Punching a player with commands

Hi, I need to figure out how to run a command that punches a player in a specific direction, preferably it should be quite a strong punch. I have discovered that I can use the /damage command with a specific direction, but whatever I try, the furthest I can knock someone is 1 block or so...
Is there another command, that could help me achieve this, or a way to modify the /damage one to for example hit with knockback?
Thanks!