{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,13]],"date-time":"2026-10-13T16:24:43Z","timestamp":1791908683210,"version":"4.3.4"},"reference-count":25,"publisher":"National Athletic Trainers' Association","issue":"9","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2017,9,1]]},"abstract":"<jats:sec>\n                  <jats:title>Context:\u2003<\/jats:title>\n                  <jats:p>The Guardian Cap provides a soft covering intended to mitigate energy transfer to the head during football contact. Yet how well it attenuates impacts remains unknown.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Objective:\u2003<\/jats:title>\n                  <jats:p>To evaluate the changes in the Gadd Severity Index (GSI) and linear acceleration during drop tests on helmeted headforms with or without Guardian Caps.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Design:\u2003<\/jats:title>\n                  <jats:p>Crossover study.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Setting:\u2003<\/jats:title>\n                  <jats:p>Laboratory.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Patients or Other Participants:\u2003<\/jats:title>\n                  <jats:p>Nine new football helmets sent directly from the manufacturer.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Intervention(s):\u2003<\/jats:title>\n                  <jats:p>We dropped the helmets at 3 velocities on 6 helmet locations (front, side, right front boss, top, rear right boss, and rear) as prescribed by the National Operating Committee on Standards for Athletic Equipment. Helmets were tested with facemasks in place but no Guardian Cap and then retested with the facemasks in place and the Guardian Cap affixed.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Main Outcome Measure(s):\u2003<\/jats:title>\n                  <jats:p>The GSI scores and linear accelerations measured in g forces.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Results:\u2003<\/jats:title>\n                  <jats:p>For the GSI, we found a significant interaction among drop location, Guardian Cap presence, and helmet brand at the high velocity (F10,50 = 3.01, P = .005) but not at the low (F3.23,16.15 = 0.84, P = .50) or medium (F10,50 = 1.29, P = .26) velocities. Similarly for linear accelerations, we found a significant interaction among drop location, Guardian Cap presence, and helmet brand at the high velocity (F10,50 = 3.01, P = .002, \u03c92 = 0.05) but not at the low (F10,50 = 0.49, P = .89, \u03c92 &amp;lt; 0.01, 1\u2013\u03b2 = 0.16) or medium (F5.20,26.01 = 2.43, P = .06, \u03c92 &amp;lt; 0.01, 1\u2013\u03b2 = 0.68) velocities.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Conclusions:\u2003<\/jats:title>\n                  <jats:p>The Guardian Cap failed to significantly improve the helmets' ability to mitigate impact forces at most locations. Limited evidence indicates how a reduction in GSI would provide clinically relevant benefits beyond reducing the risk of skull fracture or a similar catastrophic event.<\/jats:p>\n               <\/jats:sec>","DOI":"10.4085\/1062-6050-52.6.01","type":"journal-article","created":{"date-parts":[[2017,8,3]],"date-time":"2017-08-03T15:17:10Z","timestamp":1501773430000},"page":"802-808","source":"Crossref","is-referenced-by-count":30,"title":["The Ability of an Aftermarket Helmet Add-On Device to Reduce Impact-Force Accelerations During Drop Tests"],"prefix":"10.4085","volume":"52","author":[{"given":"Katherine M.","family":"Breedlove","sequence":"first","affiliation":[{"name":"University of Delaware, Newark"},{"name":"Purdue University, West Lafayette, IN"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Evan","family":"Breedlove","sequence":"first","affiliation":[{"name":"Purdue University, West Lafayette, IN"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Eric","family":"Nauman","sequence":"first","affiliation":[{"name":"Purdue University, West Lafayette, IN"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Thomas G.","family":"Bowman","sequence":"first","affiliation":[{"name":"Lynchburg College, VA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Monica R.","family":"Lininger","sequence":"first","affiliation":[{"name":"Northern Arizona University, Flagstaff"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"2557","reference":[{"issue":"4","key":"2020060411510055300_i1062-6050-52-9-802-b01","doi-asserted-by":"crossref","first-page":"230","DOI":"10.1038\/nrneurol.2015.30","article-title":"Expert