{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,15]],"date-time":"2026-05-15T04:36:49Z","timestamp":1778819809635,"version":"3.51.4"},"reference-count":30,"publisher":"SAGE Publications","issue":"12","license":[{"start":{"date-parts":[[2016,8,20]],"date-time":"2016-08-20T00:00:00Z","timestamp":1471651200000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":["journals.sagepub.com"],"crossmark-restriction":true},"short-container-title":["Am J Sports Med"],"published-print":{"date-parts":[[2016,12]]},"abstract":"<jats:sec>\n                    <jats:title>Background:<\/jats:title>\n                    <jats:p>Sports-related concussions (SRCs) have gained increased societal interest in the past decade. The National Collegiate Athletic Association (NCAA) has implemented legislation and rule changes to decrease the incidence and risk of head injury impacts. The \u201ctargeting\u201d rule forbids initiating contact with the crown of a helmet and targeting defenseless players in the head and neck area; however, there are concerns that this rule change has unintentionally led to an increased incidence of lower extremity injuries.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Purpose\/Hypothesis:<\/jats:title>\n                    <jats:p>The purpose of this study was to evaluate the change in lower extremity injury rates in NCAA football during the 2009-2010 to 2014-2015 seasons. We hypothesized that the lower extremity injury rate has increased across the time period.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Study Design:<\/jats:title>\n                    <jats:p>Descriptive epidemiology study.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods:<\/jats:title>\n                    <jats:p>Sixty-eight NCAA football programs provided 153 team-seasons of data to the NCAA Injury Surveillance Program. Lower extremity injuries (ie, hip\/groin, upper leg\/thigh, knee, lower leg\/Achilles, foot\/toes) and SRCs sustained during NCAA football games were examined. We calculated injury rates per 1000 athlete-exposures (AEs) for lower extremity injuries and SRCs. Rate ratios (RRs) compared injury rates between the 2009-2010 to 2011-2012 and 2012-2013 to 2014-2015 seasons.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results:<\/jats:title>\n                    <jats:p>Overall, 2400 lower extremity injuries were reported during the 2009-2010 to 2014-2015 seasons; most were to the knee (33.6%) and ankle (28.5%) and caused by player contact (59.2%). The lower extremity injury rate increased in 2012-2013 to 2014-2015 compared with 2009-2010 to 2011-2012 (23.55 vs 20.45\/1000 AEs, respectively; RR, 1.15; 95% CI, 1.06-1.25). This finding was retained when restricted to injuries due to player contact (RR, 1.19; 95% CI, 1.07-1.32) but not for injuries due to noncontact\/overuse (RR, 0.96; 95% CI, 0.80-1.14). When examining player contact injury rates by anatomic site, only ankle injuries had an increase (RR, 1.36; 95% CI, 1.13-1.64). The SRC rate also increased in 2012-2013 to 2014-2015 compared with 2009-2010 to 2011-2012 (3.52 vs 2.63\/1000 AEs, respectively; RR, 1.34; 95% CI, 1.08-1.66).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion:<\/jats:title>\n                    <jats:p>The lower extremity injury rate has increased in NCAA football athletes. Similarly, SRC rates have increased, although this may be caused by concurrent policies related to better education, identification, and management. Targeting rule changes may be contributing to increased rates of player contact\u2013related ankle injuries. Alongside continued surveillance research to examine longitudinal time trends, more in-depth individual-level examinations of how targeting rule changes influence coaching and player behaviors are warranted.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1177\/0363546516659290","type":"journal-article","created":{"date-parts":[[2016,8,10]],"date-time":"2016-08-10T23:43:29Z","timestamp":1470872609000},"page":"3230-3236","update-policy":"https:\/\/doi.org\/10.1177\/sage-journals-update-policy","source":"Crossref","is-referenced-by-count":54,"title":["Increasing Lower Extremity Injury Rates Across the 2009-2010 to 2014-2015 Seasons of National Collegiate Athletic Association Football"],"prefix":"10.1177","volume":"44","author":[{"given":"Robert W.","family":"Westermann","sequence":"first","affiliation":[{"name":"University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zachary Y.","family":"Kerr","sequence":"additional","affiliation":[{"name":"Datalys Center for Sports Injury Research and Prevention, Indianapolis, Indiana, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Peter","family":"Wehr","sequence":"additional","affiliation":[{"name":"University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Annuziato","family":"Amendola","sequence":"additional","affiliation":[{"name":"Duke University, Durham, North Carolina, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"179","published-online":{"date-parts":[[2016,8,20]]},"reference":[{"key":"bibr1-0363546516659290","unstructured":"Barzilai P, Brady E. Knee injuries worry NFL players more than concussions. USA TODAY Sports. January 27, 2014. Available at: http:\/\/www.usatoday.com\/story\/sports\/nfl\/2014\/01\/27\/nfl-players-injury-survey-knee-head-concussions\/4918341\/. Accessed December 21, 2015."