{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,2]],"date-time":"2026-02-02T20:10:05Z","timestamp":1770063005854,"version":"3.49.0"},"reference-count":29,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2024,8,17]],"date-time":"2024-08-17T00:00:00Z","timestamp":1723852800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"University of Pittsburgh\u2019s Clinical and Translational Science Institute (CTSI)","award":["U19AR076725-01"],"award-info":[{"award-number":["U19AR076725-01"]}]},{"name":"National Institutes of Health","award":["U19AR076725-01"],"award-info":[{"award-number":["U19AR076725-01"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Assessing physical activity is important in the treatment of chronic conditions, including chronic low back pain (cLBP). ActiGraph\u2122, a widely used physical activity monitor, collects raw acceleration data, and processes these data through proprietary algorithms to produce physical activity measures. The purpose of this study was to replicate ActiGraph\u2122 algorithms in MATLAB and test the validity of this method with both healthy controls and participants with cLBP. MATLAB code was developed to replicate ActiGraph\u2122\u2019s activity counts and step counts algorithms, to sum the activity counts into counts per minute (CPM), and categorize each minute into activity intensity cut points. A free-living validation was performed where 24 individuals, 12 cLBP and 12 healthy, wore an ActiGraph\u2122 GT9X on their non-dominant hip for up to seven days. The raw acceleration data were processed in both ActiLife\u2122 (v6), ActiGraph\u2122\u2019s data analysis software platform, and through MATLAB (2022a). Percent errors between methods for all 24 participants, as well as separated by cLBP and healthy, were all less than 2%. ActiGraph\u2122 algorithms were replicated and validated for both populations, based on minimal error differences between ActiLife\u2122 and MATLAB, allowing researchers to analyze data from any accelerometer in a manner comparable to ActiLife\u2122.<\/jats:p>","DOI":"10.3390\/s24165323","type":"journal-article","created":{"date-parts":[[2024,8,19]],"date-time":"2024-08-19T06:41:31Z","timestamp":1724049691000},"page":"5323","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Algorithm Validation for Quantifying ActiGraph\u2122 Physical Activity Metrics in Individuals with Chronic Low Back Pain and Healthy Controls"],"prefix":"10.3390","volume":"24","author":[{"given":"Jordan F.","family":"Hoydick","sequence":"first","affiliation":[{"name":"Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15213, USA"}]},{"given":"Marit E.","family":"Johnson","sequence":"additional","affiliation":[{"name":"Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA 15213, USA"}]},{"given":"Harold A.","family":"Cook","sequence":"additional","affiliation":[{"name":"Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15213, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1661-1079","authenticated-orcid":false,"given":"Zakiy F.","family":"Alfikri","sequence":"additional","affiliation":[{"name":"Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15213, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6800-9368","authenticated-orcid":false,"given":"John M.","family":"Jakicic","sequence":"additional","affiliation":[{"name":"Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS 66160, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1716-3151","authenticated-orcid":false,"given":"Sara R.","family":"Piva","sequence":"additional","affiliation":[{"name":"Department of Physical Therapy, University of Pittsburgh, Pittsburgh, PA 15213, USA"}]},{"given":"April J.","family":"Chambers","sequence":"additional","affiliation":[{"name":"Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15213, USA"},{"name":"Department of Health and Human Development, University of Pittsburgh, Pittsburgh, PA 15213, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2099-413X","authenticated-orcid":false,"given":"Kevin M.","family":"Bell","sequence":"additional","affiliation":[{"name":"Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15213, USA"}]}],"member":"1968","published-online":{"date-parts":[[2024,8,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2356","DOI":"10.1016\/S0140-6736(18)30480-X","article-title":"What low back pain is and why we need to pay attention","volume":"391","author":"Hartvigsen","year":"2018","journal-title":"Lancet"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1545","DOI":"10.1016\/S0140-6736(16)31678-6","article-title":"Global, regional, and national incidence, prevalence, and years lived with disability for 310 diseases and injuries, 1990\u20132015 2015: A systematic analysis for the Global Burden of Disease Study 2015","volume":"388","author":"Vos","year":"2016","journal-title":"Lancet"},{"key":"ref_3","unstructured":"(2023, November 03). 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