A Journey Through the Jins – Rolling Back

One of the best examples of how you can use the laws of physics to your advantage is in the application of rolling-back energy (Lu Jin).

If an opponent’s fist is coming towards you, one natural reaction might be to try to grab the incoming arm and pull it sideways with brute strength, which is unlikely to work if your opponent is physically stronger than you or hits you before you have a chance to do any grabbing.

Instead of relying on the size of your muscles, an alternative strategy is to use a combination of three simple forces to whizz the opponent sideways and fling them across the room or deposit them safely on the floor next to you, without any effort at all. This might sound too good to be true but it’s just a matter of using the laws of physics to your own advantage: namely a combination of linear and circular momentum and gravity to create a ‘resultant vector’ that bypasses your body and causes them to overextend and fall into a ‘void’ where they don’t have a leg to stand on.

This process can be very quick and effective, but we can break it down into its individual components to see what’s going on.

It begins by using your ward-off energy (peng jin) to intercept (Jie), adhere (Zhan) and stick to (Lian) the incoming arm as you borrow their incoming energy and redirect it in a preferred direction, like the train being switched to an alternative track.

Even without any use of your arms, if someone pushes on you, you can remain balanced and upright, your vertical spine acting like the axis of a rotating drum or prayer wheel. As your opponent’s hard, yang force comes towards you, you can become yin by moving backwards to draw them in, by sinking your weight into your back leg or actually taking a step backwards. At the same time, your waist turns, deflecting the incoming force in much the same way that Jupiter captures voyager probes and hurtles them off towards the stars.

With your arms in play, however, you don’t need to let them get that close. As a fist comes in, one hand can close around the opponent’s wrist while your other hand or forearm takes control of their upper arm, just above the elbow. This is particularly effective if you use a pincer grip between your thumb and middle finger to control and twist their wrist as you apply pressure just above their elbow using your other hand (at long range), or the rolling bone of your forearm (if you are close enough), to control their arm.

Meanwhile, you can apply a downwards force to their arm simply by relaxing and allowing the weight of your bones under gravity to drop them towards the floor as your weight sinks into your back leg and your waist turns. It’s the simultaneous combination of these three forces that makes a roll-back so effective.

It’s not the same as using your muscles to tug or pull the opponent, and it’s important not to lean in any direction, otherwise, even if you were to succeed in taking them to the floor, you would risk losing your balance and ending up on top of them. When you use Lu Jin properly, you remain upright, maintain your own centre of gravity and relax into your legs as you move backwards, turn your waist, drop your arms and use the resultant vector created by this back-down-turn combo to spin them off effortlessly and lead them to where you want them to go. You don’t need to add anything extra as their own momentum is what propels them on their way.

These three forces are most noticeable if your opponent is taken down towards the floor, but even in a horizontal roll back, where an observer might not notice much of the downward force, it’s still there and it prevents the opponent from escaping by lifting their arm or pulling away.

Once your roll-back has moved the opponent off to the side and unbalanced them, a small push (An) or press (Ji) applied at right angles to their new trajectory can be very effective in helping to introduce them to the floor or send them on their way, as long as this is applied before they have time to come right back at you with an elbow (Zhou) or shoulder (Kao). These are all types of Jin we can go on to explore.