"I find that most people aren't so good at running backwards.
First, most people take mincing, baby steps when in reverse.
Second, pesky obstacles and trip hazards rear their ugly heads.
I find that moving in diagonals off the X works much better. This is an area where training can go a long way to help.
So, for me, a Tueller drill with knife would involve drawing and shooting with one hand, while moving off the line (probably on a 45deg advance to his weak side) and using the free hand to deflect."