| 1. |
- Arvidsson, Daniel, 1974, et al.
(författare)
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Med accelerometrar kan fysisk aktivitet mätas objektivt- Snabb metodutveckling, men mer kompetens krävs för användning fullt ut i klinisk praxis : Physical Activity Measured With Accelerometers
- 2019
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Ingår i: Läkartidningen. - 1652-7518. ; 116
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Forskningsöversikt (refereegranskat)abstract
- The development of accelerometers has revolutionized measurement of physical activity, and they are used to a large extent in research and have started to be implemented into clinical settings. However, achievement of reliable outcomes requires good methodological knowledge and skills by the user. Otherwise, significant measurement errors may occur, interfering with assessment of the physical activity level in the population, group differences, associations with health parameters or effect of treatments. This paper by the Swedish Network for Objective Measurement of Movement (NORM) provides an overview of physical activity measurement including sections of data collection, processing of raw data into useful metrics and statistical analysis. It targets users of accelerometer in research, health care and national surveys.
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| 2. |
- Arvidsson, Daniel, 1974, et al.
(författare)
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A Longitudinal Analysis of the Relationships of Physical Activity and Body Fat With Nerve Growth Factor and Brain-Derived Neural Factor in Children
- 2018
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Ingår i: Journal of Physical Activity & Health. - : Human Kinetics. - 1543-3080 .- 1543-5474. ; 15:8, s. 620-625
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Tidskriftsartikel (refereegranskat)abstract
- Background: Nerve growth factor (NGF) and brain-derived neural factor (BDNF) are important for brain function and detectable in the blood. This study explored the longitudinal associations of physical activity and body fat with serum NGF and BDNF in children. Methods: Two waves of measurements were performed 2 years apart in 8- to 11-year-old children, including physical activity using the ActiGraph model 7164, body composition by dual-energy X-ray absorptiometry, and serum NGF and BDNF determined by multiplex immunoassay. The first wave included 248 children. Full information maximum likelihood estimation with robust standard errors was applied in structural equation modeling. Results: Vigorous physical activity showed a direct positive longitudinal relationship with NGF (standardized coefficient beta = 0.30, P = .01) but not with BDNF (beta = 0.04, P = .84). At the same time, body fat percentage was positively related to both NGF (beta = 0.59, P < .001) and BDNF (beta = 0.17, P = .04). There was an indication of an indirect relationship of vigorous physical activity with NGF (product of unstandardized coefficient beta = -0.18, P = .02) and BDNF (beta = -0.07, P = .05) through the negative relationship with body fat percentage (beta = -0.36, P < .001). Conclusions: Vigorous physical activity is directly related to serum NGF and indirectly through the level of body fat. The relationships with serum BDNF are more complex.
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| 3. |
- Arvidsson, Daniel, 1974, et al.
(författare)
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Guide till metoder för att mäta fysisk aktivitet.
- 2016
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Ingår i: Idrottsmedicin. - 2001-3302. ; 16:3, s. 16-19
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Inom såväl forskning som klinik behöver man ofta uppskatta fysisk aktivitet på olika sätt. Det är viktigt att man använder rätt mätmetoder och är förtrogen med deras fördelar och begränsningar. Utvecklingen inom detta område går snabbt. Denna artikel är en kort guide över de vanligaste metoderna.
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| 4. |
- Arvidsson, Daniel, 1974, et al.
(författare)
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Measurement of physical activity in clinical practice using accelerometers.
- 2019
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Ingår i: Journal of internal medicine. - : Wiley. - 1365-2796 .- 0954-6820. ; 286:2, s. 137-153
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Forskningsöversikt (refereegranskat)abstract
- Accelerometers are commonly used in clinical and epidemiological research for more detailed measures of physical activity and to target the limitations of self-report methods. Sensors are attached at the hip, wrist and thigh, and the acceleration data are processed and calibrated in different waysto determine activity intensity, body position and/or activity type. Simple linear modelling can be used to assess activity intensity from hip andthighdata, whilst more advanced machine-learning modelling is to prefer for the wrist. The thigh position is most optimal to assess body position and activity type using machine-learning modelling. Frequency filtering and measurement resolution needs to be considered for correct assessment of activity intensity. Simple physical activity measures and statistical methods are mostly used to investigate relationship with health, but do not take advantage of all information provided by accelerometers and do not consider all components of the physical activity behaviour and their interrelationships. More advanced statistical methods are suggested that analyse patterns of multiple measures of physical activity to demonstrate stronger and more specific relationships with health. However, evaluations of accelerometer methods show considerable measurement errors, especially at individual level, which interferes with their use in clinical research and practice. Therefore, better objective methods are needed with improved data processing andcalibration techniques, exploring both simple linear and machine-learning alternatives. Development and implementation of accelerometer methods into clinical research and practice requires interdisciplinary collaboration to cover all aspects contributing to useful and accurate measures of physical activity behaviours related to health.
