Head impact exposure in Judo: Implication for head injury prevention

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K11471
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 59020:Sports sciences-related
• Research Institution: Ryotokuji University
• Principal Investigator: Koshida Sentaro 了徳寺大学, 健康科学部, 教授 (60532637)
• Co-Investigator(Kenkyū-buntansha): 石井 孝法 了徳寺大学, 健康科学部, 教授 (60735041)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 頭部外傷予防 / 柔道 / 頭部衝撃 / 慣性センサ

Outline of Final Research Achievements

The present study aimed to quantify head contact exposure during judo practice and to distinguish it between different throwing techniques. The eight male and female collegiate judo athletes took part in the study. Resultant acceleration imposed to the head was monitor using mouth guard-style inertial sensor during judo practices.
Head impacts exceeding 8g were reported in approximately 9% of all thrown cases. In addition, the majority of the head impacts were identified at 15 g or lower. While osoto-gari was identified in many cases, which has been associated with a greater risk of head injuries in previous studies, head impact was detected in less than　1.5% of all the osoto-gari cases. The current findings suggest that, while osoto-gari is a common judo technique, it may not considerably increase the risk of head injury in skilled judo practitioners.

Free Research Field

スポーツ科学

Academic Significance and Societal Importance of the Research Achievements

これまでに、柔道練習時に頭部に加わる衝撃を実測した研究は存在しない。本研究は、実際の柔道自由練習での頭部衝撃を定量化した初めての研究である。特筆すべき結果として、投技によって加わる頭部衝撃の頻度は比較的低いこと、さらに大外刈が、熟練者においては必ずしも高リスクな技ではないことが示された。この知見は、柔道頭部外傷予防を考える上で柔道技能レベルの影響が重要であり、今後の研究の方向性を示唆している。また、本研究における頭部衝撃測定にはマウスガード型慣性センサを用いており、早期発見や見逃しの防止、柔道の安全評価システムの構築への活用可能性を示唆しており、社会への貢献が期待される。