A blood clot, possibly formed in the leg, had moved upward and lodged in the lung, causing cardiac arrest.

有一个血块，可能在腿部形成，顺血管向上流动，最后停留在肺部，造成了心脏停跳。

youdao

Your guy lies on his back, one leg outstretched and the other bent, knee pointing upward.

让你的男伴躺下，一条腿伸向一旁，另一条腿弯曲，膝盖朝上。

youdao

So, the action of extending the leg backward creates a forward and upward movement (the flight phase).

因此，腿向后伸展的作用力，产生一个向前向上的运动(腾空阶段)。

youdao