I have generally seen in many of the youtube videos, which attempt to teach how to hit a knuckleball perfectly, they tell that after striking the ball, one should not take the foot too far ahead, rather stop it almost instantly. For some specific type of passes like the ping, the driven ball, etc a similar advice is given.
What I want to ask is why does it matter to instantly stop our foot movement after the impact with the ball during a shoot or a pass?
The reason why I am asking this is that sometimes I think that after we have struck the ball, the ball will do what it has to just because of the impact of our foot at the moment of shooting, not because how we end up our shoot or if we arrest our foot movement or not.
I hope I'm clear with my question, and also that it's not a stupid question. However, I know that if I take my foot along with the ball after striking it, it will not go as I wish (in case of knuckleball). So I want to ask why that is so.