The primary study outcome will be mean proportion of participant-days step goal reached during the postintervention follow-up period (week 24). Mean proportion of participant-days step goal reached during the intervention period (week 12) will be a secondary outcome. Results Enrollment for the study will be completed in February 2017. Data analysis will commence in September 2017. Study results are to be published in the winter of 2018. Conclusions This protocol was designed to examine the impact of guaranteed rewards on physical activity maintenance in lower active hospital employees. ClinicalTrial ClinicalTrials.gov NCT02638675; https://clinicaltrials.gov/ct2/show/NCT0 2638675 (Archived by WebCite at http://www.webcitation.org/6g4pvZvhW) PMID:27956377

Accelerometer-derived activity correlates with volitional swimming speed in lake sturgeon (Acipenser fulvescens)

USGS Publications Warehouse

Thiem, J.D.; Dawson, J.W.; Gleiss, A.C.; Martins, E.G.; Haro, Alexander J.; Castro-Santos, Theodore R.; Danylchuk, A.J.; Wilson, R.P.; Cooke, S.J.

2015-01-01

Quantifying fine-scale locomotor behaviours associated with different activities is challenging for free-swimming fish.Biologging and biotelemetry tools can help address this problem. An open channel flume was used to generate volitionalswimming speed (Us) estimates of cultured lake sturgeon (Acipenser fulvescens Rafinesque, 1817) and these were paired withsimultaneously recorded accelerometer-derived metrics of activity obtained from three types of data-storage tags. This studyexamined whether a predictive relationship could be established between four different activity metrics (tail-beat frequency(TBF), tail-beat acceleration amplitude (TBAA), overall dynamic body acceleration (ODBA), and vectorial dynamic body acceleration(VeDBA)) and the swimming speed of A. fulvescens. Volitional Us of sturgeon ranged from 0.48 to 2.70 m·s−1 (0.51–3.18 bodylengths (BL) · s−1). Swimming speed increased linearly with all accelerometer-derived metrics, and when all tag types werecombined, Us increased 0.46 BL·s−1 for every 1 Hz increase in TBF, and 0.94, 0.61, and 0.94 BL·s−1 for every 1g increase in TBAA,ODBA, and VeDBA, respectively. Predictive relationships varied among tag types and tag-specific parameter estimates of Us arepresented for all metrics. This use of acceleration data-storage tags demonstrated their applicability for the field quantificationof sturgeon swimming speed.

Comparison of 3 measures of physical activity and associations with blood pressure, HDL, and body composition in a sample of adolescents.

PubMed

Hearst, Mary O; Sirard, John R; Lytle, Leslie; Dengel, Donald R; Berrigan, David

2012-01-01

The association of physical activity (PA), measured 3 ways, and biomarkers were compared in a sample of adolescents. PA data were collected on 2 cohorts of adolescents (N = 700) in the Twin Cities, Minnesota, 2007-2008. PA was measured using 2 survey questions [Modified Activity Questionnaire (MAQ)], the 3-Day Physical Activity Recall (3DPAR), and accelerometers. Biomarkers included systolic (SBP) and diastolic blood pressure (DBP), lipids, percent body fat (%BF), and body mass index (BMI) percentile. Bivariate relationships among PA measures and biomarkers were examined followed by generalized estimating equations for multivariate analysis. The 3 measures were significantly correlated with each other (r = .22-.36, P < .001). Controlling for study, puberty, age, and gender, all 3 PA measures were associated with %BF (MAQ = -1.93, P < .001; 3DPAR = -1.64, P < .001; accelerometer = -1.06, P = .001). The MAQ and accelerometers were negatively associated with BMI percentile. None of the 3 PA measures were significantly associated with SBP or lipids. The percentage of adolescents meeting the national PA recommendations varied by instrument. All 3 instruments demonstrated consistent findings when estimating associations with %BF, but were different for prevalence estimates. Researchers must carefully consider the intended use of PA data when choosing a measurement instrument.

Health Benefits of Light-Intensity Physical Activity: A Systematic Review of Accelerometer Data of the National Health and Nutrition Examination Survey (NHANES).

PubMed

Füzéki, Eszter; Engeroff, Tobias; Banzer, Winfried

2017-09-01

The health effects of light-intensity physical activity (PA) are not well known today. We conducted a systematic review to assess the association of accelerometer-measured light-intensity PA with modifiable health outcomes in adults and older adults. A systematic literature search up to March 2016 was performed in the PubMed, EMBASE, Web of Science and Google Scholar electronic databases, without language limitations, for studies of modifiable health outcomes in adults and older adults in the National Health and Nutrition Examination Survey accelerometer dataset. Overall, 37 cross-sectional studies and three longitudinal studies were included in the analysis, with considerable variation observed between the studies with regard to their operationalization of light-intensity PA. Light-intensity PA was found to be beneficially associated with obesity, markers of lipid and glucose metabolism, and mortality. Few data were available on musculoskeletal outcomes and results were mixed. Observational evidence that light-intensity PA can confer health benefits is accumulating. Currently inactive or insufficiently active people should be encouraged to engage in PA of any intensity. If longitudinal and intervention studies corroborate our findings, the revision of PA recommendations to include light-intensity activities, at least for currently inactive populations, might be warranted.

Moderating effects of age, gender and education on the associations of perceived neighborhood environment attributes with accelerometer-based physical activity: the IPEN Adult study Moderating effects of age, gender and education on the associations of perceived neighborhood environment attributes with accelerometer-based physical activity: the IPEN Adult study

PubMed Central

Van Dyck, Delfien; Cerin, Ester; De Bourdeaudhuij, Ilse; Salvo, Deborah; Christiansen, Lars B; Macfarlane, Duncan; Owen, Neville; Mitas, Josef; Troelsen, Jens; Aguinaga-Ontoso, Ines; Davey, Rachel; Reis, Rodrigo; Sarmiento, Olga L; Schofield, Grant; Conway, Terry L; Sallis, James F

2015-01-01

The study's purpose was to examine age, gender, and education as potential moderators of the associations of perceived neighborhood environment variables with accelerometer-based moderate-to-vigorous physical activity (MVPA). Data were from 7273 adults from 16 sites (11 countries) that were part of a coordinated multi-country cross-sectional study. Age moderated the associations of perceived crime safety, and perceiving no major physical barriers to walking, with MVPA: positive associations were only found in older adults. Perceived land use mix-access was linearly (positive) associated with MVPA in men, and curvilinearly in women. Perceived crime safety was related to MVPA only in women. No moderating relationships were found for education. Overall the associations of adults’ perceptions of environmental attributes with MVPA were largely independent of the socio-demographic factors examined. These findings are encouraging, suggesting that efforts to optimize the perceived built and social environment may act in a socially-equitable manner to facilitate MVPA. PMID:26454247

