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The aim of the study was the evaluation of a joint stress test to assess joint discomfort in subjects with activity-related knee joint discomfort (ArJD).<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Results<\/jats:title>\n                <jats:p>Forty-five subjects were recruited to perform the single-leg-step-down (SLSD) test (15 subjects per group). Subjects with ArJD of the knee (age 22\u201362 years) were compared to healthy subjects (age 24\u201359 years) with no knee joint discomfort during daily life sporting activity and to subjects with mild-to-moderate osteoarthritis of the knee joint (OA, Kellgren score 2\u20133, age 42\u201364 years). The subjects performed the SLSD test with two different protocols: (I) standardization for knee joint discomfort; (II) standardization for load on the knee joint. In addition, range of motion (ROM), reach test, acute pain at rest and after a single-leg squat and knee injury, and osteoarthritis outcome score (KOOS) were assessed.<\/jats:p>\n                <jats:p>In OA and ArJD subjects, knee joint discomfort could be reproducibly induced in a short time interval of less than 10 min (200 steps). In healthy subjects, no pain was recorded. A clear differentiation between study groups was observed with the SLSD test (maximal step number) as well as KOOS questionnaire, ROM, and reach test. In addition, a moderate to good intra-class correlation was shown for the investigated outcomes.<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Conclusions<\/jats:title>\n                <jats:p>These results suggest the SLSD test is a reliable tool for the assessment of knee joint health function in ArJD and OA subjects to study the improvements in their activities. Further, this model can be used as a stress model in intervention studies to study the impact of stress on knee joint health function.<\/jats:p>\n              <\/jats:sec>","DOI":"10.1186\/s40798-021-00317-7","type":"journal-article","created":{"date-parts":[[2021,4,6]],"date-time":"2021-04-06T19:03:01Z","timestamp":1617735781000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Evaluation and Validation of a Joint Stress Test to Induce Activity-Related Knee Joint Discomfort\u00a0\u2014\u00a0a Prospective Case-Control Study"],"prefix":"10.1186","volume":"7","author":[{"given":"Christiane","family":"Sch\u00f6n","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Claudia","family":"Reule","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8001-8694","authenticated-orcid":false,"given":"Katharina","family":"Knaub","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Antje","family":"Micka","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Manfred","family":"Wilhelm","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wilfried","family":"Alt","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Daniel","family":"Menzel","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"297","published-online":{"date-parts":[[2021,4,6]]},"reference":[{"key":"317_CR1","doi-asserted-by":"publisher","unstructured":"Witvrouw E, Callaghan MJ, Stefanik JJ, Noehren B, Bazett-Jones DM, Willson JD, et al. 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The trial was reviewed by the Institutional Review board (IRB) of the Landes\u00e4rztekammer Baden-W\u00fcrttemberg without having concerns. The study was retrospectively registered (13 July 2018) in the German Clinical Trials Register (DRKS00014277), ttps:\/\/.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Ethics approval and consent to participate"}},{"value":"Permission was obtained from the subject in Fig.  and Fig.  for the inclusion of these photographs in the publication.","order":3,"name":"Ethics","group":{"name":"EthicsHeading","label":"Consent for publication"}},{"value":"Christiane Sch\u00f6n, Claudia Reule, Katharina Knaub, Antje Micka, Manfred Wilhelm, Wilfried Alt, and Daniel Menzel declare that there is no conflict of interest regarding the publication of this paper. Lonza Consumer Health Inc. sponsored the study. The sponsor was involved in the discussions on the study design and on the outcome measures prior to study start. Study conduction, data collection and analysis, as well as drafting the publication was independently undertaken by BioTeSys GmbH.","order":4,"name":"Ethics","group":{"name":"EthicsHeading","label":"Competing interests"}}],"article-number":"24"}}