consensus document: mind the gaps\u2014advancing research into short-term and long-term neuropsychological outcomes of youth sports-related concussions","volume":"11","author":"Carman","year":"2015","journal-title":"Nat Rev Neurol"},{"issue":"4","key":"2020060411510055300_i1062-6050-52-9-802-b02","doi-asserted-by":"crossref","first-page":"577","DOI":"10.1016\/j.pmr.2011.08.002","article-title":"The pathophysiology of concussions in youth","volume":"22","author":"Shrey","year":"2011","journal-title":"Phys Med Rehabil Clin N Am"},{"issue":"4","key":"2020060411510055300_i1062-6050-52-9-802-b03","first-page":"495","article-title":"Concussions among United States high school and collegiate athletes","volume":"42","author":"Gessel","year":"2007","journal-title":"J Athl Train"},{"issue":"7","key":"2020060411510055300_i1062-6050-52-9-802-b04","doi-asserted-by":"crossref","first-page":"1265","DOI":"10.1016\/j.jbiomech.2012.01.034","article-title":"Biomechanical correlates of symptomatic and asymptomatic neurophysiological impairment in high school football","volume":"45","author":"Breedlove","year":"2012","journal-title":"J Biomech"},{"issue":"3","key":"2020060411510055300_i1062-6050-52-9-802-b05","doi-asserted-by":"crossref","first-page":"119","DOI":"10.3928\/19425864-20140507-02","article-title":"Detecting neurocognitive and neurophysiological changes as a result of subconcussive blows among high school football athletes","volume":"6","author":"Breedlove","year":"2014","journal-title":"Athl Train Sports Health Care"},{"issue":"6","key":"2020060411510055300_i1062-6050-52-9-802-b06","doi-asserted-by":"crossref","first-page":"459","DOI":"10.1080\/87565641.2014.940619","article-title":"MR spectroscopic evidence of brain injury in the non-diagnosed collision sport athlete","volume":"39","author":"Poole","year":"2014","journal-title":"Dev Neuropsychol"},{"issue":"2","key":"2020060411510055300_i1062-6050-52-9-802-b07","doi-asserted-by":"crossref","first-page":"91","DOI":"10.1089\/brain.2014.0279","article-title":"Alteration of default mode network in high school football athletes due to repetitive subconcussive mild traumatic brain injury: a resting-state functional magnetic resonance imaging study","volume":"5","author":"Abbas","year":"2015","journal-title":"Brain Connect"},{"issue":"4","key":"2020060411510055300_i1062-6050-52-9-802-b08","doi-asserted-by":"crossref","first-page":"327","DOI":"10.1089\/neu.2010.1512","article-title":"Functionally-detected cognitive impairment in high school football players without clinically-diagnosed concussion","volume":"31","author":"Talavage","year":"2014","journal-title":"J Neurotrauma"},{"issue":"2","key":"2020060411510055300_i1062-6050-52-9-802-b09","doi-asserted-by":"crossref","first-page":"171","DOI":"10.1016\/j.mri.2011.10.001","article-title":"Subject-specific changes in brain white matter on diffusion tensor imaging after sports-related concussion","volume":"30","author":"Bazarian","year":"2012","journal-title":"Magn Reson Imaging"},{"issue":"23","key":"2020060411510055300_i1062-6050-52-9-802-b10","doi-asserted-by":"crossref","first-page":"2133","DOI":"10.1089\/neu.2015.4267","article-title":"Abnormalities in diffusional kurtosis metrics related to head impact exposure in a season of high school varsity football","volume":"33","author":"Davenport","year":"2016","journal-title":"J Neurotrauma"},{"issue":"2","key":"2020060411510055300_i1062-6050-52-9-802-b11","doi-asserted-by":"crossref","first-page":"85","DOI":"10.1080\/87565641.2015.1016161","article-title":"Post-season neurophysiological deficits assessed by ImPACT and fMRI in athletes competing in American football","volume":"40","author":"Nauman","year":"2015","journal-title":"Dev Neuropsychol"},{"issue":"14","key":"2020060411510055300_i1062-6050-52-9-802-b12","doi-asserted-by":"crossref","first-page":"3782","DOI":"10.1016\/j.jbiomech.2015.08.026","article-title":"Force attenuation of new and used lacrosse helmets","volume":"48","author":"Bowman","year":"2015","journal-title":"J Biomech"},{"key":"2020060411510055300_i1062-6050-52-9-802-b13","article-title":"Laboratory procedural guide for certifying newly manufactured lacrosse helmets; NOCSAE DOC (ND) 042-04m11a","year":"2014","journal-title":"National Operating Committee on Standards for Athletic Equipment Web site"},{"key":"2020060411510055300_i1062-6050-52-9-802-b14","article-title":"Standard test method and equipment used in evaluating the performance characteristics