{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,1]],"date-time":"2026-08-01T00:45:02Z","timestamp":1785545102341,"version":"3.56.0"},"reference-count":25,"publisher":"Georg Thieme Verlag KG","issue":"09","funder":[{"DOI":"10.13039\/501100001691","name":"Japan Society for the Promotion of Science","doi-asserted-by":"crossref","award":["19K11497"],"award-info":[{"award-number":["19K11497"]}],"id":[{"id":"10.13039\/501100001691","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Int J Sports Med"],"published-print":{"date-parts":[[2026,8]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>The incidence of ankle sprains and chronic ankle instability is higher in women\nthan in men. One sex-specific factor may be the greater ligamentous laxity in\nwomen compared with men, potentially influenced by estrogen and relaxin\nactivity. This study aimed to investigate changes in ankle joint laxity and its\nassociation with hormone levels in women with and without recurrent ankle\nsprains. Eleven female college students with recurrent ankle sprains and seven\nstudents with no or a single prior sprain participated. Ankle joint laxity was\nassessed using an ankle arthrometer with a 125-N load for anterior\u2013posterior\ndisplacement and with a 4000 N-mm for inversion\u2013eversion rotation. Serum\nestradiol and relaxin-2 levels were measured. Ankle laxity assessments and blood\nsampling were performed in the follicular, ovulation, and luteal phases of the\nparticipant\u2019s individual menstrual cycle. A significant group\u00d7phase interaction\nwas found for inversion\u2013eversion ankle joint laxity; however, post hoc analyses\nadjusted for Bonferroni multiple comparisons were not significant, implying a\nlack of clinical interest or potential sampling fluctuations. A positive\ncorrelation was found between serum relaxin-2 level and anterior\u2013posterior ankle\njoint laxity during the luteal phase (r=0.557 and p=0.048). This\nassociation should be interpreted as an observational finding that may help\ngenerate hypotheses regarding potential hormone-related factors in ankle sprains\nin women.<\/jats:p>","DOI":"10.1055\/a-2804-6786","type":"journal-article","created":{"date-parts":[[2026,2,4]],"date-time":"2026-02-04T23:55:26Z","timestamp":1770249326000},"page":"710-715","source":"Crossref","is-referenced-by-count":0,"title":["Ankle Laxity Fluctuation and Sex Hormones in Women with\/without\nRecurrent Sprains"],"prefix":"10.1055","volume":"47","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9767-7557","authenticated-orcid":false,"given":"Mako","family":"Fukano","sequence":"additional","affiliation":[{"name":"College of Engineering, Shibaura Institute of\nTechnology, Saitamashi, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Namie","family":"Takahashi","sequence":"additional","affiliation":[{"name":"Faculty of Health Sciences, Tokyo Ariake Iryo Daigaku,\nKoto, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Takakuni","family":"Sakurai","sequence":"additional","affiliation":[{"name":"Faculty of Health Sciences, Tokyo Ariake Iryo Daigaku,\nKoto, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"194","published-online":{"date-parts":[[2026,2,20]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"14","DOI":"10.1186\/1758-2555-1-14","article-title":"Understanding acute ankle ligamentous sprain injury in sports","volume":"1","author":"D T Fong","year":"2009","journal-title":"Sports Med Arthrosc Rehabil Ther Technol"},{"key":"ref2","doi-asserted-by":"publisher","first-page":"190","DOI":"10.1097\/JSM.0b013e31827d21fe","article-title":"Epidemiology of U.S. high school sports-related ligamentous ankle injuries,\n2005\/06-2010\/11","volume":"23","author":"D M Swenson","year":"2013","journal-title":"Clin J Sport Med"},{"key":"ref3","doi-asserted-by":"publisher","first-page":"123","DOI":"10.1007\/s40279-013-0102-5","article-title":"The