Fabrication of a Miniaturized ZnO Nanowire Accelerometer and Its Performance Tests

PubMed Central

Kim, Hyun Chan; Song, Sangho; Kim, Jaehwan

2016-01-01

This paper reports a miniaturized piezoelectric accelerometer suitable for a small haptic actuator array. The accelerometer is made with zinc oxide (ZnO) nanowire (NW) grown on a copper wafer by a hydrothermal process. The size of the accelerometer is 1.5 × 1.5 mm2, thus fitting the 1.8 × 1.8 mm2 haptic actuator array cell. The detailed fabrication process of the miniaturized accelerometer is illustrated. Performance evaluation of the fabricated accelerometer is conducted by comparing it with a commercial piezoelectric accelerometer. The output current of the fabricated accelerometer increases linearly with the acceleration. The miniaturized ZnO NW accelerometer is feasible for acceleration measurement of small and lightweight devices. PMID:27649184

Progress Toward a Bulk Micromachined Tunneling Tip Microaccelerometer

NASA Technical Reports Server (NTRS)

Frank T. Hartley, Ben Dolgen, Paul M. Zavracky

1995-01-01

Ultrasensitive accelerometers are needed for microgravity measurement of orbital drag and active isolation systems. We have designed an accelerometer capable of measuring accelerations of the order of 10(i) g. A tunneling tip sensor can be used as a position sensor with a potential performance advantage of two orders of magnitude over capacitive sensors. In this paper, we disclose our progress in the fabrication and measurement of a bulk microaccelerometer which employs a tunneling tip. Fully assembled accelerometers consisting of four separate die have been fabricated. The device employs a unique folded spring system with a low spring constant. To protect the tunneling tip, we have employed electrostatic clamping. Stiction has not been observed, but the required clamping voltage is greater than expected. We have developed a simple model to analyze our results.

Physical activity in an indigenous Ecuadorian forager-horticulturalist population as measured using accelerometry.

PubMed

Madimenos, Felicia C; Snodgrass, J Josh; Blackwell, Aaron D; Liebert, Melissa A; Sugiyama, Lawrence S

2011-01-01

Minimal information on physical activity is available for non-Western populations undergoing the transition to a market economy. This is unfortunate given the importance of these data for understanding health issues such as the global obesity epidemic. We consider the utility of using accelerometry technology to examine activity patterns and energy use regulation among indigenous Shuar, an Ecuadorian forager-horticulturalist population undergoing economic and lifestyle change. We investigate sex differences in Shuar activity patterns and the effects of reproductive status on activity. Finally, we discuss the potential of accelerometry use in human biology research. Physical activity levels were measured using Actical accelerometers in 49 indigenous Shuar adults (23 males, 26 females) from a rural Ecuadorian community. Female participants were in various reproductive states including pregnant, lactating, and nonpregnant/nonlactating. Activity counts (AC), activity energy expenditure (AEE), and physical activity levels (PAL) were significantly higher (P < 0.05) in males than females. Significant differences in energy expenditure were found among pregnant or lactating females and males with pregnant or lactating partners (P < 0.001). Males with pregnant or lactating partners also had significantly higher activity levels than did other men (P < 0.01). Shuar activity levels are relatively low compared to other non-Western populations. Despite increasing market integration, pregnant and lactating females seem to be adopting a strategy noted in other subsistence populations where male participation in subsistence activities increases to compensate for their partners' elevated reproductive costs. Despite certain limitations, use of accelerometry in human biology research shows promise. Copyright © 2011 Wiley-Liss, Inc.

Physical activity in an indigenous Ecuadorian forager-horticulturalist population as measured using accelerometry

PubMed Central

Madimenos, Felicia C.; Snodgrass, J. Josh; Blackwell, Aaron D.; Liebert, Melissa A.; Sugiyama, Lawrence S.

2011-01-01

Objective Minimal information on physical activity is available for non-Western populations undergoing the transition to a market economy. This is unfortunate given the importance of these data for understanding health issues such as the global obesity epidemic. We consider the utility of using accelerometry technology to examine activity patterns and energy use regulation among indigenous Shuar, an Ecuadorian forager-horticulturalist population undergoing economic and lifestyle change. We investigate sex differences in Shuar activity patterns and the effects of reproductive status on activity. Finally, we discuss the potential of accelerometry use in human biology research. Methods Physical activity levels were measured using Actical accelerometers in 49 indigenous Shuar adults (23 males, 26 females) from a rural Ecuadorian community. Female participants were in various reproductive states including pregnant, lactating, and non-pregnant/non-lactating. Results Activity counts (AC), activity energy expenditure (AEE), and physical activity levels (PAL) were significantly higher (P < 0.05) in males than females. Significant differences in energy expenditure were found among pregnant or lactating females and males with pregnant or lactating partners (P < 0.001). Males with pregnant or lactating partners also had significantly higher activity levels than did other men (P < 0.01). Conclusions Shuar activity levels are relatively low compared to other non-Western populations. Despite increasing market integration, pregnant and lactating females seem to be adopting a strategy noted in other subsistence populations where male participation in subsistence activities increases to compensate for their partners’ elevated reproductive costs. Despite certain limitations, use of accelerometry in human biology research shows promise. PMID:21538650

Calibration of self-report tools for physical activity research: the Physical Activity Questionnaire (PAQ)

PubMed Central

2014-01-01

Background The utility of self-report measures of physical activity (PA) in youth can be greatly enhanced by calibrating self-report output against objectively measured PA data. This study demonstrates the potential of calibrating self-report output against objectively measured physical activity (PA) in youth by using a commonly used self-report tool called the Physical Activity Questionnaire (PAQ). Methods A total of 148 participants (grades 4 through 12) from 9 schools (during the 2009–2010 school year) wore an Actigraph accelerometer for 7 days and then completed the PAQ. Multiple linear regression modeling was used on 70% of the available sample to develop a calibration equation and this was cross validated on an independent sample of participants (30% of sample). Results A calibration model with age, gender, and PAQ scores explained 40% of the variance in values for the percentage of time in moderate-to-vigorous PA (%MVPA) measured from the accelerometers (%MVPA = 14.56 - (sex*0.98) - (0.84*age) + (1.01*PAQ)). When tested on an independent, hold-out sample, the model estimated %MVPA values that were highly correlated with the recorded accelerometer values (r = .63) and there was no significant difference between the estimated and recorded activity values (mean diff. = 25.3 ± 18.1 min; p = .17). Conclusions These results suggest that the calibrated PAQ may be a valid alternative tool to activity monitoring instruments for estimating %MVPA in groups of youth. PMID:24886625

Calibration of self-report tools for physical activity research: the Physical Activity Questionnaire (PAQ).

