{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,16]],"date-time":"2026-09-16T18:03:28Z","timestamp":1789581808726,"version":"build-2803163510"},"reference-count":30,"publisher":"Public Library of Science (PLoS)","issue":"9","license":[{"start":{"date-parts":[[2026,9,16]],"date-time":"2026-09-16T00:00:00Z","timestamp":1789516800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Luxembourg National Research Fund\/ Ministry of the Economy","award":["16748995"],"award-info":[{"award-number":["16748995"]}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS One"],"abstract":"<jats:sec id=\"sec001\">\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Accurate monitoring of activities of daily living (ADLs) in real\u2011world environments is essential for preventive care and rehabilitation, yet it remains difficult to achieve outside controlled laboratory settings. Instrumented insoles provide a promising, unobtrusive solution for continuous monitoring. However, the use of multimodal systems integrating plantar pressure and inertial data in naturalistic conditions and larger cohorts is still limited. This study therefore aims to evaluate the accuracy of a wireless instrumented insole (WalkinSense) that fuses pressure and inertial sensor data to classify ADLs within a semi free-living setting.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"sec002\">\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>A total of 99 participants performed a broad set of indoor and outdoor activities. Frame-by-frame performance was compared to ground truth (direct observation) using overall accuracy, Cohen\u2019s Kappa, precision, recall, F1-scores and a normalised confusion matrix. Agreement on total activity duration was assessed using mean absolute percentage error (MAPE) scores and Bland-Altman plots.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"sec003\">\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Activity classification showed almost perfect agreement (mean overall accuracy 0.87, mean Cohen\u2019s Kappa 0.84). Excellent performance (F1\u2009&gt;\u20090.90) was achieved for sitting, walking with crutches and cycling, while standing, level and non-level walking showed good performance (F1\u2009&gt;\u20090.80). Most misclassifications occurred between level walking, hill walking and stairs. Duration-based analysis confirmed high accuracy for sitting, walking with crutches and cycling (MAPE\u2009\u2264\u200910%). Bland-Altman plots indicated overestimation of level walking and underestimation of hill and stair walking. Step count was highly accurate (MAPE\u2009&lt;\u20095%), whereas stair count showed only reasonable accuracy (MAPE\u2009\u2248\u200926%).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"sec004\">\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>These findings demonstrate the system\u2019s strong potential for real-world monitoring and classification of ADLs while also highlighting the need for improved detection of non-level walking activities.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1371\/journal.pone.0357961","type":"journal-article","created":{"date-parts":[[2026,9,16]],"date-time":"2026-09-16T17:30:41Z","timestamp":1789579841000},"page":"e0357961","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":0,"title":["Classification of daily activities using a wireless instrumented insole (WalkinSense) in a semi free-living setting"],"prefix":"10.1371","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2026-5762","authenticated-orcid":true,"given":"Anne","family":"Backes","sequence":"first","affiliation":[{"name":"Luxembourg Institute of Health","place":["Strassen, Luxembourg"],"department":["Department of Precision Health"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Melanie","family":"Eckelt","sequence":"additional","affiliation":[{"name":"Luxembourg Institute of Health","place":["Strassen, Luxembourg"],"department":["Department of Precision Health"]},{"name":"Luxembourg Institute of Research in Orthopedics, Sports Medicine and Science","place":["Eich, Luxembourg"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jennifer","family":"Fayad","sequence":"additional","affiliation":[{"name":"Luxembourg Institute of Health","place":["Strassen, Luxembourg"],"department":["Department of Precision Health"]},{"name":"Luxembourg Institute of Research in Orthopedics, Sports Medicine and Science","place":["Eich, Luxembourg"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Valeria","family":"Serchi","sequence":"additional","affiliation":[{"name":"IEE