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The United States and Japan\u2014two of the largest baseball participation populations in the world\u2014have developed unique nationwide initiatives to address these throwing injury \u201cepidemics.\u201d Given the substantial interest and research in baseball and throwing injuries in both countries, curiosity about throwing injuries with respect to similarities and differences between the countries has been growing. When taking into account heterogeneous definitions of injury and injury collection methods, this review found higher rates of youth elbow injuries in Japan. Unlike Japan, U.S. injury surveillance methods included large national databases, whereas Japanese injury surveillance focused primarily on annual physical examinations, often with ultrasound. Biomechanically, U.S. pitchers threw faster and had greater joint torques, which increased injury risk. Regarding workload, the United States was the first of the two countries to implement pitch count regulations in hopes of mitigating injury risk. In Japan, smaller youth baseballs and a workload\u2010limiting professional league structure may reduce injury risk factors. Furthermore, cultural differences appear to impact youth workload. Lastly, Japan's health care structure may provide better access to orthopedic sports medicine physicians but limits access to primary care sports medicine physicians. We present injury rates, risk factors, screening practices, and management approaches in both countries to inform strategies to address the throwing\u2010injury epidemic.<\/jats:p>","DOI":"10.1002\/pmrj.70129","type":"journal-article","created":{"date-parts":[[2026,4,1]],"date-time":"2026-04-01T12:21:22Z","timestamp":1775046082000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Baseball\u2010related throwing injuries in Japan versus the\n                    <scp>United States<\/scp>\n                    : A comprehensive comparison"],"prefix":"10.1002","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2144-3965","authenticated-orcid":false,"given":"Dylan B.","family":"Combs","sequence":"first","affiliation":[{"name":"Department of Physical Medicine and Rehabilitation; Spaulding Rehabilitation Hospital Harvard Medical School  Charlestown Massachusetts USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yuka","family":"Tsukahara","sequence":"additional","affiliation":[{"name":"Department of Family and Community Medicine, Caver College of Medicine The University of Iowa  Iowa City Iowa USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Dai","family":"Sugimoto","sequence":"additional","affiliation":[{"name":"Division of Sports Medicine, Boston Children's Hospital  Boston Massachusetts USA"},{"name":"The Micheli Center for Sports Injury Prevention  Waltham USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2741-3772","authenticated-orcid":false,"given":"MaryBeth","family":"Horodyski","sequence":"additional","affiliation":[{"name":"Department of Orthopaedic Surgery &amp; Sports Medicine University of Florida  Gainesville USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yoshikazu","family":"Kida","sequence":"additional","affiliation":[{"name":"Department of Orthopaedics, Graduate School of Medical Science Kyoto Prefectural University of Medicine  Kyoto Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jason L.","family":"Zaremski","sequence":"additional","affiliation":[{"name":"Department of Physical Medicine &amp; Rehabilitation University of Florida  Gainesville Florida USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2026,4,1]]},"reference":[{"key":"e_1_2_11_2_1","doi-asserted-by":"publisher","DOI":"10.1177\/2325967119825625"},{"key":"e_1_2_11_3_1","volume-title":"Dodgers put Roki Sasaki on IL with right shoulder impingement","author":"Associated Press","year":"2025"},{"key":"e_1_2_11_4_1","unstructured":"ESPN News Services.Dodgers Put Yoshinobu Yamamoto on IL with Strained Rotator Cuff.2024Accessed December 3 2025.https:\/\/www.espn.com\/mlb\/story\/_\/id\/40364760\/dodgers-put-yoshinobu-yamamoto-il-triceps-tightness"},{"key":"e_1_2_11_5_1","doi-asserted-by":"publisher","DOI":"10.1177\/23259671211008810"},{"key":"e_1_2_11_6_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.jseint.2021.09.011"},{"key":"e_1_2_11_7_1","doi-asserted-by":"publisher","DOI":"10.3928\/19425864\u201020110331\u201001"},{"key":"e_1_2_11_8_1","doi-asserted-by":"publisher","DOI":"10.1177\/0363546514555506"},{"key":"e_1_2_11_9_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00167\u2010016\u20104364\u2010y"},{"key":"e_1_2_11_10_1","doi-asserted-by":"publisher","DOI":"10.4085\/1062\u20106050\u2010432\u201020"},{"key":"e_1_2_11_11_1","unstructured":"TsuburayaM.Can unprecedented \u201cSamurai Japan fever\u201d lead to revival of baseball's popularity. 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