plantarflexion
noun [ U ] medical specialized uk/ˌplæn.təˈflek.ʃən/ us/ˌplæn.tɚˈflek.ʃən/
跖曲，跖屈
downward movement of the foot away from the leg
Plantarflexion is the movement used to press the accelerator pedal in a car. 跖屈是开车时脚踩油门时的动作。