PubMed

Saint-Maurice, Pedro F; Welk, Gregory J; Beyler, Nicholas K; Bartee, Roderick T; Heelan, Kate A

2014-05-16

The utility of self-report measures of physical activity (PA) in youth can be greatly enhanced by calibrating self-report output against objectively measured PA data.This study demonstrates the potential of calibrating self-report output against objectively measured physical activity (PA) in youth by using a commonly used self-report tool called the Physical Activity Questionnaire (PAQ). A total of 148 participants (grades 4 through 12) from 9 schools (during the 2009-2010 school year) wore an Actigraph accelerometer for 7 days and then completed the PAQ. Multiple linear regression modeling was used on 70% of the available sample to develop a calibration equation and this was cross validated on an independent sample of participants (30% of sample). A calibration model with age, gender, and PAQ scores explained 40% of the variance in values for the percentage of time in moderate-to-vigorous PA (%MVPA) measured from the accelerometers (%MVPA = 14.56 - (sex*0.98) - (0.84*age) + (1.01*PAQ)). When tested on an independent, hold-out sample, the model estimated %MVPA values that were highly correlated with the recorded accelerometer values (r = .63) and there was no significant difference between the estimated and recorded activity values (mean diff. = 25.3 ± 18.1 min; p = .17). These results suggest that the calibrated PAQ may be a valid alternative tool to activity monitoring instruments for estimating %MVPA in groups of youth.

Evaluating a Model of Youth Physical Activity

ERIC Educational Resources Information Center

Heitzler, Carrie D.; Lytle, Leslie A.; Erickson, Darin J.; Barr-Anderson, Daheia; Sirard, John R.; Story, Mary

2010-01-01

Objective: To explore the relationship between social influences, self-efficacy, enjoyment, and barriers and physical activity. Methods: Structural equation modeling examined relationships between parent and peer support, parent physical activity, individual perceptions, and objectively measured physical activity using accelerometers among a…

A microcomputer-based daily living activity recording system.

PubMed

Matsuoka, Shingo; Yonezawa, Yoshiharu; Maki, Hiromichi; Ogawa, Hidekuni; Hahn, Allen W; Thayer, Julian F; Caldwell, W Morton

2003-01-01

A new daily living activity recording system has been developed for monitoring health conditions and living patterns, such as respiration, posture, activity/rest ratios and general activity level. The system employs a piezoelectric sensor, a dual axis accelerometer, two low-power active filters, a low-power 8-bit single chip microcomputer and a 128 MB compact flash memory. The piezoelectric sensor, whose electrical polarization voltage is produced by mechanical strain, detects body movements. Its high-frequency output components reflect body movements produced by walking and running activities, while the low frequency components are mainly respiratory. The dual axis accelerometer detects, from body X and Y tilt angles, whether the patient is standing, sitting or lying down (prone, supine, left side or right side). The detected respiratory, behavior and posture signals are stored by the compact flash memory. After recording, these data are downloaded to a desktop computer and analyzed.

Associations of objectively measured physical activity with daily mood ratings and psychophysiological stress responses in women.

PubMed

Poole, Lydia; Steptoe, Andrew; Wawrzyniak, Andrew J; Bostock, Sophie; Mitchell, Ellen S; Hamer, Mark

2011-08-01

The aim of this study was to examine associations of objectively measured physical activity with daily mood ratings and psychophysiological stress responses. We recruited 40 healthy females (aged 28.7 ± 6.1 yrs) who completed a once-a-day mood rating scale for 7 days, along with a 7-day assessment of physical activity using accelerometers and psychophysiological stress testing. The findings suggest that levels of physical activity as measured using an accelerometer are associated with both depressive symptoms over the past 2 weeks (CES-D) (r = - .33, p = .038) and with daily positive emotional style (r = .49, p = .001). The relationship between physical activity and positive emotional style remained after controlling for age, body mass index, and negative emotional style (t = 3.31, p = .002). Physical activity was not related to any psychophysiological stress responses. Copyright © 2011 Society for Psychophysiological Research.

Physical activity outside of structured therapy during inpatient spinal cord injury rehabilitation.

PubMed

Zbogar, Dominik; Eng, Janice J; Miller, William C; Krassioukov, Andrei V; Verrier, Mary C

2016-11-15

Little information exists on the content of inpatient rehabilitation stay when individuals with spinal cord injury (SCI) are not engaged in structured rehabilitation therapy sessions. Investigation of inpatient therapy content is incomplete without the context of activities outside of this time. We sought to quantify physical activity occurring outside of physical therapy (PT) and occupational therapy (OT) sessions during inpatient SCI rehabilitation and examine how this activity changes over time from admission to discharge. In this longitudinal observational study at two inpatient SCI rehabilitation centres, 95 participants were recruited through consecutive admissions. Physical activity at admission and discharge was recorded by 1) self-report (PARA-SCI questionnaire) and 2) real-time accelerometers worn on the dominant wrist, and hip if ambulatory. For analyses, we separated participants into those with paraplegia or tetraplegia, and a subgroup of those ambulatory at discharge. Wilcoxon signed rank tests (admission vs. discharge) were used for PARA-SCI minutes and accelerometry activity kilocounts. There was no change in self-report physical activity, where the majority of time was spent in leisure time sedentary activity (~4 h) and leisure time physical activity at a higher intensity had a median value of 0 min. In contrast, significant increases in physical activity outside PT and OT sessions from admission to discharge were found for wrist accelerometers for individuals with tetraplegia (i.e., upper limb activity) and hip accelerometers for ambulatory individuals (i.e., walking activity). Physical activity is low in the inpatient SCI rehabilitation setting outside of structured therapy with a substantial amount of time spent in leisure time sedentary activity. Individuals appear to have the capacity to increase their levels of physical activity over the inpatient stay.

Fusion of smartphone motion sensors for physical activity recognition.

PubMed

Shoaib, Muhammad; Bosch, Stephan; Incel, Ozlem Durmaz; Scholten, Hans; Havinga, Paul J M

2014-06-10

For physical activity recognition, smartphone sensors, such as an accelerometer and a gyroscope, are being utilized in many research studies. So far, particularly, the accelerometer has been extensively studied. In a few recent studies, a combination of a gyroscope, a magnetometer (in a supporting role) and an accelerometer (in a lead role) has been used with the aim to improve the recognition performance. How and when are various motion sensors, which are available on a smartphone, best used for better recognition performance, either individually or in combination? This is yet to be explored. In order to investigate this question, in this paper, we explore how these various motion sensors behave in different situations in the activity recognition process. For this purpose, we designed a data collection experiment where ten participants performed seven different activities carrying smart phones at different positions. Based on the analysis of this data set, we show that these sensors, except the magnetometer, are each capable of taking the lead roles individually, depending on the type of activity being recognized, the body position, the used data features and the classification method employed (personalized or generalized). We also show that their combination only improves the overall recognition performance when their individual performances are not very high, so that there is room for performance improvement. We have made our data set and our data collection application publicly available, thereby making our experiments reproducible.

