{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,29]],"date-time":"2026-09-29T19:43:59Z","timestamp":1790711039658,"version":"4.1.0"},"reference-count":41,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2023,1,27]],"date-time":"2023-01-27T00:00:00Z","timestamp":1674777600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001691","name":"Japan Society for the Promotion of Science","doi-asserted-by":"publisher","award":["22K19739"],"award-info":[{"award-number":["22K19739"]}],"id":[{"id":"10.13039\/501100001691","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJERPH"],"abstract":"<jats:p>The aim of this study was to compare anterior knee laxity (AKL), genu recurvatum (GR), and muscle stiffness between reconstructed and contralateral sides in females who underwent anterior cruciate ligament (ACL) reconstruction during early follicular and ovulatory phases. AKL was measured as an anterior displacement of the tibia using a KS measure. GR was measured as the range of motion of knee hyperextension using a hyperextension apparatus. Muscle stiffness was measured for semitendinosus (ST) and biceps femoris long head (BF) using a MyotonPRO. The study investigated eighteen knees in nine females (Age, 20.4 \u00b1 1.5 years; BMI, 21.5 \u00b1 1.5) with normal menstrual cycles at least 1 year after reconstruction using hamstring autograft. E2 (Estradiol) concentration did not differ between the two phases, but AKL on the reconstructed side was lower during the ovulatory phase (8.3 [5.9\u20139.3] mm) than during the early follicular phase (9.4 [7.3\u20139.7] mm) (p = 0.044, r = 0.756), whereas there was no significant difference between the two phases on the contralateral side. AKL side-to-side difference, GR, and muscle stiffness (ST and BF) on both sides did not differ in either phase. These results indicate that AKL may behave differently on the reconstructed and contralateral sides during the menstrual cycle.<\/jats:p>","DOI":"10.3390\/ijerph20032277","type":"journal-article","created":{"date-parts":[[2023,1,30]],"date-time":"2023-01-30T03:31:11Z","timestamp":1675049471000},"page":"2277","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Knee Laxity in the Menstrual Cycle after Anterior Cruciate Ligament Reconstruction: A Case Series"],"prefix":"10.3390","volume":"20","author":[{"given":"Mayuu","family":"Shagawa","sequence":"first","affiliation":[{"name":"Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata 950-3198, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sae","family":"Maruyama","sequence":"additional","affiliation":[{"name":"Albirex Niigata Inc.  5-1923-23, Higashiko, Seiro-machi, Kitakanbara-gun, Niigata 957-0101, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0687-605X","authenticated-orcid":false,"given":"Chie","family":"Sekine","sequence":"additional","affiliation":[{"name":"Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata 950-3198, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0752-5574","authenticated-orcid":false,"given":"Hirotake","family":"Yokota","sequence":"additional","affiliation":[{"name":"Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata 950-3198, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9698-9276","authenticated-orcid":false,"given":"Ryo","family":"Hirabayashi","sequence":"additional","affiliation":[{"name":"Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata 950-3198, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ryoya","family":"Togashi","sequence":"additional","affiliation":[{"name":"Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata 950-3198, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuki","family":"Yamada","sequence":"additional","affiliation":[{"name":"Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata 950-3198, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Haruki","family":"Osanami","sequence":"additional","affiliation":[{"name":"Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata 950-3198, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3227-3129","authenticated-orcid":false,"given":"Daisuke","family":"Sato","sequence":"additional","affiliation":[{"name":"Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata 950-3198, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2784-6466","authenticated-orcid":false,"given":"Mutsuaki","family":"Edama","sequence":"additional","affiliation":[{"name":"Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata 950-3198, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,1,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"637","DOI":"10.1016\/S0030-5898(02)00028-7","article-title":"The female ACL: Why is it more prone to injury?","volume":"33","author":"Ireland","year":"2002","journal-title":"Orthop. 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