expression, noun, noun or participle which takes 'suru'
loss of momentum on impact; getting knocked aside
Sports term describing a player losing balance, momentum, or follow-through after physical contact with an opponent. Often used in contexts like rugby, soccer, or martial arts.
彼はタックルを受けて当たり負けし、ボールを落とした。
He lost momentum from the tackle and dropped the ball.
体が小さいと、どうしても当たり負けしやすい。
If you have a small build, you tend to get knocked aside easily.