Drivers Are More Physically Active Than Non-Drivers in Older Adults.

PubMed

Amagasa, Shiho; Fukushima, Noritoshi; Kikuchi, Hiroyuki; Takamiya, Tomoko; Odagiri, Yuko; Oka, Koichiro; Inoue, Shigeru

2018-05-28

Car use has been identified as sedentary behavior, although it may enhance mobility, particularly in the older population. This cross-sectional study aimed to compare the time spent in objectively determined sedentary behavior (SB) and physical activity (PA) between older drivers and non-drivers. Four hundred and fifty Japanese older adults (74.3 ± 2.9 years) who had valid accelerometer data were included. They were asked to respond to a questionnaire and wear an accelerometer (HJA-350IT, Omron Healthcare) on their waist for 7 consecutive days in 2015. To compare activity time between drivers and non-drivers, we calculated estimated means using analysis of covariance, adjusting for sociodemographic, physical, and psychological factors and accelerometer wear time. Compared to non-drivers, drivers engaged in more light-intensity PA (LPA) (drivers: 325.0 vs. non-drivers: 289.0 min/day) and moderate-to-vigorous PA (drivers: 37.5 vs. non-drivers: 30.0 min/day) and less SB (drivers: 493.4 vs. non-drivers: 535.9 min/day) (all p < 0.05). After stratification by age, sex, and residential area, larger effect of driving on PA time was found in older-older adults, in men, and in rural residents. Older drivers were found to be more physically active than non-drivers, suggesting more access to outdoor activities or expanding social network.

Classification accuracies of physical activities using smartphone motion sensors.

PubMed

Wu, Wanmin; Dasgupta, Sanjoy; Ramirez, Ernesto E; Peterson, Carlyn; Norman, Gregory J

2012-10-05

Over the past few years, the world has witnessed an unprecedented growth in smartphone use. With sensors such as accelerometers and gyroscopes on board, smartphones have the potential to enhance our understanding of health behavior, in particular physical activity or the lack thereof. However, reliable and valid activity measurement using only a smartphone in situ has not been realized. To examine the validity of the iPod Touch (Apple, Inc.) and particularly to understand the value of using gyroscopes for classifying types of physical activity, with the goal of creating a measurement and feedback system that easily integrates into individuals' daily living. We collected accelerometer and gyroscope data for 16 participants on 13 activities with an iPod Touch, a device that has essentially the same sensors and computing platform as an iPhone. The 13 activities were sitting, walking, jogging, and going upstairs and downstairs at different paces. We extracted time and frequency features, including mean and variance of acceleration and gyroscope on each axis, vector magnitude of acceleration, and fast Fourier transform magnitude for each axis of acceleration. Different classifiers were compared using the Waikato Environment for Knowledge Analysis (WEKA) toolkit, including C4.5 (J48) decision tree, multilayer perception, naive Bayes, logistic, k-nearest neighbor (kNN), and meta-algorithms such as boosting and bagging. The 10-fold cross-validation protocol was used. Overall, the kNN classifier achieved the best accuracies: 52.3%-79.4% for up and down stair walking, 91.7% for jogging, 90.1%-94.1% for walking on a level ground, and 100% for sitting. A 2-second sliding window size with a 1-second overlap worked the best. Adding gyroscope measurements proved to be more beneficial than relying solely on accelerometer readings for all activities (with improvement ranging from 3.1% to 13.4%). Common categories of physical activity and sedentary behavior (walking, jogging, and sitting) can be recognized with high accuracies using both the accelerometer and gyroscope onboard the iPod touch or iPhone. This suggests the potential of developing just-in-time classification and feedback tools on smartphones.

Characterizing coarse bedload transport during floods with RFID and accelerometer tracers, in-stream RFID antennas and HEC-RAS modeling

NASA Astrophysics Data System (ADS)

Olinde, L.; Johnson, J. P.

2013-12-01

By monitoring the transport timing and distances of tracer grains in a steep mountains stream, we collected data that can constrain numerical bedload transport models considered for these systems. We captured bedload activity during a weeks-spanning snowmelt period in Reynolds Creek, Idaho by deploying Radio Frequency Identification (RFID) and accelerometer embedded tracers with in-stream stationary RFID antennas. During transport events, RFID dataloggers recorded the times when tracers passed over stationary antennas. The accelerometer tracers also logged x, y, z-axis accelerations every 10 minutes to identify times of motion and rest. After snowmelt flows receded, we found tracers with mobile antennas and surveyed their positions. We know the timing and tracer locations when accelerometer tracers were initially entrained, passed stationary antennas, and were finally deposited at the surveyed locations. The fraction of moving accelerometers over time correlates well with discharge. Comparisons of the transported tracer fraction between rising and falling limbs over multiple flood peaks suggest that some degree of clockwise hysteresis persisted during the snowmelt period. Additionally, we apply accelerometer transport durations and displacement distances to calculate virtual velocities over full tracer path lengths and over lengths between initial locations to stationary antennas as well as between stationary antennas to final positions. The accelerometer-based virtual velocities are significantly faster than those estimated from traditional tracer methods that estimate bedload transport durations by assuming threshold flow conditions. We also subsample the motion data to calculate how virtual velocities change over the measurement intervals. Regressions of these relations are in turn used to extrapolate virtual velocities at smaller sampling timescales. Minimum hop lengths are also evaluated for each accelerometer tracer. Finally, flow conditions during the snowmelt hydrograph are modeled over the 11 kilometers of surveyed stream by utilizing 1m airborne LiDAR and HEC-GeoRAS. Cross-sectional HEC-RAS results are used to estimate the spatial distribution of longitudinal shear velocities over the observed discharges. At final accelerometer tracer positions, we analyze the HEC-RAS generated flow conditions for each disentrainment discharge magnitude. The techniques developed here have the potential to link individual grain characteristics during floods to a range of time and length scales.

Physical Activity Is Positively Associated with Episodic Memory in Aging

PubMed Central

Hayes, Scott M.; Alosco, Michael L.; Hayes, Jasmeet P.; Cadden, Margaret; Peterson, Kristina M.; Allsup, Kelly; Forman, Daniel E.; Sperling, Reisa A.; Verfaellie, Mieke

2016-01-01

Aging is associated with performance reductions in executive function and episodic memory, although there is substantial individual variability in cognition among older adults. One factor that may be positively associated with cognition in aging is physical activity. To date, few studies have objectively assessed physical activity in young and older adults, and examined whether physical activity is differentially associated with cognition in aging. Young (n = 29, age 18–31 years) and older adults (n = 31, ages 55–82 years) completed standardized neuropsychological testing to assess executive function and episodic memory capacities. An experimental face-name relational memory task was administered to augment assessment of episodic memory. Physical activity (total step count and step rate) was objectively assessed using an accelerometer, and hierarchical regressions were used to evaluate relationships between cognition and physical activity. Older adults performed more poorly on tasks of executive function and episodic memory. Physical activity was positively associated with a composite measure of visual episodic memory and face-name memory accuracy in older adults. Physical activity associations with cognition were independent of sedentary behavior, which was negatively correlated with memory performance. Physical activity was not associated with cognitive performance in younger adults. Physical activity is positively associated with episodic memory performance in aging. The relationship appears to be strongest for face-name relational memory and visual episodic memory, likely attributable to the fact that these tasks make strong demands on the hippocampus. The results suggest that physical activity relates to cognition in older, but not younger adults. PMID:26581790

A Preliminary Investigation of Accelerometer-Derived Sleep and Physical Activity Following Sport-Related Concussion.

