“向上打腿”在英语中常见的表达是 “upward leg kick” 或 “upward kicking of the legs” ，具体使用可根据语境和表达习惯选择：
“upward leg kick”：较为简洁直接，适用于一般描述，比如“在游泳时，要注意向上打腿的动作”（When swimming, pay attention to the upward leg kick.）。
“upward kicking of the legs”：表述稍显正式、详细，强调打腿这一动作，“upward kicking”是动名词形式作主语，“of the legs”明确指出动作部位，例如“教练强调了向上打腿对提升游泳速度的重要性”（The coach emphasized the importance of the upward kicking of the legs for improving swimming speed.） 。