{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,13]],"date-time":"2026-10-13T16:24:38Z","timestamp":1791908678246,"version":"4.3.4"},"reference-count":27,"publisher":"MDPI AG","issue":"21","license":[{"start":{"date-parts":[[2023,10,28]],"date-time":"2023-10-28T00:00:00Z","timestamp":1698451200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Football Research Inc.","award":["A22-0340-001"],"award-info":[{"award-number":["A22-0340-001"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJERPH"],"abstract":"<jats:p>Sport-related concussion prevention strategies in collision sports are a primary interest for sporting organizations and policy makers. After-market soft-shell padding purports to augment the protective capabilities of standard football helmets and to reduce head impact severity. We compared head impact kinematics [peak linear acceleration (PLA) and peak rotational acceleration (PRA)] in athletes wearing Guardian Cap soft-shell padding to teammates without soft-shell padding. Ten Division I college football players were enrolled [soft-shell padding (SHELL) included four defensive linemen and one tight end; non-soft-shell (CONTROL) included two offensive linemen, two defensive linemen, and one tight end]. Participants wore helmets equipped with the Head Impact Telemetry System to quantify PLA (g) and PRA (rad\/s2) during 14 practices. Two-way ANOVAs were conducted to compare log-transformed PLA and PRA between groups across helmet location and gameplay characteristics. In total, 968 video-confirmed head impacts between SHELL (n = 421) and CONTROL (n = 547) were analyzed. We observed a Group x Stance interaction for PRA (F1,963 = 7.21; p = 0.007) indicating greater PRA by SHELL during 2-point stance and lower PRA during 3- or 4-point stances compared to CONTROL. There were no between-group main effects. Protective soft-shell padding did not reduce head impact kinematic outcomes among college football athletes.<\/jats:p>","DOI":"10.3390\/ijerph20216991","type":"journal-article","created":{"date-parts":[[2023,10,29]],"date-time":"2023-10-29T05:01:08Z","timestamp":1698555668000},"page":"6991","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["Efficacy of Guardian Cap Soft-Shell Padding on Head Impact Kinematics in American Football: Pilot Findings"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8887-759X","authenticated-orcid":false,"given":"Aaron M.","family":"Sinnott","sequence":"first","affiliation":[{"name":"Matthew Gfeller Center, Department of Exercise and Sport Science, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4909-7379","authenticated-orcid":false,"given":"Madison C.","family":"Chandler","sequence":"additional","affiliation":[{"name":"Matthew Gfeller Center, Department of Exercise and Sport Science, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Charles","family":"Van Dyke","sequence":"additional","affiliation":[{"name":"Matthew Gfeller Center, Department of Exercise and Sport Science, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"David L.","family":"Mincberg","sequence":"additional","affiliation":[{"name":"Campus Health Services, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hari","family":"Pinapaka","sequence":"additional","affiliation":[{"name":"Matthew Gfeller Center, Department of Exercise and Sport Science, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6071-8944","authenticated-orcid":false,"given":"Bradley J.","family":"Lauck","sequence":"additional","affiliation":[{"name":"Matthew Gfeller Center, Department of Exercise and Sport Science, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6085-8322","authenticated-orcid":false,"given":"Jason P.","family":"Mihalik","sequence":"additional","affiliation":[{"name":"Matthew Gfeller Center, Department of Exercise and Sport Science, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,10,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"838","DOI":"10.1136\/bjsports-2017-097699","article-title":"Consensus statement on concussion in sport-the 5(th) international conference on concussion in sport held in Berlin, October 2016","volume":"51","author":"McCrory","year":"2017","journal-title":"Br. J. Sports Med."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"727089","DOI":"10.3389\/fneur.2021.727089","article-title":"Age of First Exposure to Contact and Collision Sports and Later in Life Brain Health: A Narrative Review","volume":"12","author":"Iverson","year":"2021","journal-title":"Front. Neurol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"511","DOI":"10.4085\/1062-6050-51.7.04","article-title":"Football Players\u2019 Head-Impact Exposure After Limiting of Full-Contact Practices","volume":"51","author":"Broglio","year":"2016","journal-title":"J. Athl. Train."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"346","DOI":"10.1001\/jamaneurol.2020.5193","article-title":"Opportunities for prevention of concussion and repetitive head impact exposure in college football players: A Concussion Assessment, Research, and Education (CARE) Consortium study","volume":"78","author":"McCrea","year":"2021","journal-title":"JAMA Neurol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"5567625","DOI":"10.1155\/2021\/5567625","article-title":"Potential of Soft-Shelled Rugby Headgear to Reduce Linear Impact Accelerations","volume":"2021","author":"Draper","year":"2021","journal-title":"J. Healthc. Eng."},{"key":"ref_6","first-page":"220","article-title":"The Efficacy of Soccer Headgear","volume":"38","author":"Broglio","year":"2003","journal-title":"J. Athl. Train."},{"key":"ref_7","first-page":"1","article-title":"Padded Helmet Shell Covers in American Football: A Comprehensive Laboratory Evaluation with Preliminary On-Field Findings","volume":"14","author":"Cecchi","year":"2023","journal-title":"Ann. Biomed. Eng."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Quigley, K.G., Hopfe, D., Taylor, M.R., Pavilionis, P., Owusu-Amankonah, V., Islas, A., and Murray, N.G. (2023). Preliminary Examination of Guardian Cap Head Impact Data Using Instrumented Mouthguards. arXiv.","DOI":"10.4085\/1062-6050-0136.23"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"2734","DOI":"10.1007\/s10439-020-02684-w","article-title":"A Review of On-Field Investigations into the Biomechanics of Concussion in Football and Translation to Head Injury Mitigation Strategies","volume":"48","author":"Rowson","year":"2020","journal-title":"Ann. Biomed. Eng."