{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,19]],"date-time":"2026-05-19T14:56:30Z","timestamp":1779202590718,"version":"3.51.4"},"reference-count":64,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2020,2,6]],"date-time":"2020-02-06T00:00:00Z","timestamp":1580947200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Rigidity is one of the cardinal symptoms of Parkinson\u2019s disease (PD). Present in up 89% of cases, it is typically assessed with clinical scales. However, these instruments show limitations due to their subjectivity and poor intra- and inter-rater reliability. To compile all of the objective quantitative methods used to assess rigidity in PD and to study their validity and reliability, a systematic review was conducted using the Web of Science, PubMed, and Scopus databases. Studies from January 1975 to June 2019 were included, all of which were written in English. The Strengthening the Reporting of observational studies in Epidemiology Statement (STROBE) checklist for observational studies was used to assess the methodological rigor of the included studies. Thirty-six studies were included. Rigidity was quantitatively assessed in three ways, using servomotors, inertial sensors, and biomechanical and neurophysiological study of muscles. All methods showed good validity and reliability, good correlation with clinical scales, and were useful for detecting rigidity and studying its evolution. People with PD exhibit higher values in terms of objective muscle stiffness than healthy controls. Rigidity depends on the angular velocity and articular amplitude of the mobilization applied. There are objective, valid, and reliable methods that can be used to quantitatively assess rigidity in people with PD.<\/jats:p>","DOI":"10.3390\/s20030880","type":"journal-article","created":{"date-parts":[[2020,2,7]],"date-time":"2020-02-07T03:13:27Z","timestamp":1581045207000},"page":"880","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":61,"title":["Quantitative Measurement of Rigidity in Parkinson\u2019s Disease: A Systematic Review"],"prefix":"10.3390","volume":"20","author":[{"given":"Mar\u00eda del Rosario","family":"Ferreira-S\u00e1nchez","sequence":"first","affiliation":[{"name":"Department of Radiology, Rehabilitation and Physiotherapy, Universidad Complutense de Madrid (UCM), 28040 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Marcos","family":"Moreno-Verd\u00fa","sequence":"additional","affiliation":[{"name":"Department of Radiology, Rehabilitation and Physiotherapy, Universidad Complutense de Madrid (UCM), 28040 Madrid, Spain"},{"name":"Asociaci\u00f3n Parkinson Madrid, 28014 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1118-4234","authenticated-orcid":false,"given":"Roberto","family":"Cano-de-la-Cuerda","sequence":"additional","affiliation":[{"name":"Department of Physical Therapy, Occupational Therapy, Physical Medicine and Rehabilitation, Universidad Rey Juan Carlos (URJC), Alcorc\u00f3n, 28922 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,2,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"901","DOI":"10.1007\/s00702-017-1686-y","article-title":"Epidemiology of Parkinson\u2019s disease","volume":"124","author":"Tysnes","year":"2017","journal-title":"J. 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