{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,9]],"date-time":"2026-06-09T10:56:35Z","timestamp":1781002595583,"version":"3.54.1"},"reference-count":39,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2021,2,22]],"date-time":"2021-02-22T00:00:00Z","timestamp":1613952000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100008666","name":"Fundaci\u00f3 la Marat\u00f3 de TV3","doi-asserted-by":"publisher","award":["201720-10"],"award-info":[{"award-number":["201720-10"]}],"id":[{"id":"10.13039\/100008666","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100008666","name":"Fundaci\u00f3 la Marat\u00f3 de TV3","doi-asserted-by":"publisher","award":["201701-10"],"award-info":[{"award-number":["201701-10"]}],"id":[{"id":"10.13039\/100008666","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100008530","name":"European Regional Development Fund","doi-asserted-by":"publisher","award":["IDIFEDER\/2018\/029"],"award-info":[{"award-number":["IDIFEDER\/2018\/029"]}],"id":[{"id":"10.13039\/501100008530","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>This study aimed to investigate the validity of using built-in smartphone accelerometers to estimate the active energy expenditures of full-time manual wheelchair users with spinal cord injury (SCI). Twenty participants with complete SCI completed 10 5-min daily activities that involved the upper limbs, during which their oxygen consumption and upper limb activity were registered using a portable gas analyzer and a smartphone (placed on the non-dominant arm), respectively. Time series of 1-min averaged oxygen consumption and 55 accelerometer variables (13 variables for each of the four axes and three additional variables for the correlations between axes) were used to estimate three multiple linear models, using a 10-fold cross-validation method. The results showed that models that included either all variables and models or that only included the linear variables showed comparable performance, with a correlation of 0.72. Slightly worse general performance was demonstrated by the model that only included non-linear variables, although it proved to be more accurate at estimating the energy expenditures (EE) during specific tasks. These results suggest that smartphones could be a promising low-cost alternative to laboratory-grade accelerometers to estimate the energy expenditure of wheelchair users with spinal cord injury during daily activities.<\/jats:p>","DOI":"10.3390\/s21041498","type":"journal-article","created":{"date-parts":[[2021,2,21]],"date-time":"2021-02-21T23:59:31Z","timestamp":1613951971000},"page":"1498","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":11,"title":["Validation of Using Smartphone Built-In Accelerometers to Estimate the Active Energy Expenditures of Full-Time Manual Wheelchair Users with Spinal Cord Injury"],"prefix":"10.3390","volume":"21","author":[{"given":"Adri\u00e0","family":"Marco-Ahull\u00f3","sequence":"first","affiliation":[{"name":"Spinal Cord Injury Unit, Physical Medicine and Rehabilitation, University Vall d\u2019Hebron Campus, 08035 Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Llu\u00efsa","family":"Montesinos-Magraner","sequence":"additional","affiliation":[{"name":"Spinal Cord Injury Unit, Physical Medicine and Rehabilitation, University Vall d\u2019Hebron Campus, 08035 Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6478-4014","authenticated-orcid":false,"given":"Luis-Mill\u00e1n","family":"Gonzalez","sequence":"additional","affiliation":[{"name":"Departamento de Educaci\u00f3n F\u00edsica y Deportiva, Universidad de Valencia, 46010 Valencia, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8677-8707","authenticated-orcid":false,"given":"Roberto","family":"Llorens","sequence":"additional","affiliation":[{"name":"Neurorehabilitation and Brain Research Group, Instituto de Investigaci\u00f3n e Innovaci\u00f3n en Bioingenier\u00eda, Universitat Polit\u00e8cnica de Val\u00e8ncia, 46022 Valencia, Spain"},{"name":"NEURORHB, Servicio de Neurorrehabilitaci\u00f3n de Hospitales Vithas, 46007 Valencia, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xurxo","family":"Segura-Navarro","sequence":"additional","affiliation":[{"name":"Spinal Cord Injury Unit, Physical Medicine and Rehabilitation, University Vall d\u2019Hebron Campus, 08035 Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5925-4537","authenticated-orcid":false,"given":"Xavier","family":"Garc\u00eda-Mass\u00f3","sequence":"additional","affiliation":[{"name":"Departamento de Expresi\u00f3n Musical, Pl\u00e1stica y Corporal, University of Valencia, 46022 Valencia, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,2,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"223","DOI":"10.4103\/0019-5413.177576","article-title":"ISCOS-Textbook on Comprehensive Management of Spinal Cord Injuries","volume":"50","author":"Jain","year":"2016","journal-title":"Indian J. 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