},{"key":"bibr2-0363546516659290","volume-title":"50 Years of College Football","author":"Boyles B","year":"2007"},{"key":"bibr3-0363546516659290","unstructured":"Coaches in conference with President Roosevelt. Washington Post. 1905. Available at: https:\/\/www.documentcloud.org\/documents\/1175005-144576144-1.html. Accessed June 6, 2016."},{"key":"bibr4-0363546516659290","doi-asserted-by":"publisher","DOI":"10.1177\/0363546509333015"},{"issue":"2","key":"bibr5-0363546516659290","first-page":"221","volume":"42","author":"Dick R","year":"2007","journal-title":"J Athl Train"},{"key":"bibr6-0363546516659290","doi-asserted-by":"publisher","DOI":"10.1016\/j.knee.2012.07.006"},{"key":"bibr7-0363546516659290","doi-asserted-by":"publisher","DOI":"10.1136\/bjsm.34.5.348"},{"key":"bibr8-0363546516659290","doi-asserted-by":"publisher","DOI":"10.1123\/jpah.6.5.638"},{"issue":"4","key":"bibr9-0363546516659290","first-page":"304","volume":"32","author":"Gorse K","year":"1997","journal-title":"J Athl Train"},{"key":"bibr10-0363546516659290","volume-title":"Sports-Related Concussions in Youth: Improving the Science, Changing the Culture","author":"Graham R","year":"2014"},{"key":"bibr11-0363546516659290","doi-asserted-by":"publisher","DOI":"10.1227\/01.NEU.0000175725.75780.DD"},{"key":"bibr12-0363546516659290","doi-asserted-by":"publisher","DOI":"10.1097\/00042752-200407000-00001"},{"issue":"1","key":"bibr13-0363546516659290","first-page":"101","volume":"39","author":"Heck JF","year":"2004","journal-title":"J Athl Train"},{"key":"bibr14-0363546516659290","doi-asserted-by":"publisher","DOI":"10.1177\/0363546512458888"},{"key":"bibr15-0363546516659290","doi-asserted-by":"publisher","DOI":"10.4085\/1062-6050-49.3.58"},{"key":"bibr16-0363546516659290","doi-asserted-by":"publisher","DOI":"10.15585\/mmwr.mm6448a2"},{"key":"bibr17-0363546516659290","doi-asserted-by":"publisher","DOI":"10.1111\/j.1600-0838.1999.tb00247.x"},{"issue":"4","key":"bibr18-0363546516659290","first-page":"717","volume":"40","author":"Lewis GM.","year":"1969","journal-title":"Res Q"},{"key":"bibr19-0363546516659290","doi-asserted-by":"publisher","DOI":"10.1177\/0363546510392326"},{"key":"bibr20-0363546516659290","doi-asserted-by":"publisher","DOI":"10.1136\/bjsports-2013-092313"},{"key":"bibr21-0363546516659290","unstructured":"Parsons JT. 2014-15 NCAA Sports Medicine Handbook. The National Collegiate Athletic Association. 25th ed. 2014. Available at: http:\/\/www.ncaapublications.com\/DownloadPublication.aspx?download=MD15.pdf. Accessed March 16, 2015."},{"key":"bibr22-0363546516659290","unstructured":"Redding R, Halpin T, eds. NCAA Football 2008 Rules and Interpretations. National Collegiate Athletic Association. 2008. Available at: http:\/\/www.ncaapublications.com\/p-3866-2008-football-rules-book.aspx. Accessed December 21, 2015."},{"key":"bibr23-0363546516659290","unstructured":"Redding R, Halpin T eds. NCAA Football 2013 and 2014 Rules and Interpretations. National Collegiate Athletic Association. 2013. Available at: http:\/\/www.ncaapublications.com\/productdownloads\/14FOOTRULES.pdf. Accessed December 21, 2015."},{"key":"bibr24-0363546516659290","first-page":"132","volume":"1397","author":"Shealy J","year":"2000","journal-title":"ASTM Special Technical Publication"},{"key":"bibr25-0363546516659290","unstructured":"Smith MD. After Gronk knee injury, Brady says rules force low hits. NBC Sports. November 30, 2015. Available at: http:\/\/profootballtalk.nbcsports.com\/2015\/11\/30\/after-gronk-knee-injury-brady-says-rules-force-low-hits\/. Accessed December 21, 2015."},{"key":"bibr26-0363546516659290","doi-asserted-by":"publisher","DOI":"10.1001\/jama.1985.03360240051033"},{"key":"bibr27-0363546516659290","doi-asserted-by":"publisher","DOI":"10.1177\/0363546515610537"},{"key":"bibr28-0363546516659290","unstructured":"Weir DR, Jackson JS, Sonnega A. National Football League Player Care Foundation study of retired NFL players. University of Michigan, Institute for Social Research. 2009. Available at: www.ns.umich.edu\/Releases\/2009\/Sep09\/FinalReport.pdf. Accessed December 21, 2015."},{"key":"bibr29-0363546516659290","doi-asserted-by":"publisher","DOI":"10.1249\/JSR.0b013e3181df1179"},{"key":"bibr30-0363546516659290","doi-asserted-by":"publisher","DOI":"10.1177\/0363546515599634"}],"container-title":["The American Journal of Sports Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/0363546516659290","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/full-xml\/10.1177\/0363546516659290","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/0363546516659290","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,28]],"date-time":"2026-04-28T09:50:04Z","timestamp":1777369804000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.sagepub.com\/doi\/10.1177\/0363546516659290"}},"subtitle":["An Unintended Consequence of the \u201cTargeting\u201d Rule Used to Prevent Concussions?"],"short-title":[],"issued":{"date-parts":[[2016,8,20]]},"references-count":30,"journal-issue":{"issue":"12","published-print":{"date-parts":[[2016,12]]}},"alternative-id":["10.1177\/0363546516659290"],"URL":"https:\/\/doi.org\/10.1177\/0363546516659290","relation":{},"ISSN":["0363-5465","1552-3365"],"issn-type":[{"value":"0363-5465","type":"print"},{"value":"1552-3365","type":"electronic"}],"subject":[],"published":{"date-parts":[[2016,8,20]]}}}