Spectator: Crawling to slow down !

I'm crawling under a block...

Do "/gamemode spectator" OR "F3 + F4"
It puts you in spectator mode. When you move, you are as slow as if you were crawling.

 
If you come back in a space of more than 2 blocks, that return to normal !
In F5, your ghost head is in the crawling position.

(sorry for my bad english)