S.A.","place":["Bissen, Luxembourg"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Thomas","family":"Solignac","sequence":"additional","affiliation":[{"name":"IEE S.A.","place":["Bissen, Luxembourg"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tobias","family":"Meyer","sequence":"additional","affiliation":[{"name":"IEE S.A.","place":["Bissen, Luxembourg"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bernd","family":"Grimm","sequence":"additional","affiliation":[{"name":"Luxembourg Institute of Health","place":["Strassen, Luxembourg"],"department":["Department of Precision Health"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Caroline","family":"Mouton","sequence":"additional","affiliation":[{"name":"Centre 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D\u2019Arco","year":"2023","journal-title":"Neural Comput & Applic"},{"issue":"4","key":"pone.0357961.ref002","doi-asserted-by":"crossref","first-page":"979","DOI":"10.1109\/JBHI.2017.2734803","article-title":"Automatic Recognition of Activities of Daily Living Utilizing Insole-Based and Wrist-Worn Wearable Sensors","volume":"22","author":"N Hegde","year":"2018","journal-title":"IEEE J Biomed Health Inform"},{"key":"pone.0357961.ref003","doi-asserted-by":"crossref","first-page":"20552076251374249","DOI":"10.1177\/20552076251374249","article-title":"Effectiveness of step-count monitoring interventions in increasing physical activity among children and adolescents: A systematic review and meta-analysis","volume":"11","author":"W Wang","year":"2025","journal-title":"Digit Health"},{"issue":"2","key":"pone.0357961.ref004","doi-asserted-by":"crossref","first-page":"1298","DOI":"10.1109\/JIOT.2019.2954387","article-title":"Bring Gait Lab to Everyday Life: Gait Analysis in Terms of Activities of Daily Living","volume":"7","author":"D Chen","year":"2020","journal-title":"IEEE Internet Things J"},{"issue":"11","key":"pone.0357961.ref005","doi-asserted-by":"crossref","first-page":"2438","DOI":"10.3390\/s19112438","article-title":"Validity of Instrumented Insoles for Step Counting, Posture and Activity Recognition: A Systematic Review","volume":"19","author":"AM Ngueleu","year":"2019","journal-title":"Sensors (Basel)"},{"issue":"17","key":"pone.0357961.ref006","doi-asserted-by":"crossref","first-page":"5972","DOI":"10.3390\/s21175972","article-title":"A Novel Tool for Gait Analysis: Validation Study of the Smart Insole PODOSmart\u00ae","volume":"21","author":"E Ziagkas","year":"2021","journal-title":"Sensors (Basel)"},{"issue":"4","key":"pone.0357961.ref007","doi-asserted-by":"crossref","DOI":"10.1002\/jeo2.70438","article-title":"Validity of a wireless instrumented insole (WalkinSense system) for measuring gait metrics","volume":"12","author":"M 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Bottom-up investigation: Human activity recognition based on feet movement and posture information. In: Proceedings of the 4th international Workshop on Sensor-based Activity Recognition and Interaction, 2017.","DOI":"10.1145\/3134230.3134240"},{"issue":"13","key":"pone.0357961.ref013","doi-asserted-by":"crossref","first-page":"5422","DOI":"10.1109\/JSEN.2018.2837674","article-title":"Classification of Five Ambulatory Activities Regarding Stair and Incline Walking Using Smart Shoes","volume":"18","author":"ND Nguyen","year":"2018","journal-title":"IEEE Sensors J"},{"key":"pone.0357961.ref014","article-title":"Random forest algorithms for recognizing daily life activities using plantar pressure information: a smart-shoe study","volume":"8","author":"D Ren","year":"2020","journal-title":"PeerJ"},{"issue":"1","key":"pone.0357961.ref015","doi-asserted-by":"crossref","first-page":"309","DOI":"10.1109\/JBHI.2013.2287400","article-title":"Highly accurate recognition of human postures and activities through classification with rejection","volume":"18","author":"W Tang","year":"2014","journal-title":"IEEE J Biomed Health Inform"},{"issue":"16","key":"pone.0357961.ref016","doi-asserted-by":"crossref","DOI":"10.1126\/sciadv.adu1598","article-title":"A wireless, self-powered smart insole for gait monitoring and recognition via nonlinear synergistic pressure sensing","volume":"11","author":"Q Wang","year":"2025","journal-title":"Sci Adv"},{"key":"pone.0357961.ref017","doi-asserted-by":"crossref","unstructured":"Haescher M, Matthies DJ, Bieber G, Urban B. Capwalk: A capacitive recognition of walking-based activities as a wearable assistive technology. In: Proceedings of the 8th ACM International Conference on Pervasive Technologies Related to Assistive Environments, 2015.","DOI":"10.1145\/2769493.2769500"},{"issue":"11","key":"pone.0357961.ref018","doi-asserted-by":"crossref","first-page":"3842","DOI":"10.3390\/s21113842","article-title":"Adaptive Accumulation of Plantar Pressure for Ambulatory Activity Recognition and Pedestrian Identification","volume":"21","author":"PH Truong","year":"2021","journal-title":"Sensors (Basel)"},{"key":"pone.0357961.ref019","unstructured":"D\u2019Arco L, Wang H, McCalmont G, Lan X, Zheng H. Artificial neural network for human activity recognition by use of smart insoles. In: 2021."