incidence and prevalence of ankle sprain injury: a systematic review and\nmeta-analysis of prospective epidemiological studies","volume":"44","author":"C Doherty","year":"2014","journal-title":"Sports Med"},{"key":"ref4","doi-asserted-by":"publisher","first-page":"1030","DOI":"10.4085\/1062-6050-0664.21","article-title":"The Epidemiology of Ankle Sprains in US High School Sports, 2011\u20132012 to\n2018\u20132019 Academic Years","volume":"57","author":"Z Y Kerr","year":"2022","journal-title":"J Athl Train"},{"key":"ref5","doi-asserted-by":"publisher","first-page":"37","DOI":"10.1177\/1938640013509670","article-title":"Prevalence of chronic ankle instability in high school and division I\nathletes","volume":"7","author":"L Tanen","year":"2014","journal-title":"Foot Ankle Spec"},{"key":"ref6","doi-asserted-by":"publisher","first-page":"154","DOI":"10.4085\/1062-6050-49.2.01","article-title":"Jump-landing biomechanics and knee-laxity change across the menstrual cycle in\nwomen with anterior cruciate ligament reconstruction","volume":"49","author":"D R Bell","year":"2014","journal-title":"J Athl Train"},{"key":"ref7","doi-asserted-by":"publisher","first-page":"174","DOI":"10.1136\/bjsm.2008.049270","article-title":"Relationship between knee joint laxity and knee joint mechanics during the\nmenstrual cycle","volume":"43","author":"S K Park","year":"2009","journal-title":"Br J Sports Med"},{"key":"ref8","doi-asserted-by":"publisher","first-page":"149","DOI":"10.1111\/j.1600-0838.1998.tb00185.x","article-title":"A prospective cohort study of anterior cruciate ligament injuries in elite\nNorwegian team handball","volume":"8","author":"G Myklebust","year":"1998","journal-title":"Scand J Med Sci Sports"},{"key":"ref9","doi-asserted-by":"publisher","first-page":"473","DOI":"10.1007\/s00402-007-0461-1","article-title":"Relationship of the menstrual cycle phase to anterior cruciate ligament injuries\nin teenaged female athletes","volume":"128","author":"N Adachi","year":"2008","journal-title":"Arch Orthop Trauma Surg"},{"key":"ref10","first-page":"275","article-title":"The Menstrual Cycle, Sex Hormones, and Anterior Cruciate Ligament Injury","volume":"37","author":"J R Slauterbeck","year":"2002","journal-title":"J Athl Train"},{"key":"ref11","doi-asserted-by":"publisher","first-page":"577","DOI":"10.1177\/03635465030310041701","article-title":"Relaxin receptors in the human female anterior cruciate ligament","volume":"31","author":"J L Dragoo","year":"2003","journal-title":"Am J Sports Med"},{"key":"ref12","doi-asserted-by":"publisher","first-page":"2175","DOI":"10.1177\/0363546511413378","article-title":"Prospective correlation between serum relaxin concentration and anterior\ncruciate ligament tears among elite collegiate female athletes","volume":"39","author":"J L Dragoo","year":"2011","journal-title":"Am J Sports Med"},{"key":"ref13","doi-asserted-by":"publisher","first-page":"143","DOI":"10.4085\/1062-6050-47.2.143","article-title":"Sex differences, hormone fluctuations, ankle stability, and dynamic postural\ncontrol","volume":"47","author":"H Ericksen","year":"2012","journal-title":"J Athl Train"},{"key":"ref14","doi-asserted-by":"publisher","first-page":"21","DOI":"10.1186\/s13047-021-00459-7","article-title":"A preliminary study exploring the change in ankle joint laxity and general joint\nlaxity during the menstrual cycle in cis women","volume":"14","author":"T Yamazaki","year":"2021","journal-title":"J Foot Ankle Res"},{"key":"ref15","doi-asserted-by":"publisher","DOI":"10.1177\/2325967117724753","article-title":"Changes in the Width of the Tibiofibular Syndesmosis Related to Lower Extremity\nJoint Dynamics and Neuromuscular Coordination on Drop Landing During the\nMenstrual Cycle","volume":"5","author":"M Okazaki","year":"2017","journal-title":"Orthop J Sports