Lesson 1: We are moving back because we had no choice. If I felt a grab on my shoulder I would not choose to step blindly into the unknown and walk into a punch, or worse, a knife in my back or kidney. This technique is teaching how to make the best of bad timing situation.
Lesson 2: Ideally I maintain my center of gravity and balance as I move back. If throughout your everyday casual movement and lifestyle, you commit to maintaining posture and an active awareness of your center, then even when surprised you will maintain good balance. Your position will change, of course, but posture and sense of center will not be lost. However, if you wait to have posture and balance once you are actually in a fight, you will be off balance because you were unaware of your center before their energy impacted you.
Lesson 3: Borrowed force. Use the force of the initial pulling to transfer that body momentum into your initial strike -- the hammerfist to the groin.
Lesson 4: Limit target exposure by having your strikes travel along a path that clears your most vulnerable target area. Self-defense is an active process and trying to block every attack that comes at us without offering retaliation would be a naive approach. Without deterrent, our attacker will likely continue the assault until eventually their strike finds the mark. Of course, when you strike your hand (or leg) is no longer in a defensive position. This vulnerability can be partially offset by having the strike travel in a path that is occupying the zone that your opponent would have to travel to hit you. On revolving hammer, our initial hammerfist is protecting our right kidney and ribs which is a target that is being accelerated towards our opponent's fist or knife. Note that our head is protected by our left hand that is doing the pinning check on their left hand which is holding our shoulder. So while the left hand does a pinning check against one attack, it is also serving as a positional check against other attacks to that zone.
Lesson 5: Repeating a combination to insure the job is done. Like an airplane with redundant features (when one engine fails you do not fall out the sky), repeating a series of strikes will amplify the damage if all the blows strike but will also allow accuracy adjustments if your initial strikes are blocked, are too far away, or simply slightly miss the target. A hammerfist to the thigh is annoying but does not create the affect we want when striking the groin. The vertical backfist to the bridge of the nose will obstruct their vision (eyes naturally tear up) and cause immediate bleeding and distracting pain. That same strike if it missed and hit the forehead will hurt our fist as much (or more!) than their forehead. So sometimes it is good to practice repeating a strike, or combination of strikes, to insure the result desired is achieved.
METHODS OF DRILLL:
1. Practice the premise of maintaining center of balance when pulled by drilling with a partner where you close your eyes and they push and pull on you a variety of directions and amount of force. Try not to anticipate where to step but just concentrate on feeling a sense of posture, relaxed rootedness, and awareness of your center. As the force travels into you move as needed (but not more) to keep balance. This is fun to do with one student with their eyes closed as two or three classmates just push and pull them around.
2. This entire technique (except the rear scoop kick) is perfect for practicing on a hanging heavy bag. This will allow you to work full power. A kicking shield also will work for this drill.
3. This technique is easily adapted for a variety of attacks from both the front and rear. Also this technique can be grafted to just about any of your existing techniques.
4. Play with "alternative endings." This techniques uses a scoop and rear kick and then covers away from opponent. However, if when unlocking your car door you got grabbed, you would not have room to cover out in that fashion. Explore alternative exit strategies.
WHAT IS IN A NAME? The repetitive swinging from the hammerfist to the groin and vertical back knuckle to the bridge of the nose is "revolving" (at least a partial revolution).