PubMed

Sufrinko, Alicia M; Howie, Erin K; Elbin, R J; Collins, Michael W; Kontos, Anthony P

2018-03-29

Describe changes in postconcussion activity levels and sleep throughout recovery in a sample of pediatric sport-related concussion (SRC) patients, and examine the predictive value of accelerometer-derived activity and sleep on subsequent clinical outcomes at a follow-up clinic visit. Outpatient concussion clinic. Twenty athletes aged 12 to 19 years with diagnosed SRC. Prospective study including visit 1 (<72 hours postinjury) and visit 2 (6-18 days postinjury). Linear regressions used to predict scores (ie, neurocognitive, vestibular/oculomotor) at visit 2 from accelerometer-derived data collected 0 to 6 days postinjury. Linear mixed models evaluated changes in activity and sleep across recovery. Symptom, neurocognitive, and vestibular/oculomotor scores; sleep and activity data (Actigraph GT3x+) RESULTS:: The maximum intensity of physical activity increased (P = .009) and time in bed decreased throughout recovery (P = .026). Several physical activity metrics from 0 to 6 days postinjury were predictive of worse vestibular/oculomotor scores at visit 2 (P < .05). Metrics indicative of poor sleep 0 to 6 days postinjury were associated with worse reaction time at visit 2 (P < .05). This exploratory study suggests physical activity and sleep change from the acute to subacute postinjury time period in adolescent SRC patients. In our small sample, excess physical activity and poor sleep the first week postinjury may be associated with worse outcomes at follow-up in the subacute stage of recovery. This study further supported the feasibility of research utilizing wearable technology in concussion patients, and future research in a large, diverse sample of concussion patients examined at concise time intervals postinjury is needed.

Reliability and Validity of the Self- and Interviewer-Administered Versions of the Global Physical Activity Questionnaire (GPAQ)

PubMed Central

Chu, Anne H. Y.; Ng, Sheryl H. X.; Koh, David; Müller-Riemenschneider, Falk

2015-01-01

Objective The Global Physical Activity Questionnaire (GPAQ) was originally designed to be interviewer-administered by the World Health Organization in assessing physical activity. The main aim of this study was to compare the psychometric properties of a self-administered GPAQ with the original interviewer-administered approach. Additionally, this study explored whether using different accelerometry-based physical activity bout definitions might affect the questionnaire’s validity. Methods A total of 110 participants were recruited and randomly allocated to an interviewer- (n = 56) or a self-administered (n = 54) group for test-retest reliability, of which 108 participants who met the wear time criteria were included in the validity study. Reliability was assessed by administration of questionnaires twice with a one-week interval. Criterion validity was assessed by comparing against seven-day accelerometer measures. Two definitions for accelerometry-data scoring were employed: (1) total-min of activity, and (2) 10-min bout. Results Participants had similar baseline characteristics in both administration groups and no significant difference was found between the two formats in terms of validity (correlations between the GPAQ and accelerometer). For validity, the GPAQ demonstrated fair-to-moderate correlations for moderate-to-vigorous physical activity (MVPA) for self-administration (r s = 0.30) and interviewer-administration (r s = 0.46). Findings were similar when considering 10-min activity bouts in the accelerometer analysis for MVPA (r s = 0.29 vs. 0.42 for self vs. interviewer). Within each mode of administration, the strongest correlations were observed for vigorous-intensity activity. However, Bland-Altman plots illustrated bias toward overestimation for higher levels of MVPA, vigorous- and moderate-intensity activities, and underestimation for lower levels of these measures. Reliability for MVPA revealed moderate correlations (r s = 0.61 vs. 0.63 for self vs. interviewer). Conclusions Our findings showed comparability between both self- and interviewer-administration modes of the GPAQ. The GPAQ in general but especially the self-administered version may offer a relatively inexpensive method for measuring physical activity of various types and at different domains. However, there may be bias in the GPAQ measurements depending on the overall physical activity. It is advisable to incorporate accelerometers in future studies, particularly when measuring different intensities of physical activity. PMID:26327457

Operational Data Reduction Procedure for Determining Density and Vertical Structure of the Martian Upper Atmosphere from Mars Global Surveyor Accelerometer Measurements

NASA Technical Reports Server (NTRS)

Cancro, George J.; Tolson, Robert H.; Keating, Gerald M.

1998-01-01

The success of aerobraking by the Mars Global Surveyor (MGS) spacecraft was partly due to the analysis of MGS accelerometer data. Accelerometer data was used to determine the effect of the atmosphere on each orbit, to characterize the nature of the atmosphere, and to predict the atmosphere for future orbits. To interpret the accelerometer data, a data reduction procedure was developed to produce density estimations utilizing inputs from the spacecraft, the Navigation Team, and pre-mission aerothermodynamic studies. This data reduction procedure was based on the calculation of aerodynamic forces from the accelerometer data by considering acceleration due to gravity gradient, solar pressure, angular motion of the MGS, instrument bias, thruster activity, and a vibration component due to the motion of the damaged solar array. Methods were developed to calculate all of the acceleration components including a 4 degree of freedom dynamics model used to gain a greater understanding of the damaged solar array. The total error inherent to the data reduction procedure was calculated as a function of altitude and density considering contributions from ephemeris errors, errors in force coefficient, and instrument errors due to bias and digitization. Comparing the results from this procedure to the data of other MGS Teams has demonstrated that this procedure can quickly and accurately describe the density and vertical structure of the Martian upper atmosphere.

Wear-Time Compliance with a Dual-Accelerometer System for Capturing 24-h Behavioural Profiles in Children and Adults.