of protective headgear\/equipment; NOCSAE DOC (ND) 001-11m13","year":"2014","journal-title":"National Operating Committee on Standards for Athletic Equipment Web site"},{"key":"2020060411510055300_i1062-6050-52-9-802-b15","article-title":"Standard performance specification for newly manufactured lacrosse helmets with faceguard; NOCSAE DOC (ND) 041-11m12","year":"2014","journal-title":"National Operating Committee on Standards for Athletic Equipment Web site"},{"key":"2020060411510055300_i1062-6050-52-9-802-b16","article-title":"Standard performance specification for newly manufactured football helmets; NOCSAE DOC (ND) 002-13m13","year":"2014","journal-title":"National Operating Committee on Standards for Athletic Equipment Web site"},{"issue":"suppl 3","key":"2020060411510055300_i1062-6050-52-9-802-b17","first-page":"S128","article-title":"Force attenuation of new and used lacrosse helmets [abstract]","volume":"49","author":"Bowman","year":"2014","journal-title":"J Athl Train"},{"issue":"13","key":"2020060411510055300_i1062-6050-52-9-802-b18","doi-asserted-by":"crossref","first-page":"2838","DOI":"10.1016\/j.jbiomech.2016.06.030","article-title":"Impact attenuation capabilities of football and lacrosse helmets","volume":"49","author":"Breedlove","year":"2016","journal-title":"J Biomech"},{"issue":"suppl 1","key":"2020060411510055300_i1062-6050-52-9-802-b19","doi-asserted-by":"crossref","first-page":"S377","DOI":"10.1080\/17461391.2012.705334","article-title":"Peak acceleration during impact with helmet materials: effects of impactor mass and speed","volume":"14","author":"Hutchinson","year":"2014","journal-title":"Eur J Sport Sci"},{"key":"2020060411510055300_i1062-6050-52-9-802-b20","doi-asserted-by":"crossref","first-page":"292","DOI":"10.1007\/978-1-4757-2264-2_13","article-title":"Biomechanics of human trauma: head protection","author":"Newman","year":"1993","journal-title":"Accidental Injury: Biomechanics and Prevention"},{"issue":"5","key":"2020060411510055300_i1062-6050-52-9-802-b21","doi-asserted-by":"crossref","first-page":"3112","DOI":"10.1016\/j.matdes.2010.12.019","article-title":"Motorcyclist helmet composite outer shell characterisation and modelling","volume":"32","author":"Tinard","year":"2011","journal-title":"Mater Des"},{"key":"2020060411510055300_i1062-6050-52-9-802-b22","doi-asserted-by":"crossref","first-page":"653","DOI":"10.1016\/j.matdes.2012.09.017","article-title":"An examination of American football helmets using brain deformation metrics associated with concussion","volume":"45","author":"Post","year":"2013","journal-title":"Mater Des"},{"issue":"1","key":"2020060411510055300_i1062-6050-52-9-802-b23","doi-asserted-by":"crossref","first-page":"169","DOI":"10.1016\/S0278-5919(05)70071-5","article-title":"Fatalities from head and cervical spine injuries occurring in tackle football: 50 years' experience","volume":"17","author":"Mueller","year":"1998","journal-title":"Clin Sports Med"},{"key":"2020060411510055300_i1062-6050-52-9-802-b24","doi-asserted-by":"crossref","first-page":"444","DOI":"10.1016\/B978-0-08-044894-7.01368-3","article-title":"Statistical significance versus effect size","author":"Fan","year":"2010","journal-title":"International Encyclopedia of Education. Vol 7"},{"issue":"5","key":"2020060411510055300_i1062-6050-52-9-802-b25","doi-asserted-by":"crossref","first-page":"275","DOI":"10.1080\/00220670109598763","article-title":"Statistical significance and effect size: two sides of a coin","volume":"94","author":"Fan","year":"2001","journal-title":"J Educ Res"}],"container-title":["Journal of Athletic Training"],"original-title":[],"language":"en","link":[{"URL":"http:\/\/meridian.allenpress.com\/jat\/article-pdf\/52\/9\/802\/1617312\/1062-6050-52_6_01.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"http:\/\/meridian.allenpress.com\/jat\/article-pdf\/52\/9\/802\/1617312\/1062-6050-52_6_01.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,6,11]],"date-time":"2025-06-11T18:57:45Z","timestamp":1749668265000},"score":1,"resource":{"primary":{"URL":"https:\/\/nata.kglmeridian.com\/view\/journals\/attr\/52\/9\/article-p802.xml"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017,9,1]]},"references-count":25,"journal-issue":{"issue":"9","published-print":{"date-parts":[[2017,9,1]]}},"URL":"https:\/\/doi.org\/10.4085\/1062-6050-52.6.01","relation":{},"ISSN":["1062-6050"],"issn-type":[{"value":"1062-6050","type":"print"}],"subject":[],"published":{"date-parts":[[2017,9,1]]}}}