{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,28]],"date-time":"2026-04-28T19:49:39Z","timestamp":1777405779148,"version":"3.51.4"},"reference-count":25,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2025,6,19]],"date-time":"2025-06-19T00:00:00Z","timestamp":1750291200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Portuguese Foundation for Science and Technology (FCT, Portugal)"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Plantar pressure monitoring is decisive in injury prevention, especially in at-risk populations such as people with diabetic foot. In this context, innovative solutions such as pneumatic insoles can be essential in plantar pressure management. This study describes the development of a variable pressure system that promotes the monitoring, stabilization, and offloading of plantar pressure through a pneumatic insole. This research was also intended to evaluate its ability to redistribute plantar pressure, reduce peak pressure in both static and dynamic conditions, and validate its pressure measurements by comparing the results with those obtained from a pedar\u00ae insole. Tests were carried out under both static and dynamic conditions, before and after the pressure stabilization process by air cells and the subsequent pressure offloading. During the validation process, methods were used to evaluate the agreement between measurements obtained by the two systems. The results of the static test showed that pressure stabilization reduced pressure on the heel by 32.43%, distributing it to the metatarsals and toes. After heel pressure offloading, the reduction reached 42.72%. In the dynamic test, despite natural dispersion of the measurements, a trend to reduce the peak pressure in the heel, metatarsals, and toes was observed. Agreement analysis recorded 96.32% in the static test and 94.02% in the dynamic test. The pneumatic insole proved effective in redistributing and reducing plantar pressure, with more evident effects in the static test. Its agreement with the pedar\u00ae system reinforces its reliability as a tool for measuring and managing plantar pressure, representing a promising solution for preventing plantar lesions.<\/jats:p>","DOI":"10.3390\/s25123820","type":"journal-article","created":{"date-parts":[[2025,6,19]],"date-time":"2025-06-19T05:08:39Z","timestamp":1750309719000},"page":"3820","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["A Portable Insole System for Actively Controlled Offloading of Plantar Pressure for Diabetic Foot Care"],"prefix":"10.3390","volume":"25","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5430-0496","authenticated-orcid":false,"given":"Pedro","family":"Castro-Martins","sequence":"first","affiliation":[{"name":"CIETI, ISEP, Polytechnic of Porto, rua Dr. Ant\u00f3nio Bernardino de Almeida, 4249-015 Porto, Portugal"},{"name":"Faculty of Engineering, University of Porto, rua Dr. Roberto Frias, 4200-465 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5528-9898","authenticated-orcid":false,"given":"Arcelina","family":"Marques","sequence":"additional","affiliation":[{"name":"CIETI, ISEP, Polytechnic of Porto, rua Dr. Ant\u00f3nio Bernardino de Almeida, 4249-015 Porto, Portugal"},{"name":"INEGI, Institute of Science and Innovation in Mechanical and Industrial Engineering, 4200-465 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5673-7306","authenticated-orcid":false,"given":"Lu\u00eds","family":"Pinto-Coelho","sequence":"additional","affiliation":[{"name":"CIETI, ISEP, Polytechnic of Porto, rua Dr. Ant\u00f3nio Bernardino de Almeida, 4249-015 Porto, Portugal"},{"name":"INESC-TEC, Centre for Robotics in Industry and Intelligent Systems, 4200-465 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4885-4924","authenticated-orcid":false,"given":"Pedro","family":"Fonseca","sequence":"additional","affiliation":[{"name":"LABIOMEP-UP, Porto Biomechanics Laboratory, Faculty of Sports, University of Porto, rua Dr. Pl\u00e1cido Costa 91, 4200-450 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6347-9608","authenticated-orcid":false,"given":"M\u00e1rio","family":"Vaz","sequence":"additional","affiliation":[{"name":"Faculty of Engineering, University