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| 5. |
- Arvidsson, Daniel, 1974, et al.
(författare)
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Re-examination of accelerometer data processing and calibration for the assessment of physical activity intensity.
- 2019
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Ingår i: Scandinavian Journal of Medicine and Science in Sports. - : John Wiley & Sons. - 0905-7188 .- 1600-0838. ; 29:10, s. 1442-1452
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Tidskriftsartikel (refereegranskat)abstract
- This review reexamines use of accelerometer and oxygen uptake data for assessment of activity intensity. Accelerometers capture mechanical work, while oxygen uptake captures the energy cost of this work. Frequency filtering needs to be considered when processing acceleration data. A too restrictive filter attenuates the acceleration signal for walking and, to a higher degree, for running. This measurement error affects shorter (children) more than taller (adults) individuals due to their higher movement frequency. Less restrictive filtering includes more movement related signals and provide measures that better capture mechanical work, but may include more noise. An optimal filter cut-point is determined where most relevant acceleration signals are included. Further, accelerometer placement affects what part of mechanical work being captured. While the waist placement captures total mechanical work and therefore contributes to measures of activity intensity equivalent by age and stature, the thigh and wrist placements capture more internal work and do not provide equivalent measures. Value calibration of accelerometer measures is usually performed using measured oxygen uptake with the metabolic equivalent of task (MET) as reference measure of activity intensity. However, the use of MET is not stringent and is not a measure of activity intensity equivalent by age and stature. A candidate measure is the mass-specific net oxygen uptake, VO2 net (VO2 tot - VO2 stand). To improve measurement of physical activity intensity using accelerometers, research developments are suggested concerning processing of accelerometer data, use of energy expenditure as reference for activity intensity, and calibration procedure with absolute versus relative intensity. This article is protected by copyright. All rights reserved.
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| 6. |
- Arvidsson, Daniel, 1974, et al.
(författare)
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Reexamination of Accelerometer Calibration with Energy Expenditure as Criterion: VO2net Instead of MET for Age-Equivalent Physical Activity Intensity
- 2019
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Ingår i: Sensors. - : MDPI AG. - 1424-8220. ; 19:15
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Tidskriftsartikel (refereegranskat)abstract
- Accelerometer calibration for physical activity (PA) intensity is commonly performed using Metabolic Equivalent of Task (MET) as criterion. However, MET is not an age-equivalent measure of PA intensity, which limits the use of MET-calibrated accelerometers for age-related PA investigations. We investigated calibration using VO2net (VO2gross - VO2stand; mL.min(-1).kg(-1)) as criterion compared to MET (VO2gross/VO2rest) and the effect on assessment of free-living PA in children, adolescents and adults. Oxygen consumption and hip/thigh accelerometer data were collected during rest, stand and treadmill walk and run. Equivalent speed (Speed(eq)) was used as indicator of the absolute speed (Speed(abs)) performed with the same effort in individuals of different body size/age. The results showed that VO2net was higher in younger age-groups for Speedabs, but was similar in the three age-groups for Speed(eq). MET was lower in younger age-groups for both Speed(abs) and Speed(eq). The same VO2net-values respective MET-values were applied to all age-groups to develop accelerometer PA intensity cut-points. Free-living moderate-and-vigorous PA was 216, 115, 74 and 71 min/d in children, adolescents, younger and older adults with VO2net-calibration, but 140, 83, 74 and 41 min/d with MET-calibration, respectively. In conclusion, VO2net calibration of accelerometers may provide age-equivalent measures of PA intensity/effort for more accurate age-related investigations of PA in epidemiological research.
