{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,26]],"date-time":"2026-08-26T18:43:14Z","timestamp":1787769794117,"version":"build-2784847793"},"reference-count":49,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2026,2,13]],"date-time":"2026-02-13T00:00:00Z","timestamp":1770940800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000065","name":"National Institutes of Health","doi-asserted-by":"publisher","award":["R01NS129115-02"],"award-info":[{"award-number":["R01NS129115-02"]}],"id":[{"id":"10.13039\/100000065","id-type":"DOI","asserted-by":"publisher"}]},{"name":"National Institutes of Health, National Center for Advancing Translational Sciences, Clinical and Translational Science Award","award":["UM1TR004528"],"award-info":[{"award-number":["UM1TR004528"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Subjective, imprecise evaluation of lower extremity function hinders the effective treatment of gait impairments in Parkinson\u2019s disease (PD). Markerless motion capture (MMC) offers opportunities for integrating objective biomechanical outcomes into clinical practice. However, validation of MMC biomechanical outcomes is necessary for clinical adoption of MMC technologies. This project evaluated the criterion validity of a custom MMC algorithm (CART-MMC) against gold-standard 3D motion capture (Traditional-MC) and its known-groups validity in differentiating PD from healthy controls (HC). Sixty-two individuals with PD and 29 HCs completed a stepping in place paradigm. The trials were recorded by an augmented reality headset with embedded RGB and depth cameras. The CART-MMC algorithm was used to reconstruct a 3D pose model and compute biomechanical measures of lower extremity performance. CART-MMC outcomes were statistically equivalent, within 5% of Traditional-MC, for measures of step count, cadence, duration, height, height asymmetry, and normalized path length. CART-MMC captured significant between-group differences in step height, height variability, height asymmetry, duration variability, and normalized path length. In conclusion, CART-MMC provides valid biomechanical outcomes that characterize important domains of PD lower extremity function. Validated biomechanical evaluation tools present opportunities for tracking subtle changes in disease progression, informing targeted therapy, and monitoring treatment efficacy.<\/jats:p>","DOI":"10.3390\/s26041216","type":"journal-article","created":{"date-parts":[[2026,2,13]],"date-time":"2026-02-13T09:09:19Z","timestamp":1770973759000},"page":"1216","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Utilizing an Augmented Reality Headset to Accurately Quantify Lower Extremity Function in Parkinson\u2019s Disease"],"prefix":"10.3390","volume":"26","author":[{"ORCID":"https:\/\/orcid.org\/0009-0007-3021-7605","authenticated-orcid":false,"given":"Andrew","family":"Bazyk","sequence":"first","affiliation":[{"name":"Center for Neurological Restoration, Neurological Institute, Cleveland Clinic, 9500 Euclid Ave., Cleveland, OH 44195, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-8598-4341","authenticated-orcid":false,"given":"Colin","family":"Waltz","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Ave., Cleveland, OH 44195, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ryan D.","family":"Kaya","sequence":"additional","affiliation":[{"name":"Center for Neurological Restoration, Neurological Institute, Cleveland Clinic, 9500 Euclid Ave., Cleveland, OH 44195, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Eric","family":"Zimmerman","sequence":"additional","affiliation":[{"name":"Center for Neurological Restoration, Neurological Institute, Cleveland Clinic, 9500 Euclid Ave., Cleveland, OH 44195, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Joshua D.","family":"Johnston","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Ave., Cleveland, OH 44195, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8323-6873","authenticated-orcid":false,"given":"Benjamin L.","family":"Walter","sequence":"additional","affiliation":[{"name":"Center for Neurological Restoration, Neurological Institute, Cleveland Clinic, 9500 Euclid Ave., Cleveland, OH 44195, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5468-8208","authenticated-orcid":false,"given":"Anson B.","family":"Rosenfeldt","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Ave., Cleveland, OH 44195, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3047-8091","authenticated-orcid":false,"given":"Mandy","family":"Miller Koop","sequence":"additional","affiliation":[{"name":"Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Ave., Cleveland, OH 44195, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jay L.","family":"Alberts","sequence":"additional","affiliation":[{"name":"Center for Neurological Restoration, Neurological Institute, Cleveland Clinic, 9500 Euclid Ave., Cleveland, OH 44195, USA"},{"name":"Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Ave., Cleveland, OH 44195, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,2,13]]},"reference":[{"key":"ref_1","first-page":"576","article-title":"Development of postural-motor, coordination, and reflex functions in children in the first year of life","volume":"52","author":"Maciak","year":"2024","journal-title":"Pol. 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