PubMed

Duncan, Scott; Stewart, Tom; Mackay, Lisa; Neville, Jono; Narayanan, Anantha; Walker, Caroline; Berry, Sarah; Morton, Susan

2018-06-21

To advance the field of time-use epidemiology, a tool capable of monitoring 24 h movement behaviours including sleep, physical activity, and sedentary behaviour is needed. This study explores compliance with a novel dual-accelerometer system for capturing 24 h movement patterns in two free-living samples of children and adults. A total of 103 children aged 8 years and 83 adults aged 20-60 years were recruited. Using a combination of medical dressing and purpose-built foam pouches, participants were fitted with two Axivity AX3 accelerometers—one to the thigh and the other to the lower back—for seven 24 h periods. AX3 accelerometers contain an inbuilt skin temperature sensor that facilitates wear time estimation. The median (IQR) wear time in children was 160 (67) h and 165 (79) h (out of a maximum of 168 h) for back and thigh placement, respectively. Wear time was significantly higher and less variable in adults, with a median (IQR) for back and thigh placement of 168 (1) and 168 (0) h. A greater proportion of adults (71.6%) achieved the maximum number of complete days when compared to children (41.7%). We conclude that a dual-accelerometer protocol using skin attachment methods holds considerable promise for monitoring 24-h movement behaviours in both children and adults.

A randomised control trial of prompt and feedback devices and their impact on quality of chest compressions--a simulation study.

PubMed

Yeung, Joyce; Davies, Robin; Gao, Fang; Perkins, Gavin D

2014-04-01

This study aims to compare the effect of three CPR prompt and feedback devices on quality of chest compressions amongst healthcare providers. A single blinded, randomised controlled trial compared a pressure sensor/metronome device (CPREzy), an accelerometer device (Phillips Q-CPR) and simple metronome on the quality of chest compressions on a manikin by trained rescuers. The primary outcome was compression depth. Secondary outcomes were compression rate, proportion of chest compressions with inadequate depth, incomplete release and user satisfaction. The pressure sensor device improved compression depth (37.24-43.64 mm, p=0.02), the accelerometer device decreased chest compression depth (37.38-33.19 mm, p=0.04) whilst the metronome had no effect (39.88 mm vs. 40.64 mm, p=0.802). Compression rate fell with all devices (pressure sensor device 114.68-98.84 min(-1), p=0.001, accelerometer 112.04-102.92 min(-1), p=0.072 and metronome 108.24 min(-1) vs. 99.36 min(-1), p=0.009). The pressure sensor feedback device reduced the proportion of compressions with inadequate depth (0.52 vs. 0.24, p=0.013) whilst the accelerometer device and metronome did not have a statistically significant effect. Incomplete release of compressions was common, but unaffected by the CPR feedback devices. Users preferred the accelerometer and metronome devices over the pressure sensor device. A post hoc study showed that de-activating the voice prompt on the accelerometer device prevented the deterioration in compression quality seen in the main study. CPR feedback devices vary in their ability to improve performance. In this study the pressure sensor device improved compression depth, whilst the accelerometer device reduced it and metronome had no effect. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

What they say and what they do: comparing physical activity across the USA, England and the Netherlands.

PubMed

Kapteyn, Arie; Banks, James; Hamer, Mark; Smith, James P; Steptoe, Andrew; van Soest, Arthur; Koster, Annemarie; Htay Wah, Saw

2018-06-01

Physical activity (PA) is important for maintaining health, but there are fundamental unanswered questions on how best it should be measured. We measured PA in the Netherlands (n=748), the USA (n=540) and England (n=254), both by a 7 day wrist-worn accelerometer and by self-reports. The self-reports included a global self-report on PA and a report on the frequency of vigorous, moderate and mild activity. The self-reported data showed only minor differences across countries and across groups within countries (such as different age groups or working vs non-working respondents). The accelerometer data, however, showed large differences; the Dutch and English appeared to be much more physically active than Americans h (For instance, among respondents aged 50 years or older 38% of Americans are in the lowest activity quintile of the Dutch distribution). In addition, accelerometer data showed a sharp decline of PA with age, while no such pattern was observed in self-reports. The differences between objective measures and self-reports occurred for both types of self-reports. It is clear that self-reports and objective measures tell vastly different stories, suggesting that across countries people use different response scales when answering questions about how physically active they are. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Single-accelerometer-based daily physical activity classification.

PubMed

Long, Xi; Yin, Bin; Aarts, Ronald M

2009-01-01

In this study, a single tri-axial accelerometer placed on the waist was used to record the acceleration data for human physical activity classification. The data collection involved 24 subjects performing daily real-life activities in a naturalistic environment without researchers' intervention. For the purpose of assessing customers' daily energy expenditure, walking, running, cycling, driving, and sports were chosen as target activities for classification. This study compared a Bayesian classification with that of a Decision Tree based approach. A Bayes classifier has the advantage to be more extensible, requiring little effort in classifier retraining and software update upon further expansion or modification of the target activities. Principal components analysis was applied to remove the correlation among features and to reduce the feature vector dimension. Experiments using leave-one-subject-out and 10-fold cross validation protocols revealed a classification accuracy of approximately 80%, which was comparable with that obtained by a Decision Tree classifier.

Smart self management: assistive technology to support people with chronic disease.

PubMed

Zheng, Huiru; Nugent, Chris; McCullagh, Paul; Huang, Yan; Zhang, Shumei; Burns, William; Davies, Richard; Black, Norman; Wright, Peter; Mawson, Sue; Eccleston, Christopher; Hawley, Mark; Mountain, Gail

2010-01-01

We have developed a personalised self management system to support self management of chronic conditions with support from health-care professionals. Accelerometers are used to measure gross levels of activity, for example walking around the house, and used to infer higher level activity states, such as standing, sitting and lying. A smart phone containing an accelerometer and a global positioning system (GPS) module can be used to monitor outdoor activity, providing both activity and location based information. Heart rate, blood pressure and weight are recorded and input to the system by the user. A decision support system (DSS) detects abnormal activity and distinguishes life style patterns. The DSS is used to assess the self management process, and automates feedback to the user, consistent with the achievement of their life goals. We have found that telecare and assistive technology is feasible to support self management for chronic conditions within the home and local community environments.

Educator engagement and interaction and children's physical activity in early childhood education and care settings: an observational study protocol.

PubMed

Tonge, Karen L; Jones, Rachel A; Hagenbuchner, Markus; Nguyen, Tuc V; Okely, Anthony D

2017-02-07

The benefits of regular physical activity for children are significant. Previous research has addressed the quantity and quality of children's physical activity while in early childhood education and care (ECEC) settings, yet little research has investigated the social and physical environmental influences on physical activity in these settings. The outcomes of this study will be to measure these social and physical environmental influences on children's physical activity using a combination of a real-time location system (RTLS) (a closed system that tracks the location of movement of participants via readers and tags), accelerometry and direct observation. This study is the first of its kind to combine RTLSs and accelerometer data in ECEC settings. It is a cross-sectional study involving ∼100 educators and 500 children from 11 ECEC settings in the Illawarra region of New South Wales, Australia. A RTLS and Actigraph GT3X+ accelerometers will be concurrently used to measure the level and location of the children's and educators' physical activity while in outside environments. Children and educators will wear accelerometers on their hip that record triaxial acceleration data at 100 Hz. Children and educators will also wear a tag watch on their wrist that transmits a signal to anchors of the RTLS and the triangulation of signals will identify their specific location. In addition to these, up to three random periods (10-25 min in length) will be used to collect observational data each day and assessed with the classroom assessment and scoring system to measure the quality of interactions. In conjunction with the real-time location system (RTLS) and accelerometers, these observations will measure the relationship between the quality of interactions and children's physical activity. The results of this study will be disseminated through peer-reviewed publications and presentations. Ethical approval was obtained through the University of Wollongong Human Research Ethics Committee (HE14/330). Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Miniaturized sensors to monitor simulated lunar locomotion.

