{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,7]],"date-time":"2026-10-07T04:45:30Z","timestamp":1791348330839,"version":"4.3.1"},"reference-count":22,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2026,1,9]],"date-time":"2026-01-09T00:00:00Z","timestamp":1767916800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Hannah-Forbes Project Fund"},{"name":"Cal Poly Graduate Research Award"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Novel smartphone-based methods offer an accessible and promising alternative to traditional tools for performing clinical gait assessments in total knee arthroplasty (TKA) patients. The OneStep app uses the smartphone\u2019s sensors and proprietary machine learning algorithms to measure gait parameters of walking trials, including stride length, step length, step width, gait velocity, cadence, and double stance time. The objectives of this study were to (1) validate the reliability of the OneStep app against a traditional motion capture (MoCap) system and (2) use the OneStep app to measure functional recovery of TKA patients pre- and post-operatively. For Objective 1, walking trials using both OneStep and MoCap were conducted with N = 17 healthy adults (9M\/8F, aged 22.29 \u00b1 2.08 years). Results showed that of all gait variables, cadence (p &lt; 0.0001) and gait velocity (p &lt; 0.0001) exhibited the strongest correlations between methods indicated by their linear regression results, and step width had the weakest correlation between methods (p = 0.67). For Objective 2, OneStep gait measurements were collected for N = 11 TKA patients (5M\/6F, aged 70.91 \u00b1 6.56 years) at their pre-operative, 2-weeks post-operative, and 6-weeks post-operative appointments. Results showed marked declines in gait properties (decreased stride length, step length, cadence, and gait velocity and increased step width and double stance time) of participants relative to pre-operative values at 2-weeks pre-operative, and an increase\/surpassing of pre-operative gait measurements 6-weeks post-operative. The greatest differences were observed in gait velocity between pre-operative and 2-weeks post-operative (p = 0.011) and 2-weeks post-operative to 6 weeks post-operative (p = 0.005).<\/jats:p>","DOI":"10.3390\/s26020432","type":"journal-article","created":{"date-parts":[[2026,1,9]],"date-time":"2026-01-09T10:35:52Z","timestamp":1767954952000},"page":"432","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Smartphone-Based Gait Assessment Captures Functional Recovery Following Total Knee Arthroplasty"],"prefix":"10.3390","volume":"26","author":[{"given":"Celeste A.","family":"Thai","sequence":"first","affiliation":[{"name":"Physical Therapy Department, College of Health Professions, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60044, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jakob R.","family":"Marrone","sequence":"additional","affiliation":[{"name":"Biomedical Engineering Department, College of Engineering, California Polytechnic State University, San Luis Obispo, CA 93407, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lauren C.","family":"Tran","sequence":"additional","affiliation":[{"name":"Biomedical Engineering Department, College of Engineering, California Polytechnic State University, San Luis Obispo, CA 93407, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0002-3595-6996","authenticated-orcid":false,"given":"Britta","family":"Berg-Johansen","sequence":"additional","affiliation":[{"name":"Biomedical Engineering Department, College of Engineering, California Polytechnic State University, San Luis Obispo, CA 93407, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,1,9]]},"reference":[{"key":"ref_1","unstructured":"Hsu, H., and Siwiec, R.M. (2023). Knee Osteoarthritis. StatPearls, StatPearls Publishing."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"75","DOI":"10.1016\/j.gaitpost.2024.06.002","article-title":"Long-term gait analysis in patients after total knee arthroplasty: A systematic review and meta-analysis","volume":"113","author":"Marino","year":"2024","journal-title":"Gait Posture"},{"key":"ref_3","unstructured":"Hsu, H., and Siwiec, R.M. (2023). Knee Arthroplasty. StatPearls, StatPearls Publishing."},{"key":"ref_4","first-page":"417","article-title":"The validity and reliability of the OneStep smartphone application under various gait conditions in healthy adults with feasibility in clinical practice","volume":"17","author":"Christensen","year":"2022","journal-title":"J. Orthop. Sports Phys. Ther."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"102","DOI":"10.1016\/j.gaitpost.2022.01.024","article-title":"Smartphone-based inertial sensors technology\u2014Validation of a new application to measure spatiotemporal gait metrics","volume":"93","author":"Beer","year":"2022","journal-title":"Gait Posture"},{"key":"ref_6","first-page":"227","article-title":"Validity of IMU sensors for assessing features of walking in laboratory and outdoor environments among older adults","volume":"114","author":"Cronin","year":"2024","journal-title":"Gait Posture"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"5350","DOI":"10.1038\/s41598-023-32550-3","article-title":"Validity and reliability of the Apple Health app on iPhone for measuring gait parameters in children, adults, and seniors","volume":"13","author":"Werner","year":"2023","journal-title":"Sci. Rep."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Brognara, L. (2024). 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Determining Initial-Contact & Toe-Off from Kinematic Data Alone. Available online: http:\/\/www.clinicalgaitanalysis.com\/faq\/toe-off.html."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"373","DOI":"10.1016\/j.arth.2024.07.039","article-title":"Staying Ahead of the Curve: The Case for Recovery Curves in Total Knee Arthroplasty","volume":"40","author":"Cushner","year":"2025","journal-title":"J Arthroplast."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Szczypi\u00f3r-Piasecka, K., Adamczewska, P., Ko\u0142odziej, \u0141., and Zi\u0119tek, P. (2025). The Temporal\u2013Spatial Parameters of Gait After Total Knee Arthroplasty. J. Clin. Med., 14.","DOI":"10.20944\/preprints202505.1580.v1"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Gu, X., Zhou, C., Zhu, X., Cao, J., and Li, H. (2025). Early postoperative gait characteristics after unicompartmental knee arthroplasty: Results and clinical implications. BMC Musculoskelet. 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