of Porto, rua Dr. Roberto Frias, 4200-465 Porto, Portugal"},{"name":"INEGI, Institute of Science and Innovation in Mechanical and Industrial Engineering, 4200-465 Porto, Portugal"},{"name":"LABIOMEP-UP, Porto Biomechanics Laboratory, Faculty of Sports, University of Porto, rua Dr. Pl\u00e1cido Costa 91, 4200-450 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2025,6,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"494","DOI":"10.3390\/biomechanics2040038","article-title":"Mechanics and Energetics of Human Feet: A Contemporary Perspective for Understanding Mobility Impairments in Older Adults","volume":"2","author":"Takahashi","year":"2022","journal-title":"Biomechanics"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Jiang, X., Napier, C., Hannigan, B., Eng, J.J., and Menon, C. (2020). Estimating Vertical Ground Reaction Force during Walking Using a Single Inertial Sensor. Sensors, 20.","DOI":"10.3390\/s20154345"},{"key":"ref_3","unstructured":"International Diabetes Federation (2021). IDF Diabetes Atlas, International Diabetes Federation. [10th ed.]."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"e3657","DOI":"10.1002\/dmrr.3657","article-title":"Practical guidelines on the prevention and management of diabetes-related foot disease (IWGDF 2023 update)","volume":"40","author":"Schaper","year":"2024","journal-title":"Diabetes Metab. Res. Rev."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"e26161","DOI":"10.1016\/j.heliyon.2024.e26161","article-title":"Plantar pressure thresholds as a strategy to prevent diabetic foot ulcers: A systematic review","volume":"10","author":"Marques","year":"2024","journal-title":"Heliyon"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"e29672","DOI":"10.1016\/j.heliyon.2024.e29672","article-title":"In-shoe plantar pressure measurement technologies for the diabetic foot: A systematic review","volume":"10","author":"Marques","year":"2024","journal-title":"Heliyon"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"e3654","DOI":"10.1002\/dmrr.3654","article-title":"Definitions and criteria for diabetes-related foot disease (IWGDF 2023 update)","volume":"40","author":"Bus","year":"2024","journal-title":"Diabetes Metab. Res. Rev."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1679","DOI":"10.2337\/dc08-9021","article-title":"Comprehensive Foot Examination and Risk Assessment: A report of the Task Force of the Foot Care Interest Group of the American Diabetes Association, with endorsement by the American Association of Clinical Endocrinologists","volume":"31","author":"Boulton","year":"2008","journal-title":"Diabetes Care"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"84","DOI":"10.1002\/dmrr.2701","article-title":"Prevention of foot ulcers in the at-risk patient with diabetes: A systematic review","volume":"32","author":"Price","year":"2016","journal-title":"Diabetes Metab. Res. Rev."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Castro-Martins, P., Pinto-Coelho, L., and Campilho, R.D. (2024). Calibration and Modeling of the Semmes\u2013Weinstein Monofilament for Diabetic Foot Management. Bioengineering, 11.","DOI":"10.20944\/preprints202404.1560.v1"},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Costa, T., Coelho, L., and Silva, M.F. (2022). Automatic Segmentation of Monofilament Testing Sites in Plantar Images for Diabetic Foot Management. Bioengineering, 9.","DOI":"10.3390\/bioengineering9030086"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"2367","DOI":"10.1056\/NEJMra1615439","article-title":"Diabetic Foot Ulcers and Their Recurrence","volume":"376","author":"Armstrong","year":"2017","journal-title":"N. Engl. J. Med."