PubMed

Hanson, Andrea M; Gilkey, Kelly M; Perusek, Gail P; Thorndike, David A; Kutnick, Gilead A; Grodsinsky, Carlos M; Rice, Andrea J; Cavanagh, Peter R

2011-02-01

Human activity monitoring is a useful tool in medical monitoring, military applications, athletic coaching, and home healthcare. We propose the use of an accelerometer-based system to track crewmember activity during space missions in reduced gravity environments. It is unclear how the partial gravity environment of the Moorn or Mars will affect human locomotion. Here we test a novel analogue of lunar gravity in combination with a custom wireless activity tracking system. A noninvasive wireless accelerometer-based sensor system, the activity tracking device (ATD), was developed. The system has two sensor units; one footwear-mounted and the other waist-mounted near the midlower back. Subjects (N=16) were recruited to test the system in the enhanced Zero Gravity Locomotion Simulator (eZLS) at NASA Glenn Research Center. Data were used to develop an artificial neural network for activity recognition. The eZLS demonstrated the ability to replicate reduced gravity environments. There was a 98% agreement between the ATD and force plate-derived stride times during running (9.7 km x h(-1)) at both 1 g and 1/6 g. A neural network was designed and successfully trained to identify lunar walking, running, hopping, and loping from ATD measurements with 100% accuracy. The eZLS is a suitable tool for examining locomotor activity at simulated lunar gravity. The accelerometer-based ATD system is capable of monitoring human activity and may be suitable for use during remote, long-duration space missions. A neural network has been developed to use data from the ATD to aid in remote activity monitoring.

Slice&Dice: Recognizing Food Preparation Activities Using Embedded Accelerometers

NASA Astrophysics Data System (ADS)

Pham, Cuong; Olivier, Patrick

Within the context of an endeavor to provide situated support for people with cognitive impairments in the kitchen, we developed and evaluated classifiers for recognizing 11 actions involved in food preparation. Data was collected from 20 lay subjects using four specially designed kitchen utensils incorporating embedded 3-axis accelerometers. Subjects were asked to prepare a mixed salad in our laboratory-based instrumented kitchen environment. Video of each subject's food preparation activities were independently annotated by three different coders. Several classifiers were trained and tested using these features. With an overall accuracy of 82.9% our investigation demonstrated that a broad set of food preparation actions can be reliably recognized using sensors embedded in kitchen utensils.

Estimation of daily energy expenditure in pregnant and non-pregnant women using a wrist-worn tri-axial accelerometer.

PubMed

van Hees, Vincent T; Renström, Frida; Wright, Antony; Gradmark, Anna; Catt, Michael; Chen, Kong Y; Löf, Marie; Bluck, Les; Pomeroy, Jeremy; Wareham, Nicholas J; Ekelund, Ulf; Brage, Søren; Franks, Paul W

2011-01-01

Few studies have compared the validity of objective measures of physical activity energy expenditure (PAEE) in pregnant and non-pregnant women. PAEE is commonly estimated with accelerometers attached to the hip or waist, but little is known about the validity and participant acceptability of wrist attachment. The objectives of the current study were to assess the validity of a simple summary measure derived from a wrist-worn accelerometer (GENEA, Unilever Discover, UK) to estimate PAEE in pregnant and non-pregnant women, and to evaluate participant acceptability. Non-pregnant (N = 73) and pregnant (N = 35) Swedish women (aged 20-35 yrs) wore the accelerometer on their wrist for 10 days during which total energy expenditure (TEE) was assessed using doubly-labelled water. PAEE was calculated as 0.9×TEE-REE. British participants (N = 99; aged 22-65 yrs) wore accelerometers on their non-dominant wrist and hip for seven days and were asked to score the acceptability of monitor placement (scored 1 [least] through 10 [most] acceptable). There was no significant correlation between body weight and PAEE. In non-pregnant women, acceleration explained 24% of the variation in PAEE, which decreased to 19% in leave-one-out cross-validation. In pregnant women, acceleration explained 11% of the variation in PAEE, which was not significant in leave-one-out cross-validation. Median (IQR) acceptability of wrist and hip placement was 9(8-10) and 9(7-10), respectively; there was a within-individual difference of 0.47 (p<.001). A simple summary measure derived from a wrist-worn tri-axial accelerometer adds significantly to the prediction of energy expenditure in non-pregnant women and is scored acceptable by participants.

Using Smartphones to Detect Earthquakes

NASA Astrophysics Data System (ADS)

Kong, Q.; Allen, R. M.

2012-12-01

We are using the accelerometers in smartphones to record earthquakes. In the future, these smartphones may work as a supplement network to the current traditional network for scientific research and real-time applications. Given the potential number of smartphones, and small separation of sensors, this new type of seismic dataset has significant potential provides that the signal can be separated from the noise. We developed an application for android phones to record the acceleration in real time. These records can be saved on the local phone or transmitted back to a server in real time. The accelerometers in the phones were evaluated by comparing performance with a high quality accelerometer while located on controlled shake tables for a variety of tests. The results show that the accelerometer in the smartphone can reproduce the characteristic of the shaking very well, even the phone left freely on the shake table. The nature of these datasets is also quite different from traditional networks due to the fact that smartphones are moving around with their owners. Therefore, we must distinguish earthquake signals from other daily use. In addition to the shake table tests that accumulated earthquake records, we also recorded different human activities such as running, walking, driving etc. An artificial neural network based approach was developed to distinguish these different records. It shows a 99.7% successful rate of distinguishing earthquakes from the other typical human activities in our database. We are now at the stage ready to develop the basic infrastructure for a smartphone seismic network.

Accelerometer-assessed sedentary work, leisure time and cardio-metabolic biomarkers during one year: Effectiveness of a cluster randomized controlled trial in parents with a sedentary occupation and young children.

