脸先着地，无力回天
Liǎn xiān zhuó dì, wúlì huí tiān
This phrase means to say that humans needs their 'face', trees needs their bark. So if one's face is facing the ground, then there is now hopeless.
Lets break down this phrase and see what it means:
脸: Face
先着地: facing towards the ground
无力: powerless
回天: to return to the sky/ heaven.
Therefore, in a way it is to say that once someone abandons their 'face' or pride/dignity, there is no way for them to stand back up.