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| 7. |
- Arvidsson, Daniel, 1974
(författare)
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Viktigt att mäta fysisk aktivitet på rätt sätt? Hur bra är olika aktivitetsmätare?
- 2019
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Ingår i: Idrottsmedicin. - 2001-3302. ; 19:1, s. 14-16
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Fysisk aktivitet mäts vanligtvis med olika former av frågeformulär eller intervjuer. Resultaten påverkas då av individens förmåga att minnas och rapportera vilket kan ge missvisande resultat. Den tekniska utvecklingen har gjort det möjligt att numer mäta fysisk aktivitet med olika typer av sensorer och därmed gjort mätningarna mer objektiva men det finns fortfarande en mätosäkerhet.
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| 8. |
- Brond, J. C., et al.
(författare)
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Generating ActiGraph Counts from Raw Acceleration Recorded by an Alternative Monitor
- 2017
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Ingår i: Medicine and Science in Sports and Exercise. - : Ovid Technologies (Wolters Kluwer Health). - 0195-9131. ; 49:11, s. 2351-2360
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: This study aimed to implement an aggregation method in Matlab for generating ActiGraph counts from raw acceleration recorded with an alternative accelerometer device and to investigate the validity of the method. Methods: The aggregation method, including the frequency band-pass filter, was implemented and optimized based on standardized sinusoidal acceleration signals generated in Matlab and processed in the ActiLife software. Evaluating the validity of the aggregation method was approached using a mechanical setup and with a 24-h free-living recording using a convenient sample of nine subjects. Counts generated with the aggregation method applied to Axivity AX3 raw acceleration data were compared with counts generated with ActiLife from ActiGraph GT3X+ data. Results: An optimal band-pass filter was fitted resulting in a root-mean-square error of 25.7 counts per 10 s and mean absolute error of 15.0 counts per second across the full frequency range. The mechanical evaluation of the proposed aggregation method resulted in an absolute mean +/- SD difference of -0.11 +/- 0.97 counts per 10 s across all rotational frequencies compared with the original ActiGraph method. Applying the aggregation method to the 24-h free-living recordings resulted in an epoch level bias ranging from -16.2 to 0.9 counts per 10 s, a relative difference in the averaged physical activity (counts per minute) ranging from -0.5% to 4.7% with a group mean +/- SD of 2.2% +/- 1.7%, and a Cohen' s kappa of 0.945, indicating almost a perfect agreement in the intensity classification. Conclusion: The proposed band-pass filter and aggregation method is highly valid for generating ActiGraph counts from raw acceleration data recorded with alternative devices. It would facilitate comparability between studies using different devices collecting raw acceleration data.
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| 9. |
- Brønd, Jan Christian, et al.
(författare)
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The ActiGraph counts processing and the assessment of vigorous activity.
- 2019
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Ingår i: Clinical physiology and functional imaging. - : Wiley. - 1475-097X .- 1475-0961. ; 39:4, s. 276-283
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study was to investigate the effect of different band-pass filters on the measurement bias with ActiGraph counts during high speed running and for estimating free-living vigorous physical activity (VPA). Two alternative band-pass filters were designed, extending the original frequency range from 0·29 to 1·66Hz (AG) to 0·29-4Hz (AC4) and 0·29-10Hz (AC10). Sixty-two subjects in three age groups participated in a structured locomotion protocol consisting of multiple walking and running speeds. The time spent in free-living VPA using the three different band-pass filters were evaluated in 1121 children. Band-pass filter specific intensity cut-points from both linear regression and ROC analysis was identified from a calibration experiment using indirect calorimetry. The ActiGraph GT3X+ device recording raw acceleration at 30Hz was used in all experiments. The linear association between counts and running speed was negative for AG but positive for AC4 and AC10 across all age groups. The time spent in free-living VPA was similar for all band-pass filters. Considering higher frequency information in the generation of ActiGraph counts with a hip/waist worn device reduces the measurement bias with running above 10km·h-1 . However, additional developments are required to accurately capture all VPA, including intermittent activities.
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| 10. |
- Börjesson, Mats, 1965, et al.
(författare)
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Return to play after infectious disease
- 2018
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Ingår i: Return to Play in Football. - Berlin, Heidelberg : Springer Verlag. - 9783662557129 ; , s. 755-70
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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