Evidence map›Paper›PMID 34337345›Full record

ArticleJournal for the measurement of physical behaviour2021

Validation of Wearable Camera Still Images to Assess Posture in Free-Living Conditions.

Julian Martinez, Autumn Decker, Chi C Cho, Aiden Doherty, Ann M Swartz, John W Staudenmayer, Scott J Strath

Abstract read
In one paragraph

Article in Journal for the measurement of physical behaviour, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed.

  1. Article
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors.

Julian MartinezDepartment of Kinesiology, University of Wisconsin-Milwaukee.
Autumn DeckerDepartment of Kinesiology, University of Wisconsin-Milwaukee.
Chi C ChoDepartment of Kinesiology, University of Wisconsin-Milwaukee.
Aiden DohertyUniversity of Oxford and National Institute of Health Research Oxford Biomedical Research Center.
Ann M SwartzDepartment of Kinesiology, University of Wisconsin-Milwaukee.
John W StaudenmayerDepartment of Mathematics and Statistics, University of Massachusetts-Amherst.
Scott J StrathDepartment of Kinesiology, University of Wisconsin-Milwaukee.

Funding

Calibrating free-living physical activity characteristics across functionally-limited populations using machine-learned accelerometer approachesR01CA215318 · NCI · UNIVERSITY OF WISCONSIN MILWAUKEE · PI STAUDENMAYER, JOHN W, STRATH, SCOTT J · 2017 to 2021
$2.9M
Physical Activity Calibration in Individuals with Movement LimitationsR21HD080828 · NICHD · UNIVERSITY OF WISCONSIN MILWAUKEE · PI STRATH, SCOTT J · 2014 to 2015
$428k
NCI NIH HHS R01 CA215318NICHD NIH HHS R21 HD080828
6 · The paper itself

Abstract

purposeTo assess the convergent validity of body worn wearable camera (WC) still-images (IMGs) for determining posture compared with activPAL (AP) classifications.

methodsParticipants (n=16, mean age 46.7±23.8yrs, 9F) wore an Autographer WC above the xyphoid process and an AP during three, 2hr free-living visits. IMGs were captured on average 8.47 seconds apart and were annotated with output consisting of events, transitory states, unknown and gaps. Events were annotations that matched AP classifications (sit, stand and move) consisting of at least 3 IMGs, transitory states were posture annotations fewer than 3 IMGs, unknown were IMGs that could not be accurately classified, and gaps were time between annotations. For analyses, annotation and AP output were converted to one-sec epochs and matched second-by-second. Total and average length of visits and events are reported in minutes. Bias and 95% CIs for event posture times from IMGs to AP posture times were calculated to determine accuracy and precision. Confusion matrices using total AP posture times were computed to determine misclassification.

results43 visits were analyzed with a total visit and event time of 5027.73 and 4237.23 minutes and average visit and event lengths being 116.92 and 98.54 minutes, respectively. Bias was not statistically significant for sitting but significant for standing and movement (0.84, -6.87 and 6.04 minutes). From confusion matrices, IMGs correctly classified sitting, standing and movement 85.69%, 54.87%, and 69.41% of total AP time, respectively.

conclusionWC IMGs provide a good estimation of overall sitting time but underestimate standing and overestimate movement time. Future work is warranted to improve posture classifications and examine IMG accuracy and precision in assessing activity type behaviors.

Indexed as

activpalautographerobjective measuring

Identifiers

PMID34337345
PMCPMC8320753

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.