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1229","DOI":"10.1227\/01.neu.0000306101.83882.c8","article-title":"Measurement of head impacts in collegiate football players: An investigation of positional and event-type differences","volume":"61","author":"Mihalik","year":"2007","journal-title":"Neurosurgery"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"912","DOI":"10.1249\/MSS.0000000000002874","article-title":"Association Between Preseason\/Regular Season Head Impact Exposure and Concussion Incidence in NCAA Football","volume":"54","author":"Stemper","year":"2022","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1473","DOI":"10.1007\/s10439-022-03032-w","article-title":"Time Delta Head Impact Frequency: An Analysis on Head Impact Exposure in the Lead Up to a Concussion: Findings from the NCAA-DOD Care Consortium","volume":"50","author":"Seifert","year":"2022","journal-title":"Ann. Biomed. Eng."},{"key":"ref_13","unstructured":"(2023, February 03). Guardian Cap Results: Exceeded Our Expectations. Available online: https:\/\/www.nfl.com\/playerhealthandsafety\/equipment-and-innovation\/engineering-technology\/guardian-cap-results-exceeded-our-expectations."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2747","DOI":"10.1007\/s10439-021-02842-8","article-title":"Laboratory Evaluation of Shell Add-On Products for American Football Helmets for Professional Linemen","volume":"49","author":"Bailey","year":"2021","journal-title":"Ann. Biomed. Eng."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"802","DOI":"10.4085\/1062-6050-52.6.01","article-title":"The Ability of an Aftermarket Helmet Add-On Device to Reduce Impact-Force Accelerations During Drop Tests","volume":"52","author":"Breedlove","year":"2017","journal-title":"J. Athl. Train."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Kercher, K., Steinfeldt, J.A., Macy, J.T., Ejima, K., and Kawata, K. (2020). Subconcussive head impact exposure between drill intensities in U.S. high school football. PLoS ONE, 15.","DOI":"10.1101\/2020.03.29.20047167"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"314","DOI":"10.1089\/neu.2014.3582","article-title":"Frequency of head-impact-related outcomes by position in NCAA division I collegiate football players","volume":"32","author":"Baugh","year":"2015","journal-title":"J. Neurotrauma"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"755","DOI":"10.1249\/MSS.0b013e3182798758","article-title":"Subconcussive head impact biomechanics: Comparing differing offensive schemes","volume":"45","author":"Martini","year":"2013","journal-title":"Med. Sci. Sports Exerc."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"90","DOI":"10.1007\/s10439-011-0401-7","article-title":"The Effect of Play Type and Collision Closing Distance on Head Impact Biomechanics","volume":"40","author":"Ocwieja","year":"2012","journal-title":"Ann. Biomed. Eng."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2310","DOI":"10.1016\/j.jbiomech.2013.05.030","article-title":"On the accuracy of the Head Impact Telemetry (HIT) System used in football helmets","volume":"46","author":"Jadischke","year":"2013","journal-title":"J. Biomech."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"e1394","DOI":"10.1542\/peds.2009-2849","article-title":"Collision type and player anticipation affect head impact severity among youth ice hockey players","volume":"125","author":"Mihalik","year":"2010","journal-title":"Pediatrics"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"e20154231","DOI":"10.1542\/peds.2015-4231","article-title":"Head Impact Magnitude in American High School Football","volume":"138","author":"Schmidt","year":"2016","journal-title":"Pediatrics"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"e245","DOI":"10.1097\/JSM.0000000000000778","article-title":"Distribution of head acceleration events varies by position and play type in North American football","volume":"31","author":"Lee","year":"2021","journal-title":"Clin. J. Sport Med."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"195","DOI":"10.4085\/1062-6050-51.12.02","article-title":"A multifactorial approach to sport-related concussion prevention and education: Application of the socioecological framework","volume":"52","author":"Baugh","year":"2017","journal-title":"J. Athl. Train."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"2227","DOI":"10.1007\/s40279-018-0953-x","article-title":"Context Matters: Revisiting the First Step of the \u2018Sequence of Prevention\u2019 of Sports Injuries","volume":"48","author":"Bolling","year":"2018","journal-title":"Sports Med."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"113","DOI":"10.4085\/1062-6050-0062.21","article-title":"National Athletic Trainers\u2019 Association Position Statement: Reducing Intentional Head-First Contact Behavior in American Football Players","volume":"57","author":"Swartz","year":"2022","journal-title":"J. Athl. Train."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1317","DOI":"10.1007\/s10439-022-03025-9","article-title":"Consensus Head Acceleration Measurement Practices (CHAMP): Origins, Methods, Transparency and Disclosure","volume":"50","author":"Arbogast","year":"2022","journal-title":"Ann. Biomed. Eng."}],"container-title":["International Journal of Environmental Research and Public Health"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1660-4601\/20\/21\/6991\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T21:13:21Z","timestamp":1760130801000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1660-4601\/20\/21\/6991"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,10,28]]},"references-count":27,"journal-issue":{"issue":"21","published-online":{"date-parts":[[2023,11]]}},"alternative-id":["ijerph20216991"],"URL":"https:\/\/doi.org\/10.3390\/ijerph20216991","relation":{},"ISSN":["1660-4601"],"issn-type":[{"value":"1660-4601","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,10,28]]}}}