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最終更新日：2025/07/19

山下 大地

ヤマシタ ダイチ (Daichi Yamashita)
論文
タイトル
タイトル（英）
Center of mass direction and speed during a 45-degree change of direction task performed with maximal effort
参照URL
https://researchmap.jp/daichiyamashita/published_papers/50426062
著者
著者（英）
Daichi Yamashita,Yuki Inaba,Masaki Asakura,Yoshihiko Ito
担当区分
筆頭著者,責任著者
概要
概要（英）
Changes in whole-body center of mass (COM) direction and speed over multiple steps during a maximal effort change of direction (COD) task have not been fully examined. This study aimed to (1) quantify COM direction and speed changes across three steps —approach (APP), execution (EXE), and following (FOL)—during a 45° COD task, and (2) compare force production between EXE and FOL. Ten male American football players performed straight running (RUN) and sidestep cutting to a 45° COD (COD45) tasks. In RUN, participants sprinted 15 yards (13.73 m) at maximal speed. In COD45, they sprinted 10 yards (9.15 m), executed a 45° cut, and completed an additional 5-yard (4.58 m) sprint. COM speed and direction were analyzed across four flight phases in COD45 (FLIGHT-2, FLIGHT-1, FLIGHT + 1, FLIGHT + 2) and three in RUN (FLIGHT-2, FLIGHT-1, FLIGHT + 1). Horizontal ground reaction impulses (GRIs) during EXE in RUN and EXE and FOL steps in COD45 were analyzed in a local coordinate system aligned with the COM velocity vector. Although COM speed remained unchanged during EXE (between FLIGHT-1 and FLIGHT + 1; p = .053), this step produced a greater medial GRI than FOL (p < .001); however, the direction change during this step was only 15.30°, one-third of the required 45°. APP and FOL contributed 9.70° and 9.05°, respectively, to the direction change while simultaneously increasing COM speed by 0.23 m/s and 0.13 m/s, respectively. Therefore, completing a maximal effort 45° COD requires multi-step role sharing, incorporating both directional changes and acceleration.
出版者・発行元
出版者・発行元（英）
誌名
誌名（英）
Frontiers in Sports and Active Living
巻
号
開始ページ
終了ページ
出版年月
2025年6月5日
査読の有無
査読有り
招待の有無
掲載種別
研究論文（学術雑誌）
ISSN
2624-9367
DOI URL
https://doi.org/10.3389/fspor.2025.1576614
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