},{"issue":"8","key":"pone.0357961.ref020","doi-asserted-by":"crossref","first-page":"1225","DOI":"10.3390\/s16081225","article-title":"Physical behavior in older persons during daily life: Insights from instrumented shoes","volume":"16","author":"C Moufawad El Achkar","year":"2016","journal-title":"Sensors"},{"issue":"1","key":"pone.0357961.ref021","doi-asserted-by":"crossref","first-page":"91","DOI":"10.1038\/s41746-024-01062-3","article-title":"Self-supervised learning for human activity recognition using 700,000 person-days of wearable data","volume":"7","author":"H Yuan","year":"2024","journal-title":"NPJ Digit Med"},{"issue":"2","key":"pone.0357961.ref022","article-title":"Sample Size for Assessing Agreement between Two Methods of Measurement by Bland-Altman Method","volume":"12","author":"M-J Lu","year":"2016","journal-title":"Int J Biostat"},{"issue":"1","key":"pone.0357961.ref023","doi-asserted-by":"crossref","first-page":"50","DOI":"10.1123\/jmpb.2019-0015","article-title":"A novel video-based direct observation system for assessing physical activity and sedentary behavior in children and young adults","volume":"3","author":"MF Cox","year":"2020","journal-title":"J Meas Phys Behav"},{"issue":"7","key":"pone.0357961.ref024","doi-asserted-by":"crossref","first-page":"2359","DOI":"10.3390\/s24072359","article-title":"Using Computer Vision to Annotate Video-Recoded Direct Observation of Physical Behavior","volume":"24","author":"SK Keadle","year":"2024","journal-title":"Sensors (Basel)"},{"issue":"4","key":"pone.0357961.ref025","doi-asserted-by":"crossref","first-page":"860","DOI":"10.1123\/jpah.2012-0290","article-title":"Direct observation is a valid criterion for estimating physical activity and sedentary behavior","volume":"11","author":"K Lyden","year":"2014","journal-title":"J Phys Act Health"},{"issue":"1","key":"pone.0357961.ref026","doi-asserted-by":"crossref","first-page":"159","DOI":"10.2307\/2529310","article-title":"The measurement of observer agreement for categorical data","volume":"33","author":"JR Landis","year":"1977","journal-title":"Biometrics"},{"issue":"8","key":"pone.0357961.ref027","doi-asserted-by":"crossref","first-page":"1767","DOI":"10.1249\/MSS.0000000000001966","article-title":"Standardizing Analytic Methods and Reporting in Activity Monitor Validation Studies","volume":"51","author":"GJ Welk","year":"2019","journal-title":"Med Sci Sports Exerc"},{"key":"pone.0357961.ref028","unstructured":"Lewis CD. Industrial and business forecasting methods: A practical guide to exponential smoothing and curve fitting. London: Butterworth Scientific; 1982."},{"key":"pone.0357961.ref029","doi-asserted-by":"crossref","first-page":"12","DOI":"10.1016\/j.gaitpost.2015.10.016","article-title":"Instrumented shoes for activity classification in the elderly","volume":"44","author":"M El Achkar","year":"2016","journal-title":"Gait & Posture"},{"issue":"1","key":"pone.0357961.ref030","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1145\/3633785","article-title":"Application of Smart Insoles for Recognition of Activities of Daily Living: A Systematic Review","volume":"5","author":"L D\u2019arco","year":"2024","journal-title":"ACM Trans Comput Healthcare"}],"container-title":["PLOS One"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0357961","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,16]],"date-time":"2026-09-16T17:30:47Z","timestamp":1789579847000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0357961"}},"subtitle":[],"editor":[{"given":"Shahnawaz","family":"Anwer","sequence":"first","affiliation":[{"name":"The Hong Kong Polytechnic University","place":["HONG KONG"]}],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2026,9,16]]},"references-count":30,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2026,9,16]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0357961","relation":{},"ISSN":["1932-6203"],"issn-type":[{"value":"1932-6203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,16]]}}}