Med"},{"key":"ref16","doi-asserted-by":"publisher","first-page":"65","DOI":"10.4085\/1062-6050-49.3.42","article-title":"Evidence of validity for the Japanese version of the foot and ankle ability\nmeasure","volume":"50","author":"D Uematsu","year":"2015","journal-title":"J Athl Train"},{"key":"ref17","doi-asserted-by":"publisher","first-page":"968","DOI":"10.1177\/107110070502601113","article-title":"Evidence of validity for the Foot and Ankle Ability Measure (FAAM)","volume":"26","author":"R L Martin","year":"2005","journal-title":"Foot Ankle Int"},{"key":"ref18","doi-asserted-by":"publisher","first-page":"179","DOI":"10.4085\/1062-6050-43.2.179","article-title":"Validity of the Foot and Ankle Ability Measure in athletes with chronic ankle\ninstability","volume":"43","author":"C R Carcia","year":"2008","journal-title":"J Athl Train"},{"key":"ref19","doi-asserted-by":"publisher","first-page":"752","DOI":"10.1093\/humrep\/15.4.752","article-title":"Side of ovulation and cycle characteristics in normally fertile women","volume":"15","author":"R Ecochard","year":"2000","journal-title":"Hum Reprod"},{"key":"ref20","doi-asserted-by":"publisher","first-page":"843","DOI":"10.1007\/s40279-021-01435-8","article-title":"Methodological Considerations for Studies in Sport and Exercise Science with\nWomen as Participants: A Working Guide for Standards of Practice for Research on\nWomen","volume":"51","author":"K J Elliott-Sale","year":"2021","journal-title":"Sports Med"},{"key":"ref21","first-page":"467","article-title":"Assessment of Ankle-Subtalar-Joint-Complex Laxity Using an Instrumented Ankle\nArthrometer: An Experimental Cadaveric Investigation","volume":"37","author":"J E Kovaleski","year":"2002","journal-title":"J Athl Train"},{"key":"ref22","doi-asserted-by":"publisher","first-page":"808","DOI":"10.1177\/107110079902001210","article-title":"Instrumented measurement of anteroposterior and inversion-eversion laxity of the\nnormal ankle joint complex","volume":"20","author":"J E Kovaleski","year":"1999","journal-title":"Foot Ankle Int"},{"key":"ref23","doi-asserted-by":"publisher","first-page":"1298","DOI":"10.1177\/0363546505275149","article-title":"The effect of estradiol and progesterone on knee and ankle joint laxity","volume":"33","author":"B D Beynnon","year":"2005","journal-title":"Am J Sports Med"},{"key":"ref24","doi-asserted-by":"crossref","first-page":"10681","DOI":"10.1016\/S0021-9258(18)87000-4","article-title":"Relaxin modulates synthesis and secretion of procollagenase and collagen by\nhuman dermal fibroblasts","volume":"265","author":"E N Unemori","year":"1990","journal-title":"J Biol Chem"},{"key":"ref25","doi-asserted-by":"publisher","first-page":"69","DOI":"10.1016\/j.knee.2008.09.005","article-title":"The effect of relaxin on the female anterior cruciate ligament: Analysis of\nmechanical properties in an animal model","volume":"16","author":"J L Dragoo","year":"2009","journal-title":"Knee"}],"container-title":["International Journal of Sports Medicine"],"original-title":[],"language":"en","link":[{"URL":"http:\/\/www.thieme-connect.de\/products\/ejournals\/pdf\/10.1055\/a-2804-6786.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,31]],"date-time":"2026-07-31T22:30:47Z","timestamp":1785537047000},"score":1,"resource":{"primary":{"URL":"http:\/\/www.thieme-connect.de\/DOI\/DOI?10.1055\/a-2804-6786"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,2,4]]},"references-count":25,"journal-issue":{"issue":"09","published-online":{"date-parts":[[2026,7,31]]},"published-print":{"date-parts":[[2026,8]]}},"URL":"https:\/\/doi.org\/10.1055\/a-2804-6786","archive":["Portico","CLOCKSS"],"relation":{},"ISSN":["0172-4622","1439-3964"],"issn-type":[{"value":"0172-4622","type":"print"},{"value":"1439-3964","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[2026,2,4]]},"published":{"date-parts":[[2026,2,4]]}}}