Definition
To lose one's balance suddenly and fall over, often in a clumsy or uncontrolled manner.
四脚朝天（粗俗语）
He was running too fast and went ass over teakeettle.
他跑得太快，结果摔了个四脚朝天。
She slipped on the ice and went ass over teakeettle.
她在冰上滑倒，摔了个四脚朝天。
The drunk man went ass over teakeettle trying to stand up.
那个醉汉试图站起来，结果摔了个四脚朝天。