The Bridge is a maneuver for those attacked and choked from the back. There may be times when an opponent attempts to control your neck and head from the back and it is necessary to take evasive action in order to protect yourself. The key point is to gain some leverage and control over the opponent’s actions while forcing a take down or solid immobilization of the attack.
Putting the hands up and grabbing the wrists of the opponent helps to ensure that they are not able to maneuver your body in any direction they desire. Where the neck and head goes the body generally follows. Grabbing the wrists offers the ability to leverage against being forced into certain positions.
Immediately one should swing their right shoulder in and under while stepping behind their left foot while forcing the opponent’s left arm over and away from your head. This ensures that the opponent no longer has any control over your body. Likewise, the opponent is left in an awkward position where both their arms are crossed and their body is partially twisted reversing the mechanisms of control.
Stepping forward will pushing their right arm into their left elbow creates a lock that forces them to fall down to avoid breaking their arm. Light pressure will force a take down while greater quick pressure will create a break. The opponent will fall in front of you leaving other maneuvers or escape possible. In Kenpo the code of honor is to remove oneself from the situation.
Bridge A (Opponent has two handed choke hold from behind)
-In single motion grab both of opponent’s wrists with both hands (hand on each by reaching overhead).
-Bow your head and step off to the left.
-Step behind your left food with your right foot as you turn right creating a bridge (crossing of opponent’s arms).
-Step forward with your right foot and break opponent’s arm (or force take down).
The video has many of the same components with the way in which I learned it. You can see the movement and some of the variations.