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Schaper, N.C., van Netten, J.J., Apelqvist, J., Bus, S.A., Hinchliffe, R.J., and Lipsky, B.A. (2019). IWGDF Guidelines on the Prevention and Management of Diabetic Foot Disease, The International Working Group on the Diabetic Foot. Available online: https:\/\/iwgdfguidelines.org\/wp-content\/uploads\/2019\/05\/IWGDF-Guidelines-2019.pdf.","DOI":"10.1002\/dmrr.3266"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1017","DOI":"10.1186\/s13063-022-06968-5","article-title":"Footwear and insole design parameters to prevent occurrence and recurrence of neuropathic plantar forefoot ulcers in patients with diabetes: A series of N-of-1 trial study protocol","volume":"23","author":"Ahmed","year":"2022","journal-title":"Trials"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Hemler, S.L., Ntella, S.L., Jeanmonod, K., K\u00f6chli, C., Tiwari, B., Civet, Y., Perriard, Y., and Pataky, Z. (2023). Intelligent plantar pressure offloading for the prevention of diabetic foot ulcers and amputations. Front. Endocrinol., 14.","DOI":"10.3389\/fendo.2023.1166513"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Erel, V., Nasirian, A., Gu, Y., Lavery, L., and Wijesundara, M.B.J. (2024). Development of Cyclic Pressure Offloading Insole for Diabetic Foot Ulcer Prevention. Int. J. Low. Extrem. Wounds.","DOI":"10.1177\/15347346241234825"},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Castro-Martins, P., Pinto-Coelho, L., Vaz, M., Pinto, M., and Marques, A. (2023). Towards an In-Shoe Pneumatic Insole to Plantar Injury Prevention in Diabetic Foot. Congress of the Portuguese Society of Biomechanics, Springer Nature Switzerland. Lecture Notes in Bioengineering.","DOI":"10.1007\/978-3-031-47790-4_29"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"2324416","DOI":"10.1155\/2024\/2324416","article-title":"Assessment of Load Manual Lifting among Shelf-Stoking Workers in Chain Stores: A Cross-Sectional Study","volume":"2024","author":"Choobineh","year":"2024","journal-title":"Appl. Bionics Biomech."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Skovlund, S.V., Bl\u00e1foss, R., Skals, S., Jakobsen, M.D., and Andersen, L.L. (2022). The Importance of Lifting Height and Load Mass for Muscular Workload during Supermarket Stocking: Cross-Sectional Field Study. Int. J. Environ. Res. Public Health, 19.","DOI":"10.3390\/ijerph19053030"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1496","DOI":"10.3390\/clinpract14040120","article-title":"Safety Footwear Impact on Workers\u2019 Gait and Foot Problems: A Comparative Study","volume":"14","author":"Arceri","year":"2024","journal-title":"Clin. Pract."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"107815","DOI":"10.1016\/j.jdiacomp.2020.107815","article-title":"In-shoe pressure thresholds for people with diabetes and neuropathy at risk of ulceration: A systematic review","volume":"35","author":"Jones","year":"2021","journal-title":"J. Diabetes Complicat."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"e3645","DOI":"10.1002\/dmrr.3645","article-title":"Classification of foot ulcers in people with diabetes: A systematic review","volume":"40","author":"Hamilton","year":"2024","journal-title":"Diabetes Metab. Res. Rev."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"16","DOI":"10.3390\/future2010002","article-title":"Association between Body Composition, Physical Activity Profile, and Occurrence of Knee and Foot Postural Alterations among Young Healthy Adults","volume":"2","author":"Ashraf","year":"2024","journal-title":"Future"},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Mei, Q., Kim, H.K., Xiang, L., Shim, V., Wang, A., Baker, J.S., Gu, Y., and Fernandez, J. (2022). Toward improved understanding of foot shape, foot posture, and foot biomechanics during running: A narrative review. Front. Physiol., 13.","DOI":"10.3389\/fphys.2022.1062598"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"39","DOI":"10.1186\/s40101-020-00246-6","article-title":"Standard reference values of weight and maximum pressure distribution in healthy adults aged 18\u201365 years in Germany","volume":"39","author":"Ohlendorf","year":"2020","journal-title":"J. Physiol. Anthropol."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/25\/12\/3820\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T17:54:43Z","timestamp":1760032483000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/25\/12\/3820"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,6,19]]},"references-count":25,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2025,6]]}},"alternative-id":["s25123820"],"URL":"https:\/\/doi.org\/10.3390\/s25123820","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,6,19]]}}}