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Appraisal of the DIERS method for calculating postural measurements: an observational study

BACKGROUND: Surface topography is increasingly used with postural analysis. One system, DIERS formetric 4D, measures 40 defined spine shape parameters from a 6-s scan. Through system algorithms, a set of spine shape parameter values from 1 of 12 recorded images obtained during a scan becomes the DIE...

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Autores principales: Degenhardt, Brian, Starks, Zane, Bhatia, Shalini, Franklin, Geoffroey-Allen
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5613330/
https://www.ncbi.nlm.nih.gov/pubmed/28975159
http://dx.doi.org/10.1186/s13013-017-0134-y
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author Degenhardt, Brian
Starks, Zane
Bhatia, Shalini
Franklin, Geoffroey-Allen
author_facet Degenhardt, Brian
Starks, Zane
Bhatia, Shalini
Franklin, Geoffroey-Allen
author_sort Degenhardt, Brian
collection PubMed
description BACKGROUND: Surface topography is increasingly used with postural analysis. One system, DIERS formetric 4D, measures 40 defined spine shape parameters from a 6-s scan. Through system algorithms, a set of spine shape parameter values from 1 of 12 recorded images obtained during a scan becomes the DIERS-reported value (DRV) for postural assessment. The purpose of the current study was to compare DRV with a standard average value (SAV) calculated from all 12 images to determine which method is more appropriate for assessing postural change. METHODS: One mannequin and 30 human participants were scanned over 5 days. Values from each image and the DRV for 40 defined spine shape parameters were exported, and mean DRV, mean SAV, mean DRV, and within-scan variance were calculated. Absolute difference and percent change between mean DRV and mean SAV were calculated for the mannequin and humans. Inter-method reliability was calculated for humans. Within-scan variance for each parameter was tested for significant variability. RESULTS: For all spine shape parameters on the mannequin, absolute difference (< 0.6 mm, 0.1°, or 0.1%) and percent change (< 2.90%) between mean DRV and mean SAV for each parameter were small. Nine parameters on human participants had a large percent change (> 7%). Absolute difference between mean DRV and mean SAV for those nine parameters was small (≤ 0.87 mm or 0.61°). Absolute difference for all other parameters ranged from 0.02 to 6.98 mm for distance measurements, from 0.01 to 1.21° for angle measurements, and from 0.15 to 0.22% for percentage measurements. Inter-method reliability between DRV and SAV was excellent (0.94–1.00). For the mannequin, within-scan variance was small (< 1.62) for all parameters. For humans, within-scan variance ranged from 0.05 to 36.04 and was different from zero for all parameters (all P < 0.001). CONCLUSIONS: The minimal variability observed in the mannequin suggested the DIERS formetric 4D instrument had high within-scan reliability. The DRV and SAV provided comparable spine shape parameter values. Because within-scan variability is not reported with the DRV, the clinical usefulness of current DRV values is limited. Establishing an estimate of variance with the SAV will allow clinicians to better identify a clinically meaningful change.
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spelling pubmed-56133302017-10-03 Appraisal of the DIERS method for calculating postural measurements: an observational study Degenhardt, Brian Starks, Zane Bhatia, Shalini Franklin, Geoffroey-Allen Scoliosis Spinal Disord Research BACKGROUND: Surface topography is increasingly used with postural analysis. One system, DIERS formetric 4D, measures 40 defined spine shape parameters from a 6-s scan. Through system algorithms, a set of spine shape parameter values from 1 of 12 recorded images obtained during a scan becomes the DIERS-reported value (DRV) for postural assessment. The purpose of the current study was to compare DRV with a standard average value (SAV) calculated from all 12 images to determine which method is more appropriate for assessing postural change. METHODS: One mannequin and 30 human participants were scanned over 5 days. Values from each image and the DRV for 40 defined spine shape parameters were exported, and mean DRV, mean SAV, mean DRV, and within-scan variance were calculated. Absolute difference and percent change between mean DRV and mean SAV were calculated for the mannequin and humans. Inter-method reliability was calculated for humans. Within-scan variance for each parameter was tested for significant variability. RESULTS: For all spine shape parameters on the mannequin, absolute difference (< 0.6 mm, 0.1°, or 0.1%) and percent change (< 2.90%) between mean DRV and mean SAV for each parameter were small. Nine parameters on human participants had a large percent change (> 7%). Absolute difference between mean DRV and mean SAV for those nine parameters was small (≤ 0.87 mm or 0.61°). Absolute difference for all other parameters ranged from 0.02 to 6.98 mm for distance measurements, from 0.01 to 1.21° for angle measurements, and from 0.15 to 0.22% for percentage measurements. Inter-method reliability between DRV and SAV was excellent (0.94–1.00). For the mannequin, within-scan variance was small (< 1.62) for all parameters. For humans, within-scan variance ranged from 0.05 to 36.04 and was different from zero for all parameters (all P < 0.001). CONCLUSIONS: The minimal variability observed in the mannequin suggested the DIERS formetric 4D instrument had high within-scan reliability. The DRV and SAV provided comparable spine shape parameter values. Because within-scan variability is not reported with the DRV, the clinical usefulness of current DRV values is limited. Establishing an estimate of variance with the SAV will allow clinicians to better identify a clinically meaningful change. BioMed Central 2017-09-26 /pmc/articles/PMC5613330/ /pubmed/28975159 http://dx.doi.org/10.1186/s13013-017-0134-y Text en © The Author(s). 2017 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
spellingShingle Research
Degenhardt, Brian
Starks, Zane
Bhatia, Shalini
Franklin, Geoffroey-Allen
Appraisal of the DIERS method for calculating postural measurements: an observational study
title Appraisal of the DIERS method for calculating postural measurements: an observational study
title_full Appraisal of the DIERS method for calculating postural measurements: an observational study
title_fullStr Appraisal of the DIERS method for calculating postural measurements: an observational study
title_full_unstemmed Appraisal of the DIERS method for calculating postural measurements: an observational study
title_short Appraisal of the DIERS method for calculating postural measurements: an observational study
title_sort appraisal of the diers method for calculating postural measurements: an observational study
topic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5613330/
https://www.ncbi.nlm.nih.gov/pubmed/28975159
http://dx.doi.org/10.1186/s13013-017-0134-y
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