PubMed

Pesola, Arto J; Laukkanen, Arto; Heikkinen, Risto; Sipilä, Sarianna; Sääkslahti, Arja; Finni, Taija

2017-01-01

It is unknown whether reducing sedentary time at work and during leisure time is possible and effective during one year. Office workers with young children were recruited for this one-year cluster-randomized controlled trial through kindergartens and primary schools from 7 clusters in the city of Jyväskylä, Finland. After a lecture, face-to-face tailored counseling was used to set contractually binding goals regarding reducing and breaking up sitting periods and increasing light intensity physical activity during work and leisure time. Primary outcomes of total, work and leisure sedentary time (<100 counts/min, cpm), light activity time (<2020 cpm), moderate-to-vigorous activity time (MVPA) and breaks/sedentary hour were assessed with a waist-worn Alive -accelerometer for 7 days, 5 times during the year. Anthropometrics (DXA), fasting biomarkers and self-reported diet were assessed as secondary outcomes. Data were collected between 2011-2013 and analyzed between 2013-2016 with a linear mixed-effects model fit by REML using likelihood ratio test and intention-to-treat-principle. Participants from intervention (N = 71) and control (N = 62) regions were assessed at baseline and 117 completed the study. Sedentary leisure time decreased [-21.2 (95% CI -37.3 to -5.1) min/8 hours, likelihood ratio P<0.001] and light activity time [13.4 (-2.2 to 29.0) min/8 hours, P = 0.008] and breaks per sedentary hour [1.0 (-0.2 to 2.2), P = 0.010] increased in the intervention group as compared to controls at 3 months. The decrease in sedentary leisure time was maintained throughout the year [-7.9 (-24.0 to 8.3) min/8 hours, P = 0.029]. Small decreases in the control group's work and leisure MVPA were observed mostly at 3 months. Small favorable intervention effects were observed for fasting plasma glucose at 3 months and for leg lean mass and apoB/apoA-1 ratio at 12 months, with no changes in other outcomes. Behavioral counseling induced a small decline in sedentary leisure time throughout one year in parents with a sedentary occupation and young children. Small concurrent changes in different biomarkers suggest that reducing sedentary leisure time during one year may be beneficial. ISRCTN28668090, registered 30 November 2011.

Racial Differences in Neighborhood Perceptions and their Influences on Physical Activity among Urban Older Women.

PubMed

Li, Wenjun; Procter-Gray, Elizabeth; Youssef, Gretchen A; Crouter, Scott E; Cheng, Jie; Brown, Kristen; Churchill, Linda; Clarke, Anthony; Ockene, Judith K; Magee, Michelle F

2017-01-01

Proper levels of physical activity (PA) are important to healthy aging. Little is known about racial differences in influences of neighborhood perceptions (NP) on PA and use of neighborhood resources among community-dwelling older women. In 2014 and 2015, 49 white and 44 black women of age 65 and older living in Washington, DC were queried about their PA, NP, use of neighborhood resources and sociodemographic characteristics. They wore an accelerometer and a Global Positioning System device concurrently for 7 consecutive days. Data were analyzed by race. Compared to Whites, Blacks had lower NP scores (71% positive vs. 77%, p = 0.01), lower mean daily step counts (mean (SD): 3256 (1918) vs. 5457 (2989), p < 0.001), and lower frequencies of all exercise activities combined (19.7 (8.7) vs. 25.2 (11.8) per week, p = 0.01). For both Whites and Blacks, better NPs were associated with more frequent PA both at ( p = 0.05) and away from home ( p = 0.01). However, better NPs were associated with higher frequencies of exercise activities, moderate-to-high intensity activities, and utilitarian walking for Whites but not Blacks ( p < 0.05 for race-perception interaction terms). In an urban setting, older Black women were more likely than older White women to have poor NPs, less PA, and weaker or no association of positive NPs with higher levels of certain PAs. Such substantial racial differences warrant further investigation and consideration in health promotion programs.

Objectively Measured Physical Activity in European Adults: Cross-Sectional Findings from the Food4Me Study.

PubMed

Marsaux, Cyril F M; Celis-Morales, Carlos; Hoonhout, Jettie; Claassen, Arjan; Goris, Annelies; Forster, Hannah; Fallaize, Rosalind; Macready, Anna L; Navas-Carretero, Santiago; Kolossa, Silvia; Walsh, Marianne C; Lambrinou, Christina-Paulina; Manios, Yannis; Godlewska, Magdalena; Traczyk, Iwona; Lovegrove, Julie A; Martinez, J Alfredo; Daniel, Hannelore; Gibney, Mike; Mathers, John C; Saris, Wim H M

2016-01-01

Comparisons of objectively measured physical activity (PA) between residents of European countries measured concurrently with the same protocol are lacking. We aimed to compare PA between the seven European countries involved in the Food4Me Study, using accelerometer data collected remotely via the Internet. Of the 1607 participants recruited, 1287 (539 men and 748 women) provided at least 3 weekdays and 2 weekend days of valid accelerometer data (TracmorD) at baseline and were included in the present analyses. Men were significantly more active than women (physical activity level = 1.74 vs. 1.70, p < 0.001). Time spent in light PA and moderate PA differed significantly between countries but only for women. Adherence to the World Health Organization recommendation to accumulate at least 150 min of moderate-equivalent PA weekly was similar between countries for men (range: 54-65%) but differed significantly between countries for women (range: 26-49%). Prevalence estimates decreased substantially for men and women in all seven countries when PA guidelines were defined as achieving 30 min of moderate and vigorous PA per day. We were able to obtain valid accelerometer data in real time via the Internet from 80% of participants. Although our estimates are higher compared with data from Sweden, Norway, Portugal and the US, there is room for improvement in PA for all countries involved in the Food4Me Study.

Calibration of context-specific survey items to assess youth physical activity behaviour.

PubMed

Saint-Maurice, Pedro F; Welk, Gregory J; Bartee, R Todd; Heelan, Kate

2017-05-01

This study tests calibration models to re-scale context-specific physical activity (PA) items to accelerometer-derived PA. A total of 195 4th-12th grades children wore an Actigraph monitor and completed the Physical Activity Questionnaire (PAQ) one week later. The relative time spent in moderate-to-vigorous PA (MVPA % ) obtained from the Actigraph at recess, PE, lunch, after-school, evening and weekend was matched with a respective item score obtained from the PAQ's. Item scores from 145 participants were calibrated against objective MVPA % using multiple linear regression with age, and sex as additional predictors. Predicted minutes of MVPA for school, out-of-school and total week were tested in the remaining sample (n = 50) using equivalence testing. The results showed that PAQ β-weights ranged from 0.06 (lunch) to 4.94 (PE) MVPA % (P < 0.05) and models root mean square error ranged from 4.2% (evening) to 20.2% (recess). When applied to an independent sample, differences between PAQ and accelerometer MVPA at school and out-of-school ranged from -15.6 to +3.8 min and the PAQ was within 10-15% of accelerometer measured activity. This study demonstrated that context-specific items can be calibrated to predict minutes of MVPA in groups of youth during in- and out-of-school periods.