External ways

Students often make the same mistakes when attempting fa jing:

1. Pushing upon impact
   - this approach is external in nature - the classic 'punch through the opponent' strategy
   - it is not taijiquan
2. 'Cocking' the pelvis and/or shoulder
3. Lunging forward
4. An obvious build-up
5. Jerky
6. A step
   - your step should occur because of the release, rather than to cause the release
7. Tension in the striking tool
8. Overall tension in the body
9. Emotional tension: anger, aggression
10. Forcing

Fa jing is altogether different to these approaches.

Soft meeting

The aim must always be to strike with the whole body, every part soft and loosely connected.
This is the essence of 'reeling silk' and is cultivated by whole-body strength.

Performed correctly, this should ensure 'soft meeting' upon impact.
Whole-body strength and reeling silk will not prevent adverse feedback on impact unless you are soft, sensitive, and have awareness. 

This is not so hard to achieve. It just takes a little practice. In time it will be second nature.
Study Newton's 3rd Law of Motion.

How much of the force you are delivering is actually going into your opponent?

If you are tense, then much of it will bang off your attacker's body and back into you.
There is a concussive shockwave that travels along your arm, into your spine and throughout your body.
This is not good for your health.

This is why 4 ounces of pressure is fundamental.
The moment of contact must be heavy, soft and penetrating. Do not push.

For every action there is an equal and opposite reaction

Do not push on impact.
That way, the kinetic energy will travel out of your body instead of just bouncing back.

Your intention goes through the opponent. Your punch does not go through your opponent. The effect goes inside your opponent. 

The bite

Upon impact, your hand/elbow/knee sinks slightly into the opponent before bouncing back off again.
This process occurs naturally and need not be contrived.
If you pull off too soon, 4 ounces of pressure has not been established and the power will diminish.

Wrong means = wrong end

The body, freed of tension, should reach a condition where the joints move freely.
Only then is the body loose enough for fa jing.
You must be sufficiently attuned to your own movements to feel when and how fa jing can be generated.

Some students are not patient enough and use force.
A common mistake is to use the pelvis and hips rather than the combined muscles of the entire body.
People become adept at rapid pelvic turns or abrupt shunts of force.
These are quite strong but they are not fa jing.
They tend to create a residual pattern of tension within the body.

Fa jing is like a wave, rippling up from the ground, through your hand and into the opponent.
Instead of using the hips and pelvis, you should use the spiralling of the legs, the opening and closing of the spine and the movement of the centre.

Conduit

If you regard your body as being a channel for the transmission of energy, you can start to understand what taijiquan striking involves. 
You do not punch or kick using local muscle groups.

The energy is transferred from the ground, passing through your frame and out into the opponent.
Your limb is simply the part that makes contact with the opponent.

Opening & closing

The fa jing release of energy is akin to a sneeze; the entire body opening and closing in an instant.

In self defence practice, we cannot use fa jing on one another with full power. The outcome is too unpredictable.
Gentle release is fine for demonstrations, but not too often.
Typically, we use soft target pads and sticks for fa jing practice.

When we attack with the internal energy,
we are not attacking with the left or right hand,
but with a line of energy that originates in the foot,
is channelled through the legs, waist and back,
and only emerges from the hand.

(Wolfe Lowenthal) 

Where does the power come from?

A practitioner learns how to generate an undulation wave.
This is passed throughout your entire structure, storing and releasing kinetic energy.
We develop this wave by learning whole-body movement. Every strike involves every body part moving as one.

The skill cannot be attained by tensing the muscles or trying hard.
Only when the body has augmented itself with neigong will fa jing emerge without effort.
You need to be soft and relaxed.
You need to let go of your tension.

Types of jing

It is necessary to differentiate clearly between the types of jing at your disposal.
Without such knowledge, how are you going to fa jing?
Energy release without focus is random and clumsy.
There is a distinct difference between each jing.

You must be conscious of the quality/nature/essence of the jing you intend to utilise.
Movement begins with intention.

Soft power

Fa jing is not hard, it is soft. The effect is hard, not the means itself.

No more than 4 ounces of pressure is applied and the moment of delivery is a split-second.
You do not have time to tense the hand.
The hand (and body) must close by itself on impact, then instantly re-open again.
Conscious strength ruins any chance you have at using fa jing, so just relax.
Be patient.

When you deliver fa jing into a focus mitt or target pad it will pass through the body and into the ground. 
It may cause the floorboards to resonate.

Hocus pocus?

There is nothing mystical or unscientific about fa jing.
Despite the exotic Chinese name, it is simply a question of body mechanics, gravity, distance and timing.
It will not develop overnight but the seeds should emerge as the student becomes increasingly adept.

Fa jing

http://news.stanford.edu/news/2008/may7/med-taichi-050708.html

Fa jing

Fa jing is the main method of striking in taijiquan: fuelling punches, palms, elbows, kicks and chin na.

It is the medium by which kinetic energy is transmitted from one body to another.

However, fa jing is not the energy itself.
It is the means by which the energy is delivered: the body mechanics which produce this outcome.

In a 2008 Stanford University experiment taijiquan master Chen Xiang generated a force 14 times his body weight when striking.
0-60 mph in less than 3 seconds.

Fa jing

http://news.stanford.edu/news/2008/may7/med-taichi-050708.html

14 times his body weight. Really think about that...
Let's assume he weighs at least 10 stones.

10 stones x 14 = 140 stones.

Fa jing

In a 2008 Stanford University experiment tai chi master Chen Xiang generated a force 14 times his body weight when striking.
0-60 mph in less than 3 seconds.

An internal strike is unique because it emulates the action of a whip.
There is no pushing.
Any appearance of hardness is caused by the inertia of the whip being pulled back upon impact.
The whip itself is soft at all times.
There is no need to lock the joints or tense the muscles.