When moving to the rear, it's a good idea to glance over your shoulder to note any obstacles between you and your destination. A quick glance should enable you to make a mental note of the curb that's two steps to your right, the broken bottle directly behind you and the rear bumper of the Hummer H2 in the parking lot. Your "mind's eye" will help you negotiate from point A to point B without having to constantly look behind you.
Even though you're moving to the rear, your weight should be forward, on the balls of your feet. As you move, drag the ball of your foot on the ground, with each step. This will ensure that your heel is up (if your mind's eye lied to you and you collide with the curb, you want your heel up to "feel" the curb prior to committing your full body weight into the step). If your heel is down, the curb will probably hit you back after you fall!
Footwork for fighting
When fighting, large lunging steps enable you to quickly evade an attack or explode into the suspect with a powerful technique. Striking with the rear hand from a bladed stance will enable you to generate tremendous power. When moving forward, lunge with the lead leg and allow the rear leg to catch up. Reverse the order when moving to the rear.
Whether shooting or fighting, lateral movement is generally accomplished by stepping first with the foot that corresponds to the direction of movement. This is essential to avoid crossing or entangling your legs and literally tripping over your own feet. Also, should you take a round or even a punch while your legs are crossed, you're likely to be knocked down like a bowling pin.
Lower body mechanics
Believe it or not, your legs were designed for more than getting you close enough to punch a suspect. Your legs are an integral component of generating powerful and effective strikes, whether using a baton or personal body weapons.
For illustrative purposes, let's consider the body mechanics involved in the execution of a proper palm heel strike.
From a bladed stance, with your left leg forward, push off the ground with your right foot to begin accelerating toward the suspect. Next, rotate your hips counterclockwise to incorporate the power of your entire body. Now, rotate your shoulders counterclockwise and thrust your right palm under the suspect's chin. KABLAM!
In this case, the whole is far greater than the sum of all the parts. Timing is a critical factor and can only be